Update GCS storage library to support GetObject API on gzipped objects (#6506)

Fixes #6280

cmd/gateway/gcs/gateway-gcs.go

@@ -775,7 +775,13 @@ func (l *gcsGateway) GetObject(ctx context.Context, bucket string, key string, s
 		return gcsToObjectError(err, bucket)
 	}
 
-	object := l.client.Bucket(bucket).Object(key)
+	// GCS storage decompresses a gzipped object by default and returns the data.
+	// Refer to https://cloud.google.com/storage/docs/transcoding#decompressive_transcoding
+	// Need to set `Accept-Encoding` header to `gzip` when issuing a GetObject call, to be able
+	// to download the object in compressed state.
+	// Calling ReadCompressed with true accomplishes that.
+	object := l.client.Bucket(bucket).Object(key).ReadCompressed(true)
+
 	r, err := object.NewRangeReader(l.ctx, startOffset, length)
 	if err != nil {
 		logger.LogIf(ctx, err)

vendor/cloud.google.com/go/LICENSE

@@ -187,7 +187,7 @@
       same "printed page" as the copyright notice for easier
       identification within third-party archives.
 
-   Copyright 2014 Google Inc.
+   Copyright [yyyy] [name of copyright owner]
 
    Licensed under the Apache License, Version 2.0 (the "License");
    you may not use this file except in compliance with the License.

vendor/cloud.google.com/go/compute/metadata/metadata.go

@@ -1,4 +1,4 @@
-// Copyright 2014 Google Inc. All Rights Reserved.
+// Copyright 2014 Google LLC
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -64,7 +64,7 @@ var (
 )
 
 var (
-	metaClient = &http.Client{
+	defaultClient = &Client{hc: &http.Client{
 		Transport: &http.Transport{
 			Dial: (&net.Dialer{
 				Timeout:   2 * time.Second,
@@ -72,15 +72,15 @@ var (
 			}).Dial,
 			ResponseHeaderTimeout: 2 * time.Second,
 		},
-	}
-	subscribeClient = &http.Client{
+	}}
+	subscribeClient = &Client{hc: &http.Client{
 		Transport: &http.Transport{
 			Dial: (&net.Dialer{
 				Timeout:   2 * time.Second,
 				KeepAlive: 30 * time.Second,
 			}).Dial,
 		},
-	}
+	}}
 )
 
 // NotDefinedError is returned when requested metadata is not defined.
@@ -95,74 +95,16 @@ func (suffix NotDefinedError) Error() string {
 	return fmt.Sprintf("metadata: GCE metadata %q not defined", string(suffix))
 }
 
-// Get returns a value from the metadata service.
-// The suffix is appended to "http://${GCE_METADATA_HOST}/computeMetadata/v1/".
-//
-// If the GCE_METADATA_HOST environment variable is not defined, a default of
-// 169.254.169.254 will be used instead.
-//
-// If the requested metadata is not defined, the returned error will
-// be of type NotDefinedError.
-func Get(suffix string) (string, error) {
-	val, _, err := getETag(metaClient, suffix)
-	return val, err
-}
-
-// getETag returns a value from the metadata service as well as the associated
-// ETag using the provided client. This func is otherwise equivalent to Get.
-func getETag(client *http.Client, suffix string) (value, etag string, err error) {
-	// Using a fixed IP makes it very difficult to spoof the metadata service in
-	// a container, which is an important use-case for local testing of cloud
-	// deployments. To enable spoofing of the metadata service, the environment
-	// variable GCE_METADATA_HOST is first inspected to decide where metadata
-	// requests shall go.
-	host := os.Getenv(metadataHostEnv)
-	if host == "" {
-		// Using 169.254.169.254 instead of "metadata" here because Go
-		// binaries built with the "netgo" tag and without cgo won't
-		// know the search suffix for "metadata" is
-		// ".google.internal", and this IP address is documented as
-		// being stable anyway.
-		host = metadataIP
-	}
-	url := "http://" + host + "/computeMetadata/v1/" + suffix
-	req, _ := http.NewRequest("GET", url, nil)
-	req.Header.Set("Metadata-Flavor", "Google")
-	req.Header.Set("User-Agent", userAgent)
-	res, err := client.Do(req)
-	if err != nil {
-		return "", "", err
-	}
-	defer res.Body.Close()
-	if res.StatusCode == http.StatusNotFound {
-		return "", "", NotDefinedError(suffix)
-	}
-	if res.StatusCode != 200 {
-		return "", "", fmt.Errorf("status code %d trying to fetch %s", res.StatusCode, url)
-	}
-	all, err := ioutil.ReadAll(res.Body)
-	if err != nil {
-		return "", "", err
-	}
-	return string(all), res.Header.Get("Etag"), nil
-}
-
-func getTrimmed(suffix string) (s string, err error) {
-	s, err = Get(suffix)
-	s = strings.TrimSpace(s)
-	return
-}
-
-func (c *cachedValue) get() (v string, err error) {
+func (c *cachedValue) get(cl *Client) (v string, err error) {
 	defer c.mu.Unlock()
 	c.mu.Lock()
 	if c.v != "" {
 		return c.v, nil
 	}
 	if c.trim {
-		v, err = getTrimmed(c.k)
+		v, err = cl.getTrimmed(c.k)
 	} else {
-		v, err = Get(c.k)
+		v, err = cl.Get(c.k)
 	}
 	if err == nil {
 		c.v = v
@@ -201,7 +143,7 @@ func testOnGCE() bool {
 	go func() {
 		req, _ := http.NewRequest("GET", "http://"+metadataIP, nil)
 		req.Header.Set("User-Agent", userAgent)
-		res, err := ctxhttp.Do(ctx, metaClient, req)
+		res, err := ctxhttp.Do(ctx, defaultClient.hc, req)
 		if err != nil {
 			resc <- false
 			return
@@ -266,6 +208,255 @@ func systemInfoSuggestsGCE() bool {
 	return name == "Google" || name == "Google Compute Engine"
 }
 
+// Subscribe calls Client.Subscribe on a client designed for subscribing (one with no
+// ResponseHeaderTimeout).
+func Subscribe(suffix string, fn func(v string, ok bool) error) error {
+	return subscribeClient.Subscribe(suffix, fn)
+}
+
+// Get calls Client.Get on the default client.
+func Get(suffix string) (string, error) { return defaultClient.Get(suffix) }
+
+// ProjectID returns the current instance's project ID string.
+func ProjectID() (string, error) { return defaultClient.ProjectID() }
+
+// NumericProjectID returns the current instance's numeric project ID.
+func NumericProjectID() (string, error) { return defaultClient.NumericProjectID() }
+
+// InternalIP returns the instance's primary internal IP address.
+func InternalIP() (string, error) { return defaultClient.InternalIP() }
+
+// ExternalIP returns the instance's primary external (public) IP address.
+func ExternalIP() (string, error) { return defaultClient.ExternalIP() }
+
+// Hostname returns the instance's hostname. This will be of the form
+// "<instanceID>.c.<projID>.internal".
+func Hostname() (string, error) { return defaultClient.Hostname() }
+
+// InstanceTags returns the list of user-defined instance tags,
+// assigned when initially creating a GCE instance.
+func InstanceTags() ([]string, error) { return defaultClient.InstanceTags() }
+
+// InstanceID returns the current VM's numeric instance ID.
+func InstanceID() (string, error) { return defaultClient.InstanceID() }
+
+// InstanceName returns the current VM's instance ID string.
+func InstanceName() (string, error) { return defaultClient.InstanceName() }
+
+// Zone returns the current VM's zone, such as "us-central1-b".
+func Zone() (string, error) { return defaultClient.Zone() }
+
+// InstanceAttributes calls Client.InstanceAttributes on the default client.
+func InstanceAttributes() ([]string, error) { return defaultClient.InstanceAttributes() }
+
+// ProjectAttributes calls Client.ProjectAttributes on the default client.
+func ProjectAttributes() ([]string, error) { return defaultClient.ProjectAttributes() }
+
+// InstanceAttributeValue calls Client.InstanceAttributeValue on the default client.
+func InstanceAttributeValue(attr string) (string, error) {
+	return defaultClient.InstanceAttributeValue(attr)
+}
+
+// ProjectAttributeValue calls Client.ProjectAttributeValue on the default client.
+func ProjectAttributeValue(attr string) (string, error) {
+	return defaultClient.ProjectAttributeValue(attr)
+}
+
+// Scopes calls Client.Scopes on the default client.
+func Scopes(serviceAccount string) ([]string, error) { return defaultClient.Scopes(serviceAccount) }
+
+func strsContains(ss []string, s string) bool {
+	for _, v := range ss {
+		if v == s {
+			return true
+		}
+	}
+	return false
+}
+
+// A Client provides metadata.
+type Client struct {
+	hc *http.Client
+}
+
+// NewClient returns a Client that can be used to fetch metadata. All HTTP requests
+// will use the given http.Client instead of the default client.
+func NewClient(c *http.Client) *Client {
+	return &Client{hc: c}
+}
+
+// getETag returns a value from the metadata service as well as the associated ETag.
+// This func is otherwise equivalent to Get.
+func (c *Client) getETag(suffix string) (value, etag string, err error) {
+	// Using a fixed IP makes it very difficult to spoof the metadata service in
+	// a container, which is an important use-case for local testing of cloud
+	// deployments. To enable spoofing of the metadata service, the environment
+	// variable GCE_METADATA_HOST is first inspected to decide where metadata
+	// requests shall go.
+	host := os.Getenv(metadataHostEnv)
+	if host == "" {
+		// Using 169.254.169.254 instead of "metadata" here because Go
+		// binaries built with the "netgo" tag and without cgo won't
+		// know the search suffix for "metadata" is
+		// ".google.internal", and this IP address is documented as
+		// being stable anyway.
+		host = metadataIP
+	}
+	url := "http://" + host + "/computeMetadata/v1/" + suffix
+	req, _ := http.NewRequest("GET", url, nil)
+	req.Header.Set("Metadata-Flavor", "Google")
+	req.Header.Set("User-Agent", userAgent)
+	res, err := c.hc.Do(req)
+	if err != nil {
+		return "", "", err
+	}
+	defer res.Body.Close()
+	if res.StatusCode == http.StatusNotFound {
+		return "", "", NotDefinedError(suffix)
+	}
+	if res.StatusCode != 200 {
+		return "", "", fmt.Errorf("status code %d trying to fetch %s", res.StatusCode, url)
+	}
+	all, err := ioutil.ReadAll(res.Body)
+	if err != nil {
+		return "", "", err
+	}
+	return string(all), res.Header.Get("Etag"), nil
+}
+
+// Get returns a value from the metadata service.
+// The suffix is appended to "http://${GCE_METADATA_HOST}/computeMetadata/v1/".
+//
+// If the GCE_METADATA_HOST environment variable is not defined, a default of
+// 169.254.169.254 will be used instead.
+//
+// If the requested metadata is not defined, the returned error will
+// be of type NotDefinedError.
+func (c *Client) Get(suffix string) (string, error) {
+	val, _, err := c.getETag(suffix)
+	return val, err
+}
+
+func (c *Client) getTrimmed(suffix string) (s string, err error) {
+	s, err = c.Get(suffix)
+	s = strings.TrimSpace(s)
+	return
+}
+
+func (c *Client) lines(suffix string) ([]string, error) {
+	j, err := c.Get(suffix)
+	if err != nil {
+		return nil, err
+	}
+	s := strings.Split(strings.TrimSpace(j), "\n")
+	for i := range s {
+		s[i] = strings.TrimSpace(s[i])
+	}
+	return s, nil
+}
+
+// ProjectID returns the current instance's project ID string.
+func (c *Client) ProjectID() (string, error) { return projID.get(c) }
+
+// NumericProjectID returns the current instance's numeric project ID.
+func (c *Client) NumericProjectID() (string, error) { return projNum.get(c) }
+
+// InstanceID returns the current VM's numeric instance ID.
+func (c *Client) InstanceID() (string, error) { return instID.get(c) }
+
+// InternalIP returns the instance's primary internal IP address.
+func (c *Client) InternalIP() (string, error) {
+	return c.getTrimmed("instance/network-interfaces/0/ip")
+}
+
+// ExternalIP returns the instance's primary external (public) IP address.
+func (c *Client) ExternalIP() (string, error) {
+	return c.getTrimmed("instance/network-interfaces/0/access-configs/0/external-ip")
+}
+
+// Hostname returns the instance's hostname. This will be of the form
+// "<instanceID>.c.<projID>.internal".
+func (c *Client) Hostname() (string, error) {
+	return c.getTrimmed("instance/hostname")
+}
+
+// InstanceTags returns the list of user-defined instance tags,
+// assigned when initially creating a GCE instance.
+func (c *Client) InstanceTags() ([]string, error) {
+	var s []string
+	j, err := c.Get("instance/tags")
+	if err != nil {
+		return nil, err
+	}
+	if err := json.NewDecoder(strings.NewReader(j)).Decode(&s); err != nil {
+		return nil, err
+	}
+	return s, nil
+}
+
+// InstanceName returns the current VM's instance ID string.
+func (c *Client) InstanceName() (string, error) {
+	host, err := c.Hostname()
+	if err != nil {
+		return "", err
+	}
+	return strings.Split(host, ".")[0], nil
+}
+
+// Zone returns the current VM's zone, such as "us-central1-b".
+func (c *Client) Zone() (string, error) {
+	zone, err := c.getTrimmed("instance/zone")
+	// zone is of the form "projects/<projNum>/zones/<zoneName>".
+	if err != nil {
+		return "", err
+	}
+	return zone[strings.LastIndex(zone, "/")+1:], nil
+}
+
+// InstanceAttributes returns the list of user-defined attributes,
+// assigned when initially creating a GCE VM instance. The value of an
+// attribute can be obtained with InstanceAttributeValue.
+func (c *Client) InstanceAttributes() ([]string, error) { return c.lines("instance/attributes/") }
+
+// ProjectAttributes returns the list of user-defined attributes
+// applying to the project as a whole, not just this VM.  The value of
+// an attribute can be obtained with ProjectAttributeValue.
+func (c *Client) ProjectAttributes() ([]string, error) { return c.lines("project/attributes/") }
+
+// InstanceAttributeValue returns the value of the provided VM
+// instance attribute.
+//
+// If the requested attribute is not defined, the returned error will
+// be of type NotDefinedError.
+//
+// InstanceAttributeValue may return ("", nil) if the attribute was
+// defined to be the empty string.
+func (c *Client) InstanceAttributeValue(attr string) (string, error) {
+	return c.Get("instance/attributes/" + attr)
+}
+
+// ProjectAttributeValue returns the value of the provided
+// project attribute.
+//
+// If the requested attribute is not defined, the returned error will
+// be of type NotDefinedError.
+//
+// ProjectAttributeValue may return ("", nil) if the attribute was
+// defined to be the empty string.
+func (c *Client) ProjectAttributeValue(attr string) (string, error) {
+	return c.Get("project/attributes/" + attr)
+}
+
+// Scopes returns the service account scopes for the given account.
+// The account may be empty or the string "default" to use the instance's
+// main account.
+func (c *Client) Scopes(serviceAccount string) ([]string, error) {
+	if serviceAccount == "" {
+		serviceAccount = "default"
+	}
+	return c.lines("instance/service-accounts/" + serviceAccount + "/scopes")
+}
+
 // Subscribe subscribes to a value from the metadata service.
 // The suffix is appended to "http://${GCE_METADATA_HOST}/computeMetadata/v1/".
 // The suffix may contain query parameters.
@@ -275,11 +466,11 @@ func systemInfoSuggestsGCE() bool {
 // and ok false. Subscribe blocks until fn returns a non-nil error or the value
 // is deleted. Subscribe returns the error value returned from the last call to
 // fn, which may be nil when ok == false.
-func Subscribe(suffix string, fn func(v string, ok bool) error) error {
+func (c *Client) Subscribe(suffix string, fn func(v string, ok bool) error) error {
 	const failedSubscribeSleep = time.Second * 5
 
 	// First check to see if the metadata value exists at all.
-	val, lastETag, err := getETag(subscribeClient, suffix)
+	val, lastETag, err := c.getETag(suffix)
 	if err != nil {
 		return err
 	}
@@ -295,7 +486,7 @@ func Subscribe(suffix string, fn func(v string, ok bool) error) error {
 		suffix += "?wait_for_change=true&last_etag="
 	}
 	for {
-		val, etag, err := getETag(subscribeClient, suffix+url.QueryEscape(lastETag))
+		val, etag, err := c.getETag(suffix + url.QueryEscape(lastETag))
 		if err != nil {
 			if _, deleted := err.(NotDefinedError); !deleted {
 				time.Sleep(failedSubscribeSleep)
@@ -310,128 +501,3 @@ func Subscribe(suffix string, fn func(v string, ok bool) error) error {
 		}
 	}
 }
-
-// ProjectID returns the current instance's project ID string.
-func ProjectID() (string, error) { return projID.get() }
-
-// NumericProjectID returns the current instance's numeric project ID.
-func NumericProjectID() (string, error) { return projNum.get() }
-
-// InternalIP returns the instance's primary internal IP address.
-func InternalIP() (string, error) {
-	return getTrimmed("instance/network-interfaces/0/ip")
-}
-
-// ExternalIP returns the instance's primary external (public) IP address.
-func ExternalIP() (string, error) {
-	return getTrimmed("instance/network-interfaces/0/access-configs/0/external-ip")
-}
-
-// Hostname returns the instance's hostname. This will be of the form
-// "<instanceID>.c.<projID>.internal".
-func Hostname() (string, error) {
-	return getTrimmed("instance/hostname")
-}
-
-// InstanceTags returns the list of user-defined instance tags,
-// assigned when initially creating a GCE instance.
-func InstanceTags() ([]string, error) {
-	var s []string
-	j, err := Get("instance/tags")
-	if err != nil {
-		return nil, err
-	}
-	if err := json.NewDecoder(strings.NewReader(j)).Decode(&s); err != nil {
-		return nil, err
-	}
-	return s, nil
-}
-
-// InstanceID returns the current VM's numeric instance ID.
-func InstanceID() (string, error) {
-	return instID.get()
-}
-
-// InstanceName returns the current VM's instance ID string.
-func InstanceName() (string, error) {
-	host, err := Hostname()
-	if err != nil {
-		return "", err
-	}
-	return strings.Split(host, ".")[0], nil
-}
-
-// Zone returns the current VM's zone, such as "us-central1-b".
-func Zone() (string, error) {
-	zone, err := getTrimmed("instance/zone")
-	// zone is of the form "projects/<projNum>/zones/<zoneName>".
-	if err != nil {
-		return "", err
-	}
-	return zone[strings.LastIndex(zone, "/")+1:], nil
-}
-
-// InstanceAttributes returns the list of user-defined attributes,
-// assigned when initially creating a GCE VM instance. The value of an
-// attribute can be obtained with InstanceAttributeValue.
-func InstanceAttributes() ([]string, error) { return lines("instance/attributes/") }
-
-// ProjectAttributes returns the list of user-defined attributes
-// applying to the project as a whole, not just this VM.  The value of
-// an attribute can be obtained with ProjectAttributeValue.
-func ProjectAttributes() ([]string, error) { return lines("project/attributes/") }
-
-func lines(suffix string) ([]string, error) {
-	j, err := Get(suffix)
-	if err != nil {
-		return nil, err
-	}
-	s := strings.Split(strings.TrimSpace(j), "\n")
-	for i := range s {
-		s[i] = strings.TrimSpace(s[i])
-	}
-	return s, nil
-}
-
-// InstanceAttributeValue returns the value of the provided VM
-// instance attribute.
-//
-// If the requested attribute is not defined, the returned error will
-// be of type NotDefinedError.
-//
-// InstanceAttributeValue may return ("", nil) if the attribute was
-// defined to be the empty string.
-func InstanceAttributeValue(attr string) (string, error) {
-	return Get("instance/attributes/" + attr)
-}
-
-// ProjectAttributeValue returns the value of the provided
-// project attribute.
-//
-// If the requested attribute is not defined, the returned error will
-// be of type NotDefinedError.
-//
-// ProjectAttributeValue may return ("", nil) if the attribute was
-// defined to be the empty string.
-func ProjectAttributeValue(attr string) (string, error) {
-	return Get("project/attributes/" + attr)
-}
-
-// Scopes returns the service account scopes for the given account.
-// The account may be empty or the string "default" to use the instance's
-// main account.
-func Scopes(serviceAccount string) ([]string, error) {
-	if serviceAccount == "" {
-		serviceAccount = "default"
-	}
-	return lines("instance/service-accounts/" + serviceAccount + "/scopes")
-}
-
-func strsContains(ss []string, s string) bool {
-	for _, v := range ss {
-		if v == s {
-			return true
-		}
-	}
-	return false
-}

vendor/cloud.google.com/go/iam/iam.go

@@ -1,4 +1,4 @@
-// Copyright 2016 Google Inc. All Rights Reserved.
+// Copyright 2016 Google LLC
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -22,9 +22,13 @@
 package iam
 
 import (
+	"time"
+
+	gax "github.com/googleapis/gax-go"
 	"golang.org/x/net/context"
 	pb "google.golang.org/genproto/googleapis/iam/v1"
 	"google.golang.org/grpc"
+	"google.golang.org/grpc/codes"
 )
 
 // client abstracts the IAMPolicy API to allow multiple implementations.
@@ -39,26 +43,50 @@ type grpcClient struct {
 	c pb.IAMPolicyClient
 }
 
+var withRetry = gax.WithRetry(func() gax.Retryer {
+	return gax.OnCodes([]codes.Code{
+		codes.DeadlineExceeded,
+		codes.Unavailable,
+	}, gax.Backoff{
+		Initial:    100 * time.Millisecond,
+		Max:        60 * time.Second,
+		Multiplier: 1.3,
+	})
+})
+
 func (g *grpcClient) Get(ctx context.Context, resource string) (*pb.Policy, error) {
-	proto, err := g.c.GetIamPolicy(ctx, &pb.GetIamPolicyRequest{Resource: resource})
+	var proto *pb.Policy
+	err := gax.Invoke(ctx, func(ctx context.Context, _ gax.CallSettings) error {
+		var err error
+		proto, err = g.c.GetIamPolicy(ctx, &pb.GetIamPolicyRequest{Resource: resource})
+		return err
+	}, withRetry)
 	if err != nil {
 		return nil, err
 	}
 	return proto, nil
 }
+
 func (g *grpcClient) Set(ctx context.Context, resource string, p *pb.Policy) error {
-	_, err := g.c.SetIamPolicy(ctx, &pb.SetIamPolicyRequest{
-		Resource: resource,
-		Policy:   p,
-	})
-	return err
+	return gax.Invoke(ctx, func(ctx context.Context, _ gax.CallSettings) error {
+		_, err := g.c.SetIamPolicy(ctx, &pb.SetIamPolicyRequest{
+			Resource: resource,
+			Policy:   p,
+		})
+		return err
+	}, withRetry)
 }
 
 func (g *grpcClient) Test(ctx context.Context, resource string, perms []string) ([]string, error) {
-	res, err := g.c.TestIamPermissions(ctx, &pb.TestIamPermissionsRequest{
-		Resource:    resource,
-		Permissions: perms,
-	})
+	var res *pb.TestIamPermissionsResponse
+	err := gax.Invoke(ctx, func(ctx context.Context, _ gax.CallSettings) error {
+		var err error
+		res, err = g.c.TestIamPermissions(ctx, &pb.TestIamPermissionsRequest{
+			Resource:    resource,
+			Permissions: perms,
+		})
+		return err
+	}, withRetry)
 	if err != nil {
 		return nil, err
 	}
@@ -76,7 +104,15 @@ type Handle struct {
 // InternalNewHandle returns a Handle for resource.
 // The conn parameter refers to a server that must support the IAMPolicy service.
 func InternalNewHandle(conn *grpc.ClientConn, resource string) *Handle {
-	return InternalNewHandleClient(&grpcClient{c: pb.NewIAMPolicyClient(conn)}, resource)
+	return InternalNewHandleGRPCClient(pb.NewIAMPolicyClient(conn), resource)
+}
+
+// InternalNewHandleGRPCClient is for use by the Google Cloud Libraries only.
+//
+// InternalNewHandleClient returns a Handle for resource using the given
+// grpc service that implements IAM as a mixin
+func InternalNewHandleGRPCClient(c pb.IAMPolicyClient, resource string) *Handle {
+	return InternalNewHandleClient(&grpcClient{c: c}, resource)
 }
 
 // InternalNewHandleClient is for use by the Google Cloud Libraries only.

vendor/cloud.google.com/go/internal/annotate.go

@@ -0,0 +1,54 @@
+// Copyright 2017 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package internal
+
+import (
+	"fmt"
+
+	"google.golang.org/api/googleapi"
+	"google.golang.org/grpc/status"
+)
+
+// Annotate prepends msg to the error message in err, attempting
+// to preserve other information in err, like an error code.
+//
+// Annotate panics if err is nil.
+//
+// Annotate knows about these error types:
+// - "google.golang.org/grpc/status".Status
+// - "google.golang.org/api/googleapi".Error
+// If the error is not one of these types, Annotate behaves
+// like
+//   fmt.Errorf("%s: %v", msg, err)
+func Annotate(err error, msg string) error {
+	if err == nil {
+		panic("Annotate called with nil")
+	}
+	if s, ok := status.FromError(err); ok {
+		p := s.Proto()
+		p.Message = msg + ": " + p.Message
+		return status.ErrorProto(p)
+	}
+	if g, ok := err.(*googleapi.Error); ok {
+		g.Message = msg + ": " + g.Message
+		return g
+	}
+	return fmt.Errorf("%s: %v", msg, err)
+}
+
+// Annotatef uses format and args to format a string, then calls Annotate.
+func Annotatef(err error, format string, args ...interface{}) error {
+	return Annotate(err, fmt.Sprintf(format, args...))
+}

vendor/cloud.google.com/go/internal/optional/optional.go

@@ -1,4 +1,4 @@
-// Copyright 2016 Google Inc. All Rights Reserved.
+// Copyright 2016 Google LLC
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -20,6 +20,7 @@ package optional
 import (
 	"fmt"
 	"strings"
+	"time"
 )
 
 type (
@@ -37,6 +38,9 @@ type (
 
 	// Float64 is either a float64 or nil.
 	Float64 interface{}
+
+	// Duration is either a time.Duration or nil.
+	Duration interface{}
 )
 
 // ToBool returns its argument as a bool.
@@ -89,6 +93,16 @@ func ToFloat64(v Float64) float64 {
 	return x
 }
 
+// ToDuration returns its argument as a time.Duration.
+// It panics if its argument is nil or not a time.Duration.
+func ToDuration(v Duration) time.Duration {
+	x, ok := v.(time.Duration)
+	if !ok {
+		doPanic("Duration", v)
+	}
+	return x
+}
+
 func doPanic(capType string, v interface{}) {
 	panic(fmt.Sprintf("optional.%s value should be %s, got %T", capType, strings.ToLower(capType), v))
 }

vendor/cloud.google.com/go/internal/retry.go

@@ -1,4 +1,4 @@
-// Copyright 2016 Google Inc. All Rights Reserved.
+// Copyright 2016 Google LLC
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -15,7 +15,6 @@
 package internal
 
 import (
-	"fmt"
 	"time"
 
 	gax "github.com/googleapis/gax-go"
@@ -48,7 +47,7 @@ func retry(ctx context.Context, bo gax.Backoff, f func() (stop bool, err error),
 		p := bo.Pause()
 		if cerr := sleep(ctx, p); cerr != nil {
 			if lastErr != nil {
-				return fmt.Errorf("%v; last function err: %v", cerr, lastErr)
+				return Annotatef(lastErr, "retry failed with %v; last error", cerr)
 			}
 			return cerr
 		}

vendor/cloud.google.com/go/internal/trace/go18.go

@@ -0,0 +1,83 @@
+// Copyright 2018 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build go1.8
+
+package trace
+
+import (
+	"go.opencensus.io/trace"
+	"golang.org/x/net/context"
+	"google.golang.org/api/googleapi"
+	"google.golang.org/genproto/googleapis/rpc/code"
+	"google.golang.org/grpc/status"
+)
+
+func StartSpan(ctx context.Context, name string) context.Context {
+	ctx, _ = trace.StartSpan(ctx, name)
+	return ctx
+}
+
+func EndSpan(ctx context.Context, err error) {
+	span := trace.FromContext(ctx)
+	if err != nil {
+		span.SetStatus(toStatus(err))
+	}
+	span.End()
+}
+
+// ToStatus interrogates an error and converts it to an appropriate
+// OpenCensus status.
+func toStatus(err error) trace.Status {
+	if err2, ok := err.(*googleapi.Error); ok {
+		return trace.Status{Code: httpStatusCodeToOCCode(err2.Code), Message: err2.Message}
+	} else if s, ok := status.FromError(err); ok {
+		return trace.Status{Code: int32(s.Code()), Message: s.Message()}
+	} else {
+		return trace.Status{Code: int32(code.Code_UNKNOWN), Message: err.Error()}
+	}
+}
+
+// TODO (deklerk): switch to using OpenCensus function when it becomes available.
+// Reference: https://github.com/googleapis/googleapis/blob/26b634d2724ac5dd30ae0b0cbfb01f07f2e4050e/google/rpc/code.proto
+func httpStatusCodeToOCCode(httpStatusCode int) int32 {
+	switch httpStatusCode {
+	case 200:
+		return int32(code.Code_OK)
+	case 499:
+		return int32(code.Code_CANCELLED)
+	case 500:
+		return int32(code.Code_UNKNOWN) // Could also be Code_INTERNAL, Code_DATA_LOSS
+	case 400:
+		return int32(code.Code_INVALID_ARGUMENT) // Could also be Code_OUT_OF_RANGE
+	case 504:
+		return int32(code.Code_DEADLINE_EXCEEDED)
+	case 404:
+		return int32(code.Code_NOT_FOUND)
+	case 409:
+		return int32(code.Code_ALREADY_EXISTS) // Could also be Code_ABORTED
+	case 403:
+		return int32(code.Code_PERMISSION_DENIED)
+	case 401:
+		return int32(code.Code_UNAUTHENTICATED)
+	case 429:
+		return int32(code.Code_RESOURCE_EXHAUSTED)
+	case 501:
+		return int32(code.Code_UNIMPLEMENTED)
+	case 503:
+		return int32(code.Code_UNAVAILABLE)
+	default:
+		return int32(code.Code_UNKNOWN)
+	}
+}

vendor/cloud.google.com/go/internal/trace/not_go18.go

@@ -0,0 +1,30 @@
+// Copyright 2018 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build !go1.8
+
+package trace
+
+import (
+	"golang.org/x/net/context"
+)
+
+// OpenCensus only supports go 1.8 and higher.
+
+func StartSpan(ctx context.Context, _ string) context.Context {
+	return ctx
+}
+
+func EndSpan(context.Context, error) {
+}

vendor/cloud.google.com/go/internal/version/version.go

@@ -1,4 +1,4 @@
-// Copyright 2016 Google Inc. All Rights Reserved.
+// Copyright 2016 Google LLC
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -26,7 +26,7 @@ import (
 
 // Repo is the current version of the client libraries in this
 // repo. It should be a date in YYYYMMDD format.
-const Repo = "20170404"
+const Repo = "20180226"
 
 // Go returns the Go runtime version. The returned string
 // has no whitespace.

vendor/cloud.google.com/go/storage/acl.go

@@ -1,4 +1,4 @@
-// Copyright 2014 Google Inc. All Rights Reserved.
+// Copyright 2014 Google LLC
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -15,9 +15,12 @@
 package storage
 
 import (
-	"fmt"
+	"net/http"
+	"reflect"
 
+	"cloud.google.com/go/internal/trace"
 	"golang.org/x/net/context"
+	"google.golang.org/api/googleapi"
 	raw "google.golang.org/api/storage/v1"
 )
 
@@ -45,22 +48,37 @@ const (
 	AllAuthenticatedUsers ACLEntity = "allAuthenticatedUsers"
 )
 
-// ACLRule represents a grant for a role to an entity (user, group or team) for a Google Cloud Storage object or bucket.
+// ACLRule represents a grant for a role to an entity (user, group or team) for a
+// Google Cloud Storage object or bucket.
 type ACLRule struct {
-	Entity ACLEntity
-	Role   ACLRole
+	Entity      ACLEntity
+	EntityID    string
+	Role        ACLRole
+	Domain      string
+	Email       string
+	ProjectTeam *ProjectTeam
+}
+
+// ProjectTeam is the project team associated with the entity, if any.
+type ProjectTeam struct {
+	ProjectNumber string
+	Team          string
 }
 
 // ACLHandle provides operations on an access control list for a Google Cloud Storage bucket or object.
 type ACLHandle struct {
-	c         *Client
-	bucket    string
-	object    string
-	isDefault bool
+	c           *Client
+	bucket      string
+	object      string
+	isDefault   bool
+	userProject string // for requester-pays buckets
 }
 
 // Delete permanently deletes the ACL entry for the given entity.
-func (a *ACLHandle) Delete(ctx context.Context, entity ACLEntity) error {
+func (a *ACLHandle) Delete(ctx context.Context, entity ACLEntity) (err error) {
+	ctx = trace.StartSpan(ctx, "cloud.google.com/go/storage.ACL.Delete")
+	defer func() { trace.EndSpan(ctx, err) }()
+
 	if a.object != "" {
 		return a.objectDelete(ctx, entity)
 	}
@@ -70,19 +88,25 @@ func (a *ACLHandle) Delete(ctx context.Context, entity ACLEntity) error {
 	return a.bucketDelete(ctx, entity)
 }
 
-// Set sets the permission level for the given entity.
-func (a *ACLHandle) Set(ctx context.Context, entity ACLEntity, role ACLRole) error {
+// Set sets the role for the given entity.
+func (a *ACLHandle) Set(ctx context.Context, entity ACLEntity, role ACLRole) (err error) {
+	ctx = trace.StartSpan(ctx, "cloud.google.com/go/storage.ACL.Set")
+	defer func() { trace.EndSpan(ctx, err) }()
+
 	if a.object != "" {
-		return a.objectSet(ctx, entity, role)
+		return a.objectSet(ctx, entity, role, false)
 	}
 	if a.isDefault {
-		return a.bucketDefaultSet(ctx, entity, role)
+		return a.objectSet(ctx, entity, role, true)
 	}
 	return a.bucketSet(ctx, entity, role)
 }
 
 // List retrieves ACL entries.
-func (a *ACLHandle) List(ctx context.Context) ([]ACLRule, error) {
+func (a *ACLHandle) List(ctx context.Context) (rules []ACLRule, err error) {
+	ctx = trace.StartSpan(ctx, "cloud.google.com/go/storage.ACL.List")
+	defer func() { trace.EndSpan(ctx, err) }()
+
 	if a.object != "" {
 		return a.objectList(ctx)
 	}
@@ -96,65 +120,38 @@ func (a *ACLHandle) bucketDefaultList(ctx context.Context) ([]ACLRule, error) {
 	var acls *raw.ObjectAccessControls
 	var err error
 	err = runWithRetry(ctx, func() error {
-		req := a.c.raw.DefaultObjectAccessControls.List(a.bucket).Context(ctx)
-		setClientHeader(req.Header())
+		req := a.c.raw.DefaultObjectAccessControls.List(a.bucket)
+		a.configureCall(req, ctx)
 		acls, err = req.Do()
 		return err
 	})
 	if err != nil {
-		return nil, fmt.Errorf("storage: error listing default object ACL for bucket %q: %v", a.bucket, err)
+		return nil, err
 	}
-	return toACLRules(acls.Items), nil
-}
-
-func (a *ACLHandle) bucketDefaultSet(ctx context.Context, entity ACLEntity, role ACLRole) error {
-	acl := &raw.ObjectAccessControl{
-		Bucket: a.bucket,
-		Entity: string(entity),
-		Role:   string(role),
-	}
-	err := runWithRetry(ctx, func() error {
-		req := a.c.raw.DefaultObjectAccessControls.Update(a.bucket, string(entity), acl).Context(ctx)
-		setClientHeader(req.Header())
-		_, err := req.Do()
-		return err
-	})
-	if err != nil {
-		return fmt.Errorf("storage: error updating default ACL entry for bucket %q, entity %q: %v", a.bucket, entity, err)
-	}
-	return nil
+	return toObjectACLRules(acls.Items), nil
 }
 
 func (a *ACLHandle) bucketDefaultDelete(ctx context.Context, entity ACLEntity) error {
-	err := runWithRetry(ctx, func() error {
-		req := a.c.raw.DefaultObjectAccessControls.Delete(a.bucket, string(entity)).Context(ctx)
-		setClientHeader(req.Header())
+	return runWithRetry(ctx, func() error {
+		req := a.c.raw.DefaultObjectAccessControls.Delete(a.bucket, string(entity))
+		a.configureCall(req, ctx)
 		return req.Do()
 	})
-	if err != nil {
-		return fmt.Errorf("storage: error deleting default ACL entry for bucket %q, entity %q: %v", a.bucket, entity, err)
-	}
-	return nil
 }
 
 func (a *ACLHandle) bucketList(ctx context.Context) ([]ACLRule, error) {
 	var acls *raw.BucketAccessControls
 	var err error
 	err = runWithRetry(ctx, func() error {
-		req := a.c.raw.BucketAccessControls.List(a.bucket).Context(ctx)
-		setClientHeader(req.Header())
+		req := a.c.raw.BucketAccessControls.List(a.bucket)
+		a.configureCall(req, ctx)
 		acls, err = req.Do()
 		return err
 	})
 	if err != nil {
-		return nil, fmt.Errorf("storage: error listing bucket ACL for bucket %q: %v", a.bucket, err)
+		return nil, err
 	}
-	r := make([]ACLRule, len(acls.Items))
-	for i, v := range acls.Items {
-		r[i].Entity = ACLEntity(v.Entity)
-		r[i].Role = ACLRole(v.Role)
-	}
-	return r, nil
+	return toBucketACLRules(acls.Items), nil
 }
 
 func (a *ACLHandle) bucketSet(ctx context.Context, entity ACLEntity, role ACLRole) error {
@@ -164,78 +161,175 @@ func (a *ACLHandle) bucketSet(ctx context.Context, entity ACLEntity, role ACLRol
 		Role:   string(role),
 	}
 	err := runWithRetry(ctx, func() error {
-		req := a.c.raw.BucketAccessControls.Update(a.bucket, string(entity), acl).Context(ctx)
-		setClientHeader(req.Header())
+		req := a.c.raw.BucketAccessControls.Update(a.bucket, string(entity), acl)
+		a.configureCall(req, ctx)
 		_, err := req.Do()
 		return err
 	})
 	if err != nil {
-		return fmt.Errorf("storage: error updating bucket ACL entry for bucket %q, entity %q: %v", a.bucket, entity, err)
+		return err
 	}
 	return nil
 }
 
 func (a *ACLHandle) bucketDelete(ctx context.Context, entity ACLEntity) error {
-	err := runWithRetry(ctx, func() error {
-		req := a.c.raw.BucketAccessControls.Delete(a.bucket, string(entity)).Context(ctx)
-		setClientHeader(req.Header())
+	return runWithRetry(ctx, func() error {
+		req := a.c.raw.BucketAccessControls.Delete(a.bucket, string(entity))
+		a.configureCall(req, ctx)
 		return req.Do()
 	})
-	if err != nil {
-		return fmt.Errorf("storage: error deleting bucket ACL entry for bucket %q, entity %q: %v", a.bucket, entity, err)
-	}
-	return nil
 }
 
 func (a *ACLHandle) objectList(ctx context.Context) ([]ACLRule, error) {
 	var acls *raw.ObjectAccessControls
 	var err error
 	err = runWithRetry(ctx, func() error {
-		req := a.c.raw.ObjectAccessControls.List(a.bucket, a.object).Context(ctx)
-		setClientHeader(req.Header())
+		req := a.c.raw.ObjectAccessControls.List(a.bucket, a.object)
+		a.configureCall(req, ctx)
 		acls, err = req.Do()
 		return err
 	})
 	if err != nil {
-		return nil, fmt.Errorf("storage: error listing object ACL for bucket %q, file %q: %v", a.bucket, a.object, err)
+		return nil, err
 	}
-	return toACLRules(acls.Items), nil
+	return toObjectACLRules(acls.Items), nil
 }
 
-func (a *ACLHandle) objectSet(ctx context.Context, entity ACLEntity, role ACLRole) error {
+func (a *ACLHandle) objectSet(ctx context.Context, entity ACLEntity, role ACLRole, isBucketDefault bool) error {
+	type setRequest interface {
+		Do(opts ...googleapi.CallOption) (*raw.ObjectAccessControl, error)
+		Header() http.Header
+	}
+
 	acl := &raw.ObjectAccessControl{
 		Bucket: a.bucket,
 		Entity: string(entity),
 		Role:   string(role),
 	}
-	err := runWithRetry(ctx, func() error {
-		req := a.c.raw.ObjectAccessControls.Update(a.bucket, a.object, string(entity), acl).Context(ctx)
-		setClientHeader(req.Header())
+	var req setRequest
+	if isBucketDefault {
+		req = a.c.raw.DefaultObjectAccessControls.Update(a.bucket, string(entity), acl)
+	} else {
+		req = a.c.raw.ObjectAccessControls.Update(a.bucket, a.object, string(entity), acl)
+	}
+	a.configureCall(req, ctx)
+	return runWithRetry(ctx, func() error {
 		_, err := req.Do()
 		return err
 	})
-	if err != nil {
-		return fmt.Errorf("storage: error updating object ACL entry for bucket %q, file %q, entity %q: %v", a.bucket, a.object, entity, err)
-	}
-	return nil
 }
 
 func (a *ACLHandle) objectDelete(ctx context.Context, entity ACLEntity) error {
-	err := runWithRetry(ctx, func() error {
-		req := a.c.raw.ObjectAccessControls.Delete(a.bucket, a.object, string(entity)).Context(ctx)
-		setClientHeader(req.Header())
+	return runWithRetry(ctx, func() error {
+		req := a.c.raw.ObjectAccessControls.Delete(a.bucket, a.object, string(entity))
+		a.configureCall(req, ctx)
 		return req.Do()
 	})
-	if err != nil {
-		return fmt.Errorf("storage: error deleting object ACL entry for bucket %q, file %q, entity %q: %v", a.bucket, a.object, entity, err)
-	}
-	return nil
 }
 
-func toACLRules(items []*raw.ObjectAccessControl) []ACLRule {
-	r := make([]ACLRule, 0, len(items))
+func (a *ACLHandle) configureCall(call interface{ Header() http.Header }, ctx context.Context) {
+	vc := reflect.ValueOf(call)
+	vc.MethodByName("Context").Call([]reflect.Value{reflect.ValueOf(ctx)})
+	if a.userProject != "" {
+		vc.MethodByName("UserProject").Call([]reflect.Value{reflect.ValueOf(a.userProject)})
+	}
+	setClientHeader(call.Header())
+}
+
+func toObjectACLRules(items []*raw.ObjectAccessControl) []ACLRule {
+	var rs []ACLRule
 	for _, item := range items {
-		r = append(r, ACLRule{Entity: ACLEntity(item.Entity), Role: ACLRole(item.Role)})
+		rs = append(rs, toObjectACLRule(item))
+	}
+	return rs
+}
+
+func toBucketACLRules(items []*raw.BucketAccessControl) []ACLRule {
+	var rs []ACLRule
+	for _, item := range items {
+		rs = append(rs, toBucketACLRule(item))
+	}
+	return rs
+}
+
+func toObjectACLRule(a *raw.ObjectAccessControl) ACLRule {
+	return ACLRule{
+		Entity:      ACLEntity(a.Entity),
+		EntityID:    a.EntityId,
+		Role:        ACLRole(a.Role),
+		Domain:      a.Domain,
+		Email:       a.Email,
+		ProjectTeam: toObjectProjectTeam(a.ProjectTeam),
+	}
+}
+
+func toBucketACLRule(a *raw.BucketAccessControl) ACLRule {
+	return ACLRule{
+		Entity:      ACLEntity(a.Entity),
+		EntityID:    a.EntityId,
+		Role:        ACLRole(a.Role),
+		Domain:      a.Domain,
+		Email:       a.Email,
+		ProjectTeam: toBucketProjectTeam(a.ProjectTeam),
+	}
+}
+
+func toRawObjectACL(rules []ACLRule) []*raw.ObjectAccessControl {
+	if len(rules) == 0 {
+		return nil
+	}
+	r := make([]*raw.ObjectAccessControl, 0, len(rules))
+	for _, rule := range rules {
+		r = append(r, rule.toRawObjectAccessControl("")) // bucket name unnecessary
 	}
 	return r
 }
+
+func toRawBucketACL(rules []ACLRule) []*raw.BucketAccessControl {
+	if len(rules) == 0 {
+		return nil
+	}
+	r := make([]*raw.BucketAccessControl, 0, len(rules))
+	for _, rule := range rules {
+		r = append(r, rule.toRawBucketAccessControl("")) // bucket name unnecessary
+	}
+	return r
+}
+
+func (r ACLRule) toRawBucketAccessControl(bucket string) *raw.BucketAccessControl {
+	return &raw.BucketAccessControl{
+		Bucket: bucket,
+		Entity: string(r.Entity),
+		Role:   string(r.Role),
+		// The other fields are not settable.
+	}
+}
+
+func (r ACLRule) toRawObjectAccessControl(bucket string) *raw.ObjectAccessControl {
+	return &raw.ObjectAccessControl{
+		Bucket: bucket,
+		Entity: string(r.Entity),
+		Role:   string(r.Role),
+		// The other fields are not settable.
+	}
+}
+
+func toBucketProjectTeam(p *raw.BucketAccessControlProjectTeam) *ProjectTeam {
+	if p == nil {
+		return nil
+	}
+	return &ProjectTeam{
+		ProjectNumber: p.ProjectNumber,
+		Team:          p.Team,
+	}
+}
+
+func toObjectProjectTeam(p *raw.ObjectAccessControlProjectTeam) *ProjectTeam {
+	if p == nil {
+		return nil
+	}
+	return &ProjectTeam{
+		ProjectNumber: p.ProjectNumber,
+		Team:          p.Team,
+	}
+}

vendor/cloud.google.com/go/storage/copy.go

@@ -1,4 +1,4 @@
-// Copyright 2016 Google Inc. All Rights Reserved.
+// Copyright 2016 Google LLC
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -18,6 +18,7 @@ import (
 	"errors"
 	"fmt"
 
+	"cloud.google.com/go/internal/trace"
 	"golang.org/x/net/context"
 	raw "google.golang.org/api/storage/v1"
 )
@@ -25,6 +26,9 @@ import (
 // CopierFrom creates a Copier that can copy src to dst.
 // You can immediately call Run on the returned Copier, or
 // you can configure it first.
+//
+// For Requester Pays buckets, the user project of dst is billed, unless it is empty,
+// in which case the user project of src is billed.
 func (dst *ObjectHandle) CopierFrom(src *ObjectHandle) *Copier {
 	return &Copier{dst: dst, src: src}
 }
@@ -42,7 +46,7 @@ type Copier struct {
 	RewriteToken string
 
 	// ProgressFunc can be used to monitor the progress of a multi-RPC copy
-	// operation. If ProgressFunc is not nil and CopyFrom requires multiple
+	// operation. If ProgressFunc is not nil and copying requires multiple
 	// calls to the underlying service (see
 	// https://cloud.google.com/storage/docs/json_api/v1/objects/rewrite), then
 	// ProgressFunc will be invoked after each call with the number of bytes of
@@ -56,47 +60,72 @@ type Copier struct {
 	// ProgressFunc should return quickly without blocking.
 	ProgressFunc func(copiedBytes, totalBytes uint64)
 
+	// The Cloud KMS key, in the form projects/P/locations/L/keyRings/R/cryptoKeys/K,
+	// that will be used to encrypt the object. Overrides the object's KMSKeyName, if
+	// any.
+	//
+	// Providing both a DestinationKMSKeyName and a customer-supplied encryption key
+	// (via ObjectHandle.Key) on the destination object will result in an error when
+	// Run is called.
+	DestinationKMSKeyName string
+
 	dst, src *ObjectHandle
 }
 
 // Run performs the copy.
-func (c *Copier) Run(ctx context.Context) (*ObjectAttrs, error) {
+func (c *Copier) Run(ctx context.Context) (attrs *ObjectAttrs, err error) {
+	ctx = trace.StartSpan(ctx, "cloud.google.com/go/storage.Copier.Run")
+	defer func() { trace.EndSpan(ctx, err) }()
+
 	if err := c.src.validate(); err != nil {
 		return nil, err
 	}
 	if err := c.dst.validate(); err != nil {
 		return nil, err
 	}
+	if c.DestinationKMSKeyName != "" && c.dst.encryptionKey != nil {
+		return nil, errors.New("storage: cannot use DestinationKMSKeyName with a customer-supplied encryption key")
+	}
 	// Convert destination attributes to raw form, omitting the bucket.
 	// If the bucket is included but name or content-type aren't, the service
 	// returns a 400 with "Required" as the only message. Omitting the bucket
 	// does not cause any problems.
 	rawObject := c.ObjectAttrs.toRawObject("")
 	for {
-		res, err := c.callRewrite(ctx, c.src, rawObject)
+		res, err := c.callRewrite(ctx, rawObject)
 		if err != nil {
 			return nil, err
 		}
 		if c.ProgressFunc != nil {
-			c.ProgressFunc(res.TotalBytesRewritten, res.ObjectSize)
+			c.ProgressFunc(uint64(res.TotalBytesRewritten), uint64(res.ObjectSize))
 		}
 		if res.Done { // Finished successfully.
 			return newObject(res.Resource), nil
 		}
 	}
-	return nil, nil
 }
 
-func (c *Copier) callRewrite(ctx context.Context, src *ObjectHandle, rawObj *raw.Object) (*raw.RewriteResponse, error) {
-	call := c.dst.c.raw.Objects.Rewrite(src.bucket, src.object, c.dst.bucket, c.dst.object, rawObj)
+func (c *Copier) callRewrite(ctx context.Context, rawObj *raw.Object) (*raw.RewriteResponse, error) {
+	call := c.dst.c.raw.Objects.Rewrite(c.src.bucket, c.src.object, c.dst.bucket, c.dst.object, rawObj)
 
 	call.Context(ctx).Projection("full")
 	if c.RewriteToken != "" {
 		call.RewriteToken(c.RewriteToken)
 	}
+	if c.DestinationKMSKeyName != "" {
+		call.DestinationKmsKeyName(c.DestinationKMSKeyName)
+	}
+	if c.PredefinedACL != "" {
+		call.DestinationPredefinedAcl(c.PredefinedACL)
+	}
 	if err := applyConds("Copy destination", c.dst.gen, c.dst.conds, call); err != nil {
 		return nil, err
 	}
+	if c.dst.userProject != "" {
+		call.UserProject(c.dst.userProject)
+	} else if c.src.userProject != "" {
+		call.UserProject(c.src.userProject)
+	}
 	if err := applySourceConds(c.src.gen, c.src.conds, call); err != nil {
 		return nil, err
 	}
@@ -129,6 +158,8 @@ func (dst *ObjectHandle) ComposerFrom(srcs ...*ObjectHandle) *Composer {
 }
 
 // A Composer composes source objects into a destination object.
+//
+// For Requester Pays buckets, the user project of dst is billed.
 type Composer struct {
 	// ObjectAttrs are optional attributes to set on the destination object.
 	// Any attributes must be initialized before any calls on the Composer. Nil
@@ -140,7 +171,10 @@ type Composer struct {
 }
 
 // Run performs the compose operation.
-func (c *Composer) Run(ctx context.Context) (*ObjectAttrs, error) {
+func (c *Composer) Run(ctx context.Context) (attrs *ObjectAttrs, err error) {
+	ctx = trace.StartSpan(ctx, "cloud.google.com/go/storage.Composer.Run")
+	defer func() { trace.EndSpan(ctx, err) }()
+
 	if err := c.dst.validate(); err != nil {
 		return nil, err
 	}
@@ -175,11 +209,16 @@ func (c *Composer) Run(ctx context.Context) (*ObjectAttrs, error) {
 	if err := applyConds("ComposeFrom destination", c.dst.gen, c.dst.conds, call); err != nil {
 		return nil, err
 	}
+	if c.dst.userProject != "" {
+		call.UserProject(c.dst.userProject)
+	}
+	if c.PredefinedACL != "" {
+		call.DestinationPredefinedAcl(c.PredefinedACL)
+	}
 	if err := setEncryptionHeaders(call.Header(), c.dst.encryptionKey, false); err != nil {
 		return nil, err
 	}
 	var obj *raw.Object
-	var err error
 	setClientHeader(call.Header())
 	err = runWithRetry(ctx, func() error { obj, err = call.Do(); return err })
 	if err != nil {

vendor/cloud.google.com/go/storage/doc.go

@@ -1,4 +1,4 @@
-// Copyright 2016 Google Inc. All Rights Reserved.
+// Copyright 2016 Google LLC
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -19,11 +19,14 @@ Google Cloud Storage stores data in named objects, which are grouped into bucket
 More information about Google Cloud Storage is available at
 https://cloud.google.com/storage/docs.
 
-All of the methods of this package use exponential backoff to retry calls
-that fail with certain errors, as described in
-https://cloud.google.com/storage/docs/exponential-backoff.
+See https://godoc.org/cloud.google.com/go for authentication, timeouts,
+connection pooling and similar aspects of this package.
 
-Note: This package is in beta.  Some backwards-incompatible changes may occur.
+All of the methods of this package use exponential backoff to retry calls that fail
+with certain errors, as described in
+https://cloud.google.com/storage/docs/exponential-backoff. Retrying continues
+indefinitely unless the controlling context is canceled or the client is closed. See
+context.WithTimeout and context.WithCancel.
 
 
 Creating a Client
@@ -36,6 +39,13 @@ To start working with this package, create a client:
         // TODO: Handle error.
     }
 
+The client will use your default application credentials.
+
+If you only wish to access public data, you can create
+an unauthenticated client with
+
+    client, err := storage.NewClient(ctx, option.WithoutAuthentication())
+
 Buckets
 
 A Google Cloud Storage bucket is a collection of objects. To work with a
@@ -56,7 +66,7 @@ global across all projects.
 
 Each bucket has associated metadata, represented in this package by
 BucketAttrs. The third argument to BucketHandle.Create allows you to set
-the intial BucketAttrs of a bucket. To retrieve a bucket's attributes, use
+the initial BucketAttrs of a bucket. To retrieve a bucket's attributes, use
 Attrs:
 
     attrs, err := bkt.Attrs(ctx)
@@ -69,15 +79,16 @@ Attrs:
 Objects
 
 An object holds arbitrary data as a sequence of bytes, like a file. You
-refer to objects using a handle, just as with buckets. You can use the
-standard Go io.Reader and io.Writer interfaces to read and write
-object data:
+refer to objects using a handle, just as with buckets, but unlike buckets
+you don't explicitly create an object. Instead, the first time you write
+to an object it will be created. You can use the standard Go io.Reader
+and io.Writer interfaces to read and write object data:
 
     obj := bkt.Object("data")
     // Write something to obj.
     // w implements io.Writer.
     w := obj.NewWriter(ctx)
-    // Write some text to obj. This will overwrite whatever is there.
+    // Write some text to obj. This will either create the object or overwrite whatever is there already.
     if _, err := fmt.Fprintf(w, "This object contains text.\n"); err != nil {
         // TODO: Handle error.
     }
@@ -153,9 +164,13 @@ SignedURL for details.
     }
     fmt.Println(url)
 
-Authentication
+Errors
 
-See examples of authorization and authentication at
-https://godoc.org/cloud.google.com/go#pkg-examples.
+Errors returned by this client are often of the type [`googleapi.Error`](https://godoc.org/google.golang.org/api/googleapi#Error).
+These errors can be introspected for more information by type asserting to the richer `googleapi.Error` type. For example:
+
+	if e, ok := err.(*googleapi.Error); ok {
+		  if e.Code = 409 { ... }
+	}
 */
 package storage // import "cloud.google.com/go/storage"

vendor/cloud.google.com/go/storage/go110.go

@@ -0,0 +1,32 @@
+// Copyright 2017 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build go1.10
+
+package storage
+
+import "google.golang.org/api/googleapi"
+
+func shouldRetry(err error) bool {
+	switch e := err.(type) {
+	case *googleapi.Error:
+		// Retry on 429 and 5xx, according to
+		// https://cloud.google.com/storage/docs/exponential-backoff.
+		return e.Code == 429 || (e.Code >= 500 && e.Code < 600)
+	case interface{ Temporary() bool }:
+		return e.Temporary()
+	default:
+		return false
+	}
+}

vendor/cloud.google.com/go/storage/go17.go

@@ -1,4 +1,4 @@
-// Copyright 2017 Google Inc. All Rights Reserved.
+// Copyright 2017 Google LLC
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -24,3 +24,7 @@ import (
 func withContext(r *http.Request, ctx context.Context) *http.Request {
 	return r.WithContext(ctx)
 }
+
+func goHTTPUncompressed(res *http.Response) bool {
+	return res.Uncompressed
+}

vendor/cloud.google.com/go/storage/iam.go

@@ -1,4 +1,4 @@
-// Copyright 2017 Google Inc. All Rights Reserved.
+// Copyright 2017 Google LLC
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -16,6 +16,7 @@ package storage
 
 import (
 	"cloud.google.com/go/iam"
+	"cloud.google.com/go/internal/trace"
 	"golang.org/x/net/context"
 	raw "google.golang.org/api/storage/v1"
 	iampb "google.golang.org/genproto/googleapis/iam/v1"
@@ -23,21 +24,30 @@ import (
 
 // IAM provides access to IAM access control for the bucket.
 func (b *BucketHandle) IAM() *iam.Handle {
-	return iam.InternalNewHandleClient(&iamClient{raw: b.c.raw}, b.name)
+	return iam.InternalNewHandleClient(&iamClient{
+		raw:         b.c.raw,
+		userProject: b.userProject,
+	}, b.name)
 }
 
 // iamClient implements the iam.client interface.
 type iamClient struct {
-	raw *raw.Service
+	raw         *raw.Service
+	userProject string
 }
 
-func (c *iamClient) Get(ctx context.Context, resource string) (*iampb.Policy, error) {
-	req := c.raw.Buckets.GetIamPolicy(resource)
-	setClientHeader(req.Header())
+func (c *iamClient) Get(ctx context.Context, resource string) (p *iampb.Policy, err error) {
+	ctx = trace.StartSpan(ctx, "cloud.google.com/go/storage.IAM.Get")
+	defer func() { trace.EndSpan(ctx, err) }()
+
+	call := c.raw.Buckets.GetIamPolicy(resource)
+	setClientHeader(call.Header())
+	if c.userProject != "" {
+		call.UserProject(c.userProject)
+	}
 	var rp *raw.Policy
-	var err error
 	err = runWithRetry(ctx, func() error {
-		rp, err = req.Context(ctx).Do()
+		rp, err = call.Context(ctx).Do()
 		return err
 	})
 	if err != nil {
@@ -46,23 +56,34 @@ func (c *iamClient) Get(ctx context.Context, resource string) (*iampb.Policy, er
 	return iamFromStoragePolicy(rp), nil
 }
 
-func (c *iamClient) Set(ctx context.Context, resource string, p *iampb.Policy) error {
+func (c *iamClient) Set(ctx context.Context, resource string, p *iampb.Policy) (err error) {
+	ctx = trace.StartSpan(ctx, "cloud.google.com/go/storage.IAM.Set")
+	defer func() { trace.EndSpan(ctx, err) }()
+
 	rp := iamToStoragePolicy(p)
-	req := c.raw.Buckets.SetIamPolicy(resource, rp)
-	setClientHeader(req.Header())
+	call := c.raw.Buckets.SetIamPolicy(resource, rp)
+	setClientHeader(call.Header())
+	if c.userProject != "" {
+		call.UserProject(c.userProject)
+	}
 	return runWithRetry(ctx, func() error {
-		_, err := req.Context(ctx).Do()
+		_, err := call.Context(ctx).Do()
 		return err
 	})
 }
 
-func (c *iamClient) Test(ctx context.Context, resource string, perms []string) ([]string, error) {
-	req := c.raw.Buckets.TestIamPermissions(resource, perms)
-	setClientHeader(req.Header())
+func (c *iamClient) Test(ctx context.Context, resource string, perms []string) (permissions []string, err error) {
+	ctx = trace.StartSpan(ctx, "cloud.google.com/go/storage.IAM.Test")
+	defer func() { trace.EndSpan(ctx, err) }()
+
+	call := c.raw.Buckets.TestIamPermissions(resource, perms)
+	setClientHeader(call.Header())
+	if c.userProject != "" {
+		call.UserProject(c.userProject)
+	}
 	var res *raw.TestIamPermissionsResponse
-	var err error
 	err = runWithRetry(ctx, func() error {
-		res, err = req.Context(ctx).Do()
+		res, err = call.Context(ctx).Do()
 		return err
 	})
 	if err != nil {

vendor/cloud.google.com/go/storage/invoke.go

@@ -1,4 +1,4 @@
-// Copyright 2014 Google Inc. All Rights Reserved.
+// Copyright 2014 Google LLC
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -18,7 +18,6 @@ import (
 	"cloud.google.com/go/internal"
 	gax "github.com/googleapis/gax-go"
 	"golang.org/x/net/context"
-	"google.golang.org/api/googleapi"
 )
 
 // runWithRetry calls the function until it returns nil or a non-retryable error, or
@@ -29,13 +28,7 @@ func runWithRetry(ctx context.Context, call func() error) error {
 		if err == nil {
 			return true, nil
 		}
-		e, ok := err.(*googleapi.Error)
-		if !ok {
-			return true, err
-		}
-		// Retry on 429 and 5xx, according to
-		// https://cloud.google.com/storage/docs/exponential-backoff.
-		if e.Code == 429 || (e.Code >= 500 && e.Code < 600) {
+		if shouldRetry(err) {
 			return false, nil
 		}
 		return true, err

vendor/cloud.google.com/go/storage/not_go110.go

@@ -0,0 +1,42 @@
+// Copyright 2017 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build !go1.10
+
+package storage
+
+import (
+	"net/url"
+	"strings"
+
+	"google.golang.org/api/googleapi"
+)
+
+func shouldRetry(err error) bool {
+	switch e := err.(type) {
+	case *googleapi.Error:
+		// Retry on 429 and 5xx, according to
+		// https://cloud.google.com/storage/docs/exponential-backoff.
+		return e.Code == 429 || (e.Code >= 500 && e.Code < 600)
+	case *url.Error:
+		// Retry on REFUSED_STREAM.
+		// Unfortunately the error type is unexported, so we resort to string
+		// matching.
+		return strings.Contains(e.Error(), "REFUSED_STREAM")
+	case interface{ Temporary() bool }:
+		return e.Temporary()
+	default:
+		return false
+	}
+}

vendor/cloud.google.com/go/storage/not_go17.go

@@ -1,4 +1,4 @@
-// Copyright 2017 Google Inc. All Rights Reserved.
+// Copyright 2017 Google LLC
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -24,3 +24,10 @@ func withContext(r *http.Request, _ interface{}) *http.Request {
 	// In Go 1.6 and below, ignore the context.
 	return r
 }
+
+// Go 1.6 doesn't have http.Response.Uncompressed, so we can't know whether the Go
+// HTTP stack uncompressed a gzip file. As a good approximation, assume that
+// the lack of a Content-Length header means that it did uncompress.
+func goHTTPUncompressed(res *http.Response) bool {
+	return res.Header.Get("Content-Length") == ""
+}

vendor/cloud.google.com/go/storage/notifications.go

@@ -0,0 +1,188 @@
+// Copyright 2017 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package storage
+
+import (
+	"errors"
+	"fmt"
+	"regexp"
+
+	"cloud.google.com/go/internal/trace"
+	"golang.org/x/net/context"
+	raw "google.golang.org/api/storage/v1"
+)
+
+// A Notification describes how to send Cloud PubSub messages when certain
+// events occur in a bucket.
+type Notification struct {
+	//The ID of the notification.
+	ID string
+
+	// The ID of the topic to which this subscription publishes.
+	TopicID string
+
+	// The ID of the project to which the topic belongs.
+	TopicProjectID string
+
+	// Only send notifications about listed event types. If empty, send notifications
+	// for all event types.
+	// See https://cloud.google.com/storage/docs/pubsub-notifications#events.
+	EventTypes []string
+
+	// If present, only apply this notification configuration to object names that
+	// begin with this prefix.
+	ObjectNamePrefix string
+
+	// An optional list of additional attributes to attach to each Cloud PubSub
+	// message published for this notification subscription.
+	CustomAttributes map[string]string
+
+	// The contents of the message payload.
+	// See https://cloud.google.com/storage/docs/pubsub-notifications#payload.
+	PayloadFormat string
+}
+
+// Values for Notification.PayloadFormat.
+const (
+	// Send no payload with notification messages.
+	NoPayload = "NONE"
+
+	// Send object metadata as JSON with notification messages.
+	JSONPayload = "JSON_API_V1"
+)
+
+// Values for Notification.EventTypes.
+const (
+	// Event that occurs when an object is successfully created.
+	ObjectFinalizeEvent = "OBJECT_FINALIZE"
+
+	// Event that occurs when the metadata of an existing object changes.
+	ObjectMetadataUpdateEvent = "OBJECT_METADATA_UPDATE"
+
+	// Event that occurs when an object is permanently deleted.
+	ObjectDeleteEvent = "OBJECT_DELETE"
+
+	// Event that occurs when the live version of an object becomes an
+	// archived version.
+	ObjectArchiveEvent = "OBJECT_ARCHIVE"
+)
+
+func toNotification(rn *raw.Notification) *Notification {
+	n := &Notification{
+		ID:               rn.Id,
+		EventTypes:       rn.EventTypes,
+		ObjectNamePrefix: rn.ObjectNamePrefix,
+		CustomAttributes: rn.CustomAttributes,
+		PayloadFormat:    rn.PayloadFormat,
+	}
+	n.TopicProjectID, n.TopicID = parseNotificationTopic(rn.Topic)
+	return n
+}
+
+var topicRE = regexp.MustCompile("^//pubsub.googleapis.com/projects/([^/]+)/topics/([^/]+)")
+
+// parseNotificationTopic extracts the project and topic IDs from from the full
+// resource name returned by the service. If the name is malformed, it returns
+// "?" for both IDs.
+func parseNotificationTopic(nt string) (projectID, topicID string) {
+	matches := topicRE.FindStringSubmatch(nt)
+	if matches == nil {
+		return "?", "?"
+	}
+	return matches[1], matches[2]
+}
+
+func toRawNotification(n *Notification) *raw.Notification {
+	return &raw.Notification{
+		Id: n.ID,
+		Topic: fmt.Sprintf("//pubsub.googleapis.com/projects/%s/topics/%s",
+			n.TopicProjectID, n.TopicID),
+		EventTypes:       n.EventTypes,
+		ObjectNamePrefix: n.ObjectNamePrefix,
+		CustomAttributes: n.CustomAttributes,
+		PayloadFormat:    string(n.PayloadFormat),
+	}
+}
+
+// AddNotification adds a notification to b. You must set n's TopicProjectID, TopicID
+// and PayloadFormat, and must not set its ID. The other fields are all optional. The
+// returned Notification's ID can be used to refer to it.
+func (b *BucketHandle) AddNotification(ctx context.Context, n *Notification) (ret *Notification, err error) {
+	ctx = trace.StartSpan(ctx, "cloud.google.com/go/storage.Bucket.AddNotification")
+	defer func() { trace.EndSpan(ctx, err) }()
+
+	if n.ID != "" {
+		return nil, errors.New("storage: AddNotification: ID must not be set")
+	}
+	if n.TopicProjectID == "" {
+		return nil, errors.New("storage: AddNotification: missing TopicProjectID")
+	}
+	if n.TopicID == "" {
+		return nil, errors.New("storage: AddNotification: missing TopicID")
+	}
+	call := b.c.raw.Notifications.Insert(b.name, toRawNotification(n))
+	setClientHeader(call.Header())
+	if b.userProject != "" {
+		call.UserProject(b.userProject)
+	}
+	rn, err := call.Context(ctx).Do()
+	if err != nil {
+		return nil, err
+	}
+	return toNotification(rn), nil
+}
+
+// Notifications returns all the Notifications configured for this bucket, as a map
+// indexed by notification ID.
+func (b *BucketHandle) Notifications(ctx context.Context) (n map[string]*Notification, err error) {
+	ctx = trace.StartSpan(ctx, "cloud.google.com/go/storage.Bucket.Notifications")
+	defer func() { trace.EndSpan(ctx, err) }()
+
+	call := b.c.raw.Notifications.List(b.name)
+	setClientHeader(call.Header())
+	if b.userProject != "" {
+		call.UserProject(b.userProject)
+	}
+	var res *raw.Notifications
+	err = runWithRetry(ctx, func() error {
+		res, err = call.Context(ctx).Do()
+		return err
+	})
+	if err != nil {
+		return nil, err
+	}
+	return notificationsToMap(res.Items), nil
+}
+
+func notificationsToMap(rns []*raw.Notification) map[string]*Notification {
+	m := map[string]*Notification{}
+	for _, rn := range rns {
+		m[rn.Id] = toNotification(rn)
+	}
+	return m
+}
+
+// DeleteNotification deletes the notification with the given ID.
+func (b *BucketHandle) DeleteNotification(ctx context.Context, id string) (err error) {
+	ctx = trace.StartSpan(ctx, "cloud.google.com/go/storage.Bucket.DeleteNotification")
+	defer func() { trace.EndSpan(ctx, err) }()
+
+	call := b.c.raw.Notifications.Delete(b.name, id)
+	setClientHeader(call.Header())
+	if b.userProject != "" {
+		call.UserProject(b.userProject)
+	}
+	return call.Context(ctx).Do()
+}

vendor/cloud.google.com/go/storage/reader.go

@@ -1,4 +1,4 @@
-// Copyright 2016 Google Inc. All Rights Reserved.
+// Copyright 2016 Google LLC
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -15,22 +15,278 @@
 package storage
 
 import (
+	"errors"
 	"fmt"
 	"hash/crc32"
 	"io"
+	"io/ioutil"
+	"net/http"
+	"net/url"
+	"reflect"
+	"strconv"
+	"strings"
+	"time"
+
+	"cloud.google.com/go/internal/trace"
+	"golang.org/x/net/context"
+	"google.golang.org/api/googleapi"
 )
 
 var crc32cTable = crc32.MakeTable(crc32.Castagnoli)
 
+// ReaderObjectAttrs are attributes about the object being read. These are populated
+// during the New call. This struct only holds a subset of object attributes: to
+// get the full set of attributes, use ObjectHandle.Attrs.
+//
+// Each field is read-only.
+type ReaderObjectAttrs struct {
+	// Size is the length of the object's content.
+	Size int64
+
+	// ContentType is the MIME type of the object's content.
+	ContentType string
+
+	// ContentEncoding is the encoding of the object's content.
+	ContentEncoding string
+
+	// CacheControl specifies whether and for how long browser and Internet
+	// caches are allowed to cache your objects.
+	CacheControl string
+
+	// LastModified is the time that the object was last modified.
+	LastModified time.Time
+
+	// Generation is the generation number of the object's content.
+	Generation int64
+
+	// Metageneration is the version of the metadata for this object at
+	// this generation. This field is used for preconditions and for
+	// detecting changes in metadata. A metageneration number is only
+	// meaningful in the context of a particular generation of a
+	// particular object.
+	Metageneration int64
+}
+
+// NewReader creates a new Reader to read the contents of the
+// object.
+// ErrObjectNotExist will be returned if the object is not found.
+//
+// The caller must call Close on the returned Reader when done reading.
+func (o *ObjectHandle) NewReader(ctx context.Context) (*Reader, error) {
+	return o.NewRangeReader(ctx, 0, -1)
+}
+
+// NewRangeReader reads part of an object, reading at most length bytes
+// starting at the given offset. If length is negative, the object is read
+// until the end.
+func (o *ObjectHandle) NewRangeReader(ctx context.Context, offset, length int64) (r *Reader, err error) {
+	ctx = trace.StartSpan(ctx, "cloud.google.com/go/storage.Object.NewRangeReader")
+	defer func() { trace.EndSpan(ctx, err) }()
+
+	if err := o.validate(); err != nil {
+		return nil, err
+	}
+	if offset < 0 {
+		return nil, fmt.Errorf("storage: invalid offset %d < 0", offset)
+	}
+	if o.conds != nil {
+		if err := o.conds.validate("NewRangeReader"); err != nil {
+			return nil, err
+		}
+	}
+	u := &url.URL{
+		Scheme: "https",
+		Host:   "storage.googleapis.com",
+		Path:   fmt.Sprintf("/%s/%s", o.bucket, o.object),
+	}
+	verb := "GET"
+	if length == 0 {
+		verb = "HEAD"
+	}
+	req, err := http.NewRequest(verb, u.String(), nil)
+	if err != nil {
+		return nil, err
+	}
+	req = withContext(req, ctx)
+	if o.userProject != "" {
+		req.Header.Set("X-Goog-User-Project", o.userProject)
+	}
+	if o.readCompressed {
+		req.Header.Set("Accept-Encoding", "gzip")
+	}
+
+	if err := setEncryptionHeaders(req.Header, o.encryptionKey, false); err != nil {
+		return nil, err
+	}
+
+	gen := o.gen
+
+	// Define a function that initiates a Read with offset and length, assuming we
+	// have already read seen bytes.
+	reopen := func(seen int64) (*http.Response, error) {
+		start := offset + seen
+		if length < 0 && start > 0 {
+			req.Header.Set("Range", fmt.Sprintf("bytes=%d-", start))
+		} else if length > 0 {
+			// The end character isn't affected by how many bytes we've seen.
+			req.Header.Set("Range", fmt.Sprintf("bytes=%d-%d", start, offset+length-1))
+		}
+		// We wait to assign conditions here because the generation number can change in between reopen() runs.
+		req.URL.RawQuery = conditionsQuery(gen, o.conds)
+		var res *http.Response
+		err = runWithRetry(ctx, func() error {
+			res, err = o.c.hc.Do(req)
+			if err != nil {
+				return err
+			}
+			if res.StatusCode == http.StatusNotFound {
+				res.Body.Close()
+				return ErrObjectNotExist
+			}
+			if res.StatusCode < 200 || res.StatusCode > 299 {
+				body, _ := ioutil.ReadAll(res.Body)
+				res.Body.Close()
+				return &googleapi.Error{
+					Code:   res.StatusCode,
+					Header: res.Header,
+					Body:   string(body),
+				}
+			}
+			if start > 0 && length != 0 && res.StatusCode != http.StatusPartialContent {
+				res.Body.Close()
+				return errors.New("storage: partial request not satisfied")
+			}
+			// If a generation hasn't been specified, and this is the first response we get, let's record the
+			// generation. In future requests we'll use this generation as a precondition to avoid data races.
+			if gen < 0 && res.Header.Get("X-Goog-Generation") != "" {
+				gen64, err := strconv.ParseInt(res.Header.Get("X-Goog-Generation"), 10, 64)
+				if err != nil {
+					return err
+				}
+				gen = gen64
+			}
+			return nil
+		})
+		if err != nil {
+			return nil, err
+		}
+		return res, nil
+	}
+
+	res, err := reopen(0)
+	if err != nil {
+		return nil, err
+	}
+	var (
+		size     int64 // total size of object, even if a range was requested.
+		checkCRC bool
+		crc      uint32
+	)
+	if res.StatusCode == http.StatusPartialContent {
+		cr := strings.TrimSpace(res.Header.Get("Content-Range"))
+		if !strings.HasPrefix(cr, "bytes ") || !strings.Contains(cr, "/") {
+
+			return nil, fmt.Errorf("storage: invalid Content-Range %q", cr)
+		}
+		size, err = strconv.ParseInt(cr[strings.LastIndex(cr, "/")+1:], 10, 64)
+		if err != nil {
+			return nil, fmt.Errorf("storage: invalid Content-Range %q", cr)
+		}
+	} else {
+		size = res.ContentLength
+		// Check the CRC iff all of the following hold:
+		// - We asked for content (length != 0).
+		// - We got all the content (status != PartialContent).
+		// - The server sent a CRC header.
+		// - The Go http stack did not uncompress the file.
+		// - We were not served compressed data that was uncompressed on download.
+		// The problem with the last two cases is that the CRC will not match -- GCS
+		// computes it on the compressed contents, but we compute it on the
+		// uncompressed contents.
+		if length != 0 && !goHTTPUncompressed(res) && !uncompressedByServer(res) {
+			crc, checkCRC = parseCRC32c(res)
+		}
+	}
+
+	remain := res.ContentLength
+	body := res.Body
+	if length == 0 {
+		remain = 0
+		body.Close()
+		body = emptyBody
+	}
+	var metaGen int64
+	if res.Header.Get("X-Goog-Generation") != "" {
+		metaGen, err = strconv.ParseInt(res.Header.Get("X-Goog-Metageneration"), 10, 64)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	var lm time.Time
+	if res.Header.Get("Last-Modified") != "" {
+		lm, err = http.ParseTime(res.Header.Get("Last-Modified"))
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	attrs := ReaderObjectAttrs{
+		Size:            size,
+		ContentType:     res.Header.Get("Content-Type"),
+		ContentEncoding: res.Header.Get("Content-Encoding"),
+		CacheControl:    res.Header.Get("Cache-Control"),
+		LastModified:    lm,
+		Generation:      gen,
+		Metageneration:  metaGen,
+	}
+	return &Reader{
+		Attrs:    attrs,
+		body:     body,
+		size:     size,
+		remain:   remain,
+		wantCRC:  crc,
+		checkCRC: checkCRC,
+		reopen:   reopen,
+	}, nil
+}
+
+func uncompressedByServer(res *http.Response) bool {
+	// If the data is stored as gzip but is not encoded as gzip, then it
+	// was uncompressed by the server.
+	return res.Header.Get("X-Goog-Stored-Content-Encoding") == "gzip" &&
+		res.Header.Get("Content-Encoding") != "gzip"
+}
+
+func parseCRC32c(res *http.Response) (uint32, bool) {
+	const prefix = "crc32c="
+	for _, spec := range res.Header["X-Goog-Hash"] {
+		if strings.HasPrefix(spec, prefix) {
+			c, err := decodeUint32(spec[len(prefix):])
+			if err == nil {
+				return c, true
+			}
+		}
+	}
+	return 0, false
+}
+
+var emptyBody = ioutil.NopCloser(strings.NewReader(""))
+
 // Reader reads a Cloud Storage object.
 // It implements io.Reader.
+//
+// Typically, a Reader computes the CRC of the downloaded content and compares it to
+// the stored CRC, returning an error from Read if there is a mismatch. This integrity check
+// is skipped if transcoding occurs. See https://cloud.google.com/storage/docs/transcoding.
 type Reader struct {
-	body         io.ReadCloser
-	remain, size int64
-	contentType  string
-	checkCRC     bool   // should we check the CRC?
-	wantCRC      uint32 // the CRC32c value the server sent in the header
-	gotCRC       uint32 // running crc
+	Attrs              ReaderObjectAttrs
+	body               io.ReadCloser
+	seen, remain, size int64
+	checkCRC           bool   // should we check the CRC?
+	wantCRC            uint32 // the CRC32c value the server sent in the header
+	gotCRC             uint32 // running crc
+	reopen             func(seen int64) (*http.Response, error)
 }
 
 // Close closes the Reader. It must be called when done reading.
@@ -39,7 +295,7 @@ func (r *Reader) Close() error {
 }
 
 func (r *Reader) Read(p []byte) (int, error) {
-	n, err := r.body.Read(p)
+	n, err := r.readWithRetry(p)
 	if r.remain != -1 {
 		r.remain -= int64(n)
 	}
@@ -48,19 +304,52 @@ func (r *Reader) Read(p []byte) (int, error) {
 		// Check CRC here. It would be natural to check it in Close, but
 		// everybody defers Close on the assumption that it doesn't return
 		// anything worth looking at.
-		if r.remain == 0 && r.gotCRC != r.wantCRC {
-			return n, fmt.Errorf("storage: bad CRC on read: got %d, want %d",
-				r.gotCRC, r.wantCRC)
+		if err == io.EOF {
+			if r.gotCRC != r.wantCRC {
+				return n, fmt.Errorf("storage: bad CRC on read: got %d, want %d",
+					r.gotCRC, r.wantCRC)
+			}
 		}
 	}
 	return n, err
 }
 
+func (r *Reader) readWithRetry(p []byte) (int, error) {
+	n := 0
+	for len(p[n:]) > 0 {
+		m, err := r.body.Read(p[n:])
+		n += m
+		r.seen += int64(m)
+		if !shouldRetryRead(err) {
+			return n, err
+		}
+		// Read failed, but we will try again. Send a ranged read request that takes
+		// into account the number of bytes we've already seen.
+		res, err := r.reopen(r.seen)
+		if err != nil {
+			// reopen already retries
+			return n, err
+		}
+		r.body.Close()
+		r.body = res.Body
+	}
+	return n, nil
+}
+
+func shouldRetryRead(err error) bool {
+	if err == nil {
+		return false
+	}
+	return strings.HasSuffix(err.Error(), "INTERNAL_ERROR") && strings.Contains(reflect.TypeOf(err).String(), "http2")
+}
+
 // Size returns the size of the object in bytes.
 // The returned value is always the same and is not affected by
 // calls to Read or Close.
+//
+// Deprecated: use Reader.Attrs.Size.
 func (r *Reader) Size() int64 {
-	return r.size
+	return r.Attrs.Size
 }
 
 // Remain returns the number of bytes left to read, or -1 if unknown.
@@ -69,6 +358,29 @@ func (r *Reader) Remain() int64 {
 }
 
 // ContentType returns the content type of the object.
+//
+// Deprecated: use Reader.Attrs.ContentType.
 func (r *Reader) ContentType() string {
-	return r.contentType
+	return r.Attrs.ContentType
+}
+
+// ContentEncoding returns the content encoding of the object.
+//
+// Deprecated: use Reader.Attrs.ContentEncoding.
+func (r *Reader) ContentEncoding() string {
+	return r.Attrs.ContentEncoding
+}
+
+// CacheControl returns the cache control of the object.
+//
+// Deprecated: use Reader.Attrs.CacheControl.
+func (r *Reader) CacheControl() string {
+	return r.Attrs.CacheControl
+}
+
+// LastModified returns the value of the Last-Modified header.
+//
+// Deprecated: use Reader.Attrs.LastModified.
+func (r *Reader) LastModified() (time.Time, error) {
+	return r.Attrs.LastModified, nil
 }

vendor/cloud.google.com/go/storage/storage.go

@@ -1,4 +1,4 @@
-// Copyright 2014 Google Inc. All Rights Reserved.
+// Copyright 2014 Google LLC
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -26,17 +26,19 @@ import (
 	"errors"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"net/http"
 	"net/url"
 	"reflect"
+	"regexp"
+	"sort"
 	"strconv"
 	"strings"
 	"time"
 	"unicode/utf8"
 
+	"cloud.google.com/go/internal/trace"
 	"google.golang.org/api/option"
-	"google.golang.org/api/transport"
+	htransport "google.golang.org/api/transport/http"
 
 	"cloud.google.com/go/internal/optional"
 	"cloud.google.com/go/internal/version"
@@ -89,7 +91,7 @@ func NewClient(ctx context.Context, opts ...option.ClientOption) (*Client, error
 		option.WithUserAgent(userAgent),
 	}
 	opts = append(o, opts...)
-	hc, ep, err := transport.NewHTTPClient(ctx, opts...)
+	hc, ep, err := htransport.NewClient(ctx, opts...)
 	if err != nil {
 		return nil, fmt.Errorf("dialing: %v", err)
 	}
@@ -110,43 +112,12 @@ func NewClient(ctx context.Context, opts ...option.ClientOption) (*Client, error
 //
 // Close need not be called at program exit.
 func (c *Client) Close() error {
+	// Set fields to nil so that subsequent uses will panic.
 	c.hc = nil
+	c.raw = nil
 	return nil
 }
 
-// BucketHandle provides operations on a Google Cloud Storage bucket.
-// Use Client.Bucket to get a handle.
-type BucketHandle struct {
-	acl              ACLHandle
-	defaultObjectACL ACLHandle
-
-	c    *Client
-	name string
-}
-
-// Bucket returns a BucketHandle, which provides operations on the named bucket.
-// This call does not perform any network operations.
-//
-// The supplied name must contain only lowercase letters, numbers, dashes,
-// underscores, and dots. The full specification for valid bucket names can be
-// found at:
-//   https://cloud.google.com/storage/docs/bucket-naming
-func (c *Client) Bucket(name string) *BucketHandle {
-	return &BucketHandle{
-		c:    c,
-		name: name,
-		acl: ACLHandle{
-			c:      c,
-			bucket: name,
-		},
-		defaultObjectACL: ACLHandle{
-			c:         c,
-			bucket:    name,
-			isDefault: true,
-		},
-	}
-}
-
 // SignedURLOptions allows you to restrict the access to the signed URL.
 type SignedURLOptions struct {
 	// GoogleAccessID represents the authorizer of the signed URL generation.
@@ -200,7 +171,7 @@ type SignedURLOptions struct {
 	// Optional.
 	ContentType string
 
-	// Headers is a list of extention headers the client must provide
+	// Headers is a list of extension headers the client must provide
 	// in order to use the generated signed URL.
 	// Optional.
 	Headers []string
@@ -212,6 +183,60 @@ type SignedURLOptions struct {
 	MD5 string
 }
 
+var (
+	canonicalHeaderRegexp    = regexp.MustCompile(`(?i)^(x-goog-[^:]+):(.*)?$`)
+	excludedCanonicalHeaders = map[string]bool{
+		"x-goog-encryption-key":        true,
+		"x-goog-encryption-key-sha256": true,
+	}
+)
+
+// sanitizeHeaders applies the specifications for canonical extension headers at
+// https://cloud.google.com/storage/docs/access-control/signed-urls#about-canonical-extension-headers.
+func sanitizeHeaders(hdrs []string) []string {
+	headerMap := map[string][]string{}
+	for _, hdr := range hdrs {
+		// No leading or trailing whitespaces.
+		sanitizedHeader := strings.TrimSpace(hdr)
+
+		// Only keep canonical headers, discard any others.
+		headerMatches := canonicalHeaderRegexp.FindStringSubmatch(sanitizedHeader)
+		if len(headerMatches) == 0 {
+			continue
+		}
+
+		header := strings.ToLower(strings.TrimSpace(headerMatches[1]))
+		if excludedCanonicalHeaders[headerMatches[1]] {
+			// Do not keep any deliberately excluded canonical headers when signing.
+			continue
+		}
+		value := strings.TrimSpace(headerMatches[2])
+		if len(value) > 0 {
+			// Remove duplicate headers by appending the values of duplicates
+			// in their order of appearance.
+			headerMap[header] = append(headerMap[header], value)
+		}
+	}
+
+	var sanitizedHeaders []string
+	for header, values := range headerMap {
+		// There should be no spaces around the colon separating the
+		// header name from the header value or around the values
+		// themselves. The values should be separated by commas.
+		// NOTE: The semantics for headers without a value are not clear.
+		//       However from specifications these should be edge-cases
+		//       anyway and we should assume that there will be no
+		//       canonical headers using empty values. Any such headers
+		//       are discarded at the regexp stage above.
+		sanitizedHeaders = append(
+			sanitizedHeaders,
+			fmt.Sprintf("%s:%s", header, strings.Join(values, ",")),
+		)
+	}
+	sort.Strings(sanitizedHeaders)
+	return sanitizedHeaders
+}
+
 // SignedURL returns a URL for the specified object. Signed URLs allow
 // the users access to a restricted resource for a limited time without having a
 // Google account or signing in. For more information about the signed
@@ -238,6 +263,7 @@ func SignedURL(bucket, name string, opts *SignedURLOptions) (string, error) {
 			return "", errors.New("storage: invalid MD5 checksum")
 		}
 	}
+	opts.Headers = sanitizeHeaders(opts.Headers)
 
 	signBytes := opts.SignBytes
 	if opts.PrivateKey != nil {
@@ -288,13 +314,15 @@ func SignedURL(bucket, name string, opts *SignedURLOptions) (string, error) {
 // ObjectHandle provides operations on an object in a Google Cloud Storage bucket.
 // Use BucketHandle.Object to get a handle.
 type ObjectHandle struct {
-	c             *Client
-	bucket        string
-	object        string
-	acl           ACLHandle
-	gen           int64 // a negative value indicates latest
-	conds         *Conditions
-	encryptionKey []byte // AES-256 key
+	c              *Client
+	bucket         string
+	object         string
+	acl            ACLHandle
+	gen            int64 // a negative value indicates latest
+	conds          *Conditions
+	encryptionKey  []byte // AES-256 key
+	userProject    string // for requester-pays buckets
+	readCompressed bool   // Accept-Encoding: gzip
 }
 
 // ACL provides access to the object's access control list.
@@ -317,7 +345,7 @@ func (o *ObjectHandle) Generation(gen int64) *ObjectHandle {
 
 // If returns a new ObjectHandle that applies a set of preconditions.
 // Preconditions already set on the ObjectHandle are ignored.
-// Operations on the new handle will only occur if the preconditions are
+// Operations on the new handle will return an error if the preconditions are not
 // satisfied. See https://cloud.google.com/storage/docs/generations-preconditions
 // for more details.
 func (o *ObjectHandle) If(conds Conditions) *ObjectHandle {
@@ -339,7 +367,10 @@ func (o *ObjectHandle) Key(encryptionKey []byte) *ObjectHandle {
 
 // Attrs returns meta information about the object.
 // ErrObjectNotExist will be returned if the object is not found.
-func (o *ObjectHandle) Attrs(ctx context.Context) (*ObjectAttrs, error) {
+func (o *ObjectHandle) Attrs(ctx context.Context) (attrs *ObjectAttrs, err error) {
+	ctx = trace.StartSpan(ctx, "cloud.google.com/go/storage.Object.Attrs")
+	defer func() { trace.EndSpan(ctx, err) }()
+
 	if err := o.validate(); err != nil {
 		return nil, err
 	}
@@ -347,11 +378,13 @@ func (o *ObjectHandle) Attrs(ctx context.Context) (*ObjectAttrs, error) {
 	if err := applyConds("Attrs", o.gen, o.conds, call); err != nil {
 		return nil, err
 	}
+	if o.userProject != "" {
+		call.UserProject(o.userProject)
+	}
 	if err := setEncryptionHeaders(call.Header(), o.encryptionKey, false); err != nil {
 		return nil, err
 	}
 	var obj *raw.Object
-	var err error
 	setClientHeader(call.Header())
 	err = runWithRetry(ctx, func() error { obj, err = call.Do(); return err })
 	if e, ok := err.(*googleapi.Error); ok && e.Code == http.StatusNotFound {
@@ -366,7 +399,10 @@ func (o *ObjectHandle) Attrs(ctx context.Context) (*ObjectAttrs, error) {
 // Update updates an object with the provided attributes.
 // All zero-value attributes are ignored.
 // ErrObjectNotExist will be returned if the object is not found.
-func (o *ObjectHandle) Update(ctx context.Context, uattrs ObjectAttrsToUpdate) (*ObjectAttrs, error) {
+func (o *ObjectHandle) Update(ctx context.Context, uattrs ObjectAttrsToUpdate) (oa *ObjectAttrs, err error) {
+	ctx = trace.StartSpan(ctx, "cloud.google.com/go/storage.Object.Update")
+	defer func() { trace.EndSpan(ctx, err) }()
+
 	if err := o.validate(); err != nil {
 		return nil, err
 	}
@@ -375,11 +411,17 @@ func (o *ObjectHandle) Update(ctx context.Context, uattrs ObjectAttrsToUpdate) (
 	var forceSendFields, nullFields []string
 	if uattrs.ContentType != nil {
 		attrs.ContentType = optional.ToString(uattrs.ContentType)
-		forceSendFields = append(forceSendFields, "ContentType")
+		// For ContentType, sending the empty string is a no-op.
+		// Instead we send a null.
+		if attrs.ContentType == "" {
+			nullFields = append(nullFields, "ContentType")
+		} else {
+			forceSendFields = append(forceSendFields, "ContentType")
+		}
 	}
 	if uattrs.ContentLanguage != nil {
 		attrs.ContentLanguage = optional.ToString(uattrs.ContentLanguage)
-		// For ContentLanguage It's an error to send the empty string.
+		// For ContentLanguage it's an error to send the empty string.
 		// Instead we send a null.
 		if attrs.ContentLanguage == "" {
 			nullFields = append(nullFields, "ContentLanguage")
@@ -389,7 +431,7 @@ func (o *ObjectHandle) Update(ctx context.Context, uattrs ObjectAttrsToUpdate) (
 	}
 	if uattrs.ContentEncoding != nil {
 		attrs.ContentEncoding = optional.ToString(uattrs.ContentEncoding)
-		forceSendFields = append(forceSendFields, "ContentType")
+		forceSendFields = append(forceSendFields, "ContentEncoding")
 	}
 	if uattrs.ContentDisposition != nil {
 		attrs.ContentDisposition = optional.ToString(uattrs.ContentDisposition)
@@ -399,6 +441,14 @@ func (o *ObjectHandle) Update(ctx context.Context, uattrs ObjectAttrsToUpdate) (
 		attrs.CacheControl = optional.ToString(uattrs.CacheControl)
 		forceSendFields = append(forceSendFields, "CacheControl")
 	}
+	if uattrs.EventBasedHold != nil {
+		attrs.EventBasedHold = optional.ToBool(uattrs.EventBasedHold)
+		forceSendFields = append(forceSendFields, "EventBasedHold")
+	}
+	if uattrs.TemporaryHold != nil {
+		attrs.TemporaryHold = optional.ToBool(uattrs.TemporaryHold)
+		forceSendFields = append(forceSendFields, "TemporaryHold")
+	}
 	if uattrs.Metadata != nil {
 		attrs.Metadata = uattrs.Metadata
 		if len(attrs.Metadata) == 0 {
@@ -421,11 +471,16 @@ func (o *ObjectHandle) Update(ctx context.Context, uattrs ObjectAttrsToUpdate) (
 	if err := applyConds("Update", o.gen, o.conds, call); err != nil {
 		return nil, err
 	}
+	if o.userProject != "" {
+		call.UserProject(o.userProject)
+	}
+	if uattrs.PredefinedACL != "" {
+		call.PredefinedAcl(uattrs.PredefinedACL)
+	}
 	if err := setEncryptionHeaders(call.Header(), o.encryptionKey, false); err != nil {
 		return nil, err
 	}
 	var obj *raw.Object
-	var err error
 	setClientHeader(call.Header())
 	err = runWithRetry(ctx, func() error { obj, err = call.Do(); return err })
 	if e, ok := err.(*googleapi.Error); ok && e.Code == http.StatusNotFound {
@@ -437,6 +492,16 @@ func (o *ObjectHandle) Update(ctx context.Context, uattrs ObjectAttrsToUpdate) (
 	return newObject(obj), nil
 }
 
+// BucketName returns the name of the bucket.
+func (o *ObjectHandle) BucketName() string {
+	return o.bucket
+}
+
+// ObjectName returns the name of the object.
+func (o *ObjectHandle) ObjectName() string {
+	return o.object
+}
+
 // ObjectAttrsToUpdate is used to update the attributes of an object.
 // Only fields set to non-nil values will be updated.
 // Set a field to its zero value to delete it.
@@ -449,6 +514,8 @@ func (o *ObjectHandle) Update(ctx context.Context, uattrs ObjectAttrsToUpdate) (
 //        Metadata: map[string]string{},
 //    }
 type ObjectAttrsToUpdate struct {
+	EventBasedHold     optional.Bool
+	TemporaryHold      optional.Bool
 	ContentType        optional.String
 	ContentLanguage    optional.String
 	ContentEncoding    optional.String
@@ -456,6 +523,10 @@ type ObjectAttrsToUpdate struct {
 	CacheControl       optional.String
 	Metadata           map[string]string // set to map[string]string{} to delete
 	ACL                []ACLRule
+
+	// If not empty, applies a predefined set of access controls. ACL must be nil.
+	// See https://cloud.google.com/storage/docs/json_api/v1/objects/patch.
+	PredefinedACL string
 }
 
 // Delete deletes the single specified object.
@@ -467,6 +538,10 @@ func (o *ObjectHandle) Delete(ctx context.Context) error {
 	if err := applyConds("Delete", o.gen, o.conds, call); err != nil {
 		return err
 	}
+	if o.userProject != "" {
+		call.UserProject(o.userProject)
+	}
+	// Encryption doesn't apply to Delete.
 	setClientHeader(call.Header())
 	err := runWithRetry(ctx, func() error { return call.Do() })
 	switch e := err.(type) {
@@ -480,136 +555,13 @@ func (o *ObjectHandle) Delete(ctx context.Context) error {
 	return err
 }
 
-// NewReader creates a new Reader to read the contents of the
-// object.
-// ErrObjectNotExist will be returned if the object is not found.
-//
-// The caller must call Close on the returned Reader when done reading.
-func (o *ObjectHandle) NewReader(ctx context.Context) (*Reader, error) {
-	return o.NewRangeReader(ctx, 0, -1)
+// ReadCompressed when true causes the read to happen without decompressing.
+func (o *ObjectHandle) ReadCompressed(compressed bool) *ObjectHandle {
+	o2 := *o
+	o2.readCompressed = compressed
+	return &o2
 }
 
-// NewRangeReader reads part of an object, reading at most length bytes
-// starting at the given offset. If length is negative, the object is read
-// until the end.
-func (o *ObjectHandle) NewRangeReader(ctx context.Context, offset, length int64) (*Reader, error) {
-	if err := o.validate(); err != nil {
-		return nil, err
-	}
-	if offset < 0 {
-		return nil, fmt.Errorf("storage: invalid offset %d < 0", offset)
-	}
-	if o.conds != nil {
-		if err := o.conds.validate("NewRangeReader"); err != nil {
-			return nil, err
-		}
-	}
-	u := &url.URL{
-		Scheme:   "https",
-		Host:     "storage.googleapis.com",
-		Path:     fmt.Sprintf("/%s/%s", o.bucket, o.object),
-		RawQuery: conditionsQuery(o.gen, o.conds),
-	}
-	verb := "GET"
-	if length == 0 {
-		verb = "HEAD"
-	}
-	req, err := http.NewRequest(verb, u.String(), nil)
-	if err != nil {
-		return nil, err
-	}
-	req = withContext(req, ctx)
-	if length < 0 && offset > 0 {
-		req.Header.Set("Range", fmt.Sprintf("bytes=%d-", offset))
-	} else if length > 0 {
-		req.Header.Set("Range", fmt.Sprintf("bytes=%d-%d", offset, offset+length-1))
-	}
-	if err := setEncryptionHeaders(req.Header, o.encryptionKey, false); err != nil {
-		return nil, err
-	}
-	var res *http.Response
-	err = runWithRetry(ctx, func() error {
-		res, err = o.c.hc.Do(req)
-		if err != nil {
-			return err
-		}
-		if res.StatusCode == http.StatusNotFound {
-			res.Body.Close()
-			return ErrObjectNotExist
-		}
-		if res.StatusCode < 200 || res.StatusCode > 299 {
-			body, _ := ioutil.ReadAll(res.Body)
-			res.Body.Close()
-			return &googleapi.Error{
-				Code:   res.StatusCode,
-				Header: res.Header,
-				Body:   string(body),
-			}
-		}
-		if offset > 0 && length != 0 && res.StatusCode != http.StatusPartialContent {
-			res.Body.Close()
-			return errors.New("storage: partial request not satisfied")
-		}
-		return nil
-	})
-	if err != nil {
-		return nil, err
-	}
-
-	var size int64 // total size of object, even if a range was requested.
-	if res.StatusCode == http.StatusPartialContent {
-		cr := strings.TrimSpace(res.Header.Get("Content-Range"))
-		if !strings.HasPrefix(cr, "bytes ") || !strings.Contains(cr, "/") {
-			return nil, fmt.Errorf("storage: invalid Content-Range %q", cr)
-		}
-		size, err = strconv.ParseInt(cr[strings.LastIndex(cr, "/")+1:], 10, 64)
-		if err != nil {
-			return nil, fmt.Errorf("storage: invalid Content-Range %q", cr)
-		}
-	} else {
-		size = res.ContentLength
-	}
-
-	remain := res.ContentLength
-	body := res.Body
-	if length == 0 {
-		remain = 0
-		body.Close()
-		body = emptyBody
-	}
-	var (
-		checkCRC bool
-		crc      uint32
-	)
-	// Even if there is a CRC header, we can't compute the hash on partial data.
-	if remain == size {
-		crc, checkCRC = parseCRC32c(res)
-	}
-	return &Reader{
-		body:        body,
-		size:        size,
-		remain:      remain,
-		contentType: res.Header.Get("Content-Type"),
-		wantCRC:     crc,
-		checkCRC:    checkCRC,
-	}, nil
-}
-
-func parseCRC32c(res *http.Response) (uint32, bool) {
-	const prefix = "crc32c="
-	for _, spec := range res.Header["X-Goog-Hash"] {
-		if strings.HasPrefix(spec, prefix) {
-			c, err := decodeUint32(spec[len(prefix):])
-			if err == nil {
-				return c, true
-			}
-		}
-	}
-	return 0, false
-}
-
-var emptyBody = ioutil.NopCloser(strings.NewReader(""))
-
 // NewWriter returns a storage Writer that writes to the GCS object
 // associated with this ObjectHandle.
 //
@@ -623,7 +575,8 @@ var emptyBody = ioutil.NopCloser(strings.NewReader(""))
 // attribute is specified, the content type will be automatically sniffed
 // using net/http.DetectContentType.
 //
-// It is the caller's responsibility to call Close when writing is done.
+// It is the caller's responsibility to call Close when writing is done. To
+// stop writing without saving the data, cancel the context.
 func (o *ObjectHandle) NewWriter(ctx context.Context) *Writer {
 	return &Writer{
 		ctx:         ctx,
@@ -647,11 +600,10 @@ func (o *ObjectHandle) validate() error {
 	return nil
 }
 
-// parseKey converts the binary contents of a private key file
-// to an *rsa.PrivateKey. It detects whether the private key is in a
-// PEM container or not. If so, it extracts the the private key
-// from PEM container before conversion. It only supports PEM
-// containers with no passphrase.
+// parseKey converts the binary contents of a private key file to an
+// *rsa.PrivateKey. It detects whether the private key is in a PEM container or
+// not. If so, it extracts the private key from PEM container before
+// conversion. It only supports PEM containers with no passphrase.
 func parseKey(key []byte) (*rsa.PrivateKey, error) {
 	if block, _ := pem.Decode(key); block != nil {
 		key = block.Bytes
@@ -670,34 +622,26 @@ func parseKey(key []byte) (*rsa.PrivateKey, error) {
 	return parsed, nil
 }
 
-func toRawObjectACL(oldACL []ACLRule) []*raw.ObjectAccessControl {
-	var acl []*raw.ObjectAccessControl
-	if len(oldACL) > 0 {
-		acl = make([]*raw.ObjectAccessControl, len(oldACL))
-		for i, rule := range oldACL {
-			acl[i] = &raw.ObjectAccessControl{
-				Entity: string(rule.Entity),
-				Role:   string(rule.Role),
-			}
-		}
-	}
-	return acl
-}
-
 // toRawObject copies the editable attributes from o to the raw library's Object type.
 func (o *ObjectAttrs) toRawObject(bucket string) *raw.Object {
-	acl := toRawObjectACL(o.ACL)
+	var ret string
+	if !o.RetentionExpirationTime.IsZero() {
+		ret = o.RetentionExpirationTime.Format(time.RFC3339)
+	}
 	return &raw.Object{
-		Bucket:             bucket,
-		Name:               o.Name,
-		ContentType:        o.ContentType,
-		ContentEncoding:    o.ContentEncoding,
-		ContentLanguage:    o.ContentLanguage,
-		CacheControl:       o.CacheControl,
-		ContentDisposition: o.ContentDisposition,
-		StorageClass:       o.StorageClass,
-		Acl:                acl,
-		Metadata:           o.Metadata,
+		Bucket:                  bucket,
+		Name:                    o.Name,
+		EventBasedHold:          o.EventBasedHold,
+		TemporaryHold:           o.TemporaryHold,
+		RetentionExpirationTime: ret,
+		ContentType:             o.ContentType,
+		ContentEncoding:         o.ContentEncoding,
+		ContentLanguage:         o.ContentLanguage,
+		CacheControl:            o.CacheControl,
+		ContentDisposition:      o.ContentDisposition,
+		StorageClass:            o.StorageClass,
+		Acl:                     toRawObjectACL(o.ACL),
+		Metadata:                o.Metadata,
 	}
 }
 
@@ -721,9 +665,32 @@ type ObjectAttrs struct {
 	// headers when serving the object data.
 	CacheControl string
 
+	// EventBasedHold specifies whether an object is under event-based hold. New
+	// objects created in a bucket whose DefaultEventBasedHold is set will
+	// default to that value.
+	EventBasedHold bool
+
+	// TemporaryHold specifies whether an object is under temporary hold. While
+	// this flag is set to true, the object is protected against deletion and
+	// overwrites.
+	TemporaryHold bool
+
+	// RetentionExpirationTime is a server-determined value that specifies the
+	// earliest time that the object's retention period expires.
+	// This is a read-only field.
+	RetentionExpirationTime time.Time
+
 	// ACL is the list of access control rules for the object.
 	ACL []ACLRule
 
+	// If not empty, applies a predefined set of access controls. It should be set
+	// only when writing, copying or composing an object. When copying or composing,
+	// it acts as the destinationPredefinedAcl parameter.
+	// PredefinedACL is always empty for ObjectAttrs returned from the service.
+	// See https://cloud.google.com/storage/docs/json_api/v1/objects/insert
+	// for valid values.
+	PredefinedACL string
+
 	// Owner is the owner of the object. This field is read-only.
 	//
 	// If non-zero, it is in the form of "user-<userId>".
@@ -739,11 +706,16 @@ type ObjectAttrs struct {
 	// sent in the response headers.
 	ContentDisposition string
 
-	// MD5 is the MD5 hash of the object's content. This field is read-only.
+	// MD5 is the MD5 hash of the object's content. This field is read-only,
+	// except when used from a Writer. If set on a Writer, the uploaded
+	// data is rejected if its MD5 hash does not match this field.
 	MD5 []byte
 
 	// CRC32C is the CRC32 checksum of the object's content using
-	// the Castagnoli93 polynomial. This field is read-only.
+	// the Castagnoli93 polynomial. This field is read-only, except when
+	// used from a Writer. If set on a Writer and Writer.SendCRC32C
+	// is true, the uploaded data is rejected if its CRC32c hash does not
+	// match this field.
 	CRC32C uint32
 
 	// MediaLink is an URL to the object's content. This field is read-only.
@@ -792,6 +764,14 @@ type ObjectAttrs struct {
 	// encryption in Google Cloud Storage.
 	CustomerKeySHA256 string
 
+	// Cloud KMS key name, in the form
+	// projects/P/locations/L/keyRings/R/cryptoKeys/K, used to encrypt this object,
+	// if the object is encrypted by such a key.
+	//
+	// Providing both a KMSKeyName and a customer-supplied encryption key (via
+	// ObjectHandle.Key) will result in an error when writing an object.
+	KMSKeyName string
+
 	// Prefix is set only for ObjectAttrs which represent synthetic "directory
 	// entries" when iterating over buckets using Query.Delimiter. See
 	// ObjectIterator.Next. When set, no other fields in ObjectAttrs will be
@@ -813,13 +793,6 @@ func newObject(o *raw.Object) *ObjectAttrs {
 	if o == nil {
 		return nil
 	}
-	acl := make([]ACLRule, len(o.Acl))
-	for i, rule := range o.Acl {
-		acl[i] = ACLRule{
-			Entity: ACLEntity(rule.Entity),
-			Role:   ACLRole(rule.Role),
-		}
-	}
 	owner := ""
 	if o.Owner != nil {
 		owner = o.Owner.Entity
@@ -831,26 +804,31 @@ func newObject(o *raw.Object) *ObjectAttrs {
 		sha256 = o.CustomerEncryption.KeySha256
 	}
 	return &ObjectAttrs{
-		Bucket:            o.Bucket,
-		Name:              o.Name,
-		ContentType:       o.ContentType,
-		ContentLanguage:   o.ContentLanguage,
-		CacheControl:      o.CacheControl,
-		ACL:               acl,
-		Owner:             owner,
-		ContentEncoding:   o.ContentEncoding,
-		Size:              int64(o.Size),
-		MD5:               md5,
-		CRC32C:            crc32c,
-		MediaLink:         o.MediaLink,
-		Metadata:          o.Metadata,
-		Generation:        o.Generation,
-		Metageneration:    o.Metageneration,
-		StorageClass:      o.StorageClass,
-		CustomerKeySHA256: sha256,
-		Created:           convertTime(o.TimeCreated),
-		Deleted:           convertTime(o.TimeDeleted),
-		Updated:           convertTime(o.Updated),
+		Bucket:                  o.Bucket,
+		Name:                    o.Name,
+		ContentType:             o.ContentType,
+		ContentLanguage:         o.ContentLanguage,
+		CacheControl:            o.CacheControl,
+		EventBasedHold:          o.EventBasedHold,
+		TemporaryHold:           o.TemporaryHold,
+		RetentionExpirationTime: convertTime(o.RetentionExpirationTime),
+		ACL:                     toObjectACLRules(o.Acl),
+		Owner:                   owner,
+		ContentEncoding:         o.ContentEncoding,
+		ContentDisposition:      o.ContentDisposition,
+		Size:                    int64(o.Size),
+		MD5:                     md5,
+		CRC32C:                  crc32c,
+		MediaLink:               o.MediaLink,
+		Metadata:                o.Metadata,
+		Generation:              o.Generation,
+		Metageneration:          o.Metageneration,
+		StorageClass:            o.StorageClass,
+		CustomerKeySHA256:       sha256,
+		KMSKeyName:              o.KmsKeyName,
+		Created:                 convertTime(o.TimeCreated),
+		Deleted:                 convertTime(o.TimeDeleted),
+		Updated:                 convertTime(o.Updated),
 	}
 }
 
@@ -905,7 +883,7 @@ func (c *contentTyper) ContentType() string {
 }
 
 // Conditions constrain methods to act on specific generations of
-// resources.
+// objects.
 //
 // The zero value is an empty set of constraints. Not all conditions or
 // combinations of conditions are applicable to all methods.
@@ -1133,4 +1111,12 @@ func setEncryptionHeaders(headers http.Header, key []byte, copySource bool) erro
 	return nil
 }
 
-// TODO(jbd): Add storage.objects.watch.
+// ServiceAccount fetches the email address of the given project's Google Cloud Storage service account.
+func (c *Client) ServiceAccount(ctx context.Context, projectID string) (string, error) {
+	r := c.raw.Projects.ServiceAccount.Get(projectID)
+	res, err := r.Context(ctx).Do()
+	if err != nil {
+		return "", err
+	}
+	return res.EmailAddress, nil
+}

vendor/cloud.google.com/go/storage/writer.go

@@ -1,4 +1,4 @@
-// Copyright 2014 Google Inc. All Rights Reserved.
+// Copyright 2014 Google LLC
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -19,6 +19,7 @@ import (
 	"errors"
 	"fmt"
 	"io"
+	"sync"
 	"unicode/utf8"
 
 	"golang.org/x/net/context"
@@ -36,6 +37,8 @@ type Writer struct {
 	// SendCRC specifies whether to transmit a CRC32C field. It should be set
 	// to true in addition to setting the Writer's CRC32C field, because zero
 	// is a valid CRC and normally a zero would not be transmitted.
+	// If a CRC32C is sent, and the data written does not match the checksum,
+	// the write will be rejected.
 	SendCRC32C bool
 
 	// ChunkSize controls the maximum number of bytes of the object that the
@@ -45,10 +48,23 @@ type Writer struct {
 	// to the nearest multiple of 256K. If zero, chunking will be disabled and
 	// the object will be uploaded in a single request.
 	//
-	// ChunkSize will default to a reasonable value. Any custom configuration
-	// must be done before the first Write call.
+	// ChunkSize will default to a reasonable value. If you perform many concurrent
+	// writes of small objects, you may wish set ChunkSize to a value that matches
+	// your objects' sizes to avoid consuming large amounts of memory.
+	//
+	// ChunkSize must be set before the first Write call.
 	ChunkSize int
 
+	// ProgressFunc can be used to monitor the progress of a large write.
+	// operation. If ProgressFunc is not nil and writing requires multiple
+	// calls to the underlying service (see
+	// https://cloud.google.com/storage/docs/json_api/v1/how-tos/resumable-upload),
+	// then ProgressFunc will be invoked after each call with the number of bytes of
+	// content copied so far.
+	//
+	// ProgressFunc should return quickly without blocking.
+	ProgressFunc func(int64)
+
 	ctx context.Context
 	o   *ObjectHandle
 
@@ -56,8 +72,10 @@ type Writer struct {
 	pw     *io.PipeWriter
 
 	donec chan struct{} // closed after err and obj are set.
-	err   error
 	obj   *ObjectAttrs
+
+	mu  sync.Mutex
+	err error
 }
 
 func (w *Writer) open() error {
@@ -70,12 +88,15 @@ func (w *Writer) open() error {
 	if !utf8.ValidString(attrs.Name) {
 		return fmt.Errorf("storage: object name %q is not valid UTF-8", attrs.Name)
 	}
+	if attrs.KMSKeyName != "" && w.o.encryptionKey != nil {
+		return errors.New("storage: cannot use KMSKeyName with a customer-supplied encryption key")
+	}
 	pr, pw := io.Pipe()
 	w.pw = pw
 	w.opened = true
 
 	if w.ChunkSize < 0 {
-		return errors.New("storage: Writer.ChunkSize must non-negative")
+		return errors.New("storage: Writer.ChunkSize must be non-negative")
 	}
 	mediaOpts := []googleapi.MediaOption{
 		googleapi.ChunkSize(w.ChunkSize),
@@ -98,20 +119,50 @@ func (w *Writer) open() error {
 			Media(pr, mediaOpts...).
 			Projection("full").
 			Context(w.ctx)
+		if w.ProgressFunc != nil {
+			call.ProgressUpdater(func(n, _ int64) { w.ProgressFunc(n) })
+		}
+		if attrs.KMSKeyName != "" {
+			call.KmsKeyName(attrs.KMSKeyName)
+		}
+		if attrs.PredefinedACL != "" {
+			call.PredefinedAcl(attrs.PredefinedACL)
+		}
 		if err := setEncryptionHeaders(call.Header(), w.o.encryptionKey, false); err != nil {
+			w.mu.Lock()
 			w.err = err
-			pr.CloseWithError(w.err)
+			w.mu.Unlock()
+			pr.CloseWithError(err)
 			return
 		}
 		var resp *raw.Object
 		err := applyConds("NewWriter", w.o.gen, w.o.conds, call)
 		if err == nil {
+			if w.o.userProject != "" {
+				call.UserProject(w.o.userProject)
+			}
 			setClientHeader(call.Header())
-			resp, err = call.Do()
+			// If the chunk size is zero, then no chunking is done on the Reader,
+			// which means we cannot retry: the first call will read the data, and if
+			// it fails, there is no way to re-read.
+			if w.ChunkSize == 0 {
+				resp, err = call.Do()
+			} else {
+				// We will only retry here if the initial POST, which obtains a URI for
+				// the resumable upload, fails with a retryable error. The upload itself
+				// has its own retry logic.
+				err = runWithRetry(w.ctx, func() error {
+					var err2 error
+					resp, err2 = call.Do()
+					return err2
+				})
+			}
 		}
 		if err != nil {
+			w.mu.Lock()
 			w.err = err
-			pr.CloseWithError(w.err)
+			w.mu.Unlock()
+			pr.CloseWithError(err)
 			return
 		}
 		w.obj = newObject(resp)
@@ -120,9 +171,17 @@ func (w *Writer) open() error {
 }
 
 // Write appends to w. It implements the io.Writer interface.
+//
+// Since writes happen asynchronously, Write may return a nil
+// error even though the write failed (or will fail). Always
+// use the error returned from Writer.Close to determine if
+// the upload was successful.
 func (w *Writer) Write(p []byte) (n int, err error) {
-	if w.err != nil {
-		return 0, w.err
+	w.mu.Lock()
+	werr := w.err
+	w.mu.Unlock()
+	if werr != nil {
+		return 0, werr
 	}
 	if !w.opened {
 		if err := w.open(); err != nil {
@@ -145,11 +204,15 @@ func (w *Writer) Close() error {
 		return err
 	}
 	<-w.donec
+	w.mu.Lock()
+	defer w.mu.Unlock()
 	return w.err
 }
 
 // CloseWithError aborts the write operation with the provided error.
 // CloseWithError always returns nil.
+//
+// Deprecated: cancel the context passed to NewWriter instead.
 func (w *Writer) CloseWithError(err error) error {
 	if !w.opened {
 		return nil

vendor/contrib.go.opencensus.io/exporter/stackdriver/LICENSE

@@ -0,0 +1,202 @@
+
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
+      control with that entity. For the purposes of this definition,
+      "control" means (i) the power, direct or indirect, to cause the
+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
+
+      "Source" form shall mean the preferred form for making modifications,
+      including but not limited to software source code, documentation
+      source, and configuration files.
+
+      "Object" form shall mean any form resulting from mechanical
+      transformation or translation of a Source form, including but
+      not limited to compiled object code, generated documentation,
+      and conversions to other media types.
+
+      "Work" shall mean the work of authorship, whether in Source or
+      Object form, made available under the License, as indicated by a
+      copyright notice that is included in or attached to the work
+      (an example is provided in the Appendix below).
+
+      "Derivative Works" shall mean any work, whether in Source or Object
+      form, that is based on (or derived from) the Work and for which the
+      editorial revisions, annotations, elaborations, or other modifications
+      represent, as a whole, an original work of authorship. For the purposes
+      of this License, Derivative Works shall not include works that remain
+      separable from, or merely link (or bind by name) to the interfaces of,
+      the Work and Derivative Works thereof.
+
+      "Contribution" shall mean any work of authorship, including
+      the original version of the Work and any modifications or additions
+      to that Work or Derivative Works thereof, that is intentionally
+      submitted to Licensor for inclusion in the Work by the copyright owner
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+      to the Licensor or its representatives, including but not limited to
+      communication on electronic mailing lists, source code control systems,
+      and issue tracking systems that are managed by, or on behalf of, the
+      Licensor for the purpose of discussing and improving the Work, but
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+      designated in writing by the copyright owner as "Not a Contribution."
+
+      "Contributor" shall mean Licensor and any individual or Legal Entity
+      on behalf of whom a Contribution has been received by Licensor and
+      subsequently incorporated within the Work.
+
+   2. Grant of Copyright License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      copyright license to reproduce, prepare Derivative Works of,
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+      Work and such Derivative Works in Source or Object form.
+
+   3. Grant of Patent License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      (except as stated in this section) patent license to make, have made,
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+      where such license applies only to those patent claims licensable
+      by such Contributor that are necessarily infringed by their
+      Contribution(s) alone or by combination of their Contribution(s)
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+      institute patent litigation against any entity (including a
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+      or a Contribution incorporated within the Work constitutes direct
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+
+   4. Redistribution. You may reproduce and distribute copies of the
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+      meet the following conditions:
+
+      (a) You must give any other recipients of the Work or
+          Derivative Works a copy of this License; and
+
+      (b) You must cause any modified files to carry prominent notices
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+
+      (c) You must retain, in the Source form of any Derivative Works
+          that You distribute, all copyright, patent, trademark, and
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+          excluding those notices that do not pertain to any part of
+          the Derivative Works; and
+
+      (d) If the Work includes a "NOTICE" text file as part of its
+          distribution, then any Derivative Works that You distribute must
+          include a readable copy of the attribution notices contained
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+          of the following places: within a NOTICE text file distributed
+          as part of the Derivative Works; within the Source form or
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+          of the NOTICE file are for informational purposes only and
+          do not modify the License. You may add Your own attribution
+          notices within Derivative Works that You distribute, alongside
+          or as an addendum to the NOTICE text from the Work, provided
+          that such additional attribution notices cannot be construed
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+
+      You may add Your own copyright statement to Your modifications and
+      may provide additional or different license terms and conditions
+      for use, reproduction, or distribution of Your modifications, or
+      for any such Derivative Works as a whole, provided Your use,
+      reproduction, and distribution of the Work otherwise complies with
+      the conditions stated in this License.
+
+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
+      except as required for reasonable and customary use in describing the
+      origin of the Work and reproducing the content of the NOTICE file.
+
+   7. Disclaimer of Warranty. Unless required by applicable law or
+      agreed to in writing, Licensor provides the Work (and each
+      Contributor provides its Contributions) on an "AS IS" BASIS,
+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
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+      appropriateness of using or redistributing the Work and assume any
+      risks associated with Your exercise of permissions under this License.
+
+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
+      liable to You for damages, including any direct, indirect, special,
+      incidental, or consequential damages of any character arising as a
+      result of this License or out of the use or inability to use the
+      Work (including but not limited to damages for loss of goodwill,
+      work stoppage, computer failure or malfunction, or any and all
+      other commercial damages or losses), even if such Contributor
+      has been advised of the possibility of such damages.
+
+   9. Accepting Warranty or Additional Liability. While redistributing
+      the Work or Derivative Works thereof, You may choose to offer,
+      and charge a fee for, acceptance of support, warranty, indemnity,
+      or other liability obligations and/or rights consistent with this
+      License. However, in accepting such obligations, You may act only
+      on Your own behalf and on Your sole responsibility, not on behalf
+      of any other Contributor, and only if You agree to indemnify,
+      defend, and hold each Contributor harmless for any liability
+      incurred by, or claims asserted against, such Contributor by reason
+      of your accepting any such warranty or additional liability.
+
+   END OF TERMS AND CONDITIONS
+
+   APPENDIX: How to apply the Apache License to your work.
+
+      To apply the Apache License to your work, attach the following
+      boilerplate notice, with the fields enclosed by brackets "[]"
+      replaced with your own identifying information. (Don't include
+      the brackets!)  The text should be enclosed in the appropriate
+      comment syntax for the file format. We also recommend that a
+      file or class name and description of purpose be included on the
+      same "printed page" as the copyright notice for easier
+      identification within third-party archives.
+
+   Copyright [yyyy] [name of copyright owner]
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.

vendor/contrib.go.opencensus.io/exporter/stackdriver/propagation/http.go

@@ -0,0 +1,94 @@
+// Copyright 2018, OpenCensus Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package propagation implement X-Cloud-Trace-Context header propagation used
+// by Google Cloud products.
+package propagation // import "contrib.go.opencensus.io/exporter/stackdriver/propagation"
+
+import (
+	"encoding/binary"
+	"encoding/hex"
+	"fmt"
+	"net/http"
+	"strconv"
+	"strings"
+
+	"go.opencensus.io/trace"
+	"go.opencensus.io/trace/propagation"
+)
+
+const (
+	httpHeaderMaxSize = 200
+	httpHeader        = `X-Cloud-Trace-Context`
+)
+
+var _ propagation.HTTPFormat = (*HTTPFormat)(nil)
+
+// HTTPFormat implements propagation.HTTPFormat to propagate
+// traces in HTTP headers for Google Cloud Platform and Stackdriver Trace.
+type HTTPFormat struct{}
+
+// SpanContextFromRequest extracts a Stackdriver Trace span context from incoming requests.
+func (f *HTTPFormat) SpanContextFromRequest(req *http.Request) (sc trace.SpanContext, ok bool) {
+	h := req.Header.Get(httpHeader)
+	// See https://cloud.google.com/trace/docs/faq for the header HTTPFormat.
+	// Return if the header is empty or missing, or if the header is unreasonably
+	// large, to avoid making unnecessary copies of a large string.
+	if h == "" || len(h) > httpHeaderMaxSize {
+		return trace.SpanContext{}, false
+	}
+
+	// Parse the trace id field.
+	slash := strings.Index(h, `/`)
+	if slash == -1 {
+		return trace.SpanContext{}, false
+	}
+	tid, h := h[:slash], h[slash+1:]
+
+	buf, err := hex.DecodeString(tid)
+	if err != nil {
+		return trace.SpanContext{}, false
+	}
+	copy(sc.TraceID[:], buf)
+
+	// Parse the span id field.
+	spanstr := h
+	semicolon := strings.Index(h, `;`)
+	if semicolon != -1 {
+		spanstr, h = h[:semicolon], h[semicolon+1:]
+	}
+	sid, err := strconv.ParseUint(spanstr, 10, 64)
+	if err != nil {
+		return trace.SpanContext{}, false
+	}
+	binary.BigEndian.PutUint64(sc.SpanID[:], sid)
+
+	// Parse the options field, options field is optional.
+	if !strings.HasPrefix(h, "o=") {
+		return sc, true
+	}
+	o, err := strconv.ParseUint(h[2:], 10, 64)
+	if err != nil {
+		return trace.SpanContext{}, false
+	}
+	sc.TraceOptions = trace.TraceOptions(o)
+	return sc, true
+}
+
+// SpanContextToRequest modifies the given request to include a Stackdriver Trace header.
+func (f *HTTPFormat) SpanContextToRequest(sc trace.SpanContext, req *http.Request) {
+	sid := binary.BigEndian.Uint64(sc.SpanID[:])
+	header := fmt.Sprintf("%s/%d;o=%d", hex.EncodeToString(sc.TraceID[:]), sid, int64(sc.TraceOptions))
+	req.Header.Set(httpHeader, header)
+}

vendor/go.opencensus.io/AUTHORS

@@ -0,0 +1 @@
+Google Inc.

vendor/go.opencensus.io/CONTRIBUTING.md

@@ -0,0 +1,56 @@
+# How to contribute
+
+We'd love to accept your patches and contributions to this project. There are
+just a few small guidelines you need to follow.
+
+## Contributor License Agreement
+
+Contributions to this project must be accompanied by a Contributor License
+Agreement. You (or your employer) retain the copyright to your contribution,
+this simply gives us permission to use and redistribute your contributions as
+part of the project. Head over to <https://cla.developers.google.com/> to see
+your current agreements on file or to sign a new one.
+
+You generally only need to submit a CLA once, so if you've already submitted one
+(even if it was for a different project), you probably don't need to do it
+again.
+
+## Code reviews
+
+All submissions, including submissions by project members, require review. We
+use GitHub pull requests for this purpose. Consult [GitHub Help] for more
+information on using pull requests.
+
+[GitHub Help]: https://help.github.com/articles/about-pull-requests/
+
+## Instructions
+
+Fork the repo, checkout the upstream repo to your GOPATH by:
+
+```
+$ go get -d go.opencensus.io
+```
+
+Add your fork as an origin:
+
+```
+cd $(go env GOPATH)/src/go.opencensus.io
+git remote add fork git@github.com:YOUR_GITHUB_USERNAME/opencensus-go.git
+```
+
+Run tests:
+
+```
+$ go test ./...
+```
+
+Checkout a new branch, make modifications and push the branch to your fork:
+
+```
+$ git checkout -b feature
+# edit files
+$ git commit
+$ git push fork feature
+```
+
+Open a pull request against the main opencensus-go repo.

vendor/go.opencensus.io/Gopkg.lock

@@ -0,0 +1,231 @@
+# This file is autogenerated, do not edit; changes may be undone by the next 'dep ensure'.
+
+
+[[projects]]
+  branch = "master"
+  digest = "1:eee9386329f4fcdf8d6c0def0c9771b634bdd5ba460d888aa98c17d59b37a76c"
+  name = "git.apache.org/thrift.git"
+  packages = ["lib/go/thrift"]
+  pruneopts = "UT"
+  revision = "6e67faa92827ece022380b211c2caaadd6145bf5"
+  source = "github.com/apache/thrift"
+
+[[projects]]
+  branch = "master"
+  digest = "1:d6afaeed1502aa28e80a4ed0981d570ad91b2579193404256ce672ed0a609e0d"
+  name = "github.com/beorn7/perks"
+  packages = ["quantile"]
+  pruneopts = "UT"
+  revision = "3a771d992973f24aa725d07868b467d1ddfceafb"
+
+[[projects]]
+  digest = "1:4c0989ca0bcd10799064318923b9bc2db6b4d6338dd75f3f2d86c3511aaaf5cf"
+  name = "github.com/golang/protobuf"
+  packages = [
+    "proto",
+    "ptypes",
+    "ptypes/any",
+    "ptypes/duration",
+    "ptypes/timestamp",
+  ]
+  pruneopts = "UT"
+  revision = "aa810b61a9c79d51363740d207bb46cf8e620ed5"
+  version = "v1.2.0"
+
+[[projects]]
+  digest = "1:ff5ebae34cfbf047d505ee150de27e60570e8c394b3b8fdbb720ff6ac71985fc"
+  name = "github.com/matttproud/golang_protobuf_extensions"
+  packages = ["pbutil"]
+  pruneopts = "UT"
+  revision = "c12348ce28de40eed0136aa2b644d0ee0650e56c"
+  version = "v1.0.1"
+
+[[projects]]
+  digest = "1:824c8f3aa4c5f23928fa84ebbd5ed2e9443b3f0cb958a40c1f2fbed5cf5e64b1"
+  name = "github.com/openzipkin/zipkin-go"
+  packages = [
+    ".",
+    "idgenerator",
+    "model",
+    "propagation",
+    "reporter",
+    "reporter/http",
+  ]
+  pruneopts = "UT"
+  revision = "d455a5674050831c1e187644faa4046d653433c2"
+  version = "v0.1.1"
+
+[[projects]]
+  digest = "1:d14a5f4bfecf017cb780bdde1b6483e5deb87e12c332544d2c430eda58734bcb"
+  name = "github.com/prometheus/client_golang"
+  packages = [
+    "prometheus",
+    "prometheus/promhttp",
+  ]
+  pruneopts = "UT"
+  revision = "c5b7fccd204277076155f10851dad72b76a49317"
+  version = "v0.8.0"
+
+[[projects]]
+  branch = "master"
+  digest = "1:2d5cd61daa5565187e1d96bae64dbbc6080dacf741448e9629c64fd93203b0d4"
+  name = "github.com/prometheus/client_model"
+  packages = ["go"]
+  pruneopts = "UT"
+  revision = "5c3871d89910bfb32f5fcab2aa4b9ec68e65a99f"
+
+[[projects]]
+  branch = "master"
+  digest = "1:63b68062b8968092eb86bedc4e68894bd096ea6b24920faca8b9dcf451f54bb5"
+  name = "github.com/prometheus/common"
+  packages = [
+    "expfmt",
+    "internal/bitbucket.org/ww/goautoneg",
+    "model",
+  ]
+  pruneopts = "UT"
+  revision = "c7de2306084e37d54b8be01f3541a8464345e9a5"
+
+[[projects]]
+  branch = "master"
+  digest = "1:8c49953a1414305f2ff5465147ee576dd705487c35b15918fcd4efdc0cb7a290"
+  name = "github.com/prometheus/procfs"
+  packages = [
+    ".",
+    "internal/util",
+    "nfs",
+    "xfs",
+  ]
+  pruneopts = "UT"
+  revision = "05ee40e3a273f7245e8777337fc7b46e533a9a92"
+
+[[projects]]
+  branch = "master"
+  digest = "1:deafe4ab271911fec7de5b693d7faae3f38796d9eb8622e2b9e7df42bb3dfea9"
+  name = "golang.org/x/net"
+  packages = [
+    "context",
+    "http/httpguts",
+    "http2",
+    "http2/hpack",
+    "idna",
+    "internal/timeseries",
+    "trace",
+  ]
+  pruneopts = "UT"
+  revision = "922f4815f713f213882e8ef45e0d315b164d705c"
+
+[[projects]]
+  branch = "master"
+  digest = "1:e0140c0c868c6e0f01c0380865194592c011fe521d6e12d78bfd33e756fe018a"
+  name = "golang.org/x/sync"
+  packages = ["semaphore"]
+  pruneopts = "UT"
+  revision = "1d60e4601c6fd243af51cc01ddf169918a5407ca"
+
+[[projects]]
+  branch = "master"
+  digest = "1:a3f00ac457c955fe86a41e1495e8f4c54cb5399d609374c5cc26aa7d72e542c8"
+  name = "golang.org/x/sys"
+  packages = ["unix"]
+  pruneopts = "UT"
+  revision = "3b58ed4ad3395d483fc92d5d14123ce2c3581fec"
+
+[[projects]]
+  digest = "1:a2ab62866c75542dd18d2b069fec854577a20211d7c0ea6ae746072a1dccdd18"
+  name = "golang.org/x/text"
+  packages = [
+    "collate",
+    "collate/build",
+    "internal/colltab",
+    "internal/gen",
+    "internal/tag",
+    "internal/triegen",
+    "internal/ucd",
+    "language",
+    "secure/bidirule",
+    "transform",
+    "unicode/bidi",
+    "unicode/cldr",
+    "unicode/norm",
+    "unicode/rangetable",
+  ]
+  pruneopts = "UT"
+  revision = "f21a4dfb5e38f5895301dc265a8def02365cc3d0"
+  version = "v0.3.0"
+
+[[projects]]
+  branch = "master"
+  digest = "1:c0c17c94fe8bc1ab34e7f586a4a8b788c5e1f4f9f750ff23395b8b2f5a523530"
+  name = "google.golang.org/api"
+  packages = ["support/bundler"]
+  pruneopts = "UT"
+  revision = "e21acd801f91da814261b938941d193bb036441a"
+
+[[projects]]
+  branch = "master"
+  digest = "1:077c1c599507b3b3e9156d17d36e1e61928ee9b53a5b420f10f28ebd4a0b275c"
+  name = "google.golang.org/genproto"
+  packages = ["googleapis/rpc/status"]
+  pruneopts = "UT"
+  revision = "c66870c02cf823ceb633bcd05be3c7cda29976f4"
+
+[[projects]]
+  digest = "1:3dd7996ce6bf52dec6a2f69fa43e7c4cefea1d4dfa3c8ab7a5f8a9f7434e239d"
+  name = "google.golang.org/grpc"
+  packages = [
+    ".",
+    "balancer",
+    "balancer/base",
+    "balancer/roundrobin",
+    "codes",
+    "connectivity",
+    "credentials",
+    "encoding",
+    "encoding/proto",
+    "grpclog",
+    "internal",
+    "internal/backoff",
+    "internal/channelz",
+    "internal/envconfig",
+    "internal/grpcrand",
+    "internal/transport",
+    "keepalive",
+    "metadata",
+    "naming",
+    "peer",
+    "resolver",
+    "resolver/dns",
+    "resolver/passthrough",
+    "stats",
+    "status",
+    "tap",
+  ]
+  pruneopts = "UT"
+  revision = "32fb0ac620c32ba40a4626ddf94d90d12cce3455"
+  version = "v1.14.0"
+
+[solve-meta]
+  analyzer-name = "dep"
+  analyzer-version = 1
+  input-imports = [
+    "git.apache.org/thrift.git/lib/go/thrift",
+    "github.com/golang/protobuf/proto",
+    "github.com/openzipkin/zipkin-go",
+    "github.com/openzipkin/zipkin-go/model",
+    "github.com/openzipkin/zipkin-go/reporter",
+    "github.com/openzipkin/zipkin-go/reporter/http",
+    "github.com/prometheus/client_golang/prometheus",
+    "github.com/prometheus/client_golang/prometheus/promhttp",
+    "golang.org/x/net/context",
+    "golang.org/x/net/http2",
+    "google.golang.org/api/support/bundler",
+    "google.golang.org/grpc",
+    "google.golang.org/grpc/codes",
+    "google.golang.org/grpc/grpclog",
+    "google.golang.org/grpc/metadata",
+    "google.golang.org/grpc/stats",
+    "google.golang.org/grpc/status",
+  ]
+  solver-name = "gps-cdcl"
+  solver-version = 1

vendor/go.opencensus.io/Gopkg.toml

@@ -0,0 +1,36 @@
+# For v0.x.y dependencies, prefer adding a constraints of the form: version=">= 0.x.y"
+# to avoid locking to a particular minor version which can cause dep to not be
+# able to find a satisfying dependency graph.
+
+[[constraint]]
+  branch = "master"
+  name = "git.apache.org/thrift.git"
+  source = "github.com/apache/thrift"
+
+[[constraint]]
+  name = "github.com/golang/protobuf"
+  version = "1.0.0"
+
+[[constraint]]
+  name = "github.com/openzipkin/zipkin-go"
+  version = ">=0.1.0"
+
+[[constraint]]
+  name = "github.com/prometheus/client_golang"
+  version = ">=0.8.0"
+
+[[constraint]]
+  branch = "master"
+  name = "golang.org/x/net"
+
+[[constraint]]
+  branch = "master"
+  name = "google.golang.org/api"
+
+[[constraint]]
+  name = "google.golang.org/grpc"
+  version = "1.11.3"
+
+[prune]
+  go-tests = true
+  unused-packages = true

vendor/go.opencensus.io/LICENSE

@@ -0,0 +1,202 @@
+
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
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+   limitations under the License.

vendor/go.opencensus.io/README.md

@@ -0,0 +1,262 @@
+# OpenCensus Libraries for Go
+
+[![Build Status][travis-image]][travis-url]
+[![Windows Build Status][appveyor-image]][appveyor-url]
+[![GoDoc][godoc-image]][godoc-url]
+[![Gitter chat][gitter-image]][gitter-url]
+
+OpenCensus Go is a Go implementation of OpenCensus, a toolkit for
+collecting application performance and behavior monitoring data.
+Currently it consists of three major components: tags, stats, and tracing.
+
+## Installation
+
+```
+$ go get -u go.opencensus.io
+```
+
+The API of this project is still evolving, see: [Deprecation Policy](#deprecation-policy).
+The use of vendoring or a dependency management tool is recommended.
+
+## Prerequisites
+
+OpenCensus Go libraries require Go 1.8 or later.
+
+## Getting Started
+
+The easiest way to get started using OpenCensus in your application is to use an existing
+integration with your RPC framework:
+
+* [net/http](https://godoc.org/go.opencensus.io/plugin/ochttp)
+* [gRPC](https://godoc.org/go.opencensus.io/plugin/ocgrpc)
+* [database/sql](https://godoc.org/github.com/basvanbeek/ocsql)
+* [Go kit](https://godoc.org/github.com/go-kit/kit/tracing/opencensus)
+* [Groupcache](https://godoc.org/github.com/orijtech/groupcache)
+* [Caddy webserver](https://godoc.org/github.com/orijtech/caddy)
+* [MongoDB](https://godoc.org/github.com/orijtech/mongo-go-driver)
+* [Redis gomodule/redigo](https://godoc.org/github.com/orijtech/redigo)
+* [Redis goredis/redis](https://godoc.org/github.com/orijtech/redis)
+* [Memcache](https://godoc.org/github.com/orijtech/gomemcache)
+
+If you're a framework not listed here, you could either implement your own middleware for your
+framework or use [custom stats](#stats) and [spans](#spans) directly in your application.
+
+## Exporters
+
+OpenCensus can export instrumentation data to various backends.
+OpenCensus has exporter implementations for the following, users
+can implement their own exporters by implementing the exporter interfaces
+([stats](https://godoc.org/go.opencensus.io/stats/view#Exporter),
+[trace](https://godoc.org/go.opencensus.io/trace#Exporter)):
+
+* [Prometheus][exporter-prom] for stats
+* [OpenZipkin][exporter-zipkin] for traces
+* [Stackdriver][exporter-stackdriver] Monitoring for stats and Trace for traces
+* [Jaeger][exporter-jaeger] for traces
+* [AWS X-Ray][exporter-xray] for traces
+* [Datadog][exporter-datadog] for stats and traces
+* [Graphite][exporter-graphite] for stats
+
+## Overview
+
+![OpenCensus Overview](https://i.imgur.com/cf4ElHE.jpg)
+
+In a microservices environment, a user request may go through
+multiple services until there is a response. OpenCensus allows
+you to instrument your services and collect diagnostics data all
+through your services end-to-end.
+
+## Tags
+
+Tags represent propagated key-value pairs. They are propagated using `context.Context`
+in the same process or can be encoded to be transmitted on the wire. Usually, this will
+be handled by an integration plugin, e.g. `ocgrpc.ServerHandler` and `ocgrpc.ClientHandler`
+for gRPC.
+
+Package tag allows adding or modifying tags in the current context.
+
+[embedmd]:# (internal/readme/tags.go new)
+```go
+ctx, err = tag.New(ctx,
+	tag.Insert(osKey, "macOS-10.12.5"),
+	tag.Upsert(userIDKey, "cde36753ed"),
+)
+if err != nil {
+	log.Fatal(err)
+}
+```
+
+## Stats
+
+OpenCensus is a low-overhead framework even if instrumentation is always enabled.
+In order to be so, it is optimized to make recording of data points fast
+and separate from the data aggregation.
+
+OpenCensus stats collection happens in two stages:
+
+* Definition of measures and recording of data points
+* Definition of views and aggregation of the recorded data
+
+### Recording
+
+Measurements are data points associated with a measure.
+Recording implicitly tags the set of Measurements with the tags from the
+provided context:
+
+[embedmd]:# (internal/readme/stats.go record)
+```go
+stats.Record(ctx, videoSize.M(102478))
+```
+
+### Views
+
+Views are how Measures are aggregated. You can think of them as queries over the
+set of recorded data points (measurements).
+
+Views have two parts: the tags to group by and the aggregation type used.
+
+Currently three types of aggregations are supported:
+* CountAggregation is used to count the number of times a sample was recorded.
+* DistributionAggregation is used to provide a histogram of the values of the samples.
+* SumAggregation is used to sum up all sample values.
+
+[embedmd]:# (internal/readme/stats.go aggs)
+```go
+distAgg := view.Distribution(0, 1<<32, 2<<32, 3<<32)
+countAgg := view.Count()
+sumAgg := view.Sum()
+```
+
+Here we create a view with the DistributionAggregation over our measure.
+
+[embedmd]:# (internal/readme/stats.go view)
+```go
+if err := view.Register(&view.View{
+	Name:        "example.com/video_size_distribution",
+	Description: "distribution of processed video size over time",
+	Measure:     videoSize,
+	Aggregation: view.Distribution(0, 1<<32, 2<<32, 3<<32),
+}); err != nil {
+	log.Fatalf("Failed to register view: %v", err)
+}
+```
+
+Register begins collecting data for the view. Registered views' data will be
+exported via the registered exporters.
+
+## Traces
+
+A distributed trace tracks the progression of a single user request as
+it is handled by the services and processes that make up an application.
+Each step is called a span in the trace. Spans include metadata about the step,
+including especially the time spent in the step, called the span’s latency.
+
+Below you see a trace and several spans underneath it.
+
+![Traces and spans](https://i.imgur.com/7hZwRVj.png)
+
+### Spans
+
+Span is the unit step in a trace. Each span has a name, latency, status and
+additional metadata.
+
+Below we are starting a span for a cache read and ending it
+when we are done:
+
+[embedmd]:# (internal/readme/trace.go startend)
+```go
+ctx, span := trace.StartSpan(ctx, "cache.Get")
+defer span.End()
+
+// Do work to get from cache.
+```
+
+### Propagation
+
+Spans can have parents or can be root spans if they don't have any parents.
+The current span is propagated in-process and across the network to allow associating
+new child spans with the parent.
+
+In the same process, context.Context is used to propagate spans.
+trace.StartSpan creates a new span as a root if the current context
+doesn't contain a span. Or, it creates a child of the span that is
+already in current context. The returned context can be used to keep
+propagating the newly created span in the current context.
+
+[embedmd]:# (internal/readme/trace.go startend)
+```go
+ctx, span := trace.StartSpan(ctx, "cache.Get")
+defer span.End()
+
+// Do work to get from cache.
+```
+
+Across the network, OpenCensus provides different propagation
+methods for different protocols.
+
+* gRPC integrations uses the OpenCensus' [binary propagation format](https://godoc.org/go.opencensus.io/trace/propagation).
+* HTTP integrations uses Zipkin's [B3](https://github.com/openzipkin/b3-propagation)
+  by default but can be configured to use a custom propagation method by setting another
+  [propagation.HTTPFormat](https://godoc.org/go.opencensus.io/trace/propagation#HTTPFormat).
+
+## Execution Tracer
+
+With Go 1.11, OpenCensus Go will support integration with the Go execution tracer.
+See [Debugging Latency in Go](https://medium.com/observability/debugging-latency-in-go-1-11-9f97a7910d68)
+for an example of their mutual use.
+
+## Profiles
+
+OpenCensus tags can be applied as profiler labels
+for users who are on Go 1.9 and above.
+
+[embedmd]:# (internal/readme/tags.go profiler)
+```go
+ctx, err = tag.New(ctx,
+	tag.Insert(osKey, "macOS-10.12.5"),
+	tag.Insert(userIDKey, "fff0989878"),
+)
+if err != nil {
+	log.Fatal(err)
+}
+tag.Do(ctx, func(ctx context.Context) {
+	// Do work.
+	// When profiling is on, samples will be
+	// recorded with the key/values from the tag map.
+})
+```
+
+A screenshot of the CPU profile from the program above:
+
+![CPU profile](https://i.imgur.com/jBKjlkw.png)
+
+## Deprecation Policy
+
+Before version 1.0.0, the following deprecation policy will be observed:
+
+No backwards-incompatible changes will be made except for the removal of symbols that have
+been marked as *Deprecated* for at least one minor release (e.g. 0.9.0 to 0.10.0). A release
+removing the *Deprecated* functionality will be made no sooner than 28 days after the first
+release in which the functionality was marked *Deprecated*.
+
+[travis-image]: https://travis-ci.org/census-instrumentation/opencensus-go.svg?branch=master
+[travis-url]: https://travis-ci.org/census-instrumentation/opencensus-go
+[appveyor-image]: https://ci.appveyor.com/api/projects/status/vgtt29ps1783ig38?svg=true
+[appveyor-url]: https://ci.appveyor.com/project/opencensusgoteam/opencensus-go/branch/master
+[godoc-image]: https://godoc.org/go.opencensus.io?status.svg
+[godoc-url]: https://godoc.org/go.opencensus.io
+[gitter-image]: https://badges.gitter.im/census-instrumentation/lobby.svg
+[gitter-url]: https://gitter.im/census-instrumentation/lobby?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge
+
+
+[new-ex]: https://godoc.org/go.opencensus.io/tag#example-NewMap
+[new-replace-ex]: https://godoc.org/go.opencensus.io/tag#example-NewMap--Replace
+
+[exporter-prom]: https://godoc.org/go.opencensus.io/exporter/prometheus
+[exporter-stackdriver]: https://godoc.org/contrib.go.opencensus.io/exporter/stackdriver
+[exporter-zipkin]: https://godoc.org/go.opencensus.io/exporter/zipkin
+[exporter-jaeger]: https://godoc.org/go.opencensus.io/exporter/jaeger
+[exporter-xray]: https://github.com/census-ecosystem/opencensus-go-exporter-aws
+[exporter-datadog]: https://github.com/DataDog/opencensus-go-exporter-datadog
+[exporter-graphite]: https://github.com/census-ecosystem/opencensus-go-exporter-graphite
+

vendor/go.opencensus.io/appveyor.yml

@@ -0,0 +1,24 @@
+version: "{build}"
+
+platform: x64
+
+clone_folder: c:\gopath\src\go.opencensus.io
+
+environment:
+  GOPATH: 'c:\gopath'
+  GOVERSION: '1.11'
+  GO111MODULE: 'on'
+  CGO_ENABLED: '0' # See: https://github.com/appveyor/ci/issues/2613
+
+install:
+  - set PATH=%GOPATH%\bin;c:\go\bin;%PATH%
+  - go version
+  - go env
+
+build: false
+deploy: false
+
+test_script:
+  - cd %APPVEYOR_BUILD_FOLDER%
+  - go build -v .\...
+  - go test -v .\... # No -race because cgo is disabled

vendor/go.opencensus.io/go.mod

@@ -0,0 +1,21 @@
+module go.opencensus.io
+
+require (
+	git.apache.org/thrift.git v0.0.0-20180902110319-2566ecd5d999
+	github.com/beorn7/perks v0.0.0-20180321164747-3a771d992973
+	github.com/golang/protobuf v1.2.0
+	github.com/google/go-cmp v0.2.0
+	github.com/matttproud/golang_protobuf_extensions v1.0.1
+	github.com/openzipkin/zipkin-go v0.1.1
+	github.com/prometheus/client_golang v0.8.0
+	github.com/prometheus/client_model v0.0.0-20180712105110-5c3871d89910
+	github.com/prometheus/common v0.0.0-20180801064454-c7de2306084e
+	github.com/prometheus/procfs v0.0.0-20180725123919-05ee40e3a273
+	golang.org/x/net v0.0.0-20180906233101-161cd47e91fd
+	golang.org/x/sync v0.0.0-20180314180146-1d60e4601c6f
+	golang.org/x/sys v0.0.0-20180909124046-d0be0721c37e
+	golang.org/x/text v0.3.0
+	google.golang.org/api v0.0.0-20180910000450-7ca32eb868bf
+	google.golang.org/genproto v0.0.0-20180831171423-11092d34479b
+	google.golang.org/grpc v1.14.0
+)

vendor/go.opencensus.io/go.sum

@@ -0,0 +1,38 @@
+git.apache.org/thrift.git v0.0.0-20180807212849-6e67faa92827/go.mod h1:fPE2ZNJGynbRyZ4dJvy6G277gSllfV2HJqblrnkyeyg=
+git.apache.org/thrift.git v0.0.0-20180902110319-2566ecd5d999 h1:sihTnRgTOUSCQz0iS0pjZuFQy/z7GXCJgSBg3+rZKHw=
+git.apache.org/thrift.git v0.0.0-20180902110319-2566ecd5d999/go.mod h1:fPE2ZNJGynbRyZ4dJvy6G277gSllfV2HJqblrnkyeyg=
+github.com/beorn7/perks v0.0.0-20180321164747-3a771d992973 h1:xJ4a3vCFaGF/jqvzLMYoU8P317H5OQ+Via4RmuPwCS0=
+github.com/beorn7/perks v0.0.0-20180321164747-3a771d992973/go.mod h1:Dwedo/Wpr24TaqPxmxbtue+5NUziq4I4S80YR8gNf3Q=
+github.com/golang/protobuf v1.2.0 h1:P3YflyNX/ehuJFLhxviNdFxQPkGK5cDcApsge1SqnvM=
+github.com/golang/protobuf v1.2.0/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
+github.com/google/go-cmp v0.2.0 h1:+dTQ8DZQJz0Mb/HjFlkptS1FeQ4cWSnN941F8aEG4SQ=
+github.com/google/go-cmp v0.2.0/go.mod h1:oXzfMopK8JAjlY9xF4vHSVASa0yLyX7SntLO5aqRK0M=
+github.com/matttproud/golang_protobuf_extensions v1.0.1 h1:4hp9jkHxhMHkqkrB3Ix0jegS5sx/RkqARlsWZ6pIwiU=
+github.com/matttproud/golang_protobuf_extensions v1.0.1/go.mod h1:D8He9yQNgCq6Z5Ld7szi9bcBfOoFv/3dc6xSMkL2PC0=
+github.com/openzipkin/zipkin-go v0.1.1 h1:A/ADD6HaPnAKj3yS7HjGHRK77qi41Hi0DirOOIQAeIw=
+github.com/openzipkin/zipkin-go v0.1.1/go.mod h1:NtoC/o8u3JlF1lSlyPNswIbeQH9bJTmOf0Erfk+hxe8=
+github.com/prometheus/client_golang v0.8.0 h1:1921Yw9Gc3iSc4VQh3PIoOqgPCZS7G/4xQNVUp8Mda8=
+github.com/prometheus/client_golang v0.8.0/go.mod h1:7SWBe2y4D6OKWSNQJUaRYU/AaXPKyh/dDVn+NZz0KFw=
+github.com/prometheus/client_model v0.0.0-20180712105110-5c3871d89910 h1:idejC8f05m9MGOsuEi1ATq9shN03HrxNkD/luQvxCv8=
+github.com/prometheus/client_model v0.0.0-20180712105110-5c3871d89910/go.mod h1:MbSGuTsp3dbXC40dX6PRTWyKYBIrTGTE9sqQNg2J8bo=
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+golang.org/x/net v0.0.0-20180906233101-161cd47e91fd h1:nTDtHvHSdCn1m6ITfMRqtOd/9+7a3s8RBNOZ3eYZzJA=
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+golang.org/x/text v0.3.0 h1:g61tztE5qeGQ89tm6NTjjM9VPIm088od1l6aSorWRWg=
+golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
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+google.golang.org/grpc v1.14.0/go.mod h1:yo6s7OP7yaDglbqo1J04qKzAhqBH6lvTonzMVmEdcZw=

vendor/go.opencensus.io/internal/internal.go

@@ -0,0 +1,37 @@
+// Copyright 2017, OpenCensus Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package internal // import "go.opencensus.io/internal"
+
+import (
+	"fmt"
+	"time"
+
+	"go.opencensus.io"
+)
+
+// UserAgent is the user agent to be added to the outgoing
+// requests from the exporters.
+var UserAgent = fmt.Sprintf("opencensus-go [%s]", opencensus.Version())
+
+// MonotonicEndTime returns the end time at present
+// but offset from start, monotonically.
+//
+// The monotonic clock is used in subtractions hence
+// the duration since start added back to start gives
+// end as a monotonic time.
+// See https://golang.org/pkg/time/#hdr-Monotonic_Clocks
+func MonotonicEndTime(start time.Time) time.Time {
+	return start.Add(time.Now().Sub(start))
+}

vendor/go.opencensus.io/internal/sanitize.go

@@ -0,0 +1,50 @@
+// Copyright 2017, OpenCensus Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package internal
+
+import (
+	"strings"
+	"unicode"
+)
+
+const labelKeySizeLimit = 100
+
+// Sanitize returns a string that is trunacated to 100 characters if it's too
+// long, and replaces non-alphanumeric characters to underscores.
+func Sanitize(s string) string {
+	if len(s) == 0 {
+		return s
+	}
+	if len(s) > labelKeySizeLimit {
+		s = s[:labelKeySizeLimit]
+	}
+	s = strings.Map(sanitizeRune, s)
+	if unicode.IsDigit(rune(s[0])) {
+		s = "key_" + s
+	}
+	if s[0] == '_' {
+		s = "key" + s
+	}
+	return s
+}
+
+// converts anything that is not a letter or digit to an underscore
+func sanitizeRune(r rune) rune {
+	if unicode.IsLetter(r) || unicode.IsDigit(r) {
+		return r
+	}
+	// Everything else turns into an underscore
+	return '_'
+}

vendor/go.opencensus.io/internal/tagencoding/tagencoding.go

@@ -0,0 +1,72 @@
+// Copyright 2017, OpenCensus Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+// Package tagencoding contains the tag encoding
+// used interally by the stats collector.
+package tagencoding // import "go.opencensus.io/internal/tagencoding"
+
+type Values struct {
+	Buffer     []byte
+	WriteIndex int
+	ReadIndex  int
+}
+
+func (vb *Values) growIfRequired(expected int) {
+	if len(vb.Buffer)-vb.WriteIndex < expected {
+		tmp := make([]byte, 2*(len(vb.Buffer)+1)+expected)
+		copy(tmp, vb.Buffer)
+		vb.Buffer = tmp
+	}
+}
+
+func (vb *Values) WriteValue(v []byte) {
+	length := len(v) & 0xff
+	vb.growIfRequired(1 + length)
+
+	// writing length of v
+	vb.Buffer[vb.WriteIndex] = byte(length)
+	vb.WriteIndex++
+
+	if length == 0 {
+		// No value was encoded for this key
+		return
+	}
+
+	// writing v
+	copy(vb.Buffer[vb.WriteIndex:], v[:length])
+	vb.WriteIndex += length
+}
+
+// ReadValue is the helper method to read the values when decoding valuesBytes to a map[Key][]byte.
+func (vb *Values) ReadValue() []byte {
+	// read length of v
+	length := int(vb.Buffer[vb.ReadIndex])
+	vb.ReadIndex++
+	if length == 0 {
+		// No value was encoded for this key
+		return nil
+	}
+
+	// read value of v
+	v := make([]byte, length)
+	endIdx := vb.ReadIndex + length
+	copy(v, vb.Buffer[vb.ReadIndex:endIdx])
+	vb.ReadIndex = endIdx
+	return v
+}
+
+func (vb *Values) Bytes() []byte {
+	return vb.Buffer[:vb.WriteIndex]
+}

vendor/go.opencensus.io/internal/traceinternals.go

@@ -0,0 +1,52 @@
+// Copyright 2017, OpenCensus Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package internal
+
+import (
+	"time"
+)
+
+// Trace allows internal access to some trace functionality.
+// TODO(#412): remove this
+var Trace interface{}
+
+var LocalSpanStoreEnabled bool
+
+// BucketConfiguration stores the number of samples to store for span buckets
+// for successful and failed spans for a particular span name.
+type BucketConfiguration struct {
+	Name                 string
+	MaxRequestsSucceeded int
+	MaxRequestsErrors    int
+}
+
+// PerMethodSummary is a summary of the spans stored for a single span name.
+type PerMethodSummary struct {
+	Active         int
+	LatencyBuckets []LatencyBucketSummary
+	ErrorBuckets   []ErrorBucketSummary
+}
+
+// LatencyBucketSummary is a summary of a latency bucket.
+type LatencyBucketSummary struct {
+	MinLatency, MaxLatency time.Duration
+	Size                   int
+}
+
+// ErrorBucketSummary is a summary of an error bucket.
+type ErrorBucketSummary struct {
+	ErrorCode int32
+	Size      int
+}

vendor/go.opencensus.io/opencensus.go

@@ -0,0 +1,21 @@
+// Copyright 2017, OpenCensus Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package opencensus contains Go support for OpenCensus.
+package opencensus // import "go.opencensus.io"
+
+// Version is the current release version of OpenCensus in use.
+func Version() string {
+	return "0.18.0"
+}

vendor/go.opencensus.io/plugin/ocgrpc/client.go

@@ -0,0 +1,56 @@
+// Copyright 2018, OpenCensus Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package ocgrpc
+
+import (
+	"go.opencensus.io/trace"
+	"golang.org/x/net/context"
+
+	"google.golang.org/grpc/stats"
+)
+
+// ClientHandler implements a gRPC stats.Handler for recording OpenCensus stats and
+// traces. Use with gRPC clients only.
+type ClientHandler struct {
+	// StartOptions allows configuring the StartOptions used to create new spans.
+	//
+	// StartOptions.SpanKind will always be set to trace.SpanKindClient
+	// for spans started by this handler.
+	StartOptions trace.StartOptions
+}
+
+// HandleConn exists to satisfy gRPC stats.Handler.
+func (c *ClientHandler) HandleConn(ctx context.Context, cs stats.ConnStats) {
+	// no-op
+}
+
+// TagConn exists to satisfy gRPC stats.Handler.
+func (c *ClientHandler) TagConn(ctx context.Context, cti *stats.ConnTagInfo) context.Context {
+	// no-op
+	return ctx
+}
+
+// HandleRPC implements per-RPC tracing and stats instrumentation.
+func (c *ClientHandler) HandleRPC(ctx context.Context, rs stats.RPCStats) {
+	traceHandleRPC(ctx, rs)
+	statsHandleRPC(ctx, rs)
+}
+
+// TagRPC implements per-RPC context management.
+func (c *ClientHandler) TagRPC(ctx context.Context, rti *stats.RPCTagInfo) context.Context {
+	ctx = c.traceTagRPC(ctx, rti)
+	ctx = c.statsTagRPC(ctx, rti)
+	return ctx
+}

vendor/go.opencensus.io/plugin/ocgrpc/client_metrics.go

@@ -0,0 +1,107 @@
+// Copyright 2017, OpenCensus Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+package ocgrpc
+
+import (
+	"go.opencensus.io/stats"
+	"go.opencensus.io/stats/view"
+	"go.opencensus.io/tag"
+)
+
+// The following variables are measures are recorded by ClientHandler:
+var (
+	ClientSentMessagesPerRPC     = stats.Int64("grpc.io/client/sent_messages_per_rpc", "Number of messages sent in the RPC (always 1 for non-streaming RPCs).", stats.UnitDimensionless)
+	ClientSentBytesPerRPC        = stats.Int64("grpc.io/client/sent_bytes_per_rpc", "Total bytes sent across all request messages per RPC.", stats.UnitBytes)
+	ClientReceivedMessagesPerRPC = stats.Int64("grpc.io/client/received_messages_per_rpc", "Number of response messages received per RPC (always 1 for non-streaming RPCs).", stats.UnitDimensionless)
+	ClientReceivedBytesPerRPC    = stats.Int64("grpc.io/client/received_bytes_per_rpc", "Total bytes received across all response messages per RPC.", stats.UnitBytes)
+	ClientRoundtripLatency       = stats.Float64("grpc.io/client/roundtrip_latency", "Time between first byte of request sent to last byte of response received, or terminal error.", stats.UnitMilliseconds)
+	ClientServerLatency          = stats.Float64("grpc.io/client/server_latency", `Propagated from the server and should have the same value as "grpc.io/server/latency".`, stats.UnitMilliseconds)
+)
+
+// Predefined views may be registered to collect data for the above measures.
+// As always, you may also define your own custom views over measures collected by this
+// package. These are declared as a convenience only; none are registered by
+// default.
+var (
+	ClientSentBytesPerRPCView = &view.View{
+		Measure:     ClientSentBytesPerRPC,
+		Name:        "grpc.io/client/sent_bytes_per_rpc",
+		Description: "Distribution of bytes sent per RPC, by method.",
+		TagKeys:     []tag.Key{KeyClientMethod},
+		Aggregation: DefaultBytesDistribution,
+	}
+
+	ClientReceivedBytesPerRPCView = &view.View{
+		Measure:     ClientReceivedBytesPerRPC,
+		Name:        "grpc.io/client/received_bytes_per_rpc",
+		Description: "Distribution of bytes received per RPC, by method.",
+		TagKeys:     []tag.Key{KeyClientMethod},
+		Aggregation: DefaultBytesDistribution,
+	}
+
+	ClientRoundtripLatencyView = &view.View{
+		Measure:     ClientRoundtripLatency,
+		Name:        "grpc.io/client/roundtrip_latency",
+		Description: "Distribution of round-trip latency, by method.",
+		TagKeys:     []tag.Key{KeyClientMethod},
+		Aggregation: DefaultMillisecondsDistribution,
+	}
+
+	ClientCompletedRPCsView = &view.View{
+		Measure:     ClientRoundtripLatency,
+		Name:        "grpc.io/client/completed_rpcs",
+		Description: "Count of RPCs by method and status.",
+		TagKeys:     []tag.Key{KeyClientMethod, KeyClientStatus},
+		Aggregation: view.Count(),
+	}
+
+	ClientSentMessagesPerRPCView = &view.View{
+		Measure:     ClientSentMessagesPerRPC,
+		Name:        "grpc.io/client/sent_messages_per_rpc",
+		Description: "Distribution of sent messages count per RPC, by method.",
+		TagKeys:     []tag.Key{KeyClientMethod},
+		Aggregation: DefaultMessageCountDistribution,
+	}
+
+	ClientReceivedMessagesPerRPCView = &view.View{
+		Measure:     ClientReceivedMessagesPerRPC,
+		Name:        "grpc.io/client/received_messages_per_rpc",
+		Description: "Distribution of received messages count per RPC, by method.",
+		TagKeys:     []tag.Key{KeyClientMethod},
+		Aggregation: DefaultMessageCountDistribution,
+	}
+
+	ClientServerLatencyView = &view.View{
+		Measure:     ClientServerLatency,
+		Name:        "grpc.io/client/server_latency",
+		Description: "Distribution of server latency as viewed by client, by method.",
+		TagKeys:     []tag.Key{KeyClientMethod},
+		Aggregation: DefaultMillisecondsDistribution,
+	}
+)
+
+// DefaultClientViews are the default client views provided by this package.
+var DefaultClientViews = []*view.View{
+	ClientSentBytesPerRPCView,
+	ClientReceivedBytesPerRPCView,
+	ClientRoundtripLatencyView,
+	ClientCompletedRPCsView,
+}
+
+// TODO(jbd): Add roundtrip_latency, uncompressed_request_bytes, uncompressed_response_bytes, request_count, response_count.
+// TODO(acetechnologist): This is temporary and will need to be replaced by a
+// mechanism to load these defaults from a common repository/config shared by
+// all supported languages. Likely a serialized protobuf of these defaults.

vendor/go.opencensus.io/plugin/ocgrpc/client_stats_handler.go

@@ -0,0 +1,49 @@
+// Copyright 2017, OpenCensus Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+package ocgrpc
+
+import (
+	"time"
+
+	"go.opencensus.io/tag"
+	"golang.org/x/net/context"
+	"google.golang.org/grpc/grpclog"
+	"google.golang.org/grpc/stats"
+)
+
+// statsTagRPC gets the tag.Map populated by the application code, serializes
+// its tags into the GRPC metadata in order to be sent to the server.
+func (h *ClientHandler) statsTagRPC(ctx context.Context, info *stats.RPCTagInfo) context.Context {
+	startTime := time.Now()
+	if info == nil {
+		if grpclog.V(2) {
+			grpclog.Infof("clientHandler.TagRPC called with nil info.", info.FullMethodName)
+		}
+		return ctx
+	}
+
+	d := &rpcData{
+		startTime: startTime,
+		method:    info.FullMethodName,
+	}
+	ts := tag.FromContext(ctx)
+	if ts != nil {
+		encoded := tag.Encode(ts)
+		ctx = stats.SetTags(ctx, encoded)
+	}
+
+	return context.WithValue(ctx, rpcDataKey, d)
+}

vendor/go.opencensus.io/plugin/ocgrpc/doc.go

@@ -0,0 +1,19 @@
+// Copyright 2017, OpenCensus Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package ocgrpc contains OpenCensus stats and trace
+// integrations for gRPC.
+//
+// Use ServerHandler for servers and ClientHandler for clients.
+package ocgrpc // import "go.opencensus.io/plugin/ocgrpc"

vendor/go.opencensus.io/plugin/ocgrpc/server.go

@@ -0,0 +1,80 @@
+// Copyright 2018, OpenCensus Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package ocgrpc
+
+import (
+	"go.opencensus.io/trace"
+	"golang.org/x/net/context"
+
+	"google.golang.org/grpc/stats"
+)
+
+// ServerHandler implements gRPC stats.Handler recording OpenCensus stats and
+// traces. Use with gRPC servers.
+//
+// When installed (see Example), tracing metadata is read from inbound RPCs
+// by default. If no tracing metadata is present, or if the tracing metadata is
+// present but the SpanContext isn't sampled, then a new trace may be started
+// (as determined by Sampler).
+type ServerHandler struct {
+	// IsPublicEndpoint may be set to true to always start a new trace around
+	// each RPC. Any SpanContext in the RPC metadata will be added as a linked
+	// span instead of making it the parent of the span created around the
+	// server RPC.
+	//
+	// Be aware that if you leave this false (the default) on a public-facing
+	// server, callers will be able to send tracing metadata in gRPC headers
+	// and trigger traces in your backend.
+	IsPublicEndpoint bool
+
+	// StartOptions to use for to spans started around RPCs handled by this server.
+	//
+	// These will apply even if there is tracing metadata already
+	// present on the inbound RPC but the SpanContext is not sampled. This
+	// ensures that each service has some opportunity to be traced. If you would
+	// like to not add any additional traces for this gRPC service, set:
+	//
+	//   StartOptions.Sampler = trace.ProbabilitySampler(0.0)
+	//
+	// StartOptions.SpanKind will always be set to trace.SpanKindServer
+	// for spans started by this handler.
+	StartOptions trace.StartOptions
+}
+
+var _ stats.Handler = (*ServerHandler)(nil)
+
+// HandleConn exists to satisfy gRPC stats.Handler.
+func (s *ServerHandler) HandleConn(ctx context.Context, cs stats.ConnStats) {
+	// no-op
+}
+
+// TagConn exists to satisfy gRPC stats.Handler.
+func (s *ServerHandler) TagConn(ctx context.Context, cti *stats.ConnTagInfo) context.Context {
+	// no-op
+	return ctx
+}
+
+// HandleRPC implements per-RPC tracing and stats instrumentation.
+func (s *ServerHandler) HandleRPC(ctx context.Context, rs stats.RPCStats) {
+	traceHandleRPC(ctx, rs)
+	statsHandleRPC(ctx, rs)
+}
+
+// TagRPC implements per-RPC context management.
+func (s *ServerHandler) TagRPC(ctx context.Context, rti *stats.RPCTagInfo) context.Context {
+	ctx = s.traceTagRPC(ctx, rti)
+	ctx = s.statsTagRPC(ctx, rti)
+	return ctx
+}

vendor/go.opencensus.io/plugin/ocgrpc/server_metrics.go

@@ -0,0 +1,97 @@
+// Copyright 2017, OpenCensus Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+package ocgrpc
+
+import (
+	"go.opencensus.io/stats"
+	"go.opencensus.io/stats/view"
+	"go.opencensus.io/tag"
+)
+
+// The following variables are measures are recorded by ServerHandler:
+var (
+	ServerReceivedMessagesPerRPC = stats.Int64("grpc.io/server/received_messages_per_rpc", "Number of messages received in each RPC. Has value 1 for non-streaming RPCs.", stats.UnitDimensionless)
+	ServerReceivedBytesPerRPC    = stats.Int64("grpc.io/server/received_bytes_per_rpc", "Total bytes received across all messages per RPC.", stats.UnitBytes)
+	ServerSentMessagesPerRPC     = stats.Int64("grpc.io/server/sent_messages_per_rpc", "Number of messages sent in each RPC. Has value 1 for non-streaming RPCs.", stats.UnitDimensionless)
+	ServerSentBytesPerRPC        = stats.Int64("grpc.io/server/sent_bytes_per_rpc", "Total bytes sent in across all response messages per RPC.", stats.UnitBytes)
+	ServerLatency                = stats.Float64("grpc.io/server/server_latency", "Time between first byte of request received to last byte of response sent, or terminal error.", stats.UnitMilliseconds)
+)
+
+// TODO(acetechnologist): This is temporary and will need to be replaced by a
+// mechanism to load these defaults from a common repository/config shared by
+// all supported languages. Likely a serialized protobuf of these defaults.
+
+// Predefined views may be registered to collect data for the above measures.
+// As always, you may also define your own custom views over measures collected by this
+// package. These are declared as a convenience only; none are registered by
+// default.
+var (
+	ServerReceivedBytesPerRPCView = &view.View{
+		Name:        "grpc.io/server/received_bytes_per_rpc",
+		Description: "Distribution of received bytes per RPC, by method.",
+		Measure:     ServerReceivedBytesPerRPC,
+		TagKeys:     []tag.Key{KeyServerMethod},
+		Aggregation: DefaultBytesDistribution,
+	}
+
+	ServerSentBytesPerRPCView = &view.View{
+		Name:        "grpc.io/server/sent_bytes_per_rpc",
+		Description: "Distribution of total sent bytes per RPC, by method.",
+		Measure:     ServerSentBytesPerRPC,
+		TagKeys:     []tag.Key{KeyServerMethod},
+		Aggregation: DefaultBytesDistribution,
+	}
+
+	ServerLatencyView = &view.View{
+		Name:        "grpc.io/server/server_latency",
+		Description: "Distribution of server latency in milliseconds, by method.",
+		TagKeys:     []tag.Key{KeyServerMethod},
+		Measure:     ServerLatency,
+		Aggregation: DefaultMillisecondsDistribution,
+	}
+
+	ServerCompletedRPCsView = &view.View{
+		Name:        "grpc.io/server/completed_rpcs",
+		Description: "Count of RPCs by method and status.",
+		TagKeys:     []tag.Key{KeyServerMethod, KeyServerStatus},
+		Measure:     ServerLatency,
+		Aggregation: view.Count(),
+	}
+
+	ServerReceivedMessagesPerRPCView = &view.View{
+		Name:        "grpc.io/server/received_messages_per_rpc",
+		Description: "Distribution of messages received count per RPC, by method.",
+		TagKeys:     []tag.Key{KeyServerMethod},
+		Measure:     ServerReceivedMessagesPerRPC,
+		Aggregation: DefaultMessageCountDistribution,
+	}
+
+	ServerSentMessagesPerRPCView = &view.View{
+		Name:        "grpc.io/server/sent_messages_per_rpc",
+		Description: "Distribution of messages sent count per RPC, by method.",
+		TagKeys:     []tag.Key{KeyServerMethod},
+		Measure:     ServerSentMessagesPerRPC,
+		Aggregation: DefaultMessageCountDistribution,
+	}
+)
+
+// DefaultServerViews are the default server views provided by this package.
+var DefaultServerViews = []*view.View{
+	ServerReceivedBytesPerRPCView,
+	ServerSentBytesPerRPCView,
+	ServerLatencyView,
+	ServerCompletedRPCsView,
+}

vendor/go.opencensus.io/plugin/ocgrpc/server_stats_handler.go

@@ -0,0 +1,63 @@
+// Copyright 2017, OpenCensus Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+package ocgrpc
+
+import (
+	"time"
+
+	"golang.org/x/net/context"
+
+	"go.opencensus.io/tag"
+	"google.golang.org/grpc/grpclog"
+	"google.golang.org/grpc/stats"
+)
+
+// statsTagRPC gets the metadata from gRPC context, extracts the encoded tags from
+// it and creates a new tag.Map and puts them into the returned context.
+func (h *ServerHandler) statsTagRPC(ctx context.Context, info *stats.RPCTagInfo) context.Context {
+	startTime := time.Now()
+	if info == nil {
+		if grpclog.V(2) {
+			grpclog.Infof("opencensus: TagRPC called with nil info.")
+		}
+		return ctx
+	}
+	d := &rpcData{
+		startTime: startTime,
+		method:    info.FullMethodName,
+	}
+	propagated := h.extractPropagatedTags(ctx)
+	ctx = tag.NewContext(ctx, propagated)
+	ctx, _ = tag.New(ctx, tag.Upsert(KeyServerMethod, methodName(info.FullMethodName)))
+	return context.WithValue(ctx, rpcDataKey, d)
+}
+
+// extractPropagatedTags creates a new tag map containing the tags extracted from the
+// gRPC metadata.
+func (h *ServerHandler) extractPropagatedTags(ctx context.Context) *tag.Map {
+	buf := stats.Tags(ctx)
+	if buf == nil {
+		return nil
+	}
+	propagated, err := tag.Decode(buf)
+	if err != nil {
+		if grpclog.V(2) {
+			grpclog.Warningf("opencensus: Failed to decode tags from gRPC metadata failed to decode: %v", err)
+		}
+		return nil
+	}
+	return propagated
+}

vendor/go.opencensus.io/plugin/ocgrpc/stats_common.go

@@ -0,0 +1,205 @@
+// Copyright 2017, OpenCensus Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+package ocgrpc
+
+import (
+	"context"
+	"strconv"
+	"strings"
+	"sync/atomic"
+	"time"
+
+	ocstats "go.opencensus.io/stats"
+	"go.opencensus.io/stats/view"
+	"go.opencensus.io/tag"
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/grpclog"
+	"google.golang.org/grpc/stats"
+	"google.golang.org/grpc/status"
+)
+
+type grpcInstrumentationKey string
+
+// rpcData holds the instrumentation RPC data that is needed between the start
+// and end of an call. It holds the info that this package needs to keep track
+// of between the various GRPC events.
+type rpcData struct {
+	// reqCount and respCount has to be the first words
+	// in order to be 64-aligned on 32-bit architectures.
+	sentCount, sentBytes, recvCount, recvBytes int64 // access atomically
+
+	// startTime represents the time at which TagRPC was invoked at the
+	// beginning of an RPC. It is an appoximation of the time when the
+	// application code invoked GRPC code.
+	startTime time.Time
+	method    string
+}
+
+// The following variables define the default hard-coded auxiliary data used by
+// both the default GRPC client and GRPC server metrics.
+var (
+	DefaultBytesDistribution        = view.Distribution(0, 1024, 2048, 4096, 16384, 65536, 262144, 1048576, 4194304, 16777216, 67108864, 268435456, 1073741824, 4294967296)
+	DefaultMillisecondsDistribution = view.Distribution(0, 0.01, 0.05, 0.1, 0.3, 0.6, 0.8, 1, 2, 3, 4, 5, 6, 8, 10, 13, 16, 20, 25, 30, 40, 50, 65, 80, 100, 130, 160, 200, 250, 300, 400, 500, 650, 800, 1000, 2000, 5000, 10000, 20000, 50000, 100000)
+	DefaultMessageCountDistribution = view.Distribution(0, 1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024, 2048, 4096, 8192, 16384, 32768, 65536)
+)
+
+// Server tags are applied to the context used to process each RPC, as well as
+// the measures at the end of each RPC.
+var (
+	KeyServerMethod, _ = tag.NewKey("grpc_server_method")
+	KeyServerStatus, _ = tag.NewKey("grpc_server_status")
+)
+
+// Client tags are applied to measures at the end of each RPC.
+var (
+	KeyClientMethod, _ = tag.NewKey("grpc_client_method")
+	KeyClientStatus, _ = tag.NewKey("grpc_client_status")
+)
+
+var (
+	rpcDataKey = grpcInstrumentationKey("opencensus-rpcData")
+)
+
+func methodName(fullname string) string {
+	return strings.TrimLeft(fullname, "/")
+}
+
+// statsHandleRPC processes the RPC events.
+func statsHandleRPC(ctx context.Context, s stats.RPCStats) {
+	switch st := s.(type) {
+	case *stats.Begin, *stats.OutHeader, *stats.InHeader, *stats.InTrailer, *stats.OutTrailer:
+		// do nothing for client
+	case *stats.OutPayload:
+		handleRPCOutPayload(ctx, st)
+	case *stats.InPayload:
+		handleRPCInPayload(ctx, st)
+	case *stats.End:
+		handleRPCEnd(ctx, st)
+	default:
+		grpclog.Infof("unexpected stats: %T", st)
+	}
+}
+
+func handleRPCOutPayload(ctx context.Context, s *stats.OutPayload) {
+	d, ok := ctx.Value(rpcDataKey).(*rpcData)
+	if !ok {
+		if grpclog.V(2) {
+			grpclog.Infoln("Failed to retrieve *rpcData from context.")
+		}
+		return
+	}
+
+	atomic.AddInt64(&d.sentBytes, int64(s.Length))
+	atomic.AddInt64(&d.sentCount, 1)
+}
+
+func handleRPCInPayload(ctx context.Context, s *stats.InPayload) {
+	d, ok := ctx.Value(rpcDataKey).(*rpcData)
+	if !ok {
+		if grpclog.V(2) {
+			grpclog.Infoln("Failed to retrieve *rpcData from context.")
+		}
+		return
+	}
+
+	atomic.AddInt64(&d.recvBytes, int64(s.Length))
+	atomic.AddInt64(&d.recvCount, 1)
+}
+
+func handleRPCEnd(ctx context.Context, s *stats.End) {
+	d, ok := ctx.Value(rpcDataKey).(*rpcData)
+	if !ok {
+		if grpclog.V(2) {
+			grpclog.Infoln("Failed to retrieve *rpcData from context.")
+		}
+		return
+	}
+
+	elapsedTime := time.Since(d.startTime)
+
+	var st string
+	if s.Error != nil {
+		s, ok := status.FromError(s.Error)
+		if ok {
+			st = statusCodeToString(s)
+		}
+	} else {
+		st = "OK"
+	}
+
+	latencyMillis := float64(elapsedTime) / float64(time.Millisecond)
+	if s.Client {
+		ctx, _ = tag.New(ctx,
+			tag.Upsert(KeyClientMethod, methodName(d.method)),
+			tag.Upsert(KeyClientStatus, st))
+		ocstats.Record(ctx,
+			ClientSentBytesPerRPC.M(atomic.LoadInt64(&d.sentBytes)),
+			ClientSentMessagesPerRPC.M(atomic.LoadInt64(&d.sentCount)),
+			ClientReceivedMessagesPerRPC.M(atomic.LoadInt64(&d.recvCount)),
+			ClientReceivedBytesPerRPC.M(atomic.LoadInt64(&d.recvBytes)),
+			ClientRoundtripLatency.M(latencyMillis))
+	} else {
+		ctx, _ = tag.New(ctx, tag.Upsert(KeyServerStatus, st))
+		ocstats.Record(ctx,
+			ServerSentBytesPerRPC.M(atomic.LoadInt64(&d.sentBytes)),
+			ServerSentMessagesPerRPC.M(atomic.LoadInt64(&d.sentCount)),
+			ServerReceivedMessagesPerRPC.M(atomic.LoadInt64(&d.recvCount)),
+			ServerReceivedBytesPerRPC.M(atomic.LoadInt64(&d.recvBytes)),
+			ServerLatency.M(latencyMillis))
+	}
+}
+
+func statusCodeToString(s *status.Status) string {
+	// see https://github.com/grpc/grpc/blob/master/doc/statuscodes.md
+	switch c := s.Code(); c {
+	case codes.OK:
+		return "OK"
+	case codes.Canceled:
+		return "CANCELLED"
+	case codes.Unknown:
+		return "UNKNOWN"
+	case codes.InvalidArgument:
+		return "INVALID_ARGUMENT"
+	case codes.DeadlineExceeded:
+		return "DEADLINE_EXCEEDED"
+	case codes.NotFound:
+		return "NOT_FOUND"
+	case codes.AlreadyExists:
+		return "ALREADY_EXISTS"
+	case codes.PermissionDenied:
+		return "PERMISSION_DENIED"
+	case codes.ResourceExhausted:
+		return "RESOURCE_EXHAUSTED"
+	case codes.FailedPrecondition:
+		return "FAILED_PRECONDITION"
+	case codes.Aborted:
+		return "ABORTED"
+	case codes.OutOfRange:
+		return "OUT_OF_RANGE"
+	case codes.Unimplemented:
+		return "UNIMPLEMENTED"
+	case codes.Internal:
+		return "INTERNAL"
+	case codes.Unavailable:
+		return "UNAVAILABLE"
+	case codes.DataLoss:
+		return "DATA_LOSS"
+	case codes.Unauthenticated:
+		return "UNAUTHENTICATED"
+	default:
+		return "CODE_" + strconv.FormatInt(int64(c), 10)
+	}
+}

vendor/go.opencensus.io/plugin/ocgrpc/trace_common.go

@@ -0,0 +1,107 @@
+// Copyright 2017, OpenCensus Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package ocgrpc
+
+import (
+	"strings"
+
+	"google.golang.org/grpc/codes"
+
+	"go.opencensus.io/trace"
+	"go.opencensus.io/trace/propagation"
+	"golang.org/x/net/context"
+	"google.golang.org/grpc/metadata"
+	"google.golang.org/grpc/stats"
+	"google.golang.org/grpc/status"
+)
+
+const traceContextKey = "grpc-trace-bin"
+
+// TagRPC creates a new trace span for the client side of the RPC.
+//
+// It returns ctx with the new trace span added and a serialization of the
+// SpanContext added to the outgoing gRPC metadata.
+func (c *ClientHandler) traceTagRPC(ctx context.Context, rti *stats.RPCTagInfo) context.Context {
+	name := strings.TrimPrefix(rti.FullMethodName, "/")
+	name = strings.Replace(name, "/", ".", -1)
+	ctx, span := trace.StartSpan(ctx, name,
+		trace.WithSampler(c.StartOptions.Sampler),
+		trace.WithSpanKind(trace.SpanKindClient)) // span is ended by traceHandleRPC
+	traceContextBinary := propagation.Binary(span.SpanContext())
+	return metadata.AppendToOutgoingContext(ctx, traceContextKey, string(traceContextBinary))
+}
+
+// TagRPC creates a new trace span for the server side of the RPC.
+//
+// It checks the incoming gRPC metadata in ctx for a SpanContext, and if
+// it finds one, uses that SpanContext as the parent context of the new span.
+//
+// It returns ctx, with the new trace span added.
+func (s *ServerHandler) traceTagRPC(ctx context.Context, rti *stats.RPCTagInfo) context.Context {
+	md, _ := metadata.FromIncomingContext(ctx)
+	name := strings.TrimPrefix(rti.FullMethodName, "/")
+	name = strings.Replace(name, "/", ".", -1)
+	traceContext := md[traceContextKey]
+	var (
+		parent     trace.SpanContext
+		haveParent bool
+	)
+	if len(traceContext) > 0 {
+		// Metadata with keys ending in -bin are actually binary. They are base64
+		// encoded before being put on the wire, see:
+		// https://github.com/grpc/grpc-go/blob/08d6261/Documentation/grpc-metadata.md#storing-binary-data-in-metadata
+		traceContextBinary := []byte(traceContext[0])
+		parent, haveParent = propagation.FromBinary(traceContextBinary)
+		if haveParent && !s.IsPublicEndpoint {
+			ctx, _ := trace.StartSpanWithRemoteParent(ctx, name, parent,
+				trace.WithSpanKind(trace.SpanKindServer),
+				trace.WithSampler(s.StartOptions.Sampler),
+			)
+			return ctx
+		}
+	}
+	ctx, span := trace.StartSpan(ctx, name,
+		trace.WithSpanKind(trace.SpanKindServer),
+		trace.WithSampler(s.StartOptions.Sampler))
+	if haveParent {
+		span.AddLink(trace.Link{TraceID: parent.TraceID, SpanID: parent.SpanID, Type: trace.LinkTypeChild})
+	}
+	return ctx
+}
+
+func traceHandleRPC(ctx context.Context, rs stats.RPCStats) {
+	span := trace.FromContext(ctx)
+	// TODO: compressed and uncompressed sizes are not populated in every message.
+	switch rs := rs.(type) {
+	case *stats.Begin:
+		span.AddAttributes(
+			trace.BoolAttribute("Client", rs.Client),
+			trace.BoolAttribute("FailFast", rs.FailFast))
+	case *stats.InPayload:
+		span.AddMessageReceiveEvent(0 /* TODO: messageID */, int64(rs.Length), int64(rs.WireLength))
+	case *stats.OutPayload:
+		span.AddMessageSendEvent(0, int64(rs.Length), int64(rs.WireLength))
+	case *stats.End:
+		if rs.Error != nil {
+			s, ok := status.FromError(rs.Error)
+			if ok {
+				span.SetStatus(trace.Status{Code: int32(s.Code()), Message: s.Message()})
+			} else {
+				span.SetStatus(trace.Status{Code: int32(codes.Internal), Message: rs.Error.Error()})
+			}
+		}
+		span.End()
+	}
+}

vendor/go.opencensus.io/plugin/ochttp/client.go

@@ -0,0 +1,107 @@
+// Copyright 2018, OpenCensus Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package ochttp
+
+import (
+	"net/http"
+	"net/http/httptrace"
+
+	"go.opencensus.io/trace"
+	"go.opencensus.io/trace/propagation"
+)
+
+// Transport is an http.RoundTripper that instruments all outgoing requests with
+// OpenCensus stats and tracing.
+//
+// The zero value is intended to be a useful default, but for
+// now it's recommended that you explicitly set Propagation, since the default
+// for this may change.
+type Transport struct {
+	// Base may be set to wrap another http.RoundTripper that does the actual
+	// requests. By default http.DefaultTransport is used.
+	//
+	// If base HTTP roundtripper implements CancelRequest,
+	// the returned round tripper will be cancelable.
+	Base http.RoundTripper
+
+	// Propagation defines how traces are propagated. If unspecified, a default
+	// (currently B3 format) will be used.
+	Propagation propagation.HTTPFormat
+
+	// StartOptions are applied to the span started by this Transport around each
+	// request.
+	//
+	// StartOptions.SpanKind will always be set to trace.SpanKindClient
+	// for spans started by this transport.
+	StartOptions trace.StartOptions
+
+	// NameFromRequest holds the function to use for generating the span name
+	// from the information found in the outgoing HTTP Request. By default the
+	// name equals the URL Path.
+	FormatSpanName func(*http.Request) string
+
+	// NewClientTrace may be set to a function allowing the current *trace.Span
+	// to be annotated with HTTP request event information emitted by the
+	// httptrace package.
+	NewClientTrace func(*http.Request, *trace.Span) *httptrace.ClientTrace
+
+	// TODO: Implement tag propagation for HTTP.
+}
+
+// RoundTrip implements http.RoundTripper, delegating to Base and recording stats and traces for the request.
+func (t *Transport) RoundTrip(req *http.Request) (*http.Response, error) {
+	rt := t.base()
+	if isHealthEndpoint(req.URL.Path) {
+		return rt.RoundTrip(req)
+	}
+	// TODO: remove excessive nesting of http.RoundTrippers here.
+	format := t.Propagation
+	if format == nil {
+		format = defaultFormat
+	}
+	spanNameFormatter := t.FormatSpanName
+	if spanNameFormatter == nil {
+		spanNameFormatter = spanNameFromURL
+	}
+	rt = &traceTransport{
+		base:   rt,
+		format: format,
+		startOptions: trace.StartOptions{
+			Sampler:  t.StartOptions.Sampler,
+			SpanKind: trace.SpanKindClient,
+		},
+		formatSpanName: spanNameFormatter,
+		newClientTrace: t.NewClientTrace,
+	}
+	rt = statsTransport{base: rt}
+	return rt.RoundTrip(req)
+}
+
+func (t *Transport) base() http.RoundTripper {
+	if t.Base != nil {
+		return t.Base
+	}
+	return http.DefaultTransport
+}
+
+// CancelRequest cancels an in-flight request by closing its connection.
+func (t *Transport) CancelRequest(req *http.Request) {
+	type canceler interface {
+		CancelRequest(*http.Request)
+	}
+	if cr, ok := t.base().(canceler); ok {
+		cr.CancelRequest(req)
+	}
+}

vendor/go.opencensus.io/plugin/ochttp/client_stats.go

@@ -0,0 +1,125 @@
+// Copyright 2018, OpenCensus Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package ochttp
+
+import (
+	"context"
+	"io"
+	"net/http"
+	"strconv"
+	"sync"
+	"time"
+
+	"go.opencensus.io/stats"
+	"go.opencensus.io/tag"
+)
+
+// statsTransport is an http.RoundTripper that collects stats for the outgoing requests.
+type statsTransport struct {
+	base http.RoundTripper
+}
+
+// RoundTrip implements http.RoundTripper, delegating to Base and recording stats for the request.
+func (t statsTransport) RoundTrip(req *http.Request) (*http.Response, error) {
+	ctx, _ := tag.New(req.Context(),
+		tag.Upsert(Host, req.URL.Host),
+		tag.Upsert(Path, req.URL.Path),
+		tag.Upsert(Method, req.Method))
+	req = req.WithContext(ctx)
+	track := &tracker{
+		start: time.Now(),
+		ctx:   ctx,
+	}
+	if req.Body == nil {
+		// TODO: Handle cases where ContentLength is not set.
+		track.reqSize = -1
+	} else if req.ContentLength > 0 {
+		track.reqSize = req.ContentLength
+	}
+	stats.Record(ctx, ClientRequestCount.M(1))
+
+	// Perform request.
+	resp, err := t.base.RoundTrip(req)
+
+	if err != nil {
+		track.statusCode = http.StatusInternalServerError
+		track.end()
+	} else {
+		track.statusCode = resp.StatusCode
+		if resp.Body == nil {
+			track.end()
+		} else {
+			track.body = resp.Body
+			resp.Body = track
+		}
+	}
+	return resp, err
+}
+
+// CancelRequest cancels an in-flight request by closing its connection.
+func (t statsTransport) CancelRequest(req *http.Request) {
+	type canceler interface {
+		CancelRequest(*http.Request)
+	}
+	if cr, ok := t.base.(canceler); ok {
+		cr.CancelRequest(req)
+	}
+}
+
+type tracker struct {
+	ctx        context.Context
+	respSize   int64
+	reqSize    int64
+	start      time.Time
+	body       io.ReadCloser
+	statusCode int
+	endOnce    sync.Once
+}
+
+var _ io.ReadCloser = (*tracker)(nil)
+
+func (t *tracker) end() {
+	t.endOnce.Do(func() {
+		m := []stats.Measurement{
+			ClientLatency.M(float64(time.Since(t.start)) / float64(time.Millisecond)),
+			ClientResponseBytes.M(t.respSize),
+		}
+		if t.reqSize >= 0 {
+			m = append(m, ClientRequestBytes.M(t.reqSize))
+		}
+		ctx, _ := tag.New(t.ctx, tag.Upsert(StatusCode, strconv.Itoa(t.statusCode)))
+		stats.Record(ctx, m...)
+	})
+}
+
+func (t *tracker) Read(b []byte) (int, error) {
+	n, err := t.body.Read(b)
+	switch err {
+	case nil:
+		t.respSize += int64(n)
+		return n, nil
+	case io.EOF:
+		t.end()
+	}
+	return n, err
+}
+
+func (t *tracker) Close() error {
+	// Invoking endSpan on Close will help catch the cases
+	// in which a read returned a non-nil error, we set the
+	// span status but didn't end the span.
+	t.end()
+	return t.body.Close()
+}

vendor/go.opencensus.io/plugin/ochttp/doc.go

@@ -0,0 +1,19 @@
+// Copyright 2018, OpenCensus Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package ochttp provides OpenCensus instrumentation for net/http package.
+//
+// For server instrumentation, see Handler. For client-side instrumentation,
+// see Transport.
+package ochttp // import "go.opencensus.io/plugin/ochttp"

vendor/go.opencensus.io/plugin/ochttp/propagation/b3/b3.go

@@ -0,0 +1,123 @@
+// Copyright 2018, OpenCensus Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package b3 contains a propagation.HTTPFormat implementation
+// for B3 propagation. See https://github.com/openzipkin/b3-propagation
+// for more details.
+package b3 // import "go.opencensus.io/plugin/ochttp/propagation/b3"
+
+import (
+	"encoding/hex"
+	"net/http"
+
+	"go.opencensus.io/trace"
+	"go.opencensus.io/trace/propagation"
+)
+
+// B3 headers that OpenCensus understands.
+const (
+	TraceIDHeader = "X-B3-TraceId"
+	SpanIDHeader  = "X-B3-SpanId"
+	SampledHeader = "X-B3-Sampled"
+)
+
+// HTTPFormat implements propagation.HTTPFormat to propagate
+// traces in HTTP headers in B3 propagation format.
+// HTTPFormat skips the X-B3-ParentId and X-B3-Flags headers
+// because there are additional fields not represented in the
+// OpenCensus span context. Spans created from the incoming
+// header will be the direct children of the client-side span.
+// Similarly, reciever of the outgoing spans should use client-side
+// span created by OpenCensus as the parent.
+type HTTPFormat struct{}
+
+var _ propagation.HTTPFormat = (*HTTPFormat)(nil)
+
+// SpanContextFromRequest extracts a B3 span context from incoming requests.
+func (f *HTTPFormat) SpanContextFromRequest(req *http.Request) (sc trace.SpanContext, ok bool) {
+	tid, ok := ParseTraceID(req.Header.Get(TraceIDHeader))
+	if !ok {
+		return trace.SpanContext{}, false
+	}
+	sid, ok := ParseSpanID(req.Header.Get(SpanIDHeader))
+	if !ok {
+		return trace.SpanContext{}, false
+	}
+	sampled, _ := ParseSampled(req.Header.Get(SampledHeader))
+	return trace.SpanContext{
+		TraceID:      tid,
+		SpanID:       sid,
+		TraceOptions: sampled,
+	}, true
+}
+
+// ParseTraceID parses the value of the X-B3-TraceId header.
+func ParseTraceID(tid string) (trace.TraceID, bool) {
+	if tid == "" {
+		return trace.TraceID{}, false
+	}
+	b, err := hex.DecodeString(tid)
+	if err != nil {
+		return trace.TraceID{}, false
+	}
+	var traceID trace.TraceID
+	if len(b) <= 8 {
+		// The lower 64-bits.
+		start := 8 + (8 - len(b))
+		copy(traceID[start:], b)
+	} else {
+		start := 16 - len(b)
+		copy(traceID[start:], b)
+	}
+
+	return traceID, true
+}
+
+// ParseSpanID parses the value of the X-B3-SpanId or X-B3-ParentSpanId headers.
+func ParseSpanID(sid string) (spanID trace.SpanID, ok bool) {
+	if sid == "" {
+		return trace.SpanID{}, false
+	}
+	b, err := hex.DecodeString(sid)
+	if err != nil {
+		return trace.SpanID{}, false
+	}
+	start := 8 - len(b)
+	copy(spanID[start:], b)
+	return spanID, true
+}
+
+// ParseSampled parses the value of the X-B3-Sampled header.
+func ParseSampled(sampled string) (trace.TraceOptions, bool) {
+	switch sampled {
+	case "true", "1":
+		return trace.TraceOptions(1), true
+	default:
+		return trace.TraceOptions(0), false
+	}
+}
+
+// SpanContextToRequest modifies the given request to include B3 headers.
+func (f *HTTPFormat) SpanContextToRequest(sc trace.SpanContext, req *http.Request) {
+	req.Header.Set(TraceIDHeader, hex.EncodeToString(sc.TraceID[:]))
+	req.Header.Set(SpanIDHeader, hex.EncodeToString(sc.SpanID[:]))
+
+	var sampled string
+	if sc.IsSampled() {
+		sampled = "1"
+	} else {
+		sampled = "0"
+	}
+	req.Header.Set(SampledHeader, sampled)
+}

vendor/go.opencensus.io/plugin/ochttp/route.go

@@ -0,0 +1,51 @@
+// Copyright 2018, OpenCensus Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package ochttp
+
+import (
+	"net/http"
+
+	"go.opencensus.io/tag"
+)
+
+// WithRouteTag returns an http.Handler that records stats with the
+// http_server_route tag set to the given value.
+func WithRouteTag(handler http.Handler, route string) http.Handler {
+	return taggedHandlerFunc(func(w http.ResponseWriter, r *http.Request) []tag.Mutator {
+		addRoute := []tag.Mutator{tag.Upsert(KeyServerRoute, route)}
+		ctx, _ := tag.New(r.Context(), addRoute...)
+		r = r.WithContext(ctx)
+		handler.ServeHTTP(w, r)
+		return addRoute
+	})
+}
+
+// taggedHandlerFunc is a http.Handler that returns tags describing the
+// processing of the request. These tags will be recorded along with the
+// measures in this package at the end of the request.
+type taggedHandlerFunc func(w http.ResponseWriter, r *http.Request) []tag.Mutator
+
+func (h taggedHandlerFunc) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	tags := h(w, r)
+	if a, ok := r.Context().Value(addedTagsKey{}).(*addedTags); ok {
+		a.t = append(a.t, tags...)
+	}
+}
+
+type addedTagsKey struct{}
+
+type addedTags struct {
+	t []tag.Mutator
+}

vendor/go.opencensus.io/plugin/ochttp/server.go

@@ -0,0 +1,430 @@
+// Copyright 2018, OpenCensus Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package ochttp
+
+import (
+	"context"
+	"io"
+	"net/http"
+	"strconv"
+	"sync"
+	"time"
+
+	"go.opencensus.io/stats"
+	"go.opencensus.io/tag"
+	"go.opencensus.io/trace"
+	"go.opencensus.io/trace/propagation"
+)
+
+// Handler is an http.Handler wrapper to instrument your HTTP server with
+// OpenCensus. It supports both stats and tracing.
+//
+// Tracing
+//
+// This handler is aware of the incoming request's span, reading it from request
+// headers as configured using the Propagation field.
+// The extracted span can be accessed from the incoming request's
+// context.
+//
+//    span := trace.FromContext(r.Context())
+//
+// The server span will be automatically ended at the end of ServeHTTP.
+type Handler struct {
+	// Propagation defines how traces are propagated. If unspecified,
+	// B3 propagation will be used.
+	Propagation propagation.HTTPFormat
+
+	// Handler is the handler used to handle the incoming request.
+	Handler http.Handler
+
+	// StartOptions are applied to the span started by this Handler around each
+	// request.
+	//
+	// StartOptions.SpanKind will always be set to trace.SpanKindServer
+	// for spans started by this transport.
+	StartOptions trace.StartOptions
+
+	// IsPublicEndpoint should be set to true for publicly accessible HTTP(S)
+	// servers. If true, any trace metadata set on the incoming request will
+	// be added as a linked trace instead of being added as a parent of the
+	// current trace.
+	IsPublicEndpoint bool
+
+	// FormatSpanName holds the function to use for generating the span name
+	// from the information found in the incoming HTTP Request. By default the
+	// name equals the URL Path.
+	FormatSpanName func(*http.Request) string
+}
+
+func (h *Handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	var tags addedTags
+	r, traceEnd := h.startTrace(w, r)
+	defer traceEnd()
+	w, statsEnd := h.startStats(w, r)
+	defer statsEnd(&tags)
+	handler := h.Handler
+	if handler == nil {
+		handler = http.DefaultServeMux
+	}
+	r = r.WithContext(context.WithValue(r.Context(), addedTagsKey{}, &tags))
+	handler.ServeHTTP(w, r)
+}
+
+func (h *Handler) startTrace(w http.ResponseWriter, r *http.Request) (*http.Request, func()) {
+	if isHealthEndpoint(r.URL.Path) {
+		return r, func() {}
+	}
+	var name string
+	if h.FormatSpanName == nil {
+		name = spanNameFromURL(r)
+	} else {
+		name = h.FormatSpanName(r)
+	}
+	ctx := r.Context()
+	var span *trace.Span
+	sc, ok := h.extractSpanContext(r)
+	if ok && !h.IsPublicEndpoint {
+		ctx, span = trace.StartSpanWithRemoteParent(ctx, name, sc,
+			trace.WithSampler(h.StartOptions.Sampler),
+			trace.WithSpanKind(trace.SpanKindServer))
+	} else {
+		ctx, span = trace.StartSpan(ctx, name,
+			trace.WithSampler(h.StartOptions.Sampler),
+			trace.WithSpanKind(trace.SpanKindServer),
+		)
+		if ok {
+			span.AddLink(trace.Link{
+				TraceID:    sc.TraceID,
+				SpanID:     sc.SpanID,
+				Type:       trace.LinkTypeChild,
+				Attributes: nil,
+			})
+		}
+	}
+	span.AddAttributes(requestAttrs(r)...)
+	return r.WithContext(ctx), span.End
+}
+
+func (h *Handler) extractSpanContext(r *http.Request) (trace.SpanContext, bool) {
+	if h.Propagation == nil {
+		return defaultFormat.SpanContextFromRequest(r)
+	}
+	return h.Propagation.SpanContextFromRequest(r)
+}
+
+func (h *Handler) startStats(w http.ResponseWriter, r *http.Request) (http.ResponseWriter, func(tags *addedTags)) {
+	ctx, _ := tag.New(r.Context(),
+		tag.Upsert(Host, r.URL.Host),
+		tag.Upsert(Path, r.URL.Path),
+		tag.Upsert(Method, r.Method))
+	track := &trackingResponseWriter{
+		start:  time.Now(),
+		ctx:    ctx,
+		writer: w,
+	}
+	if r.Body == nil {
+		// TODO: Handle cases where ContentLength is not set.
+		track.reqSize = -1
+	} else if r.ContentLength > 0 {
+		track.reqSize = r.ContentLength
+	}
+	stats.Record(ctx, ServerRequestCount.M(1))
+	return track.wrappedResponseWriter(), track.end
+}
+
+type trackingResponseWriter struct {
+	ctx        context.Context
+	reqSize    int64
+	respSize   int64
+	start      time.Time
+	statusCode int
+	statusLine string
+	endOnce    sync.Once
+	writer     http.ResponseWriter
+}
+
+// Compile time assertion for ResponseWriter interface
+var _ http.ResponseWriter = (*trackingResponseWriter)(nil)
+
+var logTagsErrorOnce sync.Once
+
+func (t *trackingResponseWriter) end(tags *addedTags) {
+	t.endOnce.Do(func() {
+		if t.statusCode == 0 {
+			t.statusCode = 200
+		}
+
+		span := trace.FromContext(t.ctx)
+		span.SetStatus(TraceStatus(t.statusCode, t.statusLine))
+
+		m := []stats.Measurement{
+			ServerLatency.M(float64(time.Since(t.start)) / float64(time.Millisecond)),
+			ServerResponseBytes.M(t.respSize),
+		}
+		if t.reqSize >= 0 {
+			m = append(m, ServerRequestBytes.M(t.reqSize))
+		}
+		allTags := make([]tag.Mutator, len(tags.t)+1)
+		allTags[0] = tag.Upsert(StatusCode, strconv.Itoa(t.statusCode))
+		copy(allTags[1:], tags.t)
+		ctx, _ := tag.New(t.ctx, allTags...)
+		stats.Record(ctx, m...)
+	})
+}
+
+func (t *trackingResponseWriter) Header() http.Header {
+	return t.writer.Header()
+}
+
+func (t *trackingResponseWriter) Write(data []byte) (int, error) {
+	n, err := t.writer.Write(data)
+	t.respSize += int64(n)
+	return n, err
+}
+
+func (t *trackingResponseWriter) WriteHeader(statusCode int) {
+	t.writer.WriteHeader(statusCode)
+	t.statusCode = statusCode
+	t.statusLine = http.StatusText(t.statusCode)
+}
+
+// wrappedResponseWriter returns a wrapped version of the original
+//  ResponseWriter and only implements the same combination of additional
+// interfaces as the original.
+// This implementation is based on https://github.com/felixge/httpsnoop.
+func (t *trackingResponseWriter) wrappedResponseWriter() http.ResponseWriter {
+	var (
+		hj, i0 = t.writer.(http.Hijacker)
+		cn, i1 = t.writer.(http.CloseNotifier)
+		pu, i2 = t.writer.(http.Pusher)
+		fl, i3 = t.writer.(http.Flusher)
+		rf, i4 = t.writer.(io.ReaderFrom)
+	)
+
+	switch {
+	case !i0 && !i1 && !i2 && !i3 && !i4:
+		return struct {
+			http.ResponseWriter
+		}{t}
+	case !i0 && !i1 && !i2 && !i3 && i4:
+		return struct {
+			http.ResponseWriter
+			io.ReaderFrom
+		}{t, rf}
+	case !i0 && !i1 && !i2 && i3 && !i4:
+		return struct {
+			http.ResponseWriter
+			http.Flusher
+		}{t, fl}
+	case !i0 && !i1 && !i2 && i3 && i4:
+		return struct {
+			http.ResponseWriter
+			http.Flusher
+			io.ReaderFrom
+		}{t, fl, rf}
+	case !i0 && !i1 && i2 && !i3 && !i4:
+		return struct {
+			http.ResponseWriter
+			http.Pusher
+		}{t, pu}
+	case !i0 && !i1 && i2 && !i3 && i4:
+		return struct {
+			http.ResponseWriter
+			http.Pusher
+			io.ReaderFrom
+		}{t, pu, rf}
+	case !i0 && !i1 && i2 && i3 && !i4:
+		return struct {
+			http.ResponseWriter
+			http.Pusher
+			http.Flusher
+		}{t, pu, fl}
+	case !i0 && !i1 && i2 && i3 && i4:
+		return struct {
+			http.ResponseWriter
+			http.Pusher
+			http.Flusher
+			io.ReaderFrom
+		}{t, pu, fl, rf}
+	case !i0 && i1 && !i2 && !i3 && !i4:
+		return struct {
+			http.ResponseWriter
+			http.CloseNotifier
+		}{t, cn}
+	case !i0 && i1 && !i2 && !i3 && i4:
+		return struct {
+			http.ResponseWriter
+			http.CloseNotifier
+			io.ReaderFrom
+		}{t, cn, rf}
+	case !i0 && i1 && !i2 && i3 && !i4:
+		return struct {
+			http.ResponseWriter
+			http.CloseNotifier
+			http.Flusher
+		}{t, cn, fl}
+	case !i0 && i1 && !i2 && i3 && i4:
+		return struct {
+			http.ResponseWriter
+			http.CloseNotifier
+			http.Flusher
+			io.ReaderFrom
+		}{t, cn, fl, rf}
+	case !i0 && i1 && i2 && !i3 && !i4:
+		return struct {
+			http.ResponseWriter
+			http.CloseNotifier
+			http.Pusher
+		}{t, cn, pu}
+	case !i0 && i1 && i2 && !i3 && i4:
+		return struct {
+			http.ResponseWriter
+			http.CloseNotifier
+			http.Pusher
+			io.ReaderFrom
+		}{t, cn, pu, rf}
+	case !i0 && i1 && i2 && i3 && !i4:
+		return struct {
+			http.ResponseWriter
+			http.CloseNotifier
+			http.Pusher
+			http.Flusher
+		}{t, cn, pu, fl}
+	case !i0 && i1 && i2 && i3 && i4:
+		return struct {
+			http.ResponseWriter
+			http.CloseNotifier
+			http.Pusher
+			http.Flusher
+			io.ReaderFrom
+		}{t, cn, pu, fl, rf}
+	case i0 && !i1 && !i2 && !i3 && !i4:
+		return struct {
+			http.ResponseWriter
+			http.Hijacker
+		}{t, hj}
+	case i0 && !i1 && !i2 && !i3 && i4:
+		return struct {
+			http.ResponseWriter
+			http.Hijacker
+			io.ReaderFrom
+		}{t, hj, rf}
+	case i0 && !i1 && !i2 && i3 && !i4:
+		return struct {
+			http.ResponseWriter
+			http.Hijacker
+			http.Flusher
+		}{t, hj, fl}
+	case i0 && !i1 && !i2 && i3 && i4:
+		return struct {
+			http.ResponseWriter
+			http.Hijacker
+			http.Flusher
+			io.ReaderFrom
+		}{t, hj, fl, rf}
+	case i0 && !i1 && i2 && !i3 && !i4:
+		return struct {
+			http.ResponseWriter
+			http.Hijacker
+			http.Pusher
+		}{t, hj, pu}
+	case i0 && !i1 && i2 && !i3 && i4:
+		return struct {
+			http.ResponseWriter
+			http.Hijacker
+			http.Pusher
+			io.ReaderFrom
+		}{t, hj, pu, rf}
+	case i0 && !i1 && i2 && i3 && !i4:
+		return struct {
+			http.ResponseWriter
+			http.Hijacker
+			http.Pusher
+			http.Flusher
+		}{t, hj, pu, fl}
+	case i0 && !i1 && i2 && i3 && i4:
+		return struct {
+			http.ResponseWriter
+			http.Hijacker
+			http.Pusher
+			http.Flusher
+			io.ReaderFrom
+		}{t, hj, pu, fl, rf}
+	case i0 && i1 && !i2 && !i3 && !i4:
+		return struct {
+			http.ResponseWriter
+			http.Hijacker
+			http.CloseNotifier
+		}{t, hj, cn}
+	case i0 && i1 && !i2 && !i3 && i4:
+		return struct {
+			http.ResponseWriter
+			http.Hijacker
+			http.CloseNotifier
+			io.ReaderFrom
+		}{t, hj, cn, rf}
+	case i0 && i1 && !i2 && i3 && !i4:
+		return struct {
+			http.ResponseWriter
+			http.Hijacker
+			http.CloseNotifier
+			http.Flusher
+		}{t, hj, cn, fl}
+	case i0 && i1 && !i2 && i3 && i4:
+		return struct {
+			http.ResponseWriter
+			http.Hijacker
+			http.CloseNotifier
+			http.Flusher
+			io.ReaderFrom
+		}{t, hj, cn, fl, rf}
+	case i0 && i1 && i2 && !i3 && !i4:
+		return struct {
+			http.ResponseWriter
+			http.Hijacker
+			http.CloseNotifier
+			http.Pusher
+		}{t, hj, cn, pu}
+	case i0 && i1 && i2 && !i3 && i4:
+		return struct {
+			http.ResponseWriter
+			http.Hijacker
+			http.CloseNotifier
+			http.Pusher
+			io.ReaderFrom
+		}{t, hj, cn, pu, rf}
+	case i0 && i1 && i2 && i3 && !i4:
+		return struct {
+			http.ResponseWriter
+			http.Hijacker
+			http.CloseNotifier
+			http.Pusher
+			http.Flusher
+		}{t, hj, cn, pu, fl}
+	case i0 && i1 && i2 && i3 && i4:
+		return struct {
+			http.ResponseWriter
+			http.Hijacker
+			http.CloseNotifier
+			http.Pusher
+			http.Flusher
+			io.ReaderFrom
+		}{t, hj, cn, pu, fl, rf}
+	default:
+		return struct {
+			http.ResponseWriter
+		}{t}
+	}
+}

vendor/go.opencensus.io/plugin/ochttp/span_annotating_client_trace.go

@@ -0,0 +1,167 @@
+// Copyright 2018, OpenCensus Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package ochttp
+
+import (
+	"crypto/tls"
+	"net/http"
+	"net/http/httptrace"
+	"strings"
+
+	"go.opencensus.io/trace"
+)
+
+type spanAnnotator struct {
+	sp *trace.Span
+}
+
+// TODO: Remove NewSpanAnnotator at the next release.
+
+// Deprecated: Use NewSpanAnnotatingClientTrace instead
+func NewSpanAnnotator(r *http.Request, s *trace.Span) *httptrace.ClientTrace {
+	return NewSpanAnnotatingClientTrace(r, s)
+}
+
+// NewSpanAnnotatingClientTrace returns a httptrace.ClientTrace which annotates
+// all emitted httptrace events on the provided Span.
+func NewSpanAnnotatingClientTrace(_ *http.Request, s *trace.Span) *httptrace.ClientTrace {
+	sa := spanAnnotator{sp: s}
+
+	return &httptrace.ClientTrace{
+		GetConn:              sa.getConn,
+		GotConn:              sa.gotConn,
+		PutIdleConn:          sa.putIdleConn,
+		GotFirstResponseByte: sa.gotFirstResponseByte,
+		Got100Continue:       sa.got100Continue,
+		DNSStart:             sa.dnsStart,
+		DNSDone:              sa.dnsDone,
+		ConnectStart:         sa.connectStart,
+		ConnectDone:          sa.connectDone,
+		TLSHandshakeStart:    sa.tlsHandshakeStart,
+		TLSHandshakeDone:     sa.tlsHandshakeDone,
+		WroteHeaders:         sa.wroteHeaders,
+		Wait100Continue:      sa.wait100Continue,
+		WroteRequest:         sa.wroteRequest,
+	}
+}
+
+func (s spanAnnotator) getConn(hostPort string) {
+	attrs := []trace.Attribute{
+		trace.StringAttribute("httptrace.get_connection.host_port", hostPort),
+	}
+	s.sp.Annotate(attrs, "GetConn")
+}
+
+func (s spanAnnotator) gotConn(info httptrace.GotConnInfo) {
+	attrs := []trace.Attribute{
+		trace.BoolAttribute("httptrace.got_connection.reused", info.Reused),
+		trace.BoolAttribute("httptrace.got_connection.was_idle", info.WasIdle),
+	}
+	if info.WasIdle {
+		attrs = append(attrs,
+			trace.StringAttribute("httptrace.got_connection.idle_time", info.IdleTime.String()))
+	}
+	s.sp.Annotate(attrs, "GotConn")
+}
+
+// PutIdleConn implements a httptrace.ClientTrace hook
+func (s spanAnnotator) putIdleConn(err error) {
+	var attrs []trace.Attribute
+	if err != nil {
+		attrs = append(attrs,
+			trace.StringAttribute("httptrace.put_idle_connection.error", err.Error()))
+	}
+	s.sp.Annotate(attrs, "PutIdleConn")
+}
+
+func (s spanAnnotator) gotFirstResponseByte() {
+	s.sp.Annotate(nil, "GotFirstResponseByte")
+}
+
+func (s spanAnnotator) got100Continue() {
+	s.sp.Annotate(nil, "Got100Continue")
+}
+
+func (s spanAnnotator) dnsStart(info httptrace.DNSStartInfo) {
+	attrs := []trace.Attribute{
+		trace.StringAttribute("httptrace.dns_start.host", info.Host),
+	}
+	s.sp.Annotate(attrs, "DNSStart")
+}
+
+func (s spanAnnotator) dnsDone(info httptrace.DNSDoneInfo) {
+	var addrs []string
+	for _, addr := range info.Addrs {
+		addrs = append(addrs, addr.String())
+	}
+	attrs := []trace.Attribute{
+		trace.StringAttribute("httptrace.dns_done.addrs", strings.Join(addrs, " , ")),
+	}
+	if info.Err != nil {
+		attrs = append(attrs,
+			trace.StringAttribute("httptrace.dns_done.error", info.Err.Error()))
+	}
+	s.sp.Annotate(attrs, "DNSDone")
+}
+
+func (s spanAnnotator) connectStart(network, addr string) {
+	attrs := []trace.Attribute{
+		trace.StringAttribute("httptrace.connect_start.network", network),
+		trace.StringAttribute("httptrace.connect_start.addr", addr),
+	}
+	s.sp.Annotate(attrs, "ConnectStart")
+}
+
+func (s spanAnnotator) connectDone(network, addr string, err error) {
+	attrs := []trace.Attribute{
+		trace.StringAttribute("httptrace.connect_done.network", network),
+		trace.StringAttribute("httptrace.connect_done.addr", addr),
+	}
+	if err != nil {
+		attrs = append(attrs,
+			trace.StringAttribute("httptrace.connect_done.error", err.Error()))
+	}
+	s.sp.Annotate(attrs, "ConnectDone")
+}
+
+func (s spanAnnotator) tlsHandshakeStart() {
+	s.sp.Annotate(nil, "TLSHandshakeStart")
+}
+
+func (s spanAnnotator) tlsHandshakeDone(_ tls.ConnectionState, err error) {
+	var attrs []trace.Attribute
+	if err != nil {
+		attrs = append(attrs,
+			trace.StringAttribute("httptrace.tls_handshake_done.error", err.Error()))
+	}
+	s.sp.Annotate(attrs, "TLSHandshakeDone")
+}
+
+func (s spanAnnotator) wroteHeaders() {
+	s.sp.Annotate(nil, "WroteHeaders")
+}
+
+func (s spanAnnotator) wait100Continue() {
+	s.sp.Annotate(nil, "Wait100Continue")
+}
+
+func (s spanAnnotator) wroteRequest(info httptrace.WroteRequestInfo) {
+	var attrs []trace.Attribute
+	if info.Err != nil {
+		attrs = append(attrs,
+			trace.StringAttribute("httptrace.wrote_request.error", info.Err.Error()))
+	}
+	s.sp.Annotate(attrs, "WroteRequest")
+}

vendor/go.opencensus.io/plugin/ochttp/stats.go

@@ -0,0 +1,186 @@
+// Copyright 2018, OpenCensus Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package ochttp
+
+import (
+	"go.opencensus.io/stats"
+	"go.opencensus.io/stats/view"
+	"go.opencensus.io/tag"
+)
+
+// The following client HTTP measures are supported for use in custom views.
+var (
+	ClientRequestCount  = stats.Int64("opencensus.io/http/client/request_count", "Number of HTTP requests started", stats.UnitDimensionless)
+	ClientRequestBytes  = stats.Int64("opencensus.io/http/client/request_bytes", "HTTP request body size if set as ContentLength (uncompressed)", stats.UnitBytes)
+	ClientResponseBytes = stats.Int64("opencensus.io/http/client/response_bytes", "HTTP response body size (uncompressed)", stats.UnitBytes)
+	ClientLatency       = stats.Float64("opencensus.io/http/client/latency", "End-to-end latency", stats.UnitMilliseconds)
+)
+
+// The following server HTTP measures are supported for use in custom views:
+var (
+	ServerRequestCount  = stats.Int64("opencensus.io/http/server/request_count", "Number of HTTP requests started", stats.UnitDimensionless)
+	ServerRequestBytes  = stats.Int64("opencensus.io/http/server/request_bytes", "HTTP request body size if set as ContentLength (uncompressed)", stats.UnitBytes)
+	ServerResponseBytes = stats.Int64("opencensus.io/http/server/response_bytes", "HTTP response body size (uncompressed)", stats.UnitBytes)
+	ServerLatency       = stats.Float64("opencensus.io/http/server/latency", "End-to-end latency", stats.UnitMilliseconds)
+)
+
+// The following tags are applied to stats recorded by this package. Host, Path
+// and Method are applied to all measures. StatusCode is not applied to
+// ClientRequestCount or ServerRequestCount, since it is recorded before the status is known.
+var (
+	// Host is the value of the HTTP Host header.
+	//
+	// The value of this tag can be controlled by the HTTP client, so you need
+	// to watch out for potentially generating high-cardinality labels in your
+	// metrics backend if you use this tag in views.
+	Host, _ = tag.NewKey("http.host")
+
+	// StatusCode is the numeric HTTP response status code,
+	// or "error" if a transport error occurred and no status code was read.
+	StatusCode, _ = tag.NewKey("http.status")
+
+	// Path is the URL path (not including query string) in the request.
+	//
+	// The value of this tag can be controlled by the HTTP client, so you need
+	// to watch out for potentially generating high-cardinality labels in your
+	// metrics backend if you use this tag in views.
+	Path, _ = tag.NewKey("http.path")
+
+	// Method is the HTTP method of the request, capitalized (GET, POST, etc.).
+	Method, _ = tag.NewKey("http.method")
+
+	// KeyServerRoute is a low cardinality string representing the logical
+	// handler of the request. This is usually the pattern registered on the a
+	// ServeMux (or similar string).
+	KeyServerRoute, _ = tag.NewKey("http_server_route")
+)
+
+// Default distributions used by views in this package.
+var (
+	DefaultSizeDistribution    = view.Distribution(0, 1024, 2048, 4096, 16384, 65536, 262144, 1048576, 4194304, 16777216, 67108864, 268435456, 1073741824, 4294967296)
+	DefaultLatencyDistribution = view.Distribution(0, 1, 2, 3, 4, 5, 6, 8, 10, 13, 16, 20, 25, 30, 40, 50, 65, 80, 100, 130, 160, 200, 250, 300, 400, 500, 650, 800, 1000, 2000, 5000, 10000, 20000, 50000, 100000)
+)
+
+// Package ochttp provides some convenience views.
+// You need to register the views for data to actually be collected.
+var (
+	ClientRequestCountView = &view.View{
+		Name:        "opencensus.io/http/client/request_count",
+		Description: "Count of HTTP requests started",
+		Measure:     ClientRequestCount,
+		Aggregation: view.Count(),
+	}
+
+	ClientRequestBytesView = &view.View{
+		Name:        "opencensus.io/http/client/request_bytes",
+		Description: "Size distribution of HTTP request body",
+		Measure:     ClientRequestBytes,
+		Aggregation: DefaultSizeDistribution,
+	}
+
+	ClientResponseBytesView = &view.View{
+		Name:        "opencensus.io/http/client/response_bytes",
+		Description: "Size distribution of HTTP response body",
+		Measure:     ClientResponseBytes,
+		Aggregation: DefaultSizeDistribution,
+	}
+
+	ClientLatencyView = &view.View{
+		Name:        "opencensus.io/http/client/latency",
+		Description: "Latency distribution of HTTP requests",
+		Measure:     ClientLatency,
+		Aggregation: DefaultLatencyDistribution,
+	}
+
+	ClientRequestCountByMethod = &view.View{
+		Name:        "opencensus.io/http/client/request_count_by_method",
+		Description: "Client request count by HTTP method",
+		TagKeys:     []tag.Key{Method},
+		Measure:     ClientRequestCount,
+		Aggregation: view.Count(),
+	}
+
+	ClientResponseCountByStatusCode = &view.View{
+		Name:        "opencensus.io/http/client/response_count_by_status_code",
+		Description: "Client response count by status code",
+		TagKeys:     []tag.Key{StatusCode},
+		Measure:     ClientLatency,
+		Aggregation: view.Count(),
+	}
+
+	ServerRequestCountView = &view.View{
+		Name:        "opencensus.io/http/server/request_count",
+		Description: "Count of HTTP requests started",
+		Measure:     ServerRequestCount,
+		Aggregation: view.Count(),
+	}
+
+	ServerRequestBytesView = &view.View{
+		Name:        "opencensus.io/http/server/request_bytes",
+		Description: "Size distribution of HTTP request body",
+		Measure:     ServerRequestBytes,
+		Aggregation: DefaultSizeDistribution,
+	}
+
+	ServerResponseBytesView = &view.View{
+		Name:        "opencensus.io/http/server/response_bytes",
+		Description: "Size distribution of HTTP response body",
+		Measure:     ServerResponseBytes,
+		Aggregation: DefaultSizeDistribution,
+	}
+
+	ServerLatencyView = &view.View{
+		Name:        "opencensus.io/http/server/latency",
+		Description: "Latency distribution of HTTP requests",
+		Measure:     ServerLatency,
+		Aggregation: DefaultLatencyDistribution,
+	}
+
+	ServerRequestCountByMethod = &view.View{
+		Name:        "opencensus.io/http/server/request_count_by_method",
+		Description: "Server request count by HTTP method",
+		TagKeys:     []tag.Key{Method},
+		Measure:     ServerRequestCount,
+		Aggregation: view.Count(),
+	}
+
+	ServerResponseCountByStatusCode = &view.View{
+		Name:        "opencensus.io/http/server/response_count_by_status_code",
+		Description: "Server response count by status code",
+		TagKeys:     []tag.Key{StatusCode},
+		Measure:     ServerLatency,
+		Aggregation: view.Count(),
+	}
+)
+
+// DefaultClientViews are the default client views provided by this package.
+var DefaultClientViews = []*view.View{
+	ClientRequestCountView,
+	ClientRequestBytesView,
+	ClientResponseBytesView,
+	ClientLatencyView,
+	ClientRequestCountByMethod,
+	ClientResponseCountByStatusCode,
+}
+
+// DefaultServerViews are the default server views provided by this package.
+var DefaultServerViews = []*view.View{
+	ServerRequestCountView,
+	ServerRequestBytesView,
+	ServerResponseBytesView,
+	ServerLatencyView,
+	ServerRequestCountByMethod,
+	ServerResponseCountByStatusCode,
+}

vendor/go.opencensus.io/plugin/ochttp/trace.go

@@ -0,0 +1,228 @@
+// Copyright 2018, OpenCensus Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package ochttp
+
+import (
+	"io"
+	"net/http"
+	"net/http/httptrace"
+
+	"go.opencensus.io/plugin/ochttp/propagation/b3"
+	"go.opencensus.io/trace"
+	"go.opencensus.io/trace/propagation"
+)
+
+// TODO(jbd): Add godoc examples.
+
+var defaultFormat propagation.HTTPFormat = &b3.HTTPFormat{}
+
+// Attributes recorded on the span for the requests.
+// Only trace exporters will need them.
+const (
+	HostAttribute       = "http.host"
+	MethodAttribute     = "http.method"
+	PathAttribute       = "http.path"
+	UserAgentAttribute  = "http.user_agent"
+	StatusCodeAttribute = "http.status_code"
+)
+
+type traceTransport struct {
+	base           http.RoundTripper
+	startOptions   trace.StartOptions
+	format         propagation.HTTPFormat
+	formatSpanName func(*http.Request) string
+	newClientTrace func(*http.Request, *trace.Span) *httptrace.ClientTrace
+}
+
+// TODO(jbd): Add message events for request and response size.
+
+// RoundTrip creates a trace.Span and inserts it into the outgoing request's headers.
+// The created span can follow a parent span, if a parent is presented in
+// the request's context.
+func (t *traceTransport) RoundTrip(req *http.Request) (*http.Response, error) {
+	name := t.formatSpanName(req)
+	// TODO(jbd): Discuss whether we want to prefix
+	// outgoing requests with Sent.
+	ctx, span := trace.StartSpan(req.Context(), name,
+		trace.WithSampler(t.startOptions.Sampler),
+		trace.WithSpanKind(trace.SpanKindClient))
+
+	if t.newClientTrace != nil {
+		req = req.WithContext(httptrace.WithClientTrace(ctx, t.newClientTrace(req, span)))
+	} else {
+		req = req.WithContext(ctx)
+	}
+
+	if t.format != nil {
+		// SpanContextToRequest will modify its Request argument, which is
+		// contrary to the contract for http.RoundTripper, so we need to
+		// pass it a copy of the Request.
+		// However, the Request struct itself was already copied by
+		// the WithContext calls above and so we just need to copy the header.
+		header := make(http.Header)
+		for k, v := range req.Header {
+			header[k] = v
+		}
+		req.Header = header
+		t.format.SpanContextToRequest(span.SpanContext(), req)
+	}
+
+	span.AddAttributes(requestAttrs(req)...)
+	resp, err := t.base.RoundTrip(req)
+	if err != nil {
+		span.SetStatus(trace.Status{Code: trace.StatusCodeUnknown, Message: err.Error()})
+		span.End()
+		return resp, err
+	}
+
+	span.AddAttributes(responseAttrs(resp)...)
+	span.SetStatus(TraceStatus(resp.StatusCode, resp.Status))
+
+	// span.End() will be invoked after
+	// a read from resp.Body returns io.EOF or when
+	// resp.Body.Close() is invoked.
+	resp.Body = &bodyTracker{rc: resp.Body, span: span}
+	return resp, err
+}
+
+// bodyTracker wraps a response.Body and invokes
+// trace.EndSpan on encountering io.EOF on reading
+// the body of the original response.
+type bodyTracker struct {
+	rc   io.ReadCloser
+	span *trace.Span
+}
+
+var _ io.ReadCloser = (*bodyTracker)(nil)
+
+func (bt *bodyTracker) Read(b []byte) (int, error) {
+	n, err := bt.rc.Read(b)
+
+	switch err {
+	case nil:
+		return n, nil
+	case io.EOF:
+		bt.span.End()
+	default:
+		// For all other errors, set the span status
+		bt.span.SetStatus(trace.Status{
+			// Code 2 is the error code for Internal server error.
+			Code:    2,
+			Message: err.Error(),
+		})
+	}
+	return n, err
+}
+
+func (bt *bodyTracker) Close() error {
+	// Invoking endSpan on Close will help catch the cases
+	// in which a read returned a non-nil error, we set the
+	// span status but didn't end the span.
+	bt.span.End()
+	return bt.rc.Close()
+}
+
+// CancelRequest cancels an in-flight request by closing its connection.
+func (t *traceTransport) CancelRequest(req *http.Request) {
+	type canceler interface {
+		CancelRequest(*http.Request)
+	}
+	if cr, ok := t.base.(canceler); ok {
+		cr.CancelRequest(req)
+	}
+}
+
+func spanNameFromURL(req *http.Request) string {
+	return req.URL.Path
+}
+
+func requestAttrs(r *http.Request) []trace.Attribute {
+	return []trace.Attribute{
+		trace.StringAttribute(PathAttribute, r.URL.Path),
+		trace.StringAttribute(HostAttribute, r.URL.Host),
+		trace.StringAttribute(MethodAttribute, r.Method),
+		trace.StringAttribute(UserAgentAttribute, r.UserAgent()),
+	}
+}
+
+func responseAttrs(resp *http.Response) []trace.Attribute {
+	return []trace.Attribute{
+		trace.Int64Attribute(StatusCodeAttribute, int64(resp.StatusCode)),
+	}
+}
+
+// TraceStatus is a utility to convert the HTTP status code to a trace.Status that
+// represents the outcome as closely as possible.
+func TraceStatus(httpStatusCode int, statusLine string) trace.Status {
+	var code int32
+	if httpStatusCode < 200 || httpStatusCode >= 400 {
+		code = trace.StatusCodeUnknown
+	}
+	switch httpStatusCode {
+	case 499:
+		code = trace.StatusCodeCancelled
+	case http.StatusBadRequest:
+		code = trace.StatusCodeInvalidArgument
+	case http.StatusGatewayTimeout:
+		code = trace.StatusCodeDeadlineExceeded
+	case http.StatusNotFound:
+		code = trace.StatusCodeNotFound
+	case http.StatusForbidden:
+		code = trace.StatusCodePermissionDenied
+	case http.StatusUnauthorized: // 401 is actually unauthenticated.
+		code = trace.StatusCodeUnauthenticated
+	case http.StatusTooManyRequests:
+		code = trace.StatusCodeResourceExhausted
+	case http.StatusNotImplemented:
+		code = trace.StatusCodeUnimplemented
+	case http.StatusServiceUnavailable:
+		code = trace.StatusCodeUnavailable
+	case http.StatusOK:
+		code = trace.StatusCodeOK
+	}
+	return trace.Status{Code: code, Message: codeToStr[code]}
+}
+
+var codeToStr = map[int32]string{
+	trace.StatusCodeOK:                 `OK`,
+	trace.StatusCodeCancelled:          `CANCELLED`,
+	trace.StatusCodeUnknown:            `UNKNOWN`,
+	trace.StatusCodeInvalidArgument:    `INVALID_ARGUMENT`,
+	trace.StatusCodeDeadlineExceeded:   `DEADLINE_EXCEEDED`,
+	trace.StatusCodeNotFound:           `NOT_FOUND`,
+	trace.StatusCodeAlreadyExists:      `ALREADY_EXISTS`,
+	trace.StatusCodePermissionDenied:   `PERMISSION_DENIED`,
+	trace.StatusCodeResourceExhausted:  `RESOURCE_EXHAUSTED`,
+	trace.StatusCodeFailedPrecondition: `FAILED_PRECONDITION`,
+	trace.StatusCodeAborted:            `ABORTED`,
+	trace.StatusCodeOutOfRange:         `OUT_OF_RANGE`,
+	trace.StatusCodeUnimplemented:      `UNIMPLEMENTED`,
+	trace.StatusCodeInternal:           `INTERNAL`,
+	trace.StatusCodeUnavailable:        `UNAVAILABLE`,
+	trace.StatusCodeDataLoss:           `DATA_LOSS`,
+	trace.StatusCodeUnauthenticated:    `UNAUTHENTICATED`,
+}
+
+func isHealthEndpoint(path string) bool {
+	// Health checking is pretty frequent and
+	// traces collected for health endpoints
+	// can be extremely noisy and expensive.
+	// Disable canonical health checking endpoints
+	// like /healthz and /_ah/health for now.
+	if path == "/healthz" || path == "/_ah/health" {
+		return true
+	}
+	return false
+}

vendor/go.opencensus.io/stats/doc.go

@@ -0,0 +1,55 @@
+// Copyright 2017, OpenCensus Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+/*
+Package stats contains support for OpenCensus stats recording.
+
+OpenCensus allows users to create typed measures, record measurements,
+aggregate the collected data, and export the aggregated data.
+
+Measures
+
+A measure represents a type of metric to be tracked and recorded.
+For example, latency, request Mb/s, and response Mb/s are measures
+to collect from a server.
+
+Each measure needs to be registered before being used. Measure
+constructors such as Int64 and Float64 automatically
+register the measure by the given name. Each registered measure needs
+to be unique by name. Measures also have a description and a unit.
+
+Libraries can define and export measures for their end users to
+create views and collect instrumentation data.
+
+Recording measurements
+
+Measurement is a data point to be collected for a measure. For example,
+for a latency (ms) measure, 100 is a measurement that represents a 100ms
+latency event. Users collect data points on the existing measures with
+the current context. Tags from the current context are recorded with the
+measurements if they are any.
+
+Recorded measurements are dropped immediately if user is not aggregating
+them via views. Users don't necessarily need to conditionally enable/disable
+recording to reduce cost. Recording of measurements is cheap.
+
+Libraries can always record measurements, and end-users can later decide
+on which measurements they want to collect by registering views. This allows
+libraries to turn on the instrumentation by default.
+*/
+package stats // import "go.opencensus.io/stats"
+
+// TODO(acetechnologist): Add a link to the language independent OpenCensus
+// spec when it is available.

vendor/go.opencensus.io/stats/internal/record.go

@@ -0,0 +1,25 @@
+// Copyright 2018, OpenCensus Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package internal
+
+import (
+	"go.opencensus.io/tag"
+)
+
+// DefaultRecorder will be called for each Record call.
+var DefaultRecorder func(*tag.Map, interface{})
+
+// SubscriptionReporter reports when a view subscribed with a measure.
+var SubscriptionReporter func(measure string)

vendor/go.opencensus.io/stats/internal/validation.go

@@ -0,0 +1,28 @@
+// Copyright 2018, OpenCensus Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package internal // import "go.opencensus.io/stats/internal"
+
+const (
+	MaxNameLength = 255
+)
+
+func IsPrintable(str string) bool {
+	for _, r := range str {
+		if !(r >= ' ' && r <= '~') {
+			return false
+		}
+	}
+	return true
+}

vendor/go.opencensus.io/stats/measure.go

@@ -0,0 +1,123 @@
+// Copyright 2017, OpenCensus Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+package stats
+
+import (
+	"sync"
+	"sync/atomic"
+)
+
+// Measure represents a single numeric value to be tracked and recorded.
+// For example, latency, request bytes, and response bytes could be measures
+// to collect from a server.
+//
+// Measures by themselves have no outside effects. In order to be exported,
+// the measure needs to be used in a View. If no Views are defined over a
+// measure, there is very little cost in recording it.
+type Measure interface {
+	// Name returns the name of this measure.
+	//
+	// Measure names are globally unique (among all libraries linked into your program).
+	// We recommend prefixing the measure name with a domain name relevant to your
+	// project or application.
+	//
+	// Measure names are never sent over the wire or exported to backends.
+	// They are only used to create Views.
+	Name() string
+
+	// Description returns the human-readable description of this measure.
+	Description() string
+
+	// Unit returns the units for the values this measure takes on.
+	//
+	// Units are encoded according to the case-sensitive abbreviations from the
+	// Unified Code for Units of Measure: http://unitsofmeasure.org/ucum.html
+	Unit() string
+}
+
+// measureDescriptor is the untyped descriptor associated with each measure.
+// Int64Measure and Float64Measure wrap measureDescriptor to provide typed
+// recording APIs.
+// Two Measures with the same name will have the same measureDescriptor.
+type measureDescriptor struct {
+	subs int32 // access atomically
+
+	name        string
+	description string
+	unit        string
+}
+
+func (m *measureDescriptor) subscribe() {
+	atomic.StoreInt32(&m.subs, 1)
+}
+
+func (m *measureDescriptor) subscribed() bool {
+	return atomic.LoadInt32(&m.subs) == 1
+}
+
+// Name returns the name of the measure.
+func (m *measureDescriptor) Name() string {
+	return m.name
+}
+
+// Description returns the description of the measure.
+func (m *measureDescriptor) Description() string {
+	return m.description
+}
+
+// Unit returns the unit of the measure.
+func (m *measureDescriptor) Unit() string {
+	return m.unit
+}
+
+var (
+	mu       sync.RWMutex
+	measures = make(map[string]*measureDescriptor)
+)
+
+func registerMeasureHandle(name, desc, unit string) *measureDescriptor {
+	mu.Lock()
+	defer mu.Unlock()
+
+	if stored, ok := measures[name]; ok {
+		return stored
+	}
+	m := &measureDescriptor{
+		name:        name,
+		description: desc,
+		unit:        unit,
+	}
+	measures[name] = m
+	return m
+}
+
+// Measurement is the numeric value measured when recording stats. Each measure
+// provides methods to create measurements of their kind. For example, Int64Measure
+// provides M to convert an int64 into a measurement.
+type Measurement struct {
+	v float64
+	m *measureDescriptor
+}
+
+// Value returns the value of the Measurement as a float64.
+func (m Measurement) Value() float64 {
+	return m.v
+}
+
+// Measure returns the Measure from which this Measurement was created.
+func (m Measurement) Measure() Measure {
+	return m.m
+}

vendor/go.opencensus.io/stats/measure_float64.go

@@ -0,0 +1,36 @@
+// Copyright 2017, OpenCensus Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+package stats
+
+// Float64Measure is a measure for float64 values.
+type Float64Measure struct {
+	*measureDescriptor
+}
+
+// M creates a new float64 measurement.
+// Use Record to record measurements.
+func (m *Float64Measure) M(v float64) Measurement {
+	return Measurement{m: m.measureDescriptor, v: v}
+}
+
+// Float64 creates a new measure for float64 values.
+//
+// See the documentation for interface Measure for more guidance on the
+// parameters of this function.
+func Float64(name, description, unit string) *Float64Measure {
+	mi := registerMeasureHandle(name, description, unit)
+	return &Float64Measure{mi}
+}

vendor/go.opencensus.io/stats/measure_int64.go

@@ -0,0 +1,36 @@
+// Copyright 2017, OpenCensus Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+package stats
+
+// Int64Measure is a measure for int64 values.
+type Int64Measure struct {
+	*measureDescriptor
+}
+
+// M creates a new int64 measurement.
+// Use Record to record measurements.
+func (m *Int64Measure) M(v int64) Measurement {
+	return Measurement{m: m.measureDescriptor, v: float64(v)}
+}
+
+// Int64 creates a new measure for int64 values.
+//
+// See the documentation for interface Measure for more guidance on the
+// parameters of this function.
+func Int64(name, description, unit string) *Int64Measure {
+	mi := registerMeasureHandle(name, description, unit)
+	return &Int64Measure{mi}
+}

vendor/go.opencensus.io/stats/record.go

@@ -0,0 +1,54 @@
+// Copyright 2018, OpenCensus Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+package stats
+
+import (
+	"context"
+
+	"go.opencensus.io/stats/internal"
+	"go.opencensus.io/tag"
+)
+
+func init() {
+	internal.SubscriptionReporter = func(measure string) {
+		mu.Lock()
+		measures[measure].subscribe()
+		mu.Unlock()
+	}
+}
+
+// Record records one or multiple measurements with the same context at once.
+// If there are any tags in the context, measurements will be tagged with them.
+func Record(ctx context.Context, ms ...Measurement) {
+	recorder := internal.DefaultRecorder
+	if recorder == nil {
+		return
+	}
+	if len(ms) == 0 {
+		return
+	}
+	record := false
+	for _, m := range ms {
+		if m.m.subscribed() {
+			record = true
+			break
+		}
+	}
+	if !record {
+		return
+	}
+	recorder(tag.FromContext(ctx), ms)
+}

vendor/go.opencensus.io/stats/units.go

@@ -0,0 +1,25 @@
+// Copyright 2018, OpenCensus Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+package stats
+
+// Units are encoded according to the case-sensitive abbreviations from the
+// Unified Code for Units of Measure: http://unitsofmeasure.org/ucum.html
+const (
+	UnitNone          = "1" // Deprecated: Use UnitDimensionless.
+	UnitDimensionless = "1"
+	UnitBytes         = "By"
+	UnitMilliseconds  = "ms"
+)

vendor/go.opencensus.io/stats/view/aggregation.go

@@ -0,0 +1,120 @@
+// Copyright 2017, OpenCensus Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+package view
+
+// AggType represents the type of aggregation function used on a View.
+type AggType int
+
+// All available aggregation types.
+const (
+	AggTypeNone         AggType = iota // no aggregation; reserved for future use.
+	AggTypeCount                       // the count aggregation, see Count.
+	AggTypeSum                         // the sum aggregation, see Sum.
+	AggTypeDistribution                // the distribution aggregation, see Distribution.
+	AggTypeLastValue                   // the last value aggregation, see LastValue.
+)
+
+func (t AggType) String() string {
+	return aggTypeName[t]
+}
+
+var aggTypeName = map[AggType]string{
+	AggTypeNone:         "None",
+	AggTypeCount:        "Count",
+	AggTypeSum:          "Sum",
+	AggTypeDistribution: "Distribution",
+	AggTypeLastValue:    "LastValue",
+}
+
+// Aggregation represents a data aggregation method. Use one of the functions:
+// Count, Sum, or Distribution to construct an Aggregation.
+type Aggregation struct {
+	Type    AggType   // Type is the AggType of this Aggregation.
+	Buckets []float64 // Buckets are the bucket endpoints if this Aggregation represents a distribution, see Distribution.
+
+	newData func() AggregationData
+}
+
+var (
+	aggCount = &Aggregation{
+		Type: AggTypeCount,
+		newData: func() AggregationData {
+			return &CountData{}
+		},
+	}
+	aggSum = &Aggregation{
+		Type: AggTypeSum,
+		newData: func() AggregationData {
+			return &SumData{}
+		},
+	}
+)
+
+// Count indicates that data collected and aggregated
+// with this method will be turned into a count value.
+// For example, total number of accepted requests can be
+// aggregated by using Count.
+func Count() *Aggregation {
+	return aggCount
+}
+
+// Sum indicates that data collected and aggregated
+// with this method will be summed up.
+// For example, accumulated request bytes can be aggregated by using
+// Sum.
+func Sum() *Aggregation {
+	return aggSum
+}
+
+// Distribution indicates that the desired aggregation is
+// a histogram distribution.
+//
+// An distribution aggregation may contain a histogram of the values in the
+// population. The bucket boundaries for that histogram are described
+// by the bounds. This defines len(bounds)+1 buckets.
+//
+// If len(bounds) >= 2 then the boundaries for bucket index i are:
+//
+//     [-infinity, bounds[i]) for i = 0
+//     [bounds[i-1], bounds[i]) for 0 < i < length
+//     [bounds[i-1], +infinity) for i = length
+//
+// If len(bounds) is 0 then there is no histogram associated with the
+// distribution. There will be a single bucket with boundaries
+// (-infinity, +infinity).
+//
+// If len(bounds) is 1 then there is no finite buckets, and that single
+// element is the common boundary of the overflow and underflow buckets.
+func Distribution(bounds ...float64) *Aggregation {
+	return &Aggregation{
+		Type:    AggTypeDistribution,
+		Buckets: bounds,
+		newData: func() AggregationData {
+			return newDistributionData(bounds)
+		},
+	}
+}
+
+// LastValue only reports the last value recorded using this
+// aggregation. All other measurements will be dropped.
+func LastValue() *Aggregation {
+	return &Aggregation{
+		Type: AggTypeLastValue,
+		newData: func() AggregationData {
+			return &LastValueData{}
+		},
+	}
+}

vendor/go.opencensus.io/stats/view/aggregation_data.go

@@ -0,0 +1,207 @@
+// Copyright 2017, OpenCensus Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+package view
+
+import (
+	"math"
+)
+
+// AggregationData represents an aggregated value from a collection.
+// They are reported on the view data during exporting.
+// Mosts users won't directly access aggregration data.
+type AggregationData interface {
+	isAggregationData() bool
+	addSample(v float64)
+	clone() AggregationData
+	equal(other AggregationData) bool
+}
+
+const epsilon = 1e-9
+
+// CountData is the aggregated data for the Count aggregation.
+// A count aggregation processes data and counts the recordings.
+//
+// Most users won't directly access count data.
+type CountData struct {
+	Value int64
+}
+
+func (a *CountData) isAggregationData() bool { return true }
+
+func (a *CountData) addSample(v float64) {
+	a.Value = a.Value + 1
+}
+
+func (a *CountData) clone() AggregationData {
+	return &CountData{Value: a.Value}
+}
+
+func (a *CountData) equal(other AggregationData) bool {
+	a2, ok := other.(*CountData)
+	if !ok {
+		return false
+	}
+
+	return a.Value == a2.Value
+}
+
+// SumData is the aggregated data for the Sum aggregation.
+// A sum aggregation processes data and sums up the recordings.
+//
+// Most users won't directly access sum data.
+type SumData struct {
+	Value float64
+}
+
+func (a *SumData) isAggregationData() bool { return true }
+
+func (a *SumData) addSample(f float64) {
+	a.Value += f
+}
+
+func (a *SumData) clone() AggregationData {
+	return &SumData{Value: a.Value}
+}
+
+func (a *SumData) equal(other AggregationData) bool {
+	a2, ok := other.(*SumData)
+	if !ok {
+		return false
+	}
+	return math.Pow(a.Value-a2.Value, 2) < epsilon
+}
+
+// DistributionData is the aggregated data for the
+// Distribution aggregation.
+//
+// Most users won't directly access distribution data.
+type DistributionData struct {
+	Count           int64     // number of data points aggregated
+	Min             float64   // minimum value in the distribution
+	Max             float64   // max value in the distribution
+	Mean            float64   // mean of the distribution
+	SumOfSquaredDev float64   // sum of the squared deviation from the mean
+	CountPerBucket  []int64   // number of occurrences per bucket
+	bounds          []float64 // histogram distribution of the values
+}
+
+func newDistributionData(bounds []float64) *DistributionData {
+	return &DistributionData{
+		CountPerBucket: make([]int64, len(bounds)+1),
+		bounds:         bounds,
+		Min:            math.MaxFloat64,
+		Max:            math.SmallestNonzeroFloat64,
+	}
+}
+
+// Sum returns the sum of all samples collected.
+func (a *DistributionData) Sum() float64 { return a.Mean * float64(a.Count) }
+
+func (a *DistributionData) variance() float64 {
+	if a.Count <= 1 {
+		return 0
+	}
+	return a.SumOfSquaredDev / float64(a.Count-1)
+}
+
+func (a *DistributionData) isAggregationData() bool { return true }
+
+func (a *DistributionData) addSample(f float64) {
+	if f < a.Min {
+		a.Min = f
+	}
+	if f > a.Max {
+		a.Max = f
+	}
+	a.Count++
+	a.incrementBucketCount(f)
+
+	if a.Count == 1 {
+		a.Mean = f
+		return
+	}
+
+	oldMean := a.Mean
+	a.Mean = a.Mean + (f-a.Mean)/float64(a.Count)
+	a.SumOfSquaredDev = a.SumOfSquaredDev + (f-oldMean)*(f-a.Mean)
+}
+
+func (a *DistributionData) incrementBucketCount(f float64) {
+	if len(a.bounds) == 0 {
+		a.CountPerBucket[0]++
+		return
+	}
+
+	for i, b := range a.bounds {
+		if f < b {
+			a.CountPerBucket[i]++
+			return
+		}
+	}
+	a.CountPerBucket[len(a.bounds)]++
+}
+
+func (a *DistributionData) clone() AggregationData {
+	counts := make([]int64, len(a.CountPerBucket))
+	copy(counts, a.CountPerBucket)
+	c := *a
+	c.CountPerBucket = counts
+	return &c
+}
+
+func (a *DistributionData) equal(other AggregationData) bool {
+	a2, ok := other.(*DistributionData)
+	if !ok {
+		return false
+	}
+	if a2 == nil {
+		return false
+	}
+	if len(a.CountPerBucket) != len(a2.CountPerBucket) {
+		return false
+	}
+	for i := range a.CountPerBucket {
+		if a.CountPerBucket[i] != a2.CountPerBucket[i] {
+			return false
+		}
+	}
+	return a.Count == a2.Count && a.Min == a2.Min && a.Max == a2.Max && math.Pow(a.Mean-a2.Mean, 2) < epsilon && math.Pow(a.variance()-a2.variance(), 2) < epsilon
+}
+
+// LastValueData returns the last value recorded for LastValue aggregation.
+type LastValueData struct {
+	Value float64
+}
+
+func (l *LastValueData) isAggregationData() bool {
+	return true
+}
+
+func (l *LastValueData) addSample(v float64) {
+	l.Value = v
+}
+
+func (l *LastValueData) clone() AggregationData {
+	return &LastValueData{l.Value}
+}
+
+func (l *LastValueData) equal(other AggregationData) bool {
+	a2, ok := other.(*LastValueData)
+	if !ok {
+		return false
+	}
+	return l.Value == a2.Value
+}

vendor/go.opencensus.io/stats/view/collector.go

@@ -0,0 +1,85 @@
+// Copyright 2017, OpenCensus Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+package view
+
+import (
+	"sort"
+
+	"go.opencensus.io/internal/tagencoding"
+	"go.opencensus.io/tag"
+)
+
+type collector struct {
+	// signatures holds the aggregations values for each unique tag signature
+	// (values for all keys) to its aggregator.
+	signatures map[string]AggregationData
+	// Aggregation is the description of the aggregation to perform for this
+	// view.
+	a *Aggregation
+}
+
+func (c *collector) addSample(s string, v float64) {
+	aggregator, ok := c.signatures[s]
+	if !ok {
+		aggregator = c.a.newData()
+		c.signatures[s] = aggregator
+	}
+	aggregator.addSample(v)
+}
+
+// collectRows returns a snapshot of the collected Row values.
+func (c *collector) collectedRows(keys []tag.Key) []*Row {
+	rows := make([]*Row, 0, len(c.signatures))
+	for sig, aggregator := range c.signatures {
+		tags := decodeTags([]byte(sig), keys)
+		row := &Row{Tags: tags, Data: aggregator.clone()}
+		rows = append(rows, row)
+	}
+	return rows
+}
+
+func (c *collector) clearRows() {
+	c.signatures = make(map[string]AggregationData)
+}
+
+// encodeWithKeys encodes the map by using values
+// only associated with the keys provided.
+func encodeWithKeys(m *tag.Map, keys []tag.Key) []byte {
+	vb := &tagencoding.Values{
+		Buffer: make([]byte, len(keys)),
+	}
+	for _, k := range keys {
+		v, _ := m.Value(k)
+		vb.WriteValue([]byte(v))
+	}
+	return vb.Bytes()
+}
+
+// decodeTags decodes tags from the buffer and
+// orders them by the keys.
+func decodeTags(buf []byte, keys []tag.Key) []tag.Tag {
+	vb := &tagencoding.Values{Buffer: buf}
+	var tags []tag.Tag
+	for _, k := range keys {
+		v := vb.ReadValue()
+		if v != nil {
+			tags = append(tags, tag.Tag{Key: k, Value: string(v)})
+		}
+	}
+	vb.ReadIndex = 0
+	sort.Slice(tags, func(i, j int) bool { return tags[i].Key.Name() < tags[j].Key.Name() })
+	return tags
+}

vendor/go.opencensus.io/stats/view/doc.go

@@ -0,0 +1,47 @@
+// Copyright 2017, OpenCensus Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+// Package view contains support for collecting and exposing aggregates over stats.
+//
+// In order to collect measurements, views need to be defined and registered.
+// A view allows recorded measurements to be filtered and aggregated.
+//
+// All recorded measurements can be grouped by a list of tags.
+//
+// OpenCensus provides several aggregation methods: Count, Distribution and Sum.
+//
+// Count only counts the number of measurement points recorded.
+// Distribution provides statistical summary of the aggregated data by counting
+// how many recorded measurements fall into each bucket.
+// Sum adds up the measurement values.
+// LastValue just keeps track of the most recently recorded measurement value.
+// All aggregations are cumulative.
+//
+// Views can be registerd and unregistered at any time during program execution.
+//
+// Libraries can define views but it is recommended that in most cases registering
+// views be left up to applications.
+//
+// Exporting
+//
+// Collected and aggregated data can be exported to a metric collection
+// backend by registering its exporter.
+//
+// Multiple exporters can be registered to upload the data to various
+// different back ends.
+package view // import "go.opencensus.io/stats/view"
+
+// TODO(acetechnologist): Add a link to the language independent OpenCensus
+// spec when it is available.

vendor/go.opencensus.io/stats/view/export.go

@@ -0,0 +1,58 @@
+// Copyright 2017, OpenCensus Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package view
+
+import "sync"
+
+var (
+	exportersMu sync.RWMutex // guards exporters
+	exporters   = make(map[Exporter]struct{})
+)
+
+// Exporter exports the collected records as view data.
+//
+// The ExportView method should return quickly; if an
+// Exporter takes a significant amount of time to
+// process a Data, that work should be done on another goroutine.
+//
+// It is safe to assume that ExportView will not be called concurrently from
+// multiple goroutines.
+//
+// The Data should not be modified.
+type Exporter interface {
+	ExportView(viewData *Data)
+}
+
+// RegisterExporter registers an exporter.
+// Collected data will be reported via all the
+// registered exporters. Once you no longer
+// want data to be exported, invoke UnregisterExporter
+// with the previously registered exporter.
+//
+// Binaries can register exporters, libraries shouldn't register exporters.
+func RegisterExporter(e Exporter) {
+	exportersMu.Lock()
+	defer exportersMu.Unlock()
+
+	exporters[e] = struct{}{}
+}
+
+// UnregisterExporter unregisters an exporter.
+func UnregisterExporter(e Exporter) {
+	exportersMu.Lock()
+	defer exportersMu.Unlock()
+
+	delete(exporters, e)
+}

vendor/go.opencensus.io/stats/view/view.go

@@ -0,0 +1,183 @@
+// Copyright 2017, OpenCensus Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+package view
+
+import (
+	"bytes"
+	"fmt"
+	"reflect"
+	"sort"
+	"sync/atomic"
+	"time"
+
+	"go.opencensus.io/stats"
+	"go.opencensus.io/stats/internal"
+	"go.opencensus.io/tag"
+)
+
+// View allows users to aggregate the recorded stats.Measurements.
+// Views need to be passed to the Register function to be before data will be
+// collected and sent to Exporters.
+type View struct {
+	Name        string // Name of View. Must be unique. If unset, will default to the name of the Measure.
+	Description string // Description is a human-readable description for this view.
+
+	// TagKeys are the tag keys describing the grouping of this view.
+	// A single Row will be produced for each combination of associated tag values.
+	TagKeys []tag.Key
+
+	// Measure is a stats.Measure to aggregate in this view.
+	Measure stats.Measure
+
+	// Aggregation is the aggregation function tp apply to the set of Measurements.
+	Aggregation *Aggregation
+}
+
+// WithName returns a copy of the View with a new name. This is useful for
+// renaming views to cope with limitations placed on metric names by various
+// backends.
+func (v *View) WithName(name string) *View {
+	vNew := *v
+	vNew.Name = name
+	return &vNew
+}
+
+// same compares two views and returns true if they represent the same aggregation.
+func (v *View) same(other *View) bool {
+	if v == other {
+		return true
+	}
+	if v == nil {
+		return false
+	}
+	return reflect.DeepEqual(v.Aggregation, other.Aggregation) &&
+		v.Measure.Name() == other.Measure.Name()
+}
+
+// canonicalize canonicalizes v by setting explicit
+// defaults for Name and Description and sorting the TagKeys
+func (v *View) canonicalize() error {
+	if v.Measure == nil {
+		return fmt.Errorf("cannot register view %q: measure not set", v.Name)
+	}
+	if v.Aggregation == nil {
+		return fmt.Errorf("cannot register view %q: aggregation not set", v.Name)
+	}
+	if v.Name == "" {
+		v.Name = v.Measure.Name()
+	}
+	if v.Description == "" {
+		v.Description = v.Measure.Description()
+	}
+	if err := checkViewName(v.Name); err != nil {
+		return err
+	}
+	sort.Slice(v.TagKeys, func(i, j int) bool {
+		return v.TagKeys[i].Name() < v.TagKeys[j].Name()
+	})
+	return nil
+}
+
+// viewInternal is the internal representation of a View.
+type viewInternal struct {
+	view       *View  // view is the canonicalized View definition associated with this view.
+	subscribed uint32 // 1 if someone is subscribed and data need to be exported, use atomic to access
+	collector  *collector
+}
+
+func newViewInternal(v *View) (*viewInternal, error) {
+	return &viewInternal{
+		view:      v,
+		collector: &collector{make(map[string]AggregationData), v.Aggregation},
+	}, nil
+}
+
+func (v *viewInternal) subscribe() {
+	atomic.StoreUint32(&v.subscribed, 1)
+}
+
+func (v *viewInternal) unsubscribe() {
+	atomic.StoreUint32(&v.subscribed, 0)
+}
+
+// isSubscribed returns true if the view is exporting
+// data by subscription.
+func (v *viewInternal) isSubscribed() bool {
+	return atomic.LoadUint32(&v.subscribed) == 1
+}
+
+func (v *viewInternal) clearRows() {
+	v.collector.clearRows()
+}
+
+func (v *viewInternal) collectedRows() []*Row {
+	return v.collector.collectedRows(v.view.TagKeys)
+}
+
+func (v *viewInternal) addSample(m *tag.Map, val float64) {
+	if !v.isSubscribed() {
+		return
+	}
+	sig := string(encodeWithKeys(m, v.view.TagKeys))
+	v.collector.addSample(sig, val)
+}
+
+// A Data is a set of rows about usage of the single measure associated
+// with the given view. Each row is specific to a unique set of tags.
+type Data struct {
+	View       *View
+	Start, End time.Time
+	Rows       []*Row
+}
+
+// Row is the collected value for a specific set of key value pairs a.k.a tags.
+type Row struct {
+	Tags []tag.Tag
+	Data AggregationData
+}
+
+func (r *Row) String() string {
+	var buffer bytes.Buffer
+	buffer.WriteString("{ ")
+	buffer.WriteString("{ ")
+	for _, t := range r.Tags {
+		buffer.WriteString(fmt.Sprintf("{%v %v}", t.Key.Name(), t.Value))
+	}
+	buffer.WriteString(" }")
+	buffer.WriteString(fmt.Sprintf("%v", r.Data))
+	buffer.WriteString(" }")
+	return buffer.String()
+}
+
+// Equal returns true if both rows are equal. Tags are expected to be ordered
+// by the key name. Even both rows have the same tags but the tags appear in
+// different orders it will return false.
+func (r *Row) Equal(other *Row) bool {
+	if r == other {
+		return true
+	}
+	return reflect.DeepEqual(r.Tags, other.Tags) && r.Data.equal(other.Data)
+}
+
+func checkViewName(name string) error {
+	if len(name) > internal.MaxNameLength {
+		return fmt.Errorf("view name cannot be larger than %v", internal.MaxNameLength)
+	}
+	if !internal.IsPrintable(name) {
+		return fmt.Errorf("view name needs to be an ASCII string")
+	}
+	return nil
+}

vendor/go.opencensus.io/stats/view/worker.go

@@ -0,0 +1,227 @@
+// Copyright 2017, OpenCensus Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+package view
+
+import (
+	"fmt"
+	"time"
+
+	"go.opencensus.io/stats"
+	"go.opencensus.io/stats/internal"
+	"go.opencensus.io/tag"
+)
+
+func init() {
+	defaultWorker = newWorker()
+	go defaultWorker.start()
+	internal.DefaultRecorder = record
+}
+
+type measureRef struct {
+	measure string
+	views   map[*viewInternal]struct{}
+}
+
+type worker struct {
+	measures   map[string]*measureRef
+	views      map[string]*viewInternal
+	startTimes map[*viewInternal]time.Time
+
+	timer      *time.Ticker
+	c          chan command
+	quit, done chan bool
+}
+
+var defaultWorker *worker
+
+var defaultReportingDuration = 10 * time.Second
+
+// Find returns a registered view associated with this name.
+// If no registered view is found, nil is returned.
+func Find(name string) (v *View) {
+	req := &getViewByNameReq{
+		name: name,
+		c:    make(chan *getViewByNameResp),
+	}
+	defaultWorker.c <- req
+	resp := <-req.c
+	return resp.v
+}
+
+// Register begins collecting data for the given views.
+// Once a view is registered, it reports data to the registered exporters.
+func Register(views ...*View) error {
+	for _, v := range views {
+		if err := v.canonicalize(); err != nil {
+			return err
+		}
+	}
+	req := &registerViewReq{
+		views: views,
+		err:   make(chan error),
+	}
+	defaultWorker.c <- req
+	return <-req.err
+}
+
+// Unregister the given views. Data will not longer be exported for these views
+// after Unregister returns.
+// It is not necessary to unregister from views you expect to collect for the
+// duration of your program execution.
+func Unregister(views ...*View) {
+	names := make([]string, len(views))
+	for i := range views {
+		names[i] = views[i].Name
+	}
+	req := &unregisterFromViewReq{
+		views: names,
+		done:  make(chan struct{}),
+	}
+	defaultWorker.c <- req
+	<-req.done
+}
+
+// RetrieveData gets a snapshot of the data collected for the the view registered
+// with the given name. It is intended for testing only.
+func RetrieveData(viewName string) ([]*Row, error) {
+	req := &retrieveDataReq{
+		now: time.Now(),
+		v:   viewName,
+		c:   make(chan *retrieveDataResp),
+	}
+	defaultWorker.c <- req
+	resp := <-req.c
+	return resp.rows, resp.err
+}
+
+func record(tags *tag.Map, ms interface{}) {
+	req := &recordReq{
+		tm: tags,
+		ms: ms.([]stats.Measurement),
+	}
+	defaultWorker.c <- req
+}
+
+// SetReportingPeriod sets the interval between reporting aggregated views in
+// the program. If duration is less than or equal to zero, it enables the
+// default behavior.
+//
+// Note: each exporter makes different promises about what the lowest supported
+// duration is. For example, the Stackdriver exporter recommends a value no
+// lower than 1 minute. Consult each exporter per your needs.
+func SetReportingPeriod(d time.Duration) {
+	// TODO(acetechnologist): ensure that the duration d is more than a certain
+	// value. e.g. 1s
+	req := &setReportingPeriodReq{
+		d: d,
+		c: make(chan bool),
+	}
+	defaultWorker.c <- req
+	<-req.c // don't return until the timer is set to the new duration.
+}
+
+func newWorker() *worker {
+	return &worker{
+		measures:   make(map[string]*measureRef),
+		views:      make(map[string]*viewInternal),
+		startTimes: make(map[*viewInternal]time.Time),
+		timer:      time.NewTicker(defaultReportingDuration),
+		c:          make(chan command, 1024),
+		quit:       make(chan bool),
+		done:       make(chan bool),
+	}
+}
+
+func (w *worker) start() {
+	for {
+		select {
+		case cmd := <-w.c:
+			cmd.handleCommand(w)
+		case <-w.timer.C:
+			w.reportUsage(time.Now())
+		case <-w.quit:
+			w.timer.Stop()
+			close(w.c)
+			w.done <- true
+			return
+		}
+	}
+}
+
+func (w *worker) stop() {
+	w.quit <- true
+	<-w.done
+}
+
+func (w *worker) getMeasureRef(name string) *measureRef {
+	if mr, ok := w.measures[name]; ok {
+		return mr
+	}
+	mr := &measureRef{
+		measure: name,
+		views:   make(map[*viewInternal]struct{}),
+	}
+	w.measures[name] = mr
+	return mr
+}
+
+func (w *worker) tryRegisterView(v *View) (*viewInternal, error) {
+	vi, err := newViewInternal(v)
+	if err != nil {
+		return nil, err
+	}
+	if x, ok := w.views[vi.view.Name]; ok {
+		if !x.view.same(vi.view) {
+			return nil, fmt.Errorf("cannot register view %q; a different view with the same name is already registered", v.Name)
+		}
+
+		// the view is already registered so there is nothing to do and the
+		// command is considered successful.
+		return x, nil
+	}
+	w.views[vi.view.Name] = vi
+	ref := w.getMeasureRef(vi.view.Measure.Name())
+	ref.views[vi] = struct{}{}
+	return vi, nil
+}
+
+func (w *worker) reportView(v *viewInternal, now time.Time) {
+	if !v.isSubscribed() {
+		return
+	}
+	rows := v.collectedRows()
+	_, ok := w.startTimes[v]
+	if !ok {
+		w.startTimes[v] = now
+	}
+	viewData := &Data{
+		View:  v.view,
+		Start: w.startTimes[v],
+		End:   time.Now(),
+		Rows:  rows,
+	}
+	exportersMu.Lock()
+	for e := range exporters {
+		e.ExportView(viewData)
+	}
+	exportersMu.Unlock()
+}
+
+func (w *worker) reportUsage(now time.Time) {
+	for _, v := range w.views {
+		w.reportView(v, now)
+	}
+}

vendor/go.opencensus.io/stats/view/worker_commands.go

@@ -0,0 +1,174 @@
+// Copyright 2017, OpenCensus Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+package view
+
+import (
+	"errors"
+	"fmt"
+	"strings"
+	"time"
+
+	"go.opencensus.io/stats"
+	"go.opencensus.io/stats/internal"
+	"go.opencensus.io/tag"
+)
+
+type command interface {
+	handleCommand(w *worker)
+}
+
+// getViewByNameReq is the command to get a view given its name.
+type getViewByNameReq struct {
+	name string
+	c    chan *getViewByNameResp
+}
+
+type getViewByNameResp struct {
+	v *View
+}
+
+func (cmd *getViewByNameReq) handleCommand(w *worker) {
+	v := w.views[cmd.name]
+	if v == nil {
+		cmd.c <- &getViewByNameResp{nil}
+		return
+	}
+	cmd.c <- &getViewByNameResp{v.view}
+}
+
+// registerViewReq is the command to register a view.
+type registerViewReq struct {
+	views []*View
+	err   chan error
+}
+
+func (cmd *registerViewReq) handleCommand(w *worker) {
+	var errstr []string
+	for _, view := range cmd.views {
+		vi, err := w.tryRegisterView(view)
+		if err != nil {
+			errstr = append(errstr, fmt.Sprintf("%s: %v", view.Name, err))
+			continue
+		}
+		internal.SubscriptionReporter(view.Measure.Name())
+		vi.subscribe()
+	}
+	if len(errstr) > 0 {
+		cmd.err <- errors.New(strings.Join(errstr, "\n"))
+	} else {
+		cmd.err <- nil
+	}
+}
+
+// unregisterFromViewReq is the command to unregister to a view. Has no
+// impact on the data collection for client that are pulling data from the
+// library.
+type unregisterFromViewReq struct {
+	views []string
+	done  chan struct{}
+}
+
+func (cmd *unregisterFromViewReq) handleCommand(w *worker) {
+	for _, name := range cmd.views {
+		vi, ok := w.views[name]
+		if !ok {
+			continue
+		}
+
+		// Report pending data for this view before removing it.
+		w.reportView(vi, time.Now())
+
+		vi.unsubscribe()
+		if !vi.isSubscribed() {
+			// this was the last subscription and view is not collecting anymore.
+			// The collected data can be cleared.
+			vi.clearRows()
+		}
+		delete(w.views, name)
+	}
+	cmd.done <- struct{}{}
+}
+
+// retrieveDataReq is the command to retrieve data for a view.
+type retrieveDataReq struct {
+	now time.Time
+	v   string
+	c   chan *retrieveDataResp
+}
+
+type retrieveDataResp struct {
+	rows []*Row
+	err  error
+}
+
+func (cmd *retrieveDataReq) handleCommand(w *worker) {
+	vi, ok := w.views[cmd.v]
+	if !ok {
+		cmd.c <- &retrieveDataResp{
+			nil,
+			fmt.Errorf("cannot retrieve data; view %q is not registered", cmd.v),
+		}
+		return
+	}
+
+	if !vi.isSubscribed() {
+		cmd.c <- &retrieveDataResp{
+			nil,
+			fmt.Errorf("cannot retrieve data; view %q has no subscriptions or collection is not forcibly started", cmd.v),
+		}
+		return
+	}
+	cmd.c <- &retrieveDataResp{
+		vi.collectedRows(),
+		nil,
+	}
+}
+
+// recordReq is the command to record data related to multiple measures
+// at once.
+type recordReq struct {
+	tm *tag.Map
+	ms []stats.Measurement
+}
+
+func (cmd *recordReq) handleCommand(w *worker) {
+	for _, m := range cmd.ms {
+		if (m == stats.Measurement{}) { // not registered
+			continue
+		}
+		ref := w.getMeasureRef(m.Measure().Name())
+		for v := range ref.views {
+			v.addSample(cmd.tm, m.Value())
+		}
+	}
+}
+
+// setReportingPeriodReq is the command to modify the duration between
+// reporting the collected data to the registered clients.
+type setReportingPeriodReq struct {
+	d time.Duration
+	c chan bool
+}
+
+func (cmd *setReportingPeriodReq) handleCommand(w *worker) {
+	w.timer.Stop()
+	if cmd.d <= 0 {
+		w.timer = time.NewTicker(defaultReportingDuration)
+	} else {
+		w.timer = time.NewTicker(cmd.d)
+	}
+	cmd.c <- true
+}

vendor/go.opencensus.io/tag/context.go

@@ -0,0 +1,41 @@
+// Copyright 2017, OpenCensus Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+package tag
+
+import "context"
+
+// FromContext returns the tag map stored in the context.
+func FromContext(ctx context.Context) *Map {
+	// The returned tag map shouldn't be mutated.
+	ts := ctx.Value(mapCtxKey)
+	if ts == nil {
+		return nil
+	}
+	return ts.(*Map)
+}
+
+// NewContext creates a new context with the given tag map.
+// To propagate a tag map to downstream methods and downstream RPCs, add a tag map
+// to the current context. NewContext will return a copy of the current context,
+// and put the tag map into the returned one.
+// If there is already a tag map in the current context, it will be replaced with m.
+func NewContext(ctx context.Context, m *Map) context.Context {
+	return context.WithValue(ctx, mapCtxKey, m)
+}
+
+type ctxKey struct{}
+
+var mapCtxKey = ctxKey{}

vendor/go.opencensus.io/tag/doc.go

@@ -0,0 +1,26 @@
+// Copyright 2017, OpenCensus Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+/*
+Package tag contains OpenCensus tags.
+
+Tags are key-value pairs. Tags provide additional cardinality to
+the OpenCensus instrumentation data.
+
+Tags can be propagated on the wire and in the same
+process via context.Context. Encode and Decode should be
+used to represent tags into their binary propagation form.
+*/
+package tag // import "go.opencensus.io/tag"

vendor/go.opencensus.io/tag/key.go

@@ -0,0 +1,35 @@
+// Copyright 2017, OpenCensus Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+package tag
+
+// Key represents a tag key.
+type Key struct {
+	name string
+}
+
+// NewKey creates or retrieves a string key identified by name.
+// Calling NewKey consequently with the same name returns the same key.
+func NewKey(name string) (Key, error) {
+	if !checkKeyName(name) {
+		return Key{}, errInvalidKeyName
+	}
+	return Key{name: name}, nil
+}
+
+// Name returns the name of the key.
+func (k Key) Name() string {
+	return k.name
+}

vendor/go.opencensus.io/tag/map.go

@@ -0,0 +1,197 @@
+// Copyright 2017, OpenCensus Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+package tag
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+	"sort"
+)
+
+// Tag is a key value pair that can be propagated on wire.
+type Tag struct {
+	Key   Key
+	Value string
+}
+
+// Map is a map of tags. Use New to create a context containing
+// a new Map.
+type Map struct {
+	m map[Key]string
+}
+
+// Value returns the value for the key if a value for the key exists.
+func (m *Map) Value(k Key) (string, bool) {
+	if m == nil {
+		return "", false
+	}
+	v, ok := m.m[k]
+	return v, ok
+}
+
+func (m *Map) String() string {
+	if m == nil {
+		return "nil"
+	}
+	keys := make([]Key, 0, len(m.m))
+	for k := range m.m {
+		keys = append(keys, k)
+	}
+	sort.Slice(keys, func(i, j int) bool { return keys[i].Name() < keys[j].Name() })
+
+	var buffer bytes.Buffer
+	buffer.WriteString("{ ")
+	for _, k := range keys {
+		buffer.WriteString(fmt.Sprintf("{%v %v}", k.name, m.m[k]))
+	}
+	buffer.WriteString(" }")
+	return buffer.String()
+}
+
+func (m *Map) insert(k Key, v string) {
+	if _, ok := m.m[k]; ok {
+		return
+	}
+	m.m[k] = v
+}
+
+func (m *Map) update(k Key, v string) {
+	if _, ok := m.m[k]; ok {
+		m.m[k] = v
+	}
+}
+
+func (m *Map) upsert(k Key, v string) {
+	m.m[k] = v
+}
+
+func (m *Map) delete(k Key) {
+	delete(m.m, k)
+}
+
+func newMap() *Map {
+	return &Map{m: make(map[Key]string)}
+}
+
+// Mutator modifies a tag map.
+type Mutator interface {
+	Mutate(t *Map) (*Map, error)
+}
+
+// Insert returns a mutator that inserts a
+// value associated with k. If k already exists in the tag map,
+// mutator doesn't update the value.
+func Insert(k Key, v string) Mutator {
+	return &mutator{
+		fn: func(m *Map) (*Map, error) {
+			if !checkValue(v) {
+				return nil, errInvalidValue
+			}
+			m.insert(k, v)
+			return m, nil
+		},
+	}
+}
+
+// Update returns a mutator that updates the
+// value of the tag associated with k with v. If k doesn't
+// exists in the tag map, the mutator doesn't insert the value.
+func Update(k Key, v string) Mutator {
+	return &mutator{
+		fn: func(m *Map) (*Map, error) {
+			if !checkValue(v) {
+				return nil, errInvalidValue
+			}
+			m.update(k, v)
+			return m, nil
+		},
+	}
+}
+
+// Upsert returns a mutator that upserts the
+// value of the tag associated with k with v. It inserts the
+// value if k doesn't exist already. It mutates the value
+// if k already exists.
+func Upsert(k Key, v string) Mutator {
+	return &mutator{
+		fn: func(m *Map) (*Map, error) {
+			if !checkValue(v) {
+				return nil, errInvalidValue
+			}
+			m.upsert(k, v)
+			return m, nil
+		},
+	}
+}
+
+// Delete returns a mutator that deletes
+// the value associated with k.
+func Delete(k Key) Mutator {
+	return &mutator{
+		fn: func(m *Map) (*Map, error) {
+			m.delete(k)
+			return m, nil
+		},
+	}
+}
+
+// New returns a new context that contains a tag map
+// originated from the incoming context and modified
+// with the provided mutators.
+func New(ctx context.Context, mutator ...Mutator) (context.Context, error) {
+	m := newMap()
+	orig := FromContext(ctx)
+	if orig != nil {
+		for k, v := range orig.m {
+			if !checkKeyName(k.Name()) {
+				return ctx, fmt.Errorf("key:%q: %v", k, errInvalidKeyName)
+			}
+			if !checkValue(v) {
+				return ctx, fmt.Errorf("key:%q value:%q: %v", k.Name(), v, errInvalidValue)
+			}
+			m.insert(k, v)
+		}
+	}
+	var err error
+	for _, mod := range mutator {
+		m, err = mod.Mutate(m)
+		if err != nil {
+			return ctx, err
+		}
+	}
+	return NewContext(ctx, m), nil
+}
+
+// Do is similar to pprof.Do: a convenience for installing the tags
+// from the context as Go profiler labels. This allows you to
+// correlated runtime profiling with stats.
+//
+// It converts the key/values from the given map to Go profiler labels
+// and calls pprof.Do.
+//
+// Do is going to do nothing if your Go version is below 1.9.
+func Do(ctx context.Context, f func(ctx context.Context)) {
+	do(ctx, f)
+}
+
+type mutator struct {
+	fn func(t *Map) (*Map, error)
+}
+
+func (m *mutator) Mutate(t *Map) (*Map, error) {
+	return m.fn(t)
+}

vendor/go.opencensus.io/tag/map_codec.go

@@ -0,0 +1,234 @@
+// Copyright 2017, OpenCensus Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+package tag
+
+import (
+	"encoding/binary"
+	"fmt"
+)
+
+// KeyType defines the types of keys allowed. Currently only keyTypeString is
+// supported.
+type keyType byte
+
+const (
+	keyTypeString keyType = iota
+	keyTypeInt64
+	keyTypeTrue
+	keyTypeFalse
+
+	tagsVersionID = byte(0)
+)
+
+type encoderGRPC struct {
+	buf               []byte
+	writeIdx, readIdx int
+}
+
+// writeKeyString writes the fieldID '0' followed by the key string and value
+// string.
+func (eg *encoderGRPC) writeTagString(k, v string) {
+	eg.writeByte(byte(keyTypeString))
+	eg.writeStringWithVarintLen(k)
+	eg.writeStringWithVarintLen(v)
+}
+
+func (eg *encoderGRPC) writeTagUint64(k string, i uint64) {
+	eg.writeByte(byte(keyTypeInt64))
+	eg.writeStringWithVarintLen(k)
+	eg.writeUint64(i)
+}
+
+func (eg *encoderGRPC) writeTagTrue(k string) {
+	eg.writeByte(byte(keyTypeTrue))
+	eg.writeStringWithVarintLen(k)
+}
+
+func (eg *encoderGRPC) writeTagFalse(k string) {
+	eg.writeByte(byte(keyTypeFalse))
+	eg.writeStringWithVarintLen(k)
+}
+
+func (eg *encoderGRPC) writeBytesWithVarintLen(bytes []byte) {
+	length := len(bytes)
+
+	eg.growIfRequired(binary.MaxVarintLen64 + length)
+	eg.writeIdx += binary.PutUvarint(eg.buf[eg.writeIdx:], uint64(length))
+	copy(eg.buf[eg.writeIdx:], bytes)
+	eg.writeIdx += length
+}
+
+func (eg *encoderGRPC) writeStringWithVarintLen(s string) {
+	length := len(s)
+
+	eg.growIfRequired(binary.MaxVarintLen64 + length)
+	eg.writeIdx += binary.PutUvarint(eg.buf[eg.writeIdx:], uint64(length))
+	copy(eg.buf[eg.writeIdx:], s)
+	eg.writeIdx += length
+}
+
+func (eg *encoderGRPC) writeByte(v byte) {
+	eg.growIfRequired(1)
+	eg.buf[eg.writeIdx] = v
+	eg.writeIdx++
+}
+
+func (eg *encoderGRPC) writeUint32(i uint32) {
+	eg.growIfRequired(4)
+	binary.LittleEndian.PutUint32(eg.buf[eg.writeIdx:], i)
+	eg.writeIdx += 4
+}
+
+func (eg *encoderGRPC) writeUint64(i uint64) {
+	eg.growIfRequired(8)
+	binary.LittleEndian.PutUint64(eg.buf[eg.writeIdx:], i)
+	eg.writeIdx += 8
+}
+
+func (eg *encoderGRPC) readByte() byte {
+	b := eg.buf[eg.readIdx]
+	eg.readIdx++
+	return b
+}
+
+func (eg *encoderGRPC) readUint32() uint32 {
+	i := binary.LittleEndian.Uint32(eg.buf[eg.readIdx:])
+	eg.readIdx += 4
+	return i
+}
+
+func (eg *encoderGRPC) readUint64() uint64 {
+	i := binary.LittleEndian.Uint64(eg.buf[eg.readIdx:])
+	eg.readIdx += 8
+	return i
+}
+
+func (eg *encoderGRPC) readBytesWithVarintLen() ([]byte, error) {
+	if eg.readEnded() {
+		return nil, fmt.Errorf("unexpected end while readBytesWithVarintLen '%x' starting at idx '%v'", eg.buf, eg.readIdx)
+	}
+	length, valueStart := binary.Uvarint(eg.buf[eg.readIdx:])
+	if valueStart <= 0 {
+		return nil, fmt.Errorf("unexpected end while readBytesWithVarintLen '%x' starting at idx '%v'", eg.buf, eg.readIdx)
+	}
+
+	valueStart += eg.readIdx
+	valueEnd := valueStart + int(length)
+	if valueEnd > len(eg.buf) {
+		return nil, fmt.Errorf("malformed encoding: length:%v, upper:%v, maxLength:%v", length, valueEnd, len(eg.buf))
+	}
+
+	eg.readIdx = valueEnd
+	return eg.buf[valueStart:valueEnd], nil
+}
+
+func (eg *encoderGRPC) readStringWithVarintLen() (string, error) {
+	bytes, err := eg.readBytesWithVarintLen()
+	if err != nil {
+		return "", err
+	}
+	return string(bytes), nil
+}
+
+func (eg *encoderGRPC) growIfRequired(expected int) {
+	if len(eg.buf)-eg.writeIdx < expected {
+		tmp := make([]byte, 2*(len(eg.buf)+1)+expected)
+		copy(tmp, eg.buf)
+		eg.buf = tmp
+	}
+}
+
+func (eg *encoderGRPC) readEnded() bool {
+	return eg.readIdx >= len(eg.buf)
+}
+
+func (eg *encoderGRPC) bytes() []byte {
+	return eg.buf[:eg.writeIdx]
+}
+
+// Encode encodes the tag map into a []byte. It is useful to propagate
+// the tag maps on wire in binary format.
+func Encode(m *Map) []byte {
+	eg := &encoderGRPC{
+		buf: make([]byte, len(m.m)),
+	}
+	eg.writeByte(byte(tagsVersionID))
+	for k, v := range m.m {
+		eg.writeByte(byte(keyTypeString))
+		eg.writeStringWithVarintLen(k.name)
+		eg.writeBytesWithVarintLen([]byte(v))
+	}
+	return eg.bytes()
+}
+
+// Decode decodes the given []byte into a tag map.
+func Decode(bytes []byte) (*Map, error) {
+	ts := newMap()
+	err := DecodeEach(bytes, ts.upsert)
+	if err != nil {
+		// no partial failures
+		return nil, err
+	}
+	return ts, nil
+}
+
+// DecodeEach decodes the given serialized tag map, calling handler for each
+// tag key and value decoded.
+func DecodeEach(bytes []byte, fn func(key Key, val string)) error {
+	eg := &encoderGRPC{
+		buf: bytes,
+	}
+	if len(eg.buf) == 0 {
+		return nil
+	}
+
+	version := eg.readByte()
+	if version > tagsVersionID {
+		return fmt.Errorf("cannot decode: unsupported version: %q; supports only up to: %q", version, tagsVersionID)
+	}
+
+	for !eg.readEnded() {
+		typ := keyType(eg.readByte())
+
+		if typ != keyTypeString {
+			return fmt.Errorf("cannot decode: invalid key type: %q", typ)
+		}
+
+		k, err := eg.readBytesWithVarintLen()
+		if err != nil {
+			return err
+		}
+
+		v, err := eg.readBytesWithVarintLen()
+		if err != nil {
+			return err
+		}
+
+		key, err := NewKey(string(k))
+		if err != nil {
+			return err
+		}
+		val := string(v)
+		if !checkValue(val) {
+			return errInvalidValue
+		}
+		fn(key, val)
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}

vendor/go.opencensus.io/tag/profile_19.go

@@ -0,0 +1,31 @@
+// Copyright 2018, OpenCensus Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build go1.9
+
+package tag
+
+import (
+	"context"
+	"runtime/pprof"
+)
+
+func do(ctx context.Context, f func(ctx context.Context)) {
+	m := FromContext(ctx)
+	keyvals := make([]string, 0, 2*len(m.m))
+	for k, v := range m.m {
+		keyvals = append(keyvals, k.Name(), v)
+	}
+	pprof.Do(ctx, pprof.Labels(keyvals...), f)
+}

vendor/go.opencensus.io/tag/profile_not19.go

@@ -0,0 +1,23 @@
+// Copyright 2018, OpenCensus Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build !go1.9
+
+package tag
+
+import "context"
+
+func do(ctx context.Context, f func(ctx context.Context)) {
+	f(ctx)
+}

vendor/go.opencensus.io/tag/validate.go

@@ -0,0 +1,56 @@
+// Copyright 2017, OpenCensus Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package tag
+
+import "errors"
+
+const (
+	maxKeyLength = 255
+
+	// valid are restricted to US-ASCII subset (range 0x20 (' ') to 0x7e ('~')).
+	validKeyValueMin = 32
+	validKeyValueMax = 126
+)
+
+var (
+	errInvalidKeyName = errors.New("invalid key name: only ASCII characters accepted; max length must be 255 characters")
+	errInvalidValue   = errors.New("invalid value: only ASCII characters accepted; max length must be 255 characters")
+)
+
+func checkKeyName(name string) bool {
+	if len(name) == 0 {
+		return false
+	}
+	if len(name) > maxKeyLength {
+		return false
+	}
+	return isASCII(name)
+}
+
+func isASCII(s string) bool {
+	for _, c := range s {
+		if (c < validKeyValueMin) || (c > validKeyValueMax) {
+			return false
+		}
+	}
+	return true
+}
+
+func checkValue(v string) bool {
+	if len(v) > maxKeyLength {
+		return false
+	}
+	return isASCII(v)
+}

vendor/go.opencensus.io/trace/basetypes.go

@@ -0,0 +1,114 @@
+// Copyright 2017, OpenCensus Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package trace
+
+import (
+	"fmt"
+	"time"
+)
+
+type (
+	// TraceID is a 16-byte identifier for a set of spans.
+	TraceID [16]byte
+
+	// SpanID is an 8-byte identifier for a single span.
+	SpanID [8]byte
+)
+
+func (t TraceID) String() string {
+	return fmt.Sprintf("%02x", t[:])
+}
+
+func (s SpanID) String() string {
+	return fmt.Sprintf("%02x", s[:])
+}
+
+// Annotation represents a text annotation with a set of attributes and a timestamp.
+type Annotation struct {
+	Time       time.Time
+	Message    string
+	Attributes map[string]interface{}
+}
+
+// Attribute represents a key-value pair on a span, link or annotation.
+// Construct with one of: BoolAttribute, Int64Attribute, or StringAttribute.
+type Attribute struct {
+	key   string
+	value interface{}
+}
+
+// BoolAttribute returns a bool-valued attribute.
+func BoolAttribute(key string, value bool) Attribute {
+	return Attribute{key: key, value: value}
+}
+
+// Int64Attribute returns an int64-valued attribute.
+func Int64Attribute(key string, value int64) Attribute {
+	return Attribute{key: key, value: value}
+}
+
+// StringAttribute returns a string-valued attribute.
+func StringAttribute(key string, value string) Attribute {
+	return Attribute{key: key, value: value}
+}
+
+// LinkType specifies the relationship between the span that had the link
+// added, and the linked span.
+type LinkType int32
+
+// LinkType values.
+const (
+	LinkTypeUnspecified LinkType = iota // The relationship of the two spans is unknown.
+	LinkTypeChild                       // The current span is a child of the linked span.
+	LinkTypeParent                      // The current span is the parent of the linked span.
+)
+
+// Link represents a reference from one span to another span.
+type Link struct {
+	TraceID TraceID
+	SpanID  SpanID
+	Type    LinkType
+	// Attributes is a set of attributes on the link.
+	Attributes map[string]interface{}
+}
+
+// MessageEventType specifies the type of message event.
+type MessageEventType int32
+
+// MessageEventType values.
+const (
+	MessageEventTypeUnspecified MessageEventType = iota // Unknown event type.
+	MessageEventTypeSent                                // Indicates a sent RPC message.
+	MessageEventTypeRecv                                // Indicates a received RPC message.
+)
+
+// MessageEvent represents an event describing a message sent or received on the network.
+type MessageEvent struct {
+	Time                 time.Time
+	EventType            MessageEventType
+	MessageID            int64
+	UncompressedByteSize int64
+	CompressedByteSize   int64
+}
+
+// Status is the status of a Span.
+type Status struct {
+	// Code is a status code.  Zero indicates success.
+	//
+	// If Code will be propagated to Google APIs, it ideally should be a value from
+	// https://github.com/googleapis/googleapis/blob/master/google/rpc/code.proto .
+	Code    int32
+	Message string
+}

vendor/go.opencensus.io/trace/config.go

@@ -0,0 +1,48 @@
+// Copyright 2018, OpenCensus Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package trace
+
+import (
+	"sync"
+
+	"go.opencensus.io/trace/internal"
+)
+
+// Config represents the global tracing configuration.
+type Config struct {
+	// DefaultSampler is the default sampler used when creating new spans.
+	DefaultSampler Sampler
+
+	// IDGenerator is for internal use only.
+	IDGenerator internal.IDGenerator
+}
+
+var configWriteMu sync.Mutex
+
+// ApplyConfig applies changes to the global tracing configuration.
+//
+// Fields not provided in the given config are going to be preserved.
+func ApplyConfig(cfg Config) {
+	configWriteMu.Lock()
+	defer configWriteMu.Unlock()
+	c := *config.Load().(*Config)
+	if cfg.DefaultSampler != nil {
+		c.DefaultSampler = cfg.DefaultSampler
+	}
+	if cfg.IDGenerator != nil {
+		c.IDGenerator = cfg.IDGenerator
+	}
+	config.Store(&c)
+}

vendor/go.opencensus.io/trace/doc.go

@@ -0,0 +1,53 @@
+// Copyright 2017, OpenCensus Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+/*
+Package trace contains support for OpenCensus distributed tracing.
+
+The following assumes a basic familiarity with OpenCensus concepts.
+See http://opencensus.io
+
+
+Exporting Traces
+
+To export collected tracing data, register at least one exporter. You can use
+one of the provided exporters or write your own.
+
+    trace.RegisterExporter(exporter)
+
+By default, traces will be sampled relatively rarely. To change the sampling
+frequency for your entire program, call ApplyConfig. Use a ProbabilitySampler
+to sample a subset of traces, or use AlwaysSample to collect a trace on every run:
+
+    trace.ApplyConfig(trace.Config{DefaultSampler: trace.AlwaysSample()})
+
+Be careful about using trace.AlwaysSample in a production application with
+significant traffic: a new trace will be started and exported for every request.
+
+Adding Spans to a Trace
+
+A trace consists of a tree of spans. In Go, the current span is carried in a
+context.Context.
+
+It is common to want to capture all the activity of a function call in a span. For
+this to work, the function must take a context.Context as a parameter. Add these two
+lines to the top of the function:
+
+    ctx, span := trace.StartSpan(ctx, "example.com/Run")
+    defer span.End()
+
+StartSpan will create a new top-level span if the context
+doesn't contain another span, otherwise it will create a child span.
+*/
+package trace // import "go.opencensus.io/trace"

vendor/go.opencensus.io/trace/export.go

@@ -0,0 +1,90 @@
+// Copyright 2017, OpenCensus Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package trace
+
+import (
+	"sync"
+	"sync/atomic"
+	"time"
+)
+
+// Exporter is a type for functions that receive sampled trace spans.
+//
+// The ExportSpan method should be safe for concurrent use and should return
+// quickly; if an Exporter takes a significant amount of time to process a
+// SpanData, that work should be done on another goroutine.
+//
+// The SpanData should not be modified, but a pointer to it can be kept.
+type Exporter interface {
+	ExportSpan(s *SpanData)
+}
+
+type exportersMap map[Exporter]struct{}
+
+var (
+	exporterMu sync.Mutex
+	exporters  atomic.Value
+)
+
+// RegisterExporter adds to the list of Exporters that will receive sampled
+// trace spans.
+//
+// Binaries can register exporters, libraries shouldn't register exporters.
+func RegisterExporter(e Exporter) {
+	exporterMu.Lock()
+	new := make(exportersMap)
+	if old, ok := exporters.Load().(exportersMap); ok {
+		for k, v := range old {
+			new[k] = v
+		}
+	}
+	new[e] = struct{}{}
+	exporters.Store(new)
+	exporterMu.Unlock()
+}
+
+// UnregisterExporter removes from the list of Exporters the Exporter that was
+// registered with the given name.
+func UnregisterExporter(e Exporter) {
+	exporterMu.Lock()
+	new := make(exportersMap)
+	if old, ok := exporters.Load().(exportersMap); ok {
+		for k, v := range old {
+			new[k] = v
+		}
+	}
+	delete(new, e)
+	exporters.Store(new)
+	exporterMu.Unlock()
+}
+
+// SpanData contains all the information collected by a Span.
+type SpanData struct {
+	SpanContext
+	ParentSpanID SpanID
+	SpanKind     int
+	Name         string
+	StartTime    time.Time
+	// The wall clock time of EndTime will be adjusted to always be offset
+	// from StartTime by the duration of the span.
+	EndTime time.Time
+	// The values of Attributes each have type string, bool, or int64.
+	Attributes    map[string]interface{}
+	Annotations   []Annotation
+	MessageEvents []MessageEvent
+	Status
+	Links           []Link
+	HasRemoteParent bool
+}

vendor/go.opencensus.io/trace/internal/internal.go

@@ -0,0 +1,21 @@
+// Copyright 2018, OpenCensus Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package internal provides trace internals.
+package internal
+
+type IDGenerator interface {
+	NewTraceID() [16]byte
+	NewSpanID() [8]byte
+}

vendor/go.opencensus.io/trace/propagation/propagation.go

@@ -0,0 +1,108 @@
+// Copyright 2017, OpenCensus Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package propagation implements the binary trace context format.
+package propagation // import "go.opencensus.io/trace/propagation"
+
+// TODO: link to external spec document.
+
+// BinaryFormat format:
+//
+// Binary value: <version_id><version_format>
+// version_id: 1 byte representing the version id.
+//
+// For version_id = 0:
+//
+// version_format: <field><field>
+// field_format: <field_id><field_format>
+//
+// Fields:
+//
+// TraceId: (field_id = 0, len = 16, default = "0000000000000000") - 16-byte array representing the trace_id.
+// SpanId: (field_id = 1, len = 8, default = "00000000") - 8-byte array representing the span_id.
+// TraceOptions: (field_id = 2, len = 1, default = "0") - 1-byte array representing the trace_options.
+//
+// Fields MUST be encoded using the field id order (smaller to higher).
+//
+// Valid value example:
+//
+// {0, 0, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 1, 97,
+// 98, 99, 100, 101, 102, 103, 104, 2, 1}
+//
+// version_id = 0;
+// trace_id = {64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79}
+// span_id = {97, 98, 99, 100, 101, 102, 103, 104};
+// trace_options = {1};
+
+import (
+	"net/http"
+
+	"go.opencensus.io/trace"
+)
+
+// Binary returns the binary format representation of a SpanContext.
+//
+// If sc is the zero value, Binary returns nil.
+func Binary(sc trace.SpanContext) []byte {
+	if sc == (trace.SpanContext{}) {
+		return nil
+	}
+	var b [29]byte
+	copy(b[2:18], sc.TraceID[:])
+	b[18] = 1
+	copy(b[19:27], sc.SpanID[:])
+	b[27] = 2
+	b[28] = uint8(sc.TraceOptions)
+	return b[:]
+}
+
+// FromBinary returns the SpanContext represented by b.
+//
+// If b has an unsupported version ID or contains no TraceID, FromBinary
+// returns with ok==false.
+func FromBinary(b []byte) (sc trace.SpanContext, ok bool) {
+	if len(b) == 0 || b[0] != 0 {
+		return trace.SpanContext{}, false
+	}
+	b = b[1:]
+	if len(b) >= 17 && b[0] == 0 {
+		copy(sc.TraceID[:], b[1:17])
+		b = b[17:]
+	} else {
+		return trace.SpanContext{}, false
+	}
+	if len(b) >= 9 && b[0] == 1 {
+		copy(sc.SpanID[:], b[1:9])
+		b = b[9:]
+	}
+	if len(b) >= 2 && b[0] == 2 {
+		sc.TraceOptions = trace.TraceOptions(b[1])
+	}
+	return sc, true
+}
+
+// HTTPFormat implementations propagate span contexts
+// in HTTP requests.
+//
+// SpanContextFromRequest extracts a span context from incoming
+// requests.
+//
+// SpanContextToRequest modifies the given request to include the given
+// span context.
+type HTTPFormat interface {
+	SpanContextFromRequest(req *http.Request) (sc trace.SpanContext, ok bool)
+	SpanContextToRequest(sc trace.SpanContext, req *http.Request)
+}
+
+// TODO(jbd): Find a more representative but short name for HTTPFormat.

vendor/go.opencensus.io/trace/sampling.go

@@ -0,0 +1,75 @@
+// Copyright 2017, OpenCensus Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package trace
+
+import (
+	"encoding/binary"
+)
+
+const defaultSamplingProbability = 1e-4
+
+// Sampler decides whether a trace should be sampled and exported.
+type Sampler func(SamplingParameters) SamplingDecision
+
+// SamplingParameters contains the values passed to a Sampler.
+type SamplingParameters struct {
+	ParentContext   SpanContext
+	TraceID         TraceID
+	SpanID          SpanID
+	Name            string
+	HasRemoteParent bool
+}
+
+// SamplingDecision is the value returned by a Sampler.
+type SamplingDecision struct {
+	Sample bool
+}
+
+// ProbabilitySampler returns a Sampler that samples a given fraction of traces.
+//
+// It also samples spans whose parents are sampled.
+func ProbabilitySampler(fraction float64) Sampler {
+	if !(fraction >= 0) {
+		fraction = 0
+	} else if fraction >= 1 {
+		return AlwaysSample()
+	}
+
+	traceIDUpperBound := uint64(fraction * (1 << 63))
+	return Sampler(func(p SamplingParameters) SamplingDecision {
+		if p.ParentContext.IsSampled() {
+			return SamplingDecision{Sample: true}
+		}
+		x := binary.BigEndian.Uint64(p.TraceID[0:8]) >> 1
+		return SamplingDecision{Sample: x < traceIDUpperBound}
+	})
+}
+
+// AlwaysSample returns a Sampler that samples every trace.
+// Be careful about using this sampler in a production application with
+// significant traffic: a new trace will be started and exported for every
+// request.
+func AlwaysSample() Sampler {
+	return func(p SamplingParameters) SamplingDecision {
+		return SamplingDecision{Sample: true}
+	}
+}
+
+// NeverSample returns a Sampler that samples no traces.
+func NeverSample() Sampler {
+	return func(p SamplingParameters) SamplingDecision {
+		return SamplingDecision{Sample: false}
+	}
+}

vendor/go.opencensus.io/trace/spanbucket.go

@@ -0,0 +1,130 @@
+// Copyright 2017, OpenCensus Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package trace
+
+import (
+	"time"
+)
+
+// samplePeriod is the minimum time between accepting spans in a single bucket.
+const samplePeriod = time.Second
+
+// defaultLatencies contains the default latency bucket bounds.
+// TODO: consider defaults, make configurable
+var defaultLatencies = [...]time.Duration{
+	10 * time.Microsecond,
+	100 * time.Microsecond,
+	time.Millisecond,
+	10 * time.Millisecond,
+	100 * time.Millisecond,
+	time.Second,
+	10 * time.Second,
+	time.Minute,
+}
+
+// bucket is a container for a set of spans for a particular error code or latency range.
+type bucket struct {
+	nextTime  time.Time   // next time we can accept a span
+	buffer    []*SpanData // circular buffer of spans
+	nextIndex int         // location next SpanData should be placed in buffer
+	overflow  bool        // whether the circular buffer has wrapped around
+}
+
+func makeBucket(bufferSize int) bucket {
+	return bucket{
+		buffer: make([]*SpanData, bufferSize),
+	}
+}
+
+// add adds a span to the bucket, if nextTime has been reached.
+func (b *bucket) add(s *SpanData) {
+	if s.EndTime.Before(b.nextTime) {
+		return
+	}
+	if len(b.buffer) == 0 {
+		return
+	}
+	b.nextTime = s.EndTime.Add(samplePeriod)
+	b.buffer[b.nextIndex] = s
+	b.nextIndex++
+	if b.nextIndex == len(b.buffer) {
+		b.nextIndex = 0
+		b.overflow = true
+	}
+}
+
+// size returns the number of spans in the bucket.
+func (b *bucket) size() int {
+	if b.overflow {
+		return len(b.buffer)
+	}
+	return b.nextIndex
+}
+
+// span returns the ith span in the bucket.
+func (b *bucket) span(i int) *SpanData {
+	if !b.overflow {
+		return b.buffer[i]
+	}
+	if i < len(b.buffer)-b.nextIndex {
+		return b.buffer[b.nextIndex+i]
+	}
+	return b.buffer[b.nextIndex+i-len(b.buffer)]
+}
+
+// resize changes the size of the bucket to n, keeping up to n existing spans.
+func (b *bucket) resize(n int) {
+	cur := b.size()
+	newBuffer := make([]*SpanData, n)
+	if cur < n {
+		for i := 0; i < cur; i++ {
+			newBuffer[i] = b.span(i)
+		}
+		b.buffer = newBuffer
+		b.nextIndex = cur
+		b.overflow = false
+		return
+	}
+	for i := 0; i < n; i++ {
+		newBuffer[i] = b.span(i + cur - n)
+	}
+	b.buffer = newBuffer
+	b.nextIndex = 0
+	b.overflow = true
+}
+
+// latencyBucket returns the appropriate bucket number for a given latency.
+func latencyBucket(latency time.Duration) int {
+	i := 0
+	for i < len(defaultLatencies) && latency >= defaultLatencies[i] {
+		i++
+	}
+	return i
+}
+
+// latencyBucketBounds returns the lower and upper bounds for a latency bucket
+// number.
+//
+// The lower bound is inclusive, the upper bound is exclusive (except for the
+// last bucket.)
+func latencyBucketBounds(index int) (lower time.Duration, upper time.Duration) {
+	if index == 0 {
+		return 0, defaultLatencies[index]
+	}
+	if index == len(defaultLatencies) {
+		return defaultLatencies[index-1], 1<<63 - 1
+	}
+	return defaultLatencies[index-1], defaultLatencies[index]
+}

vendor/go.opencensus.io/trace/spanstore.go

@@ -0,0 +1,306 @@
+// Copyright 2017, OpenCensus Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package trace
+
+import (
+	"sync"
+	"time"
+
+	"go.opencensus.io/internal"
+)
+
+const (
+	maxBucketSize     = 100000
+	defaultBucketSize = 10
+)
+
+var (
+	ssmu       sync.RWMutex // protects spanStores
+	spanStores = make(map[string]*spanStore)
+)
+
+// This exists purely to avoid exposing internal methods used by z-Pages externally.
+type internalOnly struct{}
+
+func init() {
+	//TODO(#412): remove
+	internal.Trace = &internalOnly{}
+}
+
+// ReportActiveSpans returns the active spans for the given name.
+func (i internalOnly) ReportActiveSpans(name string) []*SpanData {
+	s := spanStoreForName(name)
+	if s == nil {
+		return nil
+	}
+	var out []*SpanData
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	for span := range s.active {
+		out = append(out, span.makeSpanData())
+	}
+	return out
+}
+
+// ReportSpansByError returns a sample of error spans.
+//
+// If code is nonzero, only spans with that status code are returned.
+func (i internalOnly) ReportSpansByError(name string, code int32) []*SpanData {
+	s := spanStoreForName(name)
+	if s == nil {
+		return nil
+	}
+	var out []*SpanData
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	if code != 0 {
+		if b, ok := s.errors[code]; ok {
+			for _, sd := range b.buffer {
+				if sd == nil {
+					break
+				}
+				out = append(out, sd)
+			}
+		}
+	} else {
+		for _, b := range s.errors {
+			for _, sd := range b.buffer {
+				if sd == nil {
+					break
+				}
+				out = append(out, sd)
+			}
+		}
+	}
+	return out
+}
+
+// ConfigureBucketSizes sets the number of spans to keep per latency and error
+// bucket for different span names.
+func (i internalOnly) ConfigureBucketSizes(bcs []internal.BucketConfiguration) {
+	for _, bc := range bcs {
+		latencyBucketSize := bc.MaxRequestsSucceeded
+		if latencyBucketSize < 0 {
+			latencyBucketSize = 0
+		}
+		if latencyBucketSize > maxBucketSize {
+			latencyBucketSize = maxBucketSize
+		}
+		errorBucketSize := bc.MaxRequestsErrors
+		if errorBucketSize < 0 {
+			errorBucketSize = 0
+		}
+		if errorBucketSize > maxBucketSize {
+			errorBucketSize = maxBucketSize
+		}
+		spanStoreSetSize(bc.Name, latencyBucketSize, errorBucketSize)
+	}
+}
+
+// ReportSpansPerMethod returns a summary of what spans are being stored for each span name.
+func (i internalOnly) ReportSpansPerMethod() map[string]internal.PerMethodSummary {
+	out := make(map[string]internal.PerMethodSummary)
+	ssmu.RLock()
+	defer ssmu.RUnlock()
+	for name, s := range spanStores {
+		s.mu.Lock()
+		p := internal.PerMethodSummary{
+			Active: len(s.active),
+		}
+		for code, b := range s.errors {
+			p.ErrorBuckets = append(p.ErrorBuckets, internal.ErrorBucketSummary{
+				ErrorCode: code,
+				Size:      b.size(),
+			})
+		}
+		for i, b := range s.latency {
+			min, max := latencyBucketBounds(i)
+			p.LatencyBuckets = append(p.LatencyBuckets, internal.LatencyBucketSummary{
+				MinLatency: min,
+				MaxLatency: max,
+				Size:       b.size(),
+			})
+		}
+		s.mu.Unlock()
+		out[name] = p
+	}
+	return out
+}
+
+// ReportSpansByLatency returns a sample of successful spans.
+//
+// minLatency is the minimum latency of spans to be returned.
+// maxLatency, if nonzero, is the maximum latency of spans to be returned.
+func (i internalOnly) ReportSpansByLatency(name string, minLatency, maxLatency time.Duration) []*SpanData {
+	s := spanStoreForName(name)
+	if s == nil {
+		return nil
+	}
+	var out []*SpanData
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	for i, b := range s.latency {
+		min, max := latencyBucketBounds(i)
+		if i+1 != len(s.latency) && max <= minLatency {
+			continue
+		}
+		if maxLatency != 0 && maxLatency < min {
+			continue
+		}
+		for _, sd := range b.buffer {
+			if sd == nil {
+				break
+			}
+			if minLatency != 0 || maxLatency != 0 {
+				d := sd.EndTime.Sub(sd.StartTime)
+				if d < minLatency {
+					continue
+				}
+				if maxLatency != 0 && d > maxLatency {
+					continue
+				}
+			}
+			out = append(out, sd)
+		}
+	}
+	return out
+}
+
+// spanStore keeps track of spans stored for a particular span name.
+//
+// It contains all active spans; a sample of spans for failed requests,
+// categorized by error code; and a sample of spans for successful requests,
+// bucketed by latency.
+type spanStore struct {
+	mu                     sync.Mutex // protects everything below.
+	active                 map[*Span]struct{}
+	errors                 map[int32]*bucket
+	latency                []bucket
+	maxSpansPerErrorBucket int
+}
+
+// newSpanStore creates a span store.
+func newSpanStore(name string, latencyBucketSize int, errorBucketSize int) *spanStore {
+	s := &spanStore{
+		active:                 make(map[*Span]struct{}),
+		latency:                make([]bucket, len(defaultLatencies)+1),
+		maxSpansPerErrorBucket: errorBucketSize,
+	}
+	for i := range s.latency {
+		s.latency[i] = makeBucket(latencyBucketSize)
+	}
+	return s
+}
+
+// spanStoreForName returns the spanStore for the given name.
+//
+// It returns nil if it doesn't exist.
+func spanStoreForName(name string) *spanStore {
+	var s *spanStore
+	ssmu.RLock()
+	s, _ = spanStores[name]
+	ssmu.RUnlock()
+	return s
+}
+
+// spanStoreForNameCreateIfNew returns the spanStore for the given name.
+//
+// It creates it if it didn't exist.
+func spanStoreForNameCreateIfNew(name string) *spanStore {
+	ssmu.RLock()
+	s, ok := spanStores[name]
+	ssmu.RUnlock()
+	if ok {
+		return s
+	}
+	ssmu.Lock()
+	defer ssmu.Unlock()
+	s, ok = spanStores[name]
+	if ok {
+		return s
+	}
+	s = newSpanStore(name, defaultBucketSize, defaultBucketSize)
+	spanStores[name] = s
+	return s
+}
+
+// spanStoreSetSize resizes the spanStore for the given name.
+//
+// It creates it if it didn't exist.
+func spanStoreSetSize(name string, latencyBucketSize int, errorBucketSize int) {
+	ssmu.RLock()
+	s, ok := spanStores[name]
+	ssmu.RUnlock()
+	if ok {
+		s.resize(latencyBucketSize, errorBucketSize)
+		return
+	}
+	ssmu.Lock()
+	defer ssmu.Unlock()
+	s, ok = spanStores[name]
+	if ok {
+		s.resize(latencyBucketSize, errorBucketSize)
+		return
+	}
+	s = newSpanStore(name, latencyBucketSize, errorBucketSize)
+	spanStores[name] = s
+}
+
+func (s *spanStore) resize(latencyBucketSize int, errorBucketSize int) {
+	s.mu.Lock()
+	for i := range s.latency {
+		s.latency[i].resize(latencyBucketSize)
+	}
+	for _, b := range s.errors {
+		b.resize(errorBucketSize)
+	}
+	s.maxSpansPerErrorBucket = errorBucketSize
+	s.mu.Unlock()
+}
+
+// add adds a span to the active bucket of the spanStore.
+func (s *spanStore) add(span *Span) {
+	s.mu.Lock()
+	s.active[span] = struct{}{}
+	s.mu.Unlock()
+}
+
+// finished removes a span from the active set, and adds a corresponding
+// SpanData to a latency or error bucket.
+func (s *spanStore) finished(span *Span, sd *SpanData) {
+	latency := sd.EndTime.Sub(sd.StartTime)
+	if latency < 0 {
+		latency = 0
+	}
+	code := sd.Status.Code
+
+	s.mu.Lock()
+	delete(s.active, span)
+	if code == 0 {
+		s.latency[latencyBucket(latency)].add(sd)
+	} else {
+		if s.errors == nil {
+			s.errors = make(map[int32]*bucket)
+		}
+		if b := s.errors[code]; b != nil {
+			b.add(sd)
+		} else {
+			b := makeBucket(s.maxSpansPerErrorBucket)
+			s.errors[code] = &b
+			b.add(sd)
+		}
+	}
+	s.mu.Unlock()
+}

vendor/go.opencensus.io/trace/status_codes.go

@@ -0,0 +1,37 @@
+// Copyright 2018, OpenCensus Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package trace
+
+// Status codes for use with Span.SetStatus. These correspond to the status
+// codes used by gRPC defined here: https://github.com/googleapis/googleapis/blob/master/google/rpc/code.proto
+const (
+	StatusCodeOK                 = 0
+	StatusCodeCancelled          = 1
+	StatusCodeUnknown            = 2
+	StatusCodeInvalidArgument    = 3
+	StatusCodeDeadlineExceeded   = 4
+	StatusCodeNotFound           = 5
+	StatusCodeAlreadyExists      = 6
+	StatusCodePermissionDenied   = 7
+	StatusCodeResourceExhausted  = 8
+	StatusCodeFailedPrecondition = 9
+	StatusCodeAborted            = 10
+	StatusCodeOutOfRange         = 11
+	StatusCodeUnimplemented      = 12
+	StatusCodeInternal           = 13
+	StatusCodeUnavailable        = 14
+	StatusCodeDataLoss           = 15
+	StatusCodeUnauthenticated    = 16
+)

vendor/go.opencensus.io/trace/trace.go

@@ -0,0 +1,513 @@
+// Copyright 2017, OpenCensus Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package trace
+
+import (
+	"context"
+	crand "crypto/rand"
+	"encoding/binary"
+	"fmt"
+	"math/rand"
+	"sync"
+	"sync/atomic"
+	"time"
+
+	"go.opencensus.io/internal"
+	"go.opencensus.io/trace/tracestate"
+)
+
+// Span represents a span of a trace.  It has an associated SpanContext, and
+// stores data accumulated while the span is active.
+//
+// Ideally users should interact with Spans by calling the functions in this
+// package that take a Context parameter.
+type Span struct {
+	// data contains information recorded about the span.
+	//
+	// It will be non-nil if we are exporting the span or recording events for it.
+	// Otherwise, data is nil, and the Span is simply a carrier for the
+	// SpanContext, so that the trace ID is propagated.
+	data        *SpanData
+	mu          sync.Mutex // protects the contents of *data (but not the pointer value.)
+	spanContext SpanContext
+	// spanStore is the spanStore this span belongs to, if any, otherwise it is nil.
+	*spanStore
+	endOnce sync.Once
+
+	executionTracerTaskEnd func() // ends the execution tracer span
+}
+
+// IsRecordingEvents returns true if events are being recorded for this span.
+// Use this check to avoid computing expensive annotations when they will never
+// be used.
+func (s *Span) IsRecordingEvents() bool {
+	if s == nil {
+		return false
+	}
+	return s.data != nil
+}
+
+// TraceOptions contains options associated with a trace span.
+type TraceOptions uint32
+
+// IsSampled returns true if the span will be exported.
+func (sc SpanContext) IsSampled() bool {
+	return sc.TraceOptions.IsSampled()
+}
+
+// setIsSampled sets the TraceOptions bit that determines whether the span will be exported.
+func (sc *SpanContext) setIsSampled(sampled bool) {
+	if sampled {
+		sc.TraceOptions |= 1
+	} else {
+		sc.TraceOptions &= ^TraceOptions(1)
+	}
+}
+
+// IsSampled returns true if the span will be exported.
+func (t TraceOptions) IsSampled() bool {
+	return t&1 == 1
+}
+
+// SpanContext contains the state that must propagate across process boundaries.
+//
+// SpanContext is not an implementation of context.Context.
+// TODO: add reference to external Census docs for SpanContext.
+type SpanContext struct {
+	TraceID      TraceID
+	SpanID       SpanID
+	TraceOptions TraceOptions
+	Tracestate   *tracestate.Tracestate
+}
+
+type contextKey struct{}
+
+// FromContext returns the Span stored in a context, or nil if there isn't one.
+func FromContext(ctx context.Context) *Span {
+	s, _ := ctx.Value(contextKey{}).(*Span)
+	return s
+}
+
+// NewContext returns a new context with the given Span attached.
+func NewContext(parent context.Context, s *Span) context.Context {
+	return context.WithValue(parent, contextKey{}, s)
+}
+
+// All available span kinds. Span kind must be either one of these values.
+const (
+	SpanKindUnspecified = iota
+	SpanKindServer
+	SpanKindClient
+)
+
+// StartOptions contains options concerning how a span is started.
+type StartOptions struct {
+	// Sampler to consult for this Span. If provided, it is always consulted.
+	//
+	// If not provided, then the behavior differs based on whether
+	// the parent of this Span is remote, local, or there is no parent.
+	// In the case of a remote parent or no parent, the
+	// default sampler (see Config) will be consulted. Otherwise,
+	// when there is a non-remote parent, no new sampling decision will be made:
+	// we will preserve the sampling of the parent.
+	Sampler Sampler
+
+	// SpanKind represents the kind of a span. If none is set,
+	// SpanKindUnspecified is used.
+	SpanKind int
+}
+
+// StartOption apply changes to StartOptions.
+type StartOption func(*StartOptions)
+
+// WithSpanKind makes new spans to be created with the given kind.
+func WithSpanKind(spanKind int) StartOption {
+	return func(o *StartOptions) {
+		o.SpanKind = spanKind
+	}
+}
+
+// WithSampler makes new spans to be be created with a custom sampler.
+// Otherwise, the global sampler is used.
+func WithSampler(sampler Sampler) StartOption {
+	return func(o *StartOptions) {
+		o.Sampler = sampler
+	}
+}
+
+// StartSpan starts a new child span of the current span in the context. If
+// there is no span in the context, creates a new trace and span.
+//
+// Returned context contains the newly created span. You can use it to
+// propagate the returned span in process.
+func StartSpan(ctx context.Context, name string, o ...StartOption) (context.Context, *Span) {
+	var opts StartOptions
+	var parent SpanContext
+	if p := FromContext(ctx); p != nil {
+		parent = p.spanContext
+	}
+	for _, op := range o {
+		op(&opts)
+	}
+	span := startSpanInternal(name, parent != SpanContext{}, parent, false, opts)
+
+	ctx, end := startExecutionTracerTask(ctx, name)
+	span.executionTracerTaskEnd = end
+	return NewContext(ctx, span), span
+}
+
+// StartSpanWithRemoteParent starts a new child span of the span from the given parent.
+//
+// If the incoming context contains a parent, it ignores. StartSpanWithRemoteParent is
+// preferred for cases where the parent is propagated via an incoming request.
+//
+// Returned context contains the newly created span. You can use it to
+// propagate the returned span in process.
+func StartSpanWithRemoteParent(ctx context.Context, name string, parent SpanContext, o ...StartOption) (context.Context, *Span) {
+	var opts StartOptions
+	for _, op := range o {
+		op(&opts)
+	}
+	span := startSpanInternal(name, parent != SpanContext{}, parent, true, opts)
+	ctx, end := startExecutionTracerTask(ctx, name)
+	span.executionTracerTaskEnd = end
+	return NewContext(ctx, span), span
+}
+
+func startSpanInternal(name string, hasParent bool, parent SpanContext, remoteParent bool, o StartOptions) *Span {
+	span := &Span{}
+	span.spanContext = parent
+
+	cfg := config.Load().(*Config)
+
+	if !hasParent {
+		span.spanContext.TraceID = cfg.IDGenerator.NewTraceID()
+	}
+	span.spanContext.SpanID = cfg.IDGenerator.NewSpanID()
+	sampler := cfg.DefaultSampler
+
+	if !hasParent || remoteParent || o.Sampler != nil {
+		// If this span is the child of a local span and no Sampler is set in the
+		// options, keep the parent's TraceOptions.
+		//
+		// Otherwise, consult the Sampler in the options if it is non-nil, otherwise
+		// the default sampler.
+		if o.Sampler != nil {
+			sampler = o.Sampler
+		}
+		span.spanContext.setIsSampled(sampler(SamplingParameters{
+			ParentContext:   parent,
+			TraceID:         span.spanContext.TraceID,
+			SpanID:          span.spanContext.SpanID,
+			Name:            name,
+			HasRemoteParent: remoteParent}).Sample)
+	}
+
+	if !internal.LocalSpanStoreEnabled && !span.spanContext.IsSampled() {
+		return span
+	}
+
+	span.data = &SpanData{
+		SpanContext:     span.spanContext,
+		StartTime:       time.Now(),
+		SpanKind:        o.SpanKind,
+		Name:            name,
+		HasRemoteParent: remoteParent,
+	}
+	if hasParent {
+		span.data.ParentSpanID = parent.SpanID
+	}
+	if internal.LocalSpanStoreEnabled {
+		var ss *spanStore
+		ss = spanStoreForNameCreateIfNew(name)
+		if ss != nil {
+			span.spanStore = ss
+			ss.add(span)
+		}
+	}
+
+	return span
+}
+
+// End ends the span.
+func (s *Span) End() {
+	if !s.IsRecordingEvents() {
+		return
+	}
+	s.endOnce.Do(func() {
+		if s.executionTracerTaskEnd != nil {
+			s.executionTracerTaskEnd()
+		}
+		exp, _ := exporters.Load().(exportersMap)
+		mustExport := s.spanContext.IsSampled() && len(exp) > 0
+		if s.spanStore != nil || mustExport {
+			sd := s.makeSpanData()
+			sd.EndTime = internal.MonotonicEndTime(sd.StartTime)
+			if s.spanStore != nil {
+				s.spanStore.finished(s, sd)
+			}
+			if mustExport {
+				for e := range exp {
+					e.ExportSpan(sd)
+				}
+			}
+		}
+	})
+}
+
+// makeSpanData produces a SpanData representing the current state of the Span.
+// It requires that s.data is non-nil.
+func (s *Span) makeSpanData() *SpanData {
+	var sd SpanData
+	s.mu.Lock()
+	sd = *s.data
+	if s.data.Attributes != nil {
+		sd.Attributes = make(map[string]interface{})
+		for k, v := range s.data.Attributes {
+			sd.Attributes[k] = v
+		}
+	}
+	s.mu.Unlock()
+	return &sd
+}
+
+// SpanContext returns the SpanContext of the span.
+func (s *Span) SpanContext() SpanContext {
+	if s == nil {
+		return SpanContext{}
+	}
+	return s.spanContext
+}
+
+// SetName sets the name of the span, if it is recording events.
+func (s *Span) SetName(name string) {
+	if !s.IsRecordingEvents() {
+		return
+	}
+	s.mu.Lock()
+	s.data.Name = name
+	s.mu.Unlock()
+}
+
+// SetStatus sets the status of the span, if it is recording events.
+func (s *Span) SetStatus(status Status) {
+	if !s.IsRecordingEvents() {
+		return
+	}
+	s.mu.Lock()
+	s.data.Status = status
+	s.mu.Unlock()
+}
+
+// AddAttributes sets attributes in the span.
+//
+// Existing attributes whose keys appear in the attributes parameter are overwritten.
+func (s *Span) AddAttributes(attributes ...Attribute) {
+	if !s.IsRecordingEvents() {
+		return
+	}
+	s.mu.Lock()
+	if s.data.Attributes == nil {
+		s.data.Attributes = make(map[string]interface{})
+	}
+	copyAttributes(s.data.Attributes, attributes)
+	s.mu.Unlock()
+}
+
+// copyAttributes copies a slice of Attributes into a map.
+func copyAttributes(m map[string]interface{}, attributes []Attribute) {
+	for _, a := range attributes {
+		m[a.key] = a.value
+	}
+}
+
+func (s *Span) lazyPrintfInternal(attributes []Attribute, format string, a ...interface{}) {
+	now := time.Now()
+	msg := fmt.Sprintf(format, a...)
+	var m map[string]interface{}
+	s.mu.Lock()
+	if len(attributes) != 0 {
+		m = make(map[string]interface{})
+		copyAttributes(m, attributes)
+	}
+	s.data.Annotations = append(s.data.Annotations, Annotation{
+		Time:       now,
+		Message:    msg,
+		Attributes: m,
+	})
+	s.mu.Unlock()
+}
+
+func (s *Span) printStringInternal(attributes []Attribute, str string) {
+	now := time.Now()
+	var a map[string]interface{}
+	s.mu.Lock()
+	if len(attributes) != 0 {
+		a = make(map[string]interface{})
+		copyAttributes(a, attributes)
+	}
+	s.data.Annotations = append(s.data.Annotations, Annotation{
+		Time:       now,
+		Message:    str,
+		Attributes: a,
+	})
+	s.mu.Unlock()
+}
+
+// Annotate adds an annotation with attributes.
+// Attributes can be nil.
+func (s *Span) Annotate(attributes []Attribute, str string) {
+	if !s.IsRecordingEvents() {
+		return
+	}
+	s.printStringInternal(attributes, str)
+}
+
+// Annotatef adds an annotation with attributes.
+func (s *Span) Annotatef(attributes []Attribute, format string, a ...interface{}) {
+	if !s.IsRecordingEvents() {
+		return
+	}
+	s.lazyPrintfInternal(attributes, format, a...)
+}
+
+// AddMessageSendEvent adds a message send event to the span.
+//
+// messageID is an identifier for the message, which is recommended to be
+// unique in this span and the same between the send event and the receive
+// event (this allows to identify a message between the sender and receiver).
+// For example, this could be a sequence id.
+func (s *Span) AddMessageSendEvent(messageID, uncompressedByteSize, compressedByteSize int64) {
+	if !s.IsRecordingEvents() {
+		return
+	}
+	now := time.Now()
+	s.mu.Lock()
+	s.data.MessageEvents = append(s.data.MessageEvents, MessageEvent{
+		Time:                 now,
+		EventType:            MessageEventTypeSent,
+		MessageID:            messageID,
+		UncompressedByteSize: uncompressedByteSize,
+		CompressedByteSize:   compressedByteSize,
+	})
+	s.mu.Unlock()
+}
+
+// AddMessageReceiveEvent adds a message receive event to the span.
+//
+// messageID is an identifier for the message, which is recommended to be
+// unique in this span and the same between the send event and the receive
+// event (this allows to identify a message between the sender and receiver).
+// For example, this could be a sequence id.
+func (s *Span) AddMessageReceiveEvent(messageID, uncompressedByteSize, compressedByteSize int64) {
+	if !s.IsRecordingEvents() {
+		return
+	}
+	now := time.Now()
+	s.mu.Lock()
+	s.data.MessageEvents = append(s.data.MessageEvents, MessageEvent{
+		Time:                 now,
+		EventType:            MessageEventTypeRecv,
+		MessageID:            messageID,
+		UncompressedByteSize: uncompressedByteSize,
+		CompressedByteSize:   compressedByteSize,
+	})
+	s.mu.Unlock()
+}
+
+// AddLink adds a link to the span.
+func (s *Span) AddLink(l Link) {
+	if !s.IsRecordingEvents() {
+		return
+	}
+	s.mu.Lock()
+	s.data.Links = append(s.data.Links, l)
+	s.mu.Unlock()
+}
+
+func (s *Span) String() string {
+	if s == nil {
+		return "<nil>"
+	}
+	if s.data == nil {
+		return fmt.Sprintf("span %s", s.spanContext.SpanID)
+	}
+	s.mu.Lock()
+	str := fmt.Sprintf("span %s %q", s.spanContext.SpanID, s.data.Name)
+	s.mu.Unlock()
+	return str
+}
+
+var config atomic.Value // access atomically
+
+func init() {
+	gen := &defaultIDGenerator{}
+	// initialize traceID and spanID generators.
+	var rngSeed int64
+	for _, p := range []interface{}{
+		&rngSeed, &gen.traceIDAdd, &gen.nextSpanID, &gen.spanIDInc,
+	} {
+		binary.Read(crand.Reader, binary.LittleEndian, p)
+	}
+	gen.traceIDRand = rand.New(rand.NewSource(rngSeed))
+	gen.spanIDInc |= 1
+
+	config.Store(&Config{
+		DefaultSampler: ProbabilitySampler(defaultSamplingProbability),
+		IDGenerator:    gen,
+	})
+}
+
+type defaultIDGenerator struct {
+	sync.Mutex
+
+	// Please keep these as the first fields
+	// so that these 8 byte fields will be aligned on addresses
+	// divisible by 8, on both 32-bit and 64-bit machines when
+	// performing atomic increments and accesses.
+	// See:
+	// * https://github.com/census-instrumentation/opencensus-go/issues/587
+	// * https://github.com/census-instrumentation/opencensus-go/issues/865
+	// * https://golang.org/pkg/sync/atomic/#pkg-note-BUG
+	nextSpanID uint64
+	spanIDInc  uint64
+
+	traceIDAdd  [2]uint64
+	traceIDRand *rand.Rand
+}
+
+// NewSpanID returns a non-zero span ID from a randomly-chosen sequence.
+func (gen *defaultIDGenerator) NewSpanID() [8]byte {
+	var id uint64
+	for id == 0 {
+		id = atomic.AddUint64(&gen.nextSpanID, gen.spanIDInc)
+	}
+	var sid [8]byte
+	binary.LittleEndian.PutUint64(sid[:], id)
+	return sid
+}
+
+// NewTraceID returns a non-zero trace ID from a randomly-chosen sequence.
+// mu should be held while this function is called.
+func (gen *defaultIDGenerator) NewTraceID() [16]byte {
+	var tid [16]byte
+	// Construct the trace ID from two outputs of traceIDRand, with a constant
+	// added to each half for additional entropy.
+	gen.Lock()
+	binary.LittleEndian.PutUint64(tid[0:8], gen.traceIDRand.Uint64()+gen.traceIDAdd[0])
+	binary.LittleEndian.PutUint64(tid[8:16], gen.traceIDRand.Uint64()+gen.traceIDAdd[1])
+	gen.Unlock()
+	return tid
+}

vendor/go.opencensus.io/trace/trace_go11.go

@@ -0,0 +1,32 @@
+// Copyright 2018, OpenCensus Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build go1.11
+
+package trace
+
+import (
+	"context"
+	t "runtime/trace"
+)
+
+func startExecutionTracerTask(ctx context.Context, name string) (context.Context, func()) {
+	if !t.IsEnabled() {
+		// Avoid additional overhead if
+		// runtime/trace is not enabled.
+		return ctx, func() {}
+	}
+	nctx, task := t.NewTask(ctx, name)
+	return nctx, task.End
+}

vendor/go.opencensus.io/trace/trace_nongo11.go

@@ -0,0 +1,25 @@
+// Copyright 2018, OpenCensus Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build !go1.11
+
+package trace
+
+import (
+	"context"
+)
+
+func startExecutionTracerTask(ctx context.Context, name string) (context.Context, func()) {
+	return ctx, func() {}
+}

vendor/go.opencensus.io/trace/tracestate/tracestate.go

@@ -0,0 +1,145 @@
+// Copyright 2018, OpenCensus Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package tracestate
+
+import (
+	"fmt"
+	"regexp"
+)
+
+const (
+	keyMaxSize       = 256
+	valueMaxSize     = 256
+	maxKeyValuePairs = 32
+)
+
+const (
+	keyWithoutVendorFormat = `[a-z][_0-9a-z\-\*\/]{0,255}`
+	keyWithVendorFormat    = `[a-z][_0-9a-z\-\*\/]{0,240}@[a-z][_0-9a-z\-\*\/]{0,13}`
+	keyFormat              = `(` + keyWithoutVendorFormat + `)|(` + keyWithVendorFormat + `)`
+	valueFormat            = `[\x20-\x2b\x2d-\x3c\x3e-\x7e]{0,255}[\x21-\x2b\x2d-\x3c\x3e-\x7e]`
+)
+
+var keyValidationRegExp = regexp.MustCompile(`^(` + keyFormat + `)$`)
+var valueValidationRegExp = regexp.MustCompile(`^(` + valueFormat + `)$`)
+
+// Tracestate represents tracing-system specific context in a list of key-value pairs. Tracestate allows different
+// vendors propagate additional information and inter-operate with their legacy Id formats.
+type Tracestate struct {
+	entries []Entry
+}
+
+// Entry represents one key-value pair in a list of key-value pair of Tracestate.
+type Entry struct {
+	// Key is an opaque string up to 256 characters printable. It MUST begin with a lowercase letter,
+	// and can only contain lowercase letters a-z, digits 0-9, underscores _, dashes -, asterisks *, and
+	// forward slashes /.
+	Key string
+
+	// Value is an opaque string up to 256 characters printable ASCII RFC0020 characters (i.e., the
+	// range 0x20 to 0x7E) except comma , and =.
+	Value string
+}
+
+// Entries returns a slice of Entry.
+func (ts *Tracestate) Entries() []Entry {
+	if ts == nil {
+		return nil
+	}
+	return ts.entries
+}
+
+func (ts *Tracestate) remove(key string) *Entry {
+	for index, entry := range ts.entries {
+		if entry.Key == key {
+			ts.entries = append(ts.entries[:index], ts.entries[index+1:]...)
+			return &entry
+		}
+	}
+	return nil
+}
+
+func (ts *Tracestate) add(entries []Entry) error {
+	for _, entry := range entries {
+		ts.remove(entry.Key)
+	}
+	if len(ts.entries)+len(entries) > maxKeyValuePairs {
+		return fmt.Errorf("adding %d key-value pairs to current %d pairs exceeds the limit of %d",
+			len(entries), len(ts.entries), maxKeyValuePairs)
+	}
+	ts.entries = append(entries, ts.entries...)
+	return nil
+}
+
+func isValid(entry Entry) bool {
+	return keyValidationRegExp.MatchString(entry.Key) &&
+		valueValidationRegExp.MatchString(entry.Value)
+}
+
+func containsDuplicateKey(entries ...Entry) (string, bool) {
+	keyMap := make(map[string]int)
+	for _, entry := range entries {
+		if _, ok := keyMap[entry.Key]; ok {
+			return entry.Key, true
+		}
+		keyMap[entry.Key] = 1
+	}
+	return "", false
+}
+
+func areEntriesValid(entries ...Entry) (*Entry, bool) {
+	for _, entry := range entries {
+		if !isValid(entry) {
+			return &entry, false
+		}
+	}
+	return nil, true
+}
+
+// New creates a Tracestate object from a parent and/or entries (key-value pair).
+// Entries from the parent are copied if present. The entries passed to this function
+// are inserted in front of those copied from the parent. If an entry copied from the
+// parent contains the same key as one of the entry in entries then the entry copied
+// from the parent is removed. See add func.
+//
+// An error is returned with nil Tracestate if
+//  1. one or more entry in entries is invalid.
+//  2. two or more entries in the input entries have the same key.
+//  3. the number of entries combined from the parent and the input entries exceeds maxKeyValuePairs.
+//     (duplicate entry is counted only once).
+func New(parent *Tracestate, entries ...Entry) (*Tracestate, error) {
+	if parent == nil && len(entries) == 0 {
+		return nil, nil
+	}
+	if entry, ok := areEntriesValid(entries...); !ok {
+		return nil, fmt.Errorf("key-value pair {%s, %s} is invalid", entry.Key, entry.Value)
+	}
+
+	if key, duplicate := containsDuplicateKey(entries...); duplicate {
+		return nil, fmt.Errorf("contains duplicate keys (%s)", key)
+	}
+
+	tracestate := Tracestate{}
+
+	if parent != nil && len(parent.entries) > 0 {
+		tracestate.entries = append([]Entry{}, parent.entries...)
+	}
+
+	err := tracestate.add(entries)
+	if err != nil {
+		return nil, err
+	}
+	return &tracestate, nil
+}

vendor/golang.org/x/oauth2/LICENSE

@@ -1,4 +1,4 @@
-Copyright (c) 2009 The oauth2 Authors. All rights reserved.
+Copyright (c) 2009 The Go Authors. All rights reserved.
 
 Redistribution and use in source and binary forms, with or without
 modification, are permitted provided that the following conditions are

vendor/golang.org/x/oauth2/google/default.go

@@ -18,14 +18,6 @@ import (
 	"golang.org/x/oauth2"
 )
 
-// DefaultCredentials holds "Application Default Credentials".
-// For more details, see:
-// https://developers.google.com/accounts/docs/application-default-credentials
-type DefaultCredentials struct {
-	ProjectID   string // may be empty
-	TokenSource oauth2.TokenSource
-}
-
 // DefaultClient returns an HTTP Client that uses the
 // DefaultTokenSource to obtain authentication credentials.
 func DefaultClient(ctx context.Context, scope ...string) (*http.Client, error) {
@@ -47,25 +39,12 @@ func DefaultTokenSource(ctx context.Context, scope ...string) (oauth2.TokenSourc
 	return creds.TokenSource, nil
 }
 
-// FindDefaultCredentials searches for "Application Default Credentials".
-//
-// It looks for credentials in the following places,
-// preferring the first location found:
-//
-//   1. A JSON file whose path is specified by the
-//      GOOGLE_APPLICATION_CREDENTIALS environment variable.
-//   2. A JSON file in a location known to the gcloud command-line tool.
-//      On Windows, this is %APPDATA%/gcloud/application_default_credentials.json.
-//      On other systems, $HOME/.config/gcloud/application_default_credentials.json.
-//   3. On Google App Engine it uses the appengine.AccessToken function.
-//   4. On Google Compute Engine and Google App Engine Managed VMs, it fetches
-//      credentials from the metadata server.
-//      (In this final case any provided scopes are ignored.)
-func FindDefaultCredentials(ctx context.Context, scope ...string) (*DefaultCredentials, error) {
+// Common implementation for FindDefaultCredentials.
+func findDefaultCredentials(ctx context.Context, scopes []string) (*DefaultCredentials, error) {
 	// First, try the environment variable.
 	const envVar = "GOOGLE_APPLICATION_CREDENTIALS"
 	if filename := os.Getenv(envVar); filename != "" {
-		creds, err := readCredentialsFile(ctx, filename, scope)
+		creds, err := readCredentialsFile(ctx, filename, scopes)
 		if err != nil {
 			return nil, fmt.Errorf("google: error getting credentials using %v environment variable: %v", envVar, err)
 		}
@@ -74,7 +53,7 @@ func FindDefaultCredentials(ctx context.Context, scope ...string) (*DefaultCrede
 
 	// Second, try a well-known file.
 	filename := wellKnownFile()
-	if creds, err := readCredentialsFile(ctx, filename, scope); err == nil {
+	if creds, err := readCredentialsFile(ctx, filename, scopes); err == nil {
 		return creds, nil
 	} else if !os.IsNotExist(err) {
 		return nil, fmt.Errorf("google: error getting credentials using well-known file (%v): %v", filename, err)
@@ -84,7 +63,7 @@ func FindDefaultCredentials(ctx context.Context, scope ...string) (*DefaultCrede
 	if appengineTokenFunc != nil && !appengineFlex {
 		return &DefaultCredentials{
 			ProjectID:   appengineAppIDFunc(ctx),
-			TokenSource: AppEngineTokenSource(ctx, scope...),
+			TokenSource: AppEngineTokenSource(ctx, scopes...),
 		}, nil
 	}
 
@@ -102,6 +81,23 @@ func FindDefaultCredentials(ctx context.Context, scope ...string) (*DefaultCrede
 	return nil, fmt.Errorf("google: could not find default credentials. See %v for more information.", url)
 }
 
+// Common implementation for CredentialsFromJSON.
+func credentialsFromJSON(ctx context.Context, jsonData []byte, scopes []string) (*DefaultCredentials, error) {
+	var f credentialsFile
+	if err := json.Unmarshal(jsonData, &f); err != nil {
+		return nil, err
+	}
+	ts, err := f.tokenSource(ctx, append([]string(nil), scopes...))
+	if err != nil {
+		return nil, err
+	}
+	return &DefaultCredentials{
+		ProjectID:   f.ProjectID,
+		TokenSource: ts,
+		JSON:        jsonData,
+	}, nil
+}
+
 func wellKnownFile() string {
 	const f = "application_default_credentials.json"
 	if runtime.GOOS == "windows" {
@@ -115,16 +111,5 @@ func readCredentialsFile(ctx context.Context, filename string, scopes []string)
 	if err != nil {
 		return nil, err
 	}
-	var f credentialsFile
-	if err := json.Unmarshal(b, &f); err != nil {
-		return nil, err
-	}
-	ts, err := f.tokenSource(ctx, append([]string(nil), scopes...))
-	if err != nil {
-		return nil, err
-	}
-	return &DefaultCredentials{
-		ProjectID:   f.ProjectID,
-		TokenSource: ts,
-	}, nil
+	return CredentialsFromJSON(ctx, b, scopes...)
 }

vendor/golang.org/x/oauth2/google/doc_go19.go

@@ -0,0 +1,42 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build go1.9
+
+// Package google provides support for making OAuth2 authorized and authenticated
+// HTTP requests to Google APIs. It supports the Web server flow, client-side
+// credentials, service accounts, Google Compute Engine service accounts, and Google
+// App Engine service accounts.
+//
+// A brief overview of the package follows. For more information, please read
+// https://developers.google.com/accounts/docs/OAuth2
+// and
+// https://developers.google.com/accounts/docs/application-default-credentials.
+//
+// OAuth2 Configs
+//
+// Two functions in this package return golang.org/x/oauth2.Config values from Google credential
+// data. Google supports two JSON formats for OAuth2 credentials: one is handled by ConfigFromJSON,
+// the other by JWTConfigFromJSON. The returned Config can be used to obtain a TokenSource or
+// create an http.Client.
+//
+//
+// Credentials
+//
+// The Credentials type represents Google credentials, including Application Default
+// Credentials.
+//
+// Use FindDefaultCredentials to obtain Application Default Credentials.
+// FindDefaultCredentials looks in some well-known places for a credentials file, and
+// will call AppEngineTokenSource or ComputeTokenSource as needed.
+//
+// DefaultClient and DefaultTokenSource are convenience methods. They first call FindDefaultCredentials,
+// then use the credentials to construct an http.Client or an oauth2.TokenSource.
+//
+// Use CredentialsFromJSON to obtain credentials from either of the two JSON formats
+// described in OAuth2 Configs, above. The TokenSource in the returned value is the
+// same as the one obtained from the oauth2.Config returned from ConfigFromJSON or
+// JWTConfigFromJSON, but the Credentials may contain additional information
+// that is useful is some circumstances.
+package google // import "golang.org/x/oauth2/google"