Squashed 'third_party/src/github.com/gorilla/context/' content from commit 14f550f

git-subtree-dir: third_party/src/github.com/gorilla/context
git-subtree-split: 14f550f51af52180c2eefed15e5fd18d63c0a64a
This commit is contained in:
Frederick F. Kautz IV 2014-11-01 21:03:30 -07:00
commit 4aa2e2eaa0
6 changed files with 427 additions and 0 deletions

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language: go
go:
- 1.0
- 1.1
- 1.2
- tip

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Copyright (c) 2012 Rodrigo Moraes. All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are
met:
* Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above
copyright notice, this list of conditions and the following disclaimer
in the documentation and/or other materials provided with the
distribution.
* Neither the name of Google Inc. nor the names of its
contributors may be used to endorse or promote products derived from
this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

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context
=======
[![Build Status](https://travis-ci.org/gorilla/context.png?branch=master)](https://travis-ci.org/gorilla/context)
gorilla/context is a general purpose registry for global request variables.
Read the full documentation here: http://www.gorillatoolkit.org/pkg/context

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// Copyright 2012 The Gorilla Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package context
import (
"net/http"
"sync"
"time"
)
var (
mutex sync.RWMutex
data = make(map[*http.Request]map[interface{}]interface{})
datat = make(map[*http.Request]int64)
)
// Set stores a value for a given key in a given request.
func Set(r *http.Request, key, val interface{}) {
mutex.Lock()
if data[r] == nil {
data[r] = make(map[interface{}]interface{})
datat[r] = time.Now().Unix()
}
data[r][key] = val
mutex.Unlock()
}
// Get returns a value stored for a given key in a given request.
func Get(r *http.Request, key interface{}) interface{} {
mutex.RLock()
if ctx := data[r]; ctx != nil {
value := ctx[key]
mutex.RUnlock()
return value
}
mutex.RUnlock()
return nil
}
// GetOk returns stored value and presence state like multi-value return of map access.
func GetOk(r *http.Request, key interface{}) (interface{}, bool) {
mutex.RLock()
if _, ok := data[r]; ok {
value, ok := data[r][key]
mutex.RUnlock()
return value, ok
}
mutex.RUnlock()
return nil, false
}
// GetAll returns all stored values for the request as a map. Nil is returned for invalid requests.
func GetAll(r *http.Request) map[interface{}]interface{} {
mutex.RLock()
if context, ok := data[r]; ok {
result := make(map[interface{}]interface{}, len(context))
for k, v := range context {
result[k] = v
}
mutex.RUnlock()
return result
}
mutex.RUnlock()
return nil
}
// GetAllOk returns all stored values for the request as a map and a boolean value that indicates if
// the request was registered.
func GetAllOk(r *http.Request) (map[interface{}]interface{}, bool) {
mutex.RLock()
context, ok := data[r]
result := make(map[interface{}]interface{}, len(context))
for k, v := range context {
result[k] = v
}
mutex.RUnlock()
return result, ok
}
// Delete removes a value stored for a given key in a given request.
func Delete(r *http.Request, key interface{}) {
mutex.Lock()
if data[r] != nil {
delete(data[r], key)
}
mutex.Unlock()
}
// Clear removes all values stored for a given request.
//
// This is usually called by a handler wrapper to clean up request
// variables at the end of a request lifetime. See ClearHandler().
func Clear(r *http.Request) {
mutex.Lock()
clear(r)
mutex.Unlock()
}
// clear is Clear without the lock.
func clear(r *http.Request) {
delete(data, r)
delete(datat, r)
}
// Purge removes request data stored for longer than maxAge, in seconds.
// It returns the amount of requests removed.
//
// If maxAge <= 0, all request data is removed.
//
// This is only used for sanity check: in case context cleaning was not
// properly set some request data can be kept forever, consuming an increasing
// amount of memory. In case this is detected, Purge() must be called
// periodically until the problem is fixed.
func Purge(maxAge int) int {
mutex.Lock()
count := 0
if maxAge <= 0 {
count = len(data)
data = make(map[*http.Request]map[interface{}]interface{})
datat = make(map[*http.Request]int64)
} else {
min := time.Now().Unix() - int64(maxAge)
for r := range data {
if datat[r] < min {
clear(r)
count++
}
}
}
mutex.Unlock()
return count
}
// ClearHandler wraps an http.Handler and clears request values at the end
// of a request lifetime.
func ClearHandler(h http.Handler) http.Handler {
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
defer Clear(r)
h.ServeHTTP(w, r)
})
}

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// Copyright 2012 The Gorilla Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package context
import (
"net/http"
"testing"
)
type keyType int
const (
key1 keyType = iota
key2
)
func TestContext(t *testing.T) {
assertEqual := func(val interface{}, exp interface{}) {
if val != exp {
t.Errorf("Expected %v, got %v.", exp, val)
}
}
r, _ := http.NewRequest("GET", "http://localhost:8080/", nil)
emptyR, _ := http.NewRequest("GET", "http://localhost:8080/", nil)
// Get()
assertEqual(Get(r, key1), nil)
// Set()
Set(r, key1, "1")
assertEqual(Get(r, key1), "1")
assertEqual(len(data[r]), 1)
Set(r, key2, "2")
assertEqual(Get(r, key2), "2")
assertEqual(len(data[r]), 2)
//GetOk
value, ok := GetOk(r, key1)
assertEqual(value, "1")
assertEqual(ok, true)
value, ok = GetOk(r, "not exists")
assertEqual(value, nil)
assertEqual(ok, false)
Set(r, "nil value", nil)
value, ok = GetOk(r, "nil value")
assertEqual(value, nil)
assertEqual(ok, true)
// GetAll()
values := GetAll(r)
assertEqual(len(values), 3)
// GetAll() for empty request
values = GetAll(emptyR)
if values != nil {
t.Error("GetAll didn't return nil value for invalid request")
}
// GetAllOk()
values, ok = GetAllOk(r)
assertEqual(len(values), 3)
assertEqual(ok, true)
// GetAllOk() for empty request
values, ok = GetAllOk(emptyR)
assertEqual(value, nil)
assertEqual(ok, false)
// Delete()
Delete(r, key1)
assertEqual(Get(r, key1), nil)
assertEqual(len(data[r]), 2)
Delete(r, key2)
assertEqual(Get(r, key2), nil)
assertEqual(len(data[r]), 1)
// Clear()
Clear(r)
assertEqual(len(data), 0)
}
func parallelReader(r *http.Request, key string, iterations int, wait, done chan struct{}) {
<-wait
for i := 0; i < iterations; i++ {
Get(r, key)
}
done <- struct{}{}
}
func parallelWriter(r *http.Request, key, value string, iterations int, wait, done chan struct{}) {
<-wait
for i := 0; i < iterations; i++ {
Get(r, key)
}
done <- struct{}{}
}
func benchmarkMutex(b *testing.B, numReaders, numWriters, iterations int) {
b.StopTimer()
r, _ := http.NewRequest("GET", "http://localhost:8080/", nil)
done := make(chan struct{})
b.StartTimer()
for i := 0; i < b.N; i++ {
wait := make(chan struct{})
for i := 0; i < numReaders; i++ {
go parallelReader(r, "test", iterations, wait, done)
}
for i := 0; i < numWriters; i++ {
go parallelWriter(r, "test", "123", iterations, wait, done)
}
close(wait)
for i := 0; i < numReaders+numWriters; i++ {
<-done
}
}
}
func BenchmarkMutexSameReadWrite1(b *testing.B) {
benchmarkMutex(b, 1, 1, 32)
}
func BenchmarkMutexSameReadWrite2(b *testing.B) {
benchmarkMutex(b, 2, 2, 32)
}
func BenchmarkMutexSameReadWrite4(b *testing.B) {
benchmarkMutex(b, 4, 4, 32)
}
func BenchmarkMutex1(b *testing.B) {
benchmarkMutex(b, 2, 8, 32)
}
func BenchmarkMutex2(b *testing.B) {
benchmarkMutex(b, 16, 4, 64)
}
func BenchmarkMutex3(b *testing.B) {
benchmarkMutex(b, 1, 2, 128)
}
func BenchmarkMutex4(b *testing.B) {
benchmarkMutex(b, 128, 32, 256)
}
func BenchmarkMutex5(b *testing.B) {
benchmarkMutex(b, 1024, 2048, 64)
}
func BenchmarkMutex6(b *testing.B) {
benchmarkMutex(b, 2048, 1024, 512)
}

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// Copyright 2012 The Gorilla Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
/*
Package context stores values shared during a request lifetime.
For example, a router can set variables extracted from the URL and later
application handlers can access those values, or it can be used to store
sessions values to be saved at the end of a request. There are several
others common uses.
The idea was posted by Brad Fitzpatrick to the go-nuts mailing list:
http://groups.google.com/group/golang-nuts/msg/e2d679d303aa5d53
Here's the basic usage: first define the keys that you will need. The key
type is interface{} so a key can be of any type that supports equality.
Here we define a key using a custom int type to avoid name collisions:
package foo
import (
"github.com/gorilla/context"
)
type key int
const MyKey key = 0
Then set a variable. Variables are bound to an http.Request object, so you
need a request instance to set a value:
context.Set(r, MyKey, "bar")
The application can later access the variable using the same key you provided:
func MyHandler(w http.ResponseWriter, r *http.Request) {
// val is "bar".
val := context.Get(r, foo.MyKey)
// returns ("bar", true)
val, ok := context.GetOk(r, foo.MyKey)
// ...
}
And that's all about the basic usage. We discuss some other ideas below.
Any type can be stored in the context. To enforce a given type, make the key
private and wrap Get() and Set() to accept and return values of a specific
type:
type key int
const mykey key = 0
// GetMyKey returns a value for this package from the request values.
func GetMyKey(r *http.Request) SomeType {
if rv := context.Get(r, mykey); rv != nil {
return rv.(SomeType)
}
return nil
}
// SetMyKey sets a value for this package in the request values.
func SetMyKey(r *http.Request, val SomeType) {
context.Set(r, mykey, val)
}
Variables must be cleared at the end of a request, to remove all values
that were stored. This can be done in an http.Handler, after a request was
served. Just call Clear() passing the request:
context.Clear(r)
...or use ClearHandler(), which conveniently wraps an http.Handler to clear
variables at the end of a request lifetime.
The Routers from the packages gorilla/mux and gorilla/pat call Clear()
so if you are using either of them you don't need to clear the context manually.
*/
package context