minio/cmd/disk-cache.go

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/*
* Minio Cloud Storage, (C) 2018 Minio, Inc.
*
* 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 cmd
import (
"context"
"errors"
"fmt"
"io"
"io/ioutil"
"net/http"
"os"
"sort"
"strconv"
"strings"
"time"
"github.com/djherbis/atime"
"github.com/minio/minio/cmd/logger"
"github.com/minio/minio/pkg/wildcard"
"github.com/minio/minio/pkg/hash"
)
// list of all errors that can be ignored in tree walk operation in disk cache
var cacheTreeWalkIgnoredErrs = append(baseIgnoredErrs, errDiskAccessDenied, errVolumeNotFound, errFileNotFound)
const (
// disk cache needs to have cacheSizeMultiplier * object size space free for a cache entry to be created.
cacheSizeMultiplier = 100
cacheTrashDir = "trash"
cacheMaxDiskUsagePct = 80 // in %
cacheCleanupInterval = 10 // in minutes
)
// abstract slice of cache drives backed by FS.
type diskCache struct {
cfs []*cacheFSObjects
}
// Abstracts disk caching - used by the S3 layer
type cacheObjects struct {
// pointer to disk cache
cache *diskCache
// ListObjects pool management.
listPool *treeWalkPool
// file path patterns to exclude from cache
exclude []string
// Object functions pointing to the corresponding functions of backend implementation.
GetObjectFn func(ctx context.Context, bucket, object string, startOffset int64, length int64, writer io.Writer, etag string) (err error)
GetObjectInfoFn func(ctx context.Context, bucket, object string) (objInfo ObjectInfo, err error)
PutObjectFn func(ctx context.Context, bucket, object string, data *hash.Reader, metadata map[string]string) (objInfo ObjectInfo, err error)
DeleteObjectFn func(ctx context.Context, bucket, object string) error
ListObjectsFn func(ctx context.Context, bucket, prefix, marker, delimiter string, maxKeys int) (result ListObjectsInfo, err error)
ListObjectsV2Fn func(ctx context.Context, bucket, prefix, continuationToken, delimiter string, maxKeys int, fetchOwner bool, startAfter string) (result ListObjectsV2Info, err error)
ListBucketsFn func(ctx context.Context) (buckets []BucketInfo, err error)
GetBucketInfoFn func(ctx context.Context, bucket string) (bucketInfo BucketInfo, err error)
NewMultipartUploadFn func(ctx context.Context, bucket, object string, metadata map[string]string) (uploadID string, err error)
PutObjectPartFn func(ctx context.Context, bucket, object, uploadID string, partID int, data *hash.Reader) (info PartInfo, err error)
AbortMultipartUploadFn func(ctx context.Context, bucket, object, uploadID string) error
CompleteMultipartUploadFn func(ctx context.Context, bucket, object, uploadID string, uploadedParts []CompletePart) (objInfo ObjectInfo, err error)
DeleteBucketFn func(ctx context.Context, bucket string) error
}
// CacheObjectLayer implements primitives for cache object API layer.
type CacheObjectLayer interface {
// Bucket operations.
ListObjects(ctx context.Context, bucket, prefix, marker, delimiter string, maxKeys int) (result ListObjectsInfo, err error)
ListObjectsV2(ctx context.Context, bucket, prefix, continuationToken, delimiter string, maxKeys int, fetchOwner bool, startAfter string) (result ListObjectsV2Info, err error)
GetBucketInfo(ctx context.Context, bucket string) (bucketInfo BucketInfo, err error)
ListBuckets(ctx context.Context) (buckets []BucketInfo, err error)
DeleteBucket(ctx context.Context, bucket string) error
// Object operations.
GetObject(ctx context.Context, bucket, object string, startOffset int64, length int64, writer io.Writer, etag string) (err error)
GetObjectInfo(ctx context.Context, bucket, object string) (objInfo ObjectInfo, err error)
PutObject(ctx context.Context, bucket, object string, data *hash.Reader, metadata map[string]string) (objInfo ObjectInfo, err error)
DeleteObject(ctx context.Context, bucket, object string) error
// Multipart operations.
NewMultipartUpload(ctx context.Context, bucket, object string, metadata map[string]string) (uploadID string, err error)
PutObjectPart(ctx context.Context, bucket, object, uploadID string, partID int, data *hash.Reader) (info PartInfo, err error)
AbortMultipartUpload(ctx context.Context, bucket, object, uploadID string) error
CompleteMultipartUpload(ctx context.Context, bucket, object, uploadID string, uploadedParts []CompletePart) (objInfo ObjectInfo, err error)
// Storage operations.
StorageInfo(ctx context.Context) StorageInfo
}
// backendDownError returns true if err is due to backend failure or faulty disk if in server mode
func backendDownError(err error) bool {
_, backendDown := err.(BackendDown)
return backendDown || IsErr(err, baseErrs...)
}
// get cache disk where object is currently cached for a GET operation. If object does not exist at that location,
// treat the list of cache drives as a circular buffer and walk through them starting at hash index
// until an online drive is found.If object is not found, fall back to the first online cache drive
// closest to the hash index, so that object can be recached.
func (c diskCache) getCachedFSLoc(ctx context.Context, bucket, object string) (*cacheFSObjects, error) {
index := c.hashIndex(bucket, object)
numDisks := len(c.cfs)
// save first online cache disk closest to the hint index
var firstOnlineDisk *cacheFSObjects
for k := 0; k < numDisks; k++ {
i := (index + k) % numDisks
if c.cfs[i] == nil {
continue
}
if c.cfs[i].IsOnline() {
if firstOnlineDisk == nil {
firstOnlineDisk = c.cfs[i]
}
if c.cfs[i].Exists(ctx, bucket, object) {
return c.cfs[i], nil
}
}
}
if firstOnlineDisk != nil {
return firstOnlineDisk, nil
}
return nil, errDiskNotFound
}
// choose a cache deterministically based on hash of bucket,object. The hash index is treated as
// a hint. In the event that the cache drive at hash index is offline, treat the list of cache drives
// as a circular buffer and walk through them starting at hash index until an online drive is found.
func (c diskCache) getCacheFS(ctx context.Context, bucket, object string) (*cacheFSObjects, error) {
index := c.hashIndex(bucket, object)
numDisks := len(c.cfs)
for k := 0; k < numDisks; k++ {
i := (index + k) % numDisks
if c.cfs[i] == nil {
continue
}
if c.cfs[i].IsOnline() {
return c.cfs[i], nil
}
}
return nil, errDiskNotFound
}
// Compute a unique hash sum for bucket and object
func (c diskCache) hashIndex(bucket, object string) int {
return crcHashMod(pathJoin(bucket, object), len(c.cfs))
}
// construct a metadata k-v map
func (c cacheObjects) getMetadata(objInfo ObjectInfo) map[string]string {
metadata := make(map[string]string)
metadata["etag"] = objInfo.ETag
metadata["content-type"] = objInfo.ContentType
metadata["content-encoding"] = objInfo.ContentEncoding
for key, val := range objInfo.UserDefined {
metadata[key] = val
}
return metadata
}
// Uses cached-object to serve the request. If object is not cached it serves the request from the backend and also
// stores it in the cache for serving subsequent requests.
func (c cacheObjects) GetObject(ctx context.Context, bucket, object string, startOffset int64, length int64, writer io.Writer, etag string) (err error) {
GetObjectFn := c.GetObjectFn
GetObjectInfoFn := c.GetObjectInfoFn
if c.isCacheExclude(bucket, object) {
return GetObjectFn(ctx, bucket, object, startOffset, length, writer, etag)
}
// fetch cacheFSObjects if object is currently cached or nearest available cache drive
dcache, err := c.cache.getCachedFSLoc(ctx, bucket, object)
if err != nil {
return GetObjectFn(ctx, bucket, object, startOffset, length, writer, etag)
}
// stat object on backend
objInfo, err := GetObjectInfoFn(ctx, bucket, object)
backendDown := backendDownError(err)
if err != nil && !backendDown {
if _, ok := err.(ObjectNotFound); ok {
// Delete the cached entry if backend object was deleted.
dcache.Delete(ctx, bucket, object)
}
return err
}
if !backendDown && filterFromCache(objInfo.UserDefined) {
return GetObjectFn(ctx, bucket, object, startOffset, length, writer, etag)
}
cachedObjInfo, err := dcache.GetObjectInfo(ctx, bucket, object)
if err == nil {
if backendDown {
// If the backend is down, serve the request from cache.
return dcache.Get(ctx, bucket, object, startOffset, length, writer, etag)
}
if cachedObjInfo.ETag == objInfo.ETag && !isStaleCache(objInfo) {
return dcache.Get(ctx, bucket, object, startOffset, length, writer, etag)
}
dcache.Delete(ctx, bucket, object)
}
if startOffset != 0 || length != objInfo.Size {
// We don't cache partial objects.
return GetObjectFn(ctx, bucket, object, startOffset, length, writer, etag)
}
if !dcache.diskAvailable(objInfo.Size * cacheSizeMultiplier) {
// cache only objects < 1/100th of disk capacity
return GetObjectFn(ctx, bucket, object, startOffset, length, writer, etag)
}
// Initialize pipe.
pipeReader, pipeWriter := io.Pipe()
hashReader, err := hash.NewReader(pipeReader, objInfo.Size, "", "")
if err != nil {
return err
}
go func() {
if err = GetObjectFn(ctx, bucket, object, 0, objInfo.Size, io.MultiWriter(writer, pipeWriter), etag); err != nil {
pipeWriter.CloseWithError(err)
return
}
pipeWriter.Close() // Close writer explicitly signalling we wrote all data.
}()
err = dcache.Put(ctx, bucket, object, hashReader, c.getMetadata(objInfo))
if err != nil {
return err
}
pipeReader.Close()
return
}
// Returns ObjectInfo from cache if available.
func (c cacheObjects) GetObjectInfo(ctx context.Context, bucket, object string) (ObjectInfo, error) {
getObjectInfoFn := c.GetObjectInfoFn
if c.isCacheExclude(bucket, object) {
return getObjectInfoFn(ctx, bucket, object)
}
// fetch cacheFSObjects if object is currently cached or nearest available cache drive
dcache, err := c.cache.getCachedFSLoc(ctx, bucket, object)
if err != nil {
return getObjectInfoFn(ctx, bucket, object)
}
objInfo, err := getObjectInfoFn(ctx, bucket, object)
if err != nil {
if _, ok := err.(ObjectNotFound); ok {
// Delete the cached entry if backend object was deleted.
dcache.Delete(ctx, bucket, object)
return ObjectInfo{}, err
}
if !backendDownError(err) {
return ObjectInfo{}, err
}
// when backend is down, serve from cache.
cachedObjInfo, cerr := dcache.GetObjectInfo(ctx, bucket, object)
if cerr == nil {
return cachedObjInfo, nil
}
return ObjectInfo{}, BackendDown{}
}
// when backend is up, do a sanity check on cached object
cachedObjInfo, err := dcache.GetObjectInfo(ctx, bucket, object)
if err != nil {
return objInfo, nil
}
if cachedObjInfo.ETag != objInfo.ETag {
// Delete the cached entry if the backend object was replaced.
dcache.Delete(ctx, bucket, object)
}
return objInfo, nil
}
// Returns function "listDir" of the type listDirFunc.
// isLeaf - is used by listDir function to check if an entry is a leaf or non-leaf entry.
// disks - list of fsObjects
func listDirCacheFactory(isLeaf isLeafFunc, treeWalkIgnoredErrs []error, disks []*cacheFSObjects) listDirFunc {
listCacheDirs := func(bucket, prefixDir, prefixEntry string) (dirs []string, err error) {
var entries []string
for _, disk := range disks {
// ignore disk-caches that might be missing/offline
if disk == nil {
continue
}
fs := disk.FSObjects
entries, err = readDir(pathJoin(fs.fsPath, bucket, prefixDir))
// For any reason disk was deleted or goes offline, continue
// and list from other disks if possible.
if err != nil {
if IsErrIgnored(err, treeWalkIgnoredErrs...) {
continue
}
return nil, err
}
// Filter entries that have the prefix prefixEntry.
entries = filterMatchingPrefix(entries, prefixEntry)
dirs = append(dirs, entries...)
}
return dirs, nil
}
// listDir - lists all the entries at a given prefix and given entry in the prefix.
listDir := func(bucket, prefixDir, prefixEntry string) (mergedEntries []string, delayIsLeaf bool, err error) {
var cacheEntries []string
cacheEntries, err = listCacheDirs(bucket, prefixDir, prefixEntry)
if err != nil {
return nil, false, err
}
for _, entry := range cacheEntries {
// Find elements in entries which are not in mergedEntries
idx := sort.SearchStrings(mergedEntries, entry)
// if entry is already present in mergedEntries don't add.
if idx < len(mergedEntries) && mergedEntries[idx] == entry {
continue
}
mergedEntries = append(mergedEntries, entry)
sort.Strings(mergedEntries)
}
return mergedEntries, false, nil
}
return listDir
}
// List all objects at prefix upto maxKeys, optionally delimited by '/' from the cache. Maintains the list pool
// state for future re-entrant list requests.
func (c cacheObjects) listCacheObjects(ctx context.Context, bucket, prefix, marker, delimiter string, maxKeys int) (result ListObjectsInfo, err error) {
var objInfos []ObjectInfo
var eof bool
var nextMarker string
recursive := true
if delimiter == slashSeparator {
recursive = false
}
walkResultCh, endWalkCh := c.listPool.Release(listParams{bucket, recursive, marker, prefix, false})
if walkResultCh == nil {
endWalkCh = make(chan struct{})
isLeaf := func(bucket, object string) bool {
fs, err := c.cache.getCacheFS(ctx, bucket, object)
if err != nil {
return false
}
_, err = fs.getObjectInfo(ctx, bucket, object)
return err == nil
}
isLeafDir := func(bucket, object string) bool {
fs, err := c.cache.getCacheFS(ctx, bucket, object)
if err != nil {
return false
}
return fs.isObjectDir(bucket, object)
}
listDir := listDirCacheFactory(isLeaf, cacheTreeWalkIgnoredErrs, c.cache.cfs)
walkResultCh = startTreeWalk(ctx, bucket, prefix, marker, recursive, listDir, isLeaf, isLeafDir, endWalkCh)
}
for i := 0; i < maxKeys; {
walkResult, ok := <-walkResultCh
if !ok {
// Closed channel.
eof = true
break
}
// For any walk error return right away.
if walkResult.err != nil {
return result, toObjectErr(walkResult.err, bucket, prefix)
}
entry := walkResult.entry
var objInfo ObjectInfo
if hasSuffix(entry, slashSeparator) {
// Object name needs to be full path.
objInfo.Bucket = bucket
objInfo.Name = entry
objInfo.IsDir = true
} else {
// Set the Mode to a "regular" file.
var err error
fs, err := c.cache.getCacheFS(ctx, bucket, entry)
if err != nil {
// Ignore errDiskNotFound
if err == errDiskNotFound {
continue
}
return result, toObjectErr(err, bucket, prefix)
}
objInfo, err = fs.getObjectInfo(ctx, bucket, entry)
if err != nil {
// Ignore ObjectNotFound error
if _, ok := err.(ObjectNotFound); ok {
continue
}
return result, toObjectErr(err, bucket, prefix)
}
}
nextMarker = objInfo.Name
objInfos = append(objInfos, objInfo)
i++
if walkResult.end {
eof = true
break
}
}
params := listParams{bucket, recursive, nextMarker, prefix, false}
if !eof {
c.listPool.Set(params, walkResultCh, endWalkCh)
}
result = ListObjectsInfo{IsTruncated: !eof}
for _, objInfo := range objInfos {
result.NextMarker = objInfo.Name
if objInfo.IsDir && delimiter == slashSeparator {
result.Prefixes = append(result.Prefixes, objInfo.Name)
continue
}
result.Objects = append(result.Objects, objInfo)
}
return result, nil
}
// listCacheV2Objects lists all blobs in bucket filtered by prefix from the cache
func (c cacheObjects) listCacheV2Objects(ctx context.Context, bucket, prefix, continuationToken, delimiter string, maxKeys int, fetchOwner bool, startAfter string) (result ListObjectsV2Info, err error) {
loi, err := c.listCacheObjects(ctx, bucket, prefix, continuationToken, delimiter, maxKeys)
if err != nil {
return result, err
}
listObjectsV2Info := ListObjectsV2Info{
IsTruncated: loi.IsTruncated,
ContinuationToken: continuationToken,
NextContinuationToken: loi.NextMarker,
Objects: loi.Objects,
Prefixes: loi.Prefixes,
}
return listObjectsV2Info, err
}
// List all objects at prefix upto maxKeys., optionally delimited by '/'. Maintains the list pool
// state for future re-entrant list requests. Retrieve from cache if backend is down
func (c cacheObjects) ListObjects(ctx context.Context, bucket, prefix, marker, delimiter string, maxKeys int) (result ListObjectsInfo, err error) {
listObjectsFn := c.ListObjectsFn
result, err = listObjectsFn(ctx, bucket, prefix, marker, delimiter, maxKeys)
if err != nil {
if backendDownError(err) {
return c.listCacheObjects(ctx, bucket, prefix, marker, delimiter, maxKeys)
}
return
}
return
}
// ListObjectsV2 lists all blobs in bucket filtered by prefix
func (c cacheObjects) ListObjectsV2(ctx context.Context, bucket, prefix, continuationToken, delimiter string, maxKeys int, fetchOwner bool, startAfter string) (result ListObjectsV2Info, err error) {
listObjectsV2Fn := c.ListObjectsV2Fn
result, err = listObjectsV2Fn(ctx, bucket, prefix, continuationToken, delimiter, maxKeys, fetchOwner, startAfter)
if err != nil {
if backendDownError(err) {
return c.listCacheV2Objects(ctx, bucket, prefix, continuationToken, delimiter, maxKeys, fetchOwner, startAfter)
}
return
}
return
}
// Lists all the buckets in the cache
func (c cacheObjects) listBuckets(ctx context.Context) (buckets []BucketInfo, err error) {
m := make(map[string]string)
for _, cache := range c.cache.cfs {
// ignore disk-caches that might be missing/offline
if cache == nil {
continue
}
entries, err := cache.ListBuckets(ctx)
if err != nil {
return nil, err
}
for _, entry := range entries {
_, ok := m[entry.Name]
if !ok {
m[entry.Name] = entry.Name
buckets = append(buckets, entry)
}
}
}
// Sort bucket infos by bucket name.
sort.Sort(byBucketName(buckets))
return
}
// Returns list of buckets from cache or the backend. If the backend is down, buckets
// available on cache are served.
func (c cacheObjects) ListBuckets(ctx context.Context) (buckets []BucketInfo, err error) {
listBucketsFn := c.ListBucketsFn
buckets, err = listBucketsFn(ctx)
if err != nil {
if backendDownError(err) {
return c.listBuckets(ctx)
}
return []BucketInfo{}, err
}
return
}
// Returns bucket info from cache if backend is down.
func (c cacheObjects) GetBucketInfo(ctx context.Context, bucket string) (bucketInfo BucketInfo, err error) {
getBucketInfoFn := c.GetBucketInfoFn
bucketInfo, err = getBucketInfoFn(ctx, bucket)
if backendDownError(err) {
for _, cache := range c.cache.cfs {
// ignore disk-caches that might be missing/offline
if cache == nil {
continue
}
if bucketInfo, err = cache.GetBucketInfo(ctx, bucket); err == nil {
return
}
}
}
return
}
// Delete Object deletes from cache as well if backend operation succeeds
func (c cacheObjects) DeleteObject(ctx context.Context, bucket, object string) (err error) {
if err = c.DeleteObjectFn(ctx, bucket, object); err != nil {
return
}
if c.isCacheExclude(bucket, object) {
return
}
dcache, cerr := c.cache.getCachedFSLoc(ctx, bucket, object)
if cerr == nil {
_ = dcache.DeleteObject(ctx, bucket, object)
}
return
}
// Returns true if object should be excluded from cache
func (c cacheObjects) isCacheExclude(bucket, object string) bool {
for _, pattern := range c.exclude {
matchStr := fmt.Sprintf("%s/%s", bucket, object)
if ok := wildcard.MatchSimple(pattern, matchStr); ok {
return true
}
}
return false
}
// PutObject - caches the uploaded object for single Put operations
func (c cacheObjects) PutObject(ctx context.Context, bucket, object string, r *hash.Reader, metadata map[string]string) (objInfo ObjectInfo, err error) {
putObjectFn := c.PutObjectFn
dcache, err := c.cache.getCacheFS(ctx, bucket, object)
if err != nil {
// disk cache could not be located,execute backend call.
return putObjectFn(ctx, bucket, object, r, metadata)
}
size := r.Size()
// fetch from backend if there is no space on cache drive
if !dcache.diskAvailable(size * cacheSizeMultiplier) {
return putObjectFn(ctx, bucket, object, r, metadata)
}
// fetch from backend if cache exclude pattern or cache-control
// directive set to exclude
if c.isCacheExclude(bucket, object) || filterFromCache(metadata) {
dcache.Delete(ctx, bucket, object)
return putObjectFn(ctx, bucket, object, r, metadata)
}
objInfo = ObjectInfo{}
// Initialize pipe to stream data to backend
pipeReader, pipeWriter := io.Pipe()
hashReader, err := hash.NewReader(pipeReader, size, r.MD5HexString(), r.SHA256HexString())
if err != nil {
return ObjectInfo{}, err
}
// Initialize pipe to stream data to cache
rPipe, wPipe := io.Pipe()
cHashReader, err := hash.NewReader(rPipe, size, r.MD5HexString(), r.SHA256HexString())
if err != nil {
return ObjectInfo{}, err
}
oinfoCh := make(chan ObjectInfo)
errCh := make(chan error)
go func() {
oinfo, perr := putObjectFn(ctx, bucket, object, hashReader, metadata)
if perr != nil {
pipeWriter.CloseWithError(perr)
wPipe.CloseWithError(perr)
close(oinfoCh)
errCh <- perr
return
}
close(errCh)
oinfoCh <- oinfo
}()
go func() {
if err = dcache.Put(ctx, bucket, object, cHashReader, metadata); err != nil {
wPipe.CloseWithError(err)
return
}
}()
mwriter := io.MultiWriter(pipeWriter, wPipe)
_, err = io.Copy(mwriter, r)
if err != nil {
err = <-errCh
return objInfo, err
}
pipeWriter.Close()
wPipe.Close()
objInfo = <-oinfoCh
return objInfo, err
}
// NewMultipartUpload - Starts a new multipart upload operation to backend and cache.
func (c cacheObjects) NewMultipartUpload(ctx context.Context, bucket, object string, metadata map[string]string) (uploadID string, err error) {
newMultipartUploadFn := c.NewMultipartUploadFn
if c.isCacheExclude(bucket, object) || filterFromCache(metadata) {
return newMultipartUploadFn(ctx, bucket, object, metadata)
}
dcache, err := c.cache.getCacheFS(ctx, bucket, object)
if err != nil {
// disk cache could not be located,execute backend call.
return newMultipartUploadFn(ctx, bucket, object, metadata)
}
uploadID, err = newMultipartUploadFn(ctx, bucket, object, metadata)
if err != nil {
return
}
// create new multipart upload in cache with same uploadID
dcache.NewMultipartUpload(ctx, bucket, object, metadata, uploadID)
return uploadID, err
}
// PutObjectPart - uploads part to backend and cache simultaneously.
func (c cacheObjects) PutObjectPart(ctx context.Context, bucket, object, uploadID string, partID int, data *hash.Reader) (info PartInfo, err error) {
putObjectPartFn := c.PutObjectPartFn
dcache, err := c.cache.getCacheFS(ctx, bucket, object)
if err != nil {
// disk cache could not be located,execute backend call.
return putObjectPartFn(ctx, bucket, object, uploadID, partID, data)
}
if c.isCacheExclude(bucket, object) {
return putObjectPartFn(ctx, bucket, object, uploadID, partID, data)
}
// make sure cache has at least cacheSizeMultiplier * size available
size := data.Size()
if !dcache.diskAvailable(size * cacheSizeMultiplier) {
select {
case dcache.purgeChan <- struct{}{}:
default:
}
return putObjectPartFn(ctx, bucket, object, uploadID, partID, data)
}
info = PartInfo{}
// Initialize pipe to stream data to backend
pipeReader, pipeWriter := io.Pipe()
hashReader, err := hash.NewReader(pipeReader, size, data.MD5HexString(), data.SHA256HexString())
if err != nil {
return
}
// Initialize pipe to stream data to cache
rPipe, wPipe := io.Pipe()
cHashReader, err := hash.NewReader(rPipe, size, data.MD5HexString(), data.SHA256HexString())
if err != nil {
return
}
pinfoCh := make(chan PartInfo)
errorCh := make(chan error)
go func() {
info, err = putObjectPartFn(ctx, bucket, object, uploadID, partID, hashReader)
if err != nil {
close(pinfoCh)
pipeWriter.CloseWithError(err)
wPipe.CloseWithError(err)
errorCh <- err
return
}
close(errorCh)
pinfoCh <- info
}()
go func() {
if _, perr := dcache.PutObjectPart(ctx, bucket, object, uploadID, partID, cHashReader); perr != nil {
wPipe.CloseWithError(perr)
return
}
}()
mwriter := io.MultiWriter(pipeWriter, wPipe)
_, err = io.Copy(mwriter, data)
if err != nil {
err = <-errorCh
return PartInfo{}, err
}
pipeWriter.Close()
wPipe.Close()
info = <-pinfoCh
return info, err
}
// AbortMultipartUpload - aborts multipart upload on backend and cache.
func (c cacheObjects) AbortMultipartUpload(ctx context.Context, bucket, object, uploadID string) error {
abortMultipartUploadFn := c.AbortMultipartUploadFn
if c.isCacheExclude(bucket, object) {
return abortMultipartUploadFn(ctx, bucket, object, uploadID)
}
dcache, err := c.cache.getCacheFS(ctx, bucket, object)
if err != nil {
// disk cache could not be located,execute backend call.
return abortMultipartUploadFn(ctx, bucket, object, uploadID)
}
// execute backend operation
err = abortMultipartUploadFn(ctx, bucket, object, uploadID)
if err != nil {
return err
}
// abort multipart upload on cache
dcache.AbortMultipartUpload(ctx, bucket, object, uploadID)
return nil
}
// CompleteMultipartUpload - completes multipart upload operation on backend and cache.
func (c cacheObjects) CompleteMultipartUpload(ctx context.Context, bucket, object, uploadID string, uploadedParts []CompletePart) (objInfo ObjectInfo, err error) {
completeMultipartUploadFn := c.CompleteMultipartUploadFn
if c.isCacheExclude(bucket, object) {
return completeMultipartUploadFn(ctx, bucket, object, uploadID, uploadedParts)
}
dcache, err := c.cache.getCacheFS(ctx, bucket, object)
if err != nil {
// disk cache could not be located,execute backend call.
return completeMultipartUploadFn(ctx, bucket, object, uploadID, uploadedParts)
}
// perform backend operation
objInfo, err = completeMultipartUploadFn(ctx, bucket, object, uploadID, uploadedParts)
if err != nil {
return
}
// create new multipart upload in cache with same uploadID
dcache.CompleteMultipartUpload(ctx, bucket, object, uploadID, uploadedParts)
return
}
// StorageInfo - returns underlying storage statistics.
func (c cacheObjects) StorageInfo(ctx context.Context) (storageInfo StorageInfo) {
var total, free uint64
for _, cfs := range c.cache.cfs {
if cfs == nil {
continue
}
info, err := getDiskInfo((cfs.fsPath))
logger.GetReqInfo(ctx).AppendTags("cachePath", cfs.fsPath)
logger.LogIf(ctx, err)
total += info.Total
free += info.Free
}
storageInfo = StorageInfo{
Total: total,
Free: free,
}
storageInfo.Backend.Type = FS
return storageInfo
}
// DeleteBucket - marks bucket to be deleted from cache if bucket is deleted from backend.
func (c cacheObjects) DeleteBucket(ctx context.Context, bucket string) (err error) {
deleteBucketFn := c.DeleteBucketFn
var toDel []*cacheFSObjects
for _, cfs := range c.cache.cfs {
// ignore disk-caches that might be missing/offline
if cfs == nil {
continue
}
if _, cerr := cfs.GetBucketInfo(ctx, bucket); cerr == nil {
toDel = append(toDel, cfs)
}
}
// perform backend operation
err = deleteBucketFn(ctx, bucket)
if err != nil {
return
}
// move bucket metadata and content to cache's trash dir
for _, d := range toDel {
d.moveBucketToTrash(ctx, bucket)
}
return
}
// newCache initializes the cacheFSObjects for the "drives" specified in config.json
// or the global env overrides.
func newCache(config CacheConfig) (*diskCache, error) {
var cfsObjects []*cacheFSObjects
ctx := logger.SetReqInfo(context.Background(), &logger.ReqInfo{})
formats, err := loadAndValidateCacheFormat(ctx, config.Drives)
if err != nil {
return nil, err
}
for i, dir := range config.Drives {
// skip cacheFSObjects creation for cache drives missing a format.json
if formats[i] == nil {
cfsObjects = append(cfsObjects, nil)
continue
}
if err := checkAtimeSupport(dir); err != nil {
return nil, errors.New("Atime support required for disk caching")
}
cache, err := newCacheFSObjects(dir, config.Expiry, cacheMaxDiskUsagePct)
if err != nil {
return nil, err
}
// Start the purging go-routine for entries that have expired
go cache.purge()
// Start trash purge routine for deleted buckets.
go cache.purgeTrash()
cfsObjects = append(cfsObjects, cache)
}
return &diskCache{cfs: cfsObjects}, nil
}
// Return error if Atime is disabled on the O/S
func checkAtimeSupport(dir string) (err error) {
file, err := ioutil.TempFile(dir, "prefix")
if err != nil {
return
}
defer os.Remove(file.Name())
finfo1, err := os.Stat(file.Name())
if err != nil {
return
}
if _, err = io.Copy(ioutil.Discard, file); err != io.EOF {
return
}
finfo2, err := os.Stat(file.Name())
if atime.Get(finfo2).Equal(atime.Get(finfo1)) {
return errors.New("Atime not supported")
}
return
}
// Returns cacheObjects for use by Server.
func newServerCacheObjects(config CacheConfig) (CacheObjectLayer, error) {
// list of disk caches for cache "drives" specified in config.json or MINIO_CACHE_DRIVES env var.
dcache, err := newCache(config)
if err != nil {
return nil, err
}
return &cacheObjects{
cache: dcache,
exclude: config.Exclude,
listPool: newTreeWalkPool(globalLookupTimeout),
GetObjectFn: func(ctx context.Context, bucket, object string, startOffset int64, length int64, writer io.Writer, etag string) error {
return newObjectLayerFn().GetObject(ctx, bucket, object, startOffset, length, writer, etag)
},
GetObjectInfoFn: func(ctx context.Context, bucket, object string) (ObjectInfo, error) {
return newObjectLayerFn().GetObjectInfo(ctx, bucket, object)
},
PutObjectFn: func(ctx context.Context, bucket, object string, data *hash.Reader, metadata map[string]string) (objInfo ObjectInfo, err error) {
return newObjectLayerFn().PutObject(ctx, bucket, object, data, metadata)
},
DeleteObjectFn: func(ctx context.Context, bucket, object string) error {
return newObjectLayerFn().DeleteObject(ctx, bucket, object)
},
ListObjectsFn: func(ctx context.Context, bucket, prefix, marker, delimiter string, maxKeys int) (result ListObjectsInfo, err error) {
return newObjectLayerFn().ListObjects(ctx, bucket, prefix, marker, delimiter, maxKeys)
},
ListObjectsV2Fn: func(ctx context.Context, bucket, prefix, continuationToken, delimiter string, maxKeys int, fetchOwner bool, startAfter string) (result ListObjectsV2Info, err error) {
return newObjectLayerFn().ListObjectsV2(ctx, bucket, prefix, continuationToken, delimiter, maxKeys, fetchOwner, startAfter)
},
ListBucketsFn: func(ctx context.Context) (buckets []BucketInfo, err error) {
return newObjectLayerFn().ListBuckets(ctx)
},
GetBucketInfoFn: func(ctx context.Context, bucket string) (bucketInfo BucketInfo, err error) {
return newObjectLayerFn().GetBucketInfo(ctx, bucket)
},
NewMultipartUploadFn: func(ctx context.Context, bucket, object string, metadata map[string]string) (uploadID string, err error) {
return newObjectLayerFn().NewMultipartUpload(ctx, bucket, object, metadata)
},
PutObjectPartFn: func(ctx context.Context, bucket, object, uploadID string, partID int, data *hash.Reader) (info PartInfo, err error) {
return newObjectLayerFn().PutObjectPart(ctx, bucket, object, uploadID, partID, data)
},
AbortMultipartUploadFn: func(ctx context.Context, bucket, object, uploadID string) error {
return newObjectLayerFn().AbortMultipartUpload(ctx, bucket, object, uploadID)
},
CompleteMultipartUploadFn: func(ctx context.Context, bucket, object, uploadID string, uploadedParts []CompletePart) (objInfo ObjectInfo, err error) {
return newObjectLayerFn().CompleteMultipartUpload(ctx, bucket, object, uploadID, uploadedParts)
},
DeleteBucketFn: func(ctx context.Context, bucket string) error {
return newObjectLayerFn().DeleteBucket(ctx, bucket)
},
}, nil
}
type cacheControl struct {
exclude bool
expiry time.Time
maxAge int
sMaxAge int
minFresh int
}
// cache exclude directives in cache-control header
var cacheExcludeDirectives = []string{
"no-cache",
"no-store",
"must-revalidate",
}
// returns true if cache exclude directives are set.
func isCacheExcludeDirective(s string) bool {
for _, directive := range cacheExcludeDirectives {
if s == directive {
return true
}
}
return false
}
// returns struct with cache-control settings from user metadata.
func getCacheControlOpts(m map[string]string) (c cacheControl, err error) {
var headerVal string
for k, v := range m {
if k == "cache-control" {
headerVal = v
}
if k == "expires" {
if e, err := http.ParseTime(v); err == nil {
c.expiry = e
}
}
}
if headerVal == "" {
return
}
headerVal = strings.ToLower(headerVal)
headerVal = strings.TrimSpace(headerVal)
vals := strings.Split(headerVal, ",")
for _, val := range vals {
val = strings.TrimSpace(val)
p := strings.Split(val, "=")
if isCacheExcludeDirective(p[0]) {
c.exclude = true
continue
}
if len(p) != 2 {
continue
}
if p[0] == "max-age" ||
p[0] == "s-maxage" ||
p[0] == "min-fresh" {
i, err := strconv.Atoi(p[1])
if err != nil {
return c, err
}
if p[0] == "max-age" {
c.maxAge = i
}
if p[0] == "s-maxage" {
c.sMaxAge = i
}
if p[0] == "min-fresh" {
c.minFresh = i
}
}
}
return c, nil
}
// return true if metadata has a cache-control header
// directive to exclude object from cache.
func filterFromCache(m map[string]string) bool {
c, err := getCacheControlOpts(m)
if err != nil {
return false
}
return c.exclude
}
// returns true if cache expiry conditions met in cache-control/expiry metadata.
func isStaleCache(objInfo ObjectInfo) bool {
c, err := getCacheControlOpts(objInfo.UserDefined)
if err != nil {
return false
}
now := time.Now()
if c.sMaxAge > 0 && c.sMaxAge > int(now.Sub(objInfo.ModTime).Seconds()) {
return true
}
if c.maxAge > 0 && c.maxAge > int(now.Sub(objInfo.ModTime).Seconds()) {
return true
}
if !c.expiry.Equal(time.Time{}) && c.expiry.Before(time.Now()) {
return true
}
if c.minFresh > 0 && c.minFresh <= int(now.Sub(objInfo.ModTime).Seconds()) {
return true
}
return false
}