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Adds new storagedriver.FileWriter interface

Browse source 
Updates registry storage code to use this for better resumable writes.
Implements this interface for the following drivers:
 + Inmemory
 + Filesystem
 + S3
 + Azure

Signed-off-by: Brian Bland <brian.bland@docker.com>
This commit is contained in:
Brian Bland 2016-02-08 14:29:21 -08:00
parent 7adddecf0b
commit c69c8a3286
25 changed files with 1059 additions and 2488 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

18
docs/client/blob_writer.go
View file

@ -6,7 +6,6 @@ import (
"io"
"io/ioutil"
"net/http"
"os"
"time"
"github.com/docker/distribution"
@ -104,21 +103,8 @@ func (hbu *httpBlobUpload) Write(p []byte) (n int, err error) {
}
func (hbu *httpBlobUpload) Seek(offset int64, whence int) (int64, error) {
newOffset := hbu.offset
switch whence {
case os.SEEK_CUR:
newOffset += int64(offset)
case os.SEEK_END:
newOffset += int64(offset)
case os.SEEK_SET:
newOffset = int64(offset)
}
hbu.offset = newOffset
return hbu.offset, nil
func (hbu *httpBlobUpload) Size() int64 {
return hbu.offset
}
func (hbu *httpBlobUpload) ID() string {

39
docs/handlers/blobupload.go
View file

@ -4,7 +4,6 @@ import (
"fmt"
"net/http"
"net/url"
"os"
"github.com/docker/distribution"
ctxu "github.com/docker/distribution/context"
@ -76,28 +75,14 @@ func blobUploadDispatcher(ctx *Context, r *http.Request) http.Handler {
}
buh.Upload = upload
if state.Offset > 0 {
// Seek the blob upload to the correct spot if it's non-zero.
// These error conditions should be rare and demonstrate really
// problems. We basically cancel the upload and tell the client to
// start over.
if nn, err := upload.Seek(buh.State.Offset, os.SEEK_SET); err != nil {
if size := upload.Size(); size != buh.State.Offset {
defer upload.Close()
ctxu.GetLogger(ctx).Infof("error seeking blob upload: %v", err)
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
buh.Errors = append(buh.Errors, v2.ErrorCodeBlobUploadInvalid.WithDetail(err))
upload.Cancel(buh)
})
} else if nn != buh.State.Offset {
defer upload.Close()
ctxu.GetLogger(ctx).Infof("seek to wrong offest: %d != %d", nn, buh.State.Offset)
ctxu.GetLogger(ctx).Infof("upload resumed at wrong offest: %d != %d", size, buh.State.Offset)
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
buh.Errors = append(buh.Errors, v2.ErrorCodeBlobUploadInvalid.WithDetail(err))
upload.Cancel(buh)
})
}
}
return closeResources(handler, buh.Upload)
}
@ -239,10 +224,7 @@ func (buh *blobUploadHandler) PutBlobUploadComplete(w http.ResponseWriter, r *ht
return
}
size := buh.State.Offset
if offset, err := buh.Upload.Seek(0, os.SEEK_CUR); err == nil {
size = offset
}
size := buh.Upload.Size()
desc, err := buh.Upload.Commit(buh, distribution.Descriptor{
Digest: dgst,
@ -308,21 +290,10 @@ func (buh *blobUploadHandler) CancelBlobUpload(w http.ResponseWriter, r *http.Re
// uploads always start at a 0 offset. This allows disabling resumable push by
// always returning a 0 offset on check status.
func (buh *blobUploadHandler) blobUploadResponse(w http.ResponseWriter, r *http.Request, fresh bool) error {
var offset int64
if !fresh {
var err error
offset, err = buh.Upload.Seek(0, os.SEEK_CUR)
if err != nil {
ctxu.GetLogger(buh).Errorf("unable get current offset of blob upload: %v", err)
return err
}
}
// TODO(stevvooe): Need a better way to manage the upload state automatically.
buh.State.Name = buh.Repository.Named().Name()
buh.State.UUID = buh.Upload.ID()
buh.State.Offset = offset
buh.State.Offset = buh.Upload.Size()
buh.State.StartedAt = buh.Upload.StartedAt()
token, err := hmacKey(buh.Config.HTTP.Secret).packUploadState(buh.State)
@ -341,7 +312,7 @@ func (buh *blobUploadHandler) blobUploadResponse(w http.ResponseWriter, r *http.
return err
}
endRange := offset
endRange := buh.Upload.Size()
if endRange > 0 {
endRange = endRange - 1
}

11
docs/storage/blob_test.go
View file

@ -41,10 +41,7 @@ func TestWriteSeek(t *testing.T) {
}
contents := []byte{1, 2, 3}
blobUpload.Write(contents)
offset, err := blobUpload.Seek(0, os.SEEK_CUR)
if err != nil {
t.Fatalf("unexpected error in blobUpload.Seek: %s", err)
}
offset := blobUpload.Size()
if offset != int64(len(contents)) {
t.Fatalf("unexpected value for blobUpload offset: %v != %v", offset, len(contents))
}
@ -113,11 +110,7 @@ func TestSimpleBlobUpload(t *testing.T) {
t.Fatalf("layer data write incomplete")
}
offset, err := blobUpload.Seek(0, os.SEEK_CUR)
if err != nil {
t.Fatalf("unexpected error seeking layer upload: %v", err)
}
offset := blobUpload.Size()
if offset != nn {
t.Fatalf("blobUpload not updated with correct offset: %v != %v", offset, nn)
}

49
docs/storage/blobwriter.go
View file

@ -21,6 +21,7 @@ var (
// layerWriter is used to control the various aspects of resumable
// layer upload. It implements the LayerUpload interface.
type blobWriter struct {
ctx context.Context
blobStore *linkedBlobStore
id string
@ -28,9 +29,9 @@ type blobWriter struct {
digester digest.Digester
written int64 // track the contiguous write
// implementes io.WriteSeeker, io.ReaderFrom and io.Closer to satisfy
// LayerUpload Interface
fileWriter
fileWriter storagedriver.FileWriter
driver storagedriver.StorageDriver
path string
resumableDigestEnabled bool
}
@ -51,7 +52,7 @@ func (bw *blobWriter) StartedAt() time.Time {
func (bw *blobWriter) Commit(ctx context.Context, desc distribution.Descriptor) (distribution.Descriptor, error) {
context.GetLogger(ctx).Debug("(*blobWriter).Commit")
if err := bw.fileWriter.Close(); err != nil {
if err := bw.fileWriter.Commit(); err != nil {
return distribution.Descriptor{}, err
}
@ -84,6 +85,10 @@ func (bw *blobWriter) Commit(ctx context.Context, desc distribution.Descriptor)
// the writer and canceling the operation.
func (bw *blobWriter) Cancel(ctx context.Context) error {
context.GetLogger(ctx).Debug("(*blobWriter).Rollback")
if err := bw.fileWriter.Cancel(); err != nil {
return err
}
if err := bw.removeResources(ctx); err != nil {
return err
}
@ -92,15 +97,19 @@ func (bw *blobWriter) Cancel(ctx context.Context) error {
return nil
}
func (bw *blobWriter) Size() int64 {
return bw.fileWriter.Size()
}
func (bw *blobWriter) Write(p []byte) (int, error) {
// Ensure that the current write offset matches how many bytes have been
// written to the digester. If not, we need to update the digest state to
// match the current write position.
if err := bw.resumeDigestAt(bw.blobStore.ctx, bw.offset); err != nil && err != errResumableDigestNotAvailable {
if err := bw.resumeDigest(bw.blobStore.ctx); err != nil && err != errResumableDigestNotAvailable {
return 0, err
}
n, err := io.MultiWriter(&bw.fileWriter, bw.digester.Hash()).Write(p)
n, err := io.MultiWriter(bw.fileWriter, bw.digester.Hash()).Write(p)
bw.written += int64(n)
return n, err
@ -110,21 +119,17 @@ func (bw *blobWriter) ReadFrom(r io.Reader) (n int64, err error) {
// Ensure that the current write offset matches how many bytes have been
// written to the digester. If not, we need to update the digest state to
// match the current write position.
if err := bw.resumeDigestAt(bw.blobStore.ctx, bw.offset); err != nil && err != errResumableDigestNotAvailable {
if err := bw.resumeDigest(bw.blobStore.ctx); err != nil && err != errResumableDigestNotAvailable {
return 0, err
}
nn, err := bw.fileWriter.ReadFrom(io.TeeReader(r, bw.digester.Hash()))
nn, err := io.Copy(io.MultiWriter(bw.fileWriter, bw.digester.Hash()), r)
bw.written += nn
return nn, err
}
func (bw *blobWriter) Close() error {
if bw.err != nil {
return bw.err
}
if err := bw.storeHashState(bw.blobStore.ctx); err != nil {
return err
}
@ -148,8 +153,10 @@ func (bw *blobWriter) validateBlob(ctx context.Context, desc distribution.Descri
}
}
var size int64
// Stat the on disk file
if fi, err := bw.fileWriter.driver.Stat(ctx, bw.path); err != nil {
if fi, err := bw.driver.Stat(ctx, bw.path); err != nil {
switch err := err.(type) {
case storagedriver.PathNotFoundError:
// NOTE(stevvooe): We really don't care if the file is
@ -165,23 +172,23 @@ func (bw *blobWriter) validateBlob(ctx context.Context, desc distribution.Descri
return distribution.Descriptor{}, fmt.Errorf("unexpected directory at upload location %q", bw.path)
}
bw.size = fi.Size()
size = fi.Size()
}
if desc.Size > 0 {
if desc.Size != bw.size {
if desc.Size != size {
return distribution.Descriptor{}, distribution.ErrBlobInvalidLength
}
} else {
// if provided 0 or negative length, we can assume caller doesn't know or
// care about length.
desc.Size = bw.size
desc.Size = size
}
// TODO(stevvooe): This section is very meandering. Need to be broken down
// to be a lot more clear.
if err := bw.resumeDigestAt(ctx, bw.size); err == nil {
if err := bw.resumeDigest(ctx); err == nil {
canonical = bw.digester.Digest()
if canonical.Algorithm() == desc.Digest.Algorithm() {
@ -206,7 +213,7 @@ func (bw *blobWriter) validateBlob(ctx context.Context, desc distribution.Descri
// the same, we don't need to read the data from the backend. This is
// because we've written the entire file in the lifecycle of the
// current instance.
if bw.written == bw.size && digest.Canonical == desc.Digest.Algorithm() {
if bw.written == size && digest.Canonical == desc.Digest.Algorithm() {
canonical = bw.digester.Digest()
verified = desc.Digest == canonical
}
@ -223,7 +230,7 @@ func (bw *blobWriter) validateBlob(ctx context.Context, desc distribution.Descri
}
// Read the file from the backend driver and validate it.
fr, err := newFileReader(ctx, bw.fileWriter.driver, bw.path, desc.Size)
fr, err := newFileReader(ctx, bw.driver, bw.path, desc.Size)
if err != nil {
return distribution.Descriptor{}, err
}
@ -357,7 +364,7 @@ func (bw *blobWriter) Reader() (io.ReadCloser, error) {
// todo(richardscothern): Change to exponential backoff, i=0.5, e=2, n=4
try := 1
for try <= 5 {
_, err := bw.fileWriter.driver.Stat(bw.ctx, bw.path)
_, err := bw.driver.Stat(bw.ctx, bw.path)
if err == nil {
break
}
@ -371,7 +378,7 @@ func (bw *blobWriter) Reader() (io.ReadCloser, error) {
}
}
readCloser, err := bw.fileWriter.driver.ReadStream(bw.ctx, bw.path, 0)
readCloser, err := bw.driver.Reader(bw.ctx, bw.path, 0)
if err != nil {
return nil, err
}

45
docs/storage/blobwriter_resumable.go
View file

@ -4,8 +4,6 @@ package storage
import (
"fmt"
"io"
"os"
"path"
"strconv"
@ -19,24 +17,18 @@ import (
_ "github.com/stevvooe/resumable/sha512"
)
// resumeDigestAt attempts to restore the state of the internal hash function
// by loading the most recent saved hash state less than or equal to the given
// offset. Any unhashed bytes remaining less than the given offset are hashed
// from the content uploaded so far.
func (bw *blobWriter) resumeDigestAt(ctx context.Context, offset int64) error {
// resumeDigest attempts to restore the state of the internal hash function
// by loading the most recent saved hash state equal to the current size of the blob.
func (bw *blobWriter) resumeDigest(ctx context.Context) error {
if !bw.resumableDigestEnabled {
return errResumableDigestNotAvailable
}
if offset < 0 {
return fmt.Errorf("cannot resume hash at negative offset: %d", offset)
}
h, ok := bw.digester.Hash().(resumable.Hash)
if !ok {
return errResumableDigestNotAvailable
}
offset := bw.fileWriter.Size()
if offset == int64(h.Len()) {
// State of digester is already at the requested offset.
return nil
@ -49,24 +41,12 @@ func (bw *blobWriter) resumeDigestAt(ctx context.Context, offset int64) error {
return fmt.Errorf("unable to get stored hash states with offset %d: %s", offset, err)
}
// Find the highest stored hashState with offset less than or equal to
// Find the highest stored hashState with offset equal to
// the requested offset.
for _, hashState := range hashStates {
if hashState.offset == offset {
hashStateMatch = hashState
break // Found an exact offset match.
} else if hashState.offset < offset && hashState.offset > hashStateMatch.offset {
// This offset is closer to the requested offset.
hashStateMatch = hashState
} else if hashState.offset > offset {
// Remove any stored hash state with offsets higher than this one
// as writes to this resumed hasher will make those invalid. This
// is probably okay to skip for now since we don't expect anyone to
// use the API in this way. For that reason, we don't treat an
// an error here as a fatal error, but only log it.
if err := bw.driver.Delete(ctx, hashState.path); err != nil {
logrus.Errorf("unable to delete stale hash state %q: %s", hashState.path, err)
}
}
}
@ -86,20 +66,7 @@ func (bw *blobWriter) resumeDigestAt(ctx context.Context, offset int64) error {
// Mind the gap.
if gapLen := offset - int64(h.Len()); gapLen > 0 {
// Need to read content from the upload to catch up to the desired offset.
fr, err := newFileReader(ctx, bw.driver, bw.path, bw.size)
if err != nil {
return err
}
defer fr.Close()
if _, err = fr.Seek(int64(h.Len()), os.SEEK_SET); err != nil {
return fmt.Errorf("unable to seek to layer reader offset %d: %s", h.Len(), err)
}
if _, err := io.CopyN(h, fr, gapLen); err != nil {
return err
}
return errResumableDigestNotAvailable
}
return nil

160
docs/storage/driver/azure/azure.go
View file

@ -3,6 +3,7 @@
package azure
import (
"bufio"
"bytes"
"fmt"
"io"
@ -26,6 +27,7 @@ const (
paramAccountKey = "accountkey"
paramContainer = "container"
paramRealm = "realm"
maxChunkSize = 4 * 1024 * 1024
)
type driver struct {
@ -117,18 +119,21 @@ func (d *driver) PutContent(ctx context.Context, path string, contents []byte) e
if _, err := d.client.DeleteBlobIfExists(d.container, path); err != nil {
return err
}
if err := d.client.CreateBlockBlob(d.container, path); err != nil {
writer, err := d.Writer(ctx, path, false)
if err != nil {
return err
}
bs := newAzureBlockStorage(d.client)
bw := newRandomBlobWriter(&bs, azure.MaxBlobBlockSize)
_, err := bw.WriteBlobAt(d.container, path, 0, bytes.NewReader(contents))
defer writer.Close()
_, err = writer.Write(contents)
if err != nil {
return err
}
return writer.Commit()
}
// ReadStream retrieves an io.ReadCloser for the content stored at "path" with a
// Reader retrieves an io.ReadCloser for the content stored at "path" with a
// given byte offset.
func (d *driver) ReadStream(ctx context.Context, path string, offset int64) (io.ReadCloser, error) {
func (d *driver) Reader(ctx context.Context, path string, offset int64) (io.ReadCloser, error) {
if ok, err := d.client.BlobExists(d.container, path); err != nil {
return nil, err
} else if !ok {
@ -153,25 +158,38 @@ func (d *driver) ReadStream(ctx context.Context, path string, offset int64) (io.
return resp, nil
}
// WriteStream stores the contents of the provided io.ReadCloser at a location
// designated by the given path.
func (d *driver) WriteStream(ctx context.Context, path string, offset int64, reader io.Reader) (int64, error) {
if blobExists, err := d.client.BlobExists(d.container, path); err != nil {
return 0, err
} else if !blobExists {
err := d.client.CreateBlockBlob(d.container, path)
// Writer returns a FileWriter which will store the content written to it
// at the location designated by "path" after the call to Commit.
func (d *driver) Writer(ctx context.Context, path string, append bool) (storagedriver.FileWriter, error) {
blobExists, err := d.client.BlobExists(d.container, path)
if err != nil {
return 0, err
return nil, err
}
var size int64
if blobExists {
if append {
blobProperties, err := d.client.GetBlobProperties(d.container, path)
if err != nil {
return nil, err
}
size = blobProperties.ContentLength
} else {
err := d.client.DeleteBlob(d.container, path)
if err != nil {
return nil, err
}
}
if offset < 0 {
return 0, storagedriver.InvalidOffsetError{Path: path, Offset: offset}
} else {
if append {
return nil, storagedriver.PathNotFoundError{Path: path}
}
err := d.client.PutAppendBlob(d.container, path, nil)
if err != nil {
return nil, err
}
}
bs := newAzureBlockStorage(d.client)
bw := newRandomBlobWriter(&bs, azure.MaxBlobBlockSize)
zw := newZeroFillWriter(&bw)
return zw.Write(d.container, path, offset, reader)
return d.newWriter(path, size), nil
}
// Stat retrieves the FileInfo for the given path, including the current size
@ -236,6 +254,9 @@ func (d *driver) List(ctx context.Context, path string) ([]string, error) {
}
list := directDescendants(blobs, path)
if path != "" && len(list) == 0 {
return nil, storagedriver.PathNotFoundError{Path: path}
}
return list, nil
}
@ -361,6 +382,101 @@ func (d *driver) listBlobs(container, virtPath string) ([]string, error) {
}
func is404(err error) bool {
e, ok := err.(azure.AzureStorageServiceError)
return ok && e.StatusCode == http.StatusNotFound
statusCodeErr, ok := err.(azure.UnexpectedStatusCodeError)
return ok && statusCodeErr.Got() == http.StatusNotFound
}
type writer struct {
driver *driver
path string
size int64
bw *bufio.Writer
closed bool
committed bool
cancelled bool
}
func (d *driver) newWriter(path string, size int64) storagedriver.FileWriter {
return &writer{
driver: d,
path: path,
size: size,
bw: bufio.NewWriterSize(&blockWriter{
client: d.client,
container: d.container,
path: path,
}, maxChunkSize),
}
}
func (w *writer) Write(p []byte) (int, error) {
if w.closed {
return 0, fmt.Errorf("already closed")
} else if w.committed {
return 0, fmt.Errorf("already committed")
} else if w.cancelled {
return 0, fmt.Errorf("already cancelled")
}
n, err := w.bw.Write(p)
w.size += int64(n)
return n, err
}
func (w *writer) Size() int64 {
return w.size
}
func (w *writer) Close() error {
if w.closed {
return fmt.Errorf("already closed")
}
w.closed = true
return w.bw.Flush()
}
func (w *writer) Cancel() error {
if w.closed {
return fmt.Errorf("already closed")
} else if w.committed {
return fmt.Errorf("already committed")
}
w.cancelled = true
return w.driver.client.DeleteBlob(w.driver.container, w.path)
}
func (w *writer) Commit() error {
if w.closed {
return fmt.Errorf("already closed")
} else if w.committed {
return fmt.Errorf("already committed")
} else if w.cancelled {
return fmt.Errorf("already cancelled")
}
w.committed = true
return w.bw.Flush()
}
type blockWriter struct {
client azure.BlobStorageClient
container string
path string
}
func (bw *blockWriter) Write(p []byte) (int, error) {
n := 0
for offset := 0; offset < len(p); offset += maxChunkSize {
chunkSize := maxChunkSize
if offset+chunkSize > len(p) {
chunkSize = len(p) - offset
}
err := bw.client.AppendBlock(bw.container, bw.path, p[offset:offset+chunkSize])
if err != nil {
return n, err
}
n += chunkSize
}
return n, nil
}

24
docs/storage/driver/azure/blockblob.go
View file

@ -1,24 +0,0 @@
package azure
import (
"fmt"
"io"
azure "github.com/Azure/azure-sdk-for-go/storage"
)
// azureBlockStorage is adaptor between azure.BlobStorageClient and
// blockStorage interface.
type azureBlockStorage struct {
azure.BlobStorageClient
}
func (b *azureBlockStorage) GetSectionReader(container, blob string, start, length int64) (io.ReadCloser, error) {
return b.BlobStorageClient.GetBlobRange(container, blob, fmt.Sprintf("%v-%v", start, start+length-1))
}
func newAzureBlockStorage(b azure.BlobStorageClient) azureBlockStorage {
a := azureBlockStorage{}
a.BlobStorageClient = b
return a
}

155
docs/storage/driver/azure/blockblob_test.go
View file

@ -1,155 +0,0 @@
package azure
import (
"bytes"
"fmt"
"io"
"io/ioutil"
azure "github.com/Azure/azure-sdk-for-go/storage"
)
type StorageSimulator struct {
blobs map[string]*BlockBlob
}
type BlockBlob struct {
blocks map[string]*DataBlock
blockList []string
}
type DataBlock struct {
data []byte
committed bool
}
func (s *StorageSimulator) path(container, blob string) string {
return fmt.Sprintf("%s/%s", container, blob)
}
func (s *StorageSimulator) BlobExists(container, blob string) (bool, error) {
_, ok := s.blobs[s.path(container, blob)]
return ok, nil
}
func (s *StorageSimulator) GetBlob(container, blob string) (io.ReadCloser, error) {
bb, ok := s.blobs[s.path(container, blob)]
if !ok {
return nil, fmt.Errorf("blob not found")
}
var readers []io.Reader
for _, bID := range bb.blockList {
readers = append(readers, bytes.NewReader(bb.blocks[bID].data))
}
return ioutil.NopCloser(io.MultiReader(readers...)), nil
}
func (s *StorageSimulator) GetSectionReader(container, blob string, start, length int64) (io.ReadCloser, error) {
r, err := s.GetBlob(container, blob)
if err != nil {
return nil, err
}
b, err := ioutil.ReadAll(r)
if err != nil {
return nil, err
}
return ioutil.NopCloser(bytes.NewReader(b[start : start+length])), nil
}
func (s *StorageSimulator) CreateBlockBlob(container, blob string) error {
path := s.path(container, blob)
bb := &BlockBlob{
blocks: make(map[string]*DataBlock),
blockList: []string{},
}
s.blobs[path] = bb
return nil
}
func (s *StorageSimulator) PutBlock(container, blob, blockID string, chunk []byte) error {
path := s.path(container, blob)
bb, ok := s.blobs[path]
if !ok {
return fmt.Errorf("blob not found")
}
data := make([]byte, len(chunk))
copy(data, chunk)
bb.blocks[blockID] = &DataBlock{data: data, committed: false} // add block to blob
return nil
}
func (s *StorageSimulator) GetBlockList(container, blob string, blockType azure.BlockListType) (azure.BlockListResponse, error) {
resp := azure.BlockListResponse{}
bb, ok := s.blobs[s.path(container, blob)]
if !ok {
return resp, fmt.Errorf("blob not found")
}
// Iterate committed blocks (in order)
if blockType == azure.BlockListTypeAll || blockType == azure.BlockListTypeCommitted {
for _, blockID := range bb.blockList {
b := bb.blocks[blockID]
block := azure.BlockResponse{
Name: blockID,
Size: int64(len(b.data)),
}
resp.CommittedBlocks = append(resp.CommittedBlocks, block)
}
}
// Iterate uncommitted blocks (in no order)
if blockType == azure.BlockListTypeAll || blockType == azure.BlockListTypeCommitted {
for blockID, b := range bb.blocks {
block := azure.BlockResponse{
Name: blockID,
Size: int64(len(b.data)),
}
if !b.committed {
resp.UncommittedBlocks = append(resp.UncommittedBlocks, block)
}
}
}
return resp, nil
}
func (s *StorageSimulator) PutBlockList(container, blob string, blocks []azure.Block) error {
bb, ok := s.blobs[s.path(container, blob)]
if !ok {
return fmt.Errorf("blob not found")
}
var blockIDs []string
for _, v := range blocks {
bl, ok := bb.blocks[v.ID]
if !ok { // check if block ID exists
return fmt.Errorf("Block id '%s' not found", v.ID)
}
bl.committed = true
blockIDs = append(blockIDs, v.ID)
}
// Mark all other blocks uncommitted
for k, b := range bb.blocks {
inList := false
for _, v := range blockIDs {
if k == v {
inList = true
break
}
}
if !inList {
b.committed = false
}
}
bb.blockList = blockIDs
return nil
}
func NewStorageSimulator() StorageSimulator {
return StorageSimulator{
blobs: make(map[string]*BlockBlob),
}
}

60
docs/storage/driver/azure/blockid.go
View file

@ -1,60 +0,0 @@
package azure
import (
"encoding/base64"
"fmt"
"math/rand"
"sync"
"time"
azure "github.com/Azure/azure-sdk-for-go/storage"
)
type blockIDGenerator struct {
pool map[string]bool
r *rand.Rand
m sync.Mutex
}
// Generate returns an unused random block id and adds the generated ID
// to list of used IDs so that the same block name is not used again.
func (b *blockIDGenerator) Generate() string {
b.m.Lock()
defer b.m.Unlock()
var id string
for {
id = toBlockID(int(b.r.Int()))
if !b.exists(id) {
break
}
}
b.pool[id] = true
return id
}
func (b *blockIDGenerator) exists(id string) bool {
_, used := b.pool[id]
return used
}
func (b *blockIDGenerator) Feed(blocks azure.BlockListResponse) {
b.m.Lock()
defer b.m.Unlock()
for _, bl := range append(blocks.CommittedBlocks, blocks.UncommittedBlocks...) {
b.pool[bl.Name] = true
}
}
func newBlockIDGenerator() *blockIDGenerator {
return &blockIDGenerator{
pool: make(map[string]bool),
r: rand.New(rand.NewSource(time.Now().UnixNano()))}
}
// toBlockId converts given integer to base64-encoded block ID of a fixed length.
func toBlockID(i int) string {
s := fmt.Sprintf("%029d", i) // add zero padding for same length-blobs
return base64.StdEncoding.EncodeToString([]byte(s))
}

74
docs/storage/driver/azure/blockid_test.go
View file

@ -1,74 +0,0 @@
package azure
import (
"math"
"testing"
azure "github.com/Azure/azure-sdk-for-go/storage"
)
func Test_blockIdGenerator(t *testing.T) {
r := newBlockIDGenerator()
for i := 1; i <= 10; i++ {
if expected := i - 1; len(r.pool) != expected {
t.Fatalf("rand pool had wrong number of items: %d, expected:%d", len(r.pool), expected)
}
if id := r.Generate(); id == "" {
t.Fatal("returned empty id")
}
if expected := i; len(r.pool) != expected {
t.Fatalf("rand pool has wrong number of items: %d, expected:%d", len(r.pool), expected)
}
}
}
func Test_blockIdGenerator_Feed(t *testing.T) {
r := newBlockIDGenerator()
if expected := 0; len(r.pool) != expected {
t.Fatalf("rand pool had wrong number of items: %d, expected:%d", len(r.pool), expected)
}
// feed empty list
blocks := azure.BlockListResponse{}
r.Feed(blocks)
if expected := 0; len(r.pool) != expected {
t.Fatalf("rand pool had wrong number of items: %d, expected:%d", len(r.pool), expected)
}
// feed blocks
blocks = azure.BlockListResponse{
CommittedBlocks: []azure.BlockResponse{
{"1", 1},
{"2", 2},
},
UncommittedBlocks: []azure.BlockResponse{
{"3", 3},
}}
r.Feed(blocks)
if expected := 3; len(r.pool) != expected {
t.Fatalf("rand pool had wrong number of items: %d, expected:%d", len(r.pool), expected)
}
// feed same block IDs with committed/uncommitted place changed
blocks = azure.BlockListResponse{
CommittedBlocks: []azure.BlockResponse{
{"3", 3},
},
UncommittedBlocks: []azure.BlockResponse{
{"1", 1},
}}
r.Feed(blocks)
if expected := 3; len(r.pool) != expected {
t.Fatalf("rand pool had wrong number of items: %d, expected:%d", len(r.pool), expected)
}
}
func Test_toBlockId(t *testing.T) {
min := 0
max := math.MaxInt64
if len(toBlockID(min)) != len(toBlockID(max)) {
t.Fatalf("different-sized blockIDs are returned")
}
}

208
docs/storage/driver/azure/randomwriter.go
View file

@ -1,208 +0,0 @@
package azure
import (
"fmt"
"io"
"io/ioutil"
azure "github.com/Azure/azure-sdk-for-go/storage"
)
// blockStorage is the interface required from a block storage service
// client implementation
type blockStorage interface {
CreateBlockBlob(container, blob string) error
GetBlob(container, blob string) (io.ReadCloser, error)
GetSectionReader(container, blob string, start, length int64) (io.ReadCloser, error)
PutBlock(container, blob, blockID string, chunk []byte) error
GetBlockList(container, blob string, blockType azure.BlockListType) (azure.BlockListResponse, error)
PutBlockList(container, blob string, blocks []azure.Block) error
}
// randomBlobWriter enables random access semantics on Azure block blobs
// by enabling writing arbitrary length of chunks to arbitrary write offsets
// within the blob. Normally, Azure Blob Storage does not support random
// access semantics on block blobs; however, this writer can download, split and
// reupload the overlapping blocks and discards those being overwritten entirely.
type randomBlobWriter struct {
bs blockStorage
blockSize int
}
func newRandomBlobWriter(bs blockStorage, blockSize int) randomBlobWriter {
return randomBlobWriter{bs: bs, blockSize: blockSize}
}
// WriteBlobAt writes the given chunk to the specified position of an existing blob.
// The offset must be equals to size of the blob or smaller than it.
func (r *randomBlobWriter) WriteBlobAt(container, blob string, offset int64, chunk io.Reader) (int64, error) {
rand := newBlockIDGenerator()
blocks, err := r.bs.GetBlockList(container, blob, azure.BlockListTypeCommitted)
if err != nil {
return 0, err
}
rand.Feed(blocks) // load existing block IDs
// Check for write offset for existing blob
size := getBlobSize(blocks)
if offset < 0 || offset > size {
return 0, fmt.Errorf("wrong offset for Write: %v", offset)
}
// Upload the new chunk as blocks
blockList, nn, err := r.writeChunkToBlocks(container, blob, chunk, rand)
if err != nil {
return 0, err
}
// For non-append operations, existing blocks may need to be splitted
if offset != size {
// Split the block on the left end (if any)
leftBlocks, err := r.blocksLeftSide(container, blob, offset, rand)
if err != nil {
return 0, err
}
blockList = append(leftBlocks, blockList...)
// Split the block on the right end (if any)
rightBlocks, err := r.blocksRightSide(container, blob, offset, nn, rand)
if err != nil {
return 0, err
}
blockList = append(blockList, rightBlocks...)
} else {
// Use existing block list
var existingBlocks []azure.Block
for _, v := range blocks.CommittedBlocks {
existingBlocks = append(existingBlocks, azure.Block{ID: v.Name, Status: azure.BlockStatusCommitted})
}
blockList = append(existingBlocks, blockList...)
}
// Put block list
return nn, r.bs.PutBlockList(container, blob, blockList)
}
func (r *randomBlobWriter) GetSize(container, blob string) (int64, error) {
blocks, err := r.bs.GetBlockList(container, blob, azure.BlockListTypeCommitted)
if err != nil {
return 0, err
}
return getBlobSize(blocks), nil
}
// writeChunkToBlocks writes given chunk to one or multiple blocks within specified
// blob and returns their block representations. Those blocks are not committed, yet
func (r *randomBlobWriter) writeChunkToBlocks(container, blob string, chunk io.Reader, rand *blockIDGenerator) ([]azure.Block, int64, error) {
var newBlocks []azure.Block
var nn int64
// Read chunks of at most size N except the last chunk to
// maximize block size and minimize block count.
buf := make([]byte, r.blockSize)
for {
n, err := io.ReadFull(chunk, buf)
if err == io.EOF {
break
}
nn += int64(n)
data := buf[:n]
blockID := rand.Generate()
if err := r.bs.PutBlock(container, blob, blockID, data); err != nil {
return newBlocks, nn, err
}
newBlocks = append(newBlocks, azure.Block{ID: blockID, Status: azure.BlockStatusUncommitted})
}
return newBlocks, nn, nil
}
// blocksLeftSide returns the blocks that are going to be at the left side of
// the writeOffset: [0, writeOffset) by identifying blocks that will remain
// the same and splitting blocks and reuploading them as needed.
func (r *randomBlobWriter) blocksLeftSide(container, blob string, writeOffset int64, rand *blockIDGenerator) ([]azure.Block, error) {
var left []azure.Block
bx, err := r.bs.GetBlockList(container, blob, azure.BlockListTypeAll)
if err != nil {
return left, err
}
o := writeOffset
elapsed := int64(0)
for _, v := range bx.CommittedBlocks {
blkSize := int64(v.Size)
if o >= blkSize { // use existing block
left = append(left, azure.Block{ID: v.Name, Status: azure.BlockStatusCommitted})
o -= blkSize
elapsed += blkSize
} else if o > 0 { // current block needs to be splitted
start := elapsed
size := o
part, err := r.bs.GetSectionReader(container, blob, start, size)
if err != nil {
return left, err
}
newBlockID := rand.Generate()
data, err := ioutil.ReadAll(part)
if err != nil {
return left, err
}
if err = r.bs.PutBlock(container, blob, newBlockID, data); err != nil {
return left, err
}
left = append(left, azure.Block{ID: newBlockID, Status: azure.BlockStatusUncommitted})
break
}
}
return left, nil
}
// blocksRightSide returns the blocks that are going to be at the right side of
// the written chunk: [writeOffset+size, +inf) by identifying blocks that will remain
// the same and splitting blocks and reuploading them as needed.
func (r *randomBlobWriter) blocksRightSide(container, blob string, writeOffset int64, chunkSize int64, rand *blockIDGenerator) ([]azure.Block, error) {
var right []azure.Block
bx, err := r.bs.GetBlockList(container, blob, azure.BlockListTypeAll)
if err != nil {
return nil, err
}
re := writeOffset + chunkSize - 1 // right end of written chunk
var elapsed int64
for _, v := range bx.CommittedBlocks {
var (
bs = elapsed // left end of current block
be = elapsed + int64(v.Size) - 1 // right end of current block
)
if bs > re { // take the block as is
right = append(right, azure.Block{ID: v.Name, Status: azure.BlockStatusCommitted})
} else if be > re { // current block needs to be splitted
part, err := r.bs.GetSectionReader(container, blob, re+1, be-(re+1)+1)
if err != nil {
return right, err
}
newBlockID := rand.Generate()
data, err := ioutil.ReadAll(part)
if err != nil {
return right, err
}
if err = r.bs.PutBlock(container, blob, newBlockID, data); err != nil {
return right, err
}
right = append(right, azure.Block{ID: newBlockID, Status: azure.BlockStatusUncommitted})
}
elapsed += int64(v.Size)
}
return right, nil
}
func getBlobSize(blocks azure.BlockListResponse) int64 {
var n int64
for _, v := range blocks.CommittedBlocks {
n += int64(v.Size)
}
return n
}

339
docs/storage/driver/azure/randomwriter_test.go
View file

@ -1,339 +0,0 @@
package azure
import (
"bytes"
"io"
"io/ioutil"
"math/rand"
"reflect"
"strings"
"testing"
azure "github.com/Azure/azure-sdk-for-go/storage"
)
func TestRandomWriter_writeChunkToBlocks(t *testing.T) {
s := NewStorageSimulator()
rw := newRandomBlobWriter(&s, 3)
rand := newBlockIDGenerator()
c := []byte("AAABBBCCCD")
if err := rw.bs.CreateBlockBlob("a", "b"); err != nil {
t.Fatal(err)
}
bw, nn, err := rw.writeChunkToBlocks("a", "b", bytes.NewReader(c), rand)
if err != nil {
t.Fatal(err)
}
if expected := int64(len(c)); nn != expected {
t.Fatalf("wrong nn:%v, expected:%v", nn, expected)
}
if expected := 4; len(bw) != expected {
t.Fatal("unexpected written block count")
}
bx, err := s.GetBlockList("a", "b", azure.BlockListTypeAll)
if err != nil {
t.Fatal(err)
}
if expected := 0; len(bx.CommittedBlocks) != expected {
t.Fatal("unexpected committed block count")
}
if expected := 4; len(bx.UncommittedBlocks) != expected {
t.Fatalf("unexpected uncommitted block count: %d -- %#v", len(bx.UncommittedBlocks), bx)
}
if err := rw.bs.PutBlockList("a", "b", bw); err != nil {
t.Fatal(err)
}
r, err := rw.bs.GetBlob("a", "b")
if err != nil {
t.Fatal(err)
}
assertBlobContents(t, r, c)
}
func TestRandomWriter_blocksLeftSide(t *testing.T) {
blob := "AAAAABBBBBCCC"
cases := []struct {
offset int64
expectedBlob string
expectedPattern []azure.BlockStatus
}{
{0, "", []azure.BlockStatus{}}, // write to beginning, discard all
{13, blob, []azure.BlockStatus{azure.BlockStatusCommitted, azure.BlockStatusCommitted, azure.BlockStatusCommitted}}, // write to end, no change
{1, "A", []azure.BlockStatus{azure.BlockStatusUncommitted}}, // write at 1
{5, "AAAAA", []azure.BlockStatus{azure.BlockStatusCommitted}}, // write just after first block
{6, "AAAAAB", []azure.BlockStatus{azure.BlockStatusCommitted, azure.BlockStatusUncommitted}}, // split the second block
{9, "AAAAABBBB", []azure.BlockStatus{azure.BlockStatusCommitted, azure.BlockStatusUncommitted}}, // write just after first block
}
for _, c := range cases {
s := NewStorageSimulator()
rw := newRandomBlobWriter(&s, 5)
rand := newBlockIDGenerator()
if err := rw.bs.CreateBlockBlob("a", "b"); err != nil {
t.Fatal(err)
}
bw, _, err := rw.writeChunkToBlocks("a", "b", strings.NewReader(blob), rand)
if err != nil {
t.Fatal(err)
}
if err := rw.bs.PutBlockList("a", "b", bw); err != nil {
t.Fatal(err)
}
bx, err := rw.blocksLeftSide("a", "b", c.offset, rand)
if err != nil {
t.Fatal(err)
}
bs := []azure.BlockStatus{}
for _, v := range bx {
bs = append(bs, v.Status)
}
if !reflect.DeepEqual(bs, c.expectedPattern) {
t.Logf("Committed blocks %v", bw)
t.Fatalf("For offset %v: Expected pattern: %v, Got: %v\n(Returned: %v)", c.offset, c.expectedPattern, bs, bx)
}
if rw.bs.PutBlockList("a", "b", bx); err != nil {
t.Fatal(err)
}
r, err := rw.bs.GetBlob("a", "b")
if err != nil {
t.Fatal(err)
}
cout, err := ioutil.ReadAll(r)
if err != nil {
t.Fatal(err)
}
outBlob := string(cout)
if outBlob != c.expectedBlob {
t.Fatalf("wrong blob contents: %v, expected: %v", outBlob, c.expectedBlob)
}
}
}
func TestRandomWriter_blocksRightSide(t *testing.T) {
blob := "AAAAABBBBBCCC"
cases := []struct {
offset int64
size int64
expectedBlob string
expectedPattern []azure.BlockStatus
}{
{0, 100, "", []azure.BlockStatus{}}, // overwrite the entire blob
{0, 3, "AABBBBBCCC", []azure.BlockStatus{azure.BlockStatusUncommitted, azure.BlockStatusCommitted, azure.BlockStatusCommitted}}, // split first block
{4, 1, "BBBBBCCC", []azure.BlockStatus{azure.BlockStatusCommitted, azure.BlockStatusCommitted}}, // write to last char of first block
{1, 6, "BBBCCC", []azure.BlockStatus{azure.BlockStatusUncommitted, azure.BlockStatusCommitted}}, // overwrite splits first and second block, last block remains
{3, 8, "CC", []azure.BlockStatus{azure.BlockStatusUncommitted}}, // overwrite a block in middle block, split end block
{10, 1, "CC", []azure.BlockStatus{azure.BlockStatusUncommitted}}, // overwrite first byte of rightmost block
{11, 2, "", []azure.BlockStatus{}}, // overwrite the rightmost index
{13, 20, "", []azure.BlockStatus{}}, // append to the end
}
for _, c := range cases {
s := NewStorageSimulator()
rw := newRandomBlobWriter(&s, 5)
rand := newBlockIDGenerator()
if err := rw.bs.CreateBlockBlob("a", "b"); err != nil {
t.Fatal(err)
}
bw, _, err := rw.writeChunkToBlocks("a", "b", strings.NewReader(blob), rand)
if err != nil {
t.Fatal(err)
}
if err := rw.bs.PutBlockList("a", "b", bw); err != nil {
t.Fatal(err)
}
bx, err := rw.blocksRightSide("a", "b", c.offset, c.size, rand)
if err != nil {
t.Fatal(err)
}
bs := []azure.BlockStatus{}
for _, v := range bx {
bs = append(bs, v.Status)
}
if !reflect.DeepEqual(bs, c.expectedPattern) {
t.Logf("Committed blocks %v", bw)
t.Fatalf("For offset %v-size:%v: Expected pattern: %v, Got: %v\n(Returned: %v)", c.offset, c.size, c.expectedPattern, bs, bx)
}
if rw.bs.PutBlockList("a", "b", bx); err != nil {
t.Fatal(err)
}
r, err := rw.bs.GetBlob("a", "b")
if err != nil {
t.Fatal(err)
}
cout, err := ioutil.ReadAll(r)
if err != nil {
t.Fatal(err)
}
outBlob := string(cout)
if outBlob != c.expectedBlob {
t.Fatalf("For offset %v-size:%v: wrong blob contents: %v, expected: %v", c.offset, c.size, outBlob, c.expectedBlob)
}
}
}
func TestRandomWriter_Write_NewBlob(t *testing.T) {
var (
s = NewStorageSimulator()
rw = newRandomBlobWriter(&s, 1024*3) // 3 KB blocks
blob = randomContents(1024 * 7) // 7 KB blob
)
if err := rw.bs.CreateBlockBlob("a", "b"); err != nil {
t.Fatal(err)
}
if _, err := rw.WriteBlobAt("a", "b", 10, bytes.NewReader(blob)); err == nil {
t.Fatal("expected error, got nil")
}
if _, err := rw.WriteBlobAt("a", "b", 100000, bytes.NewReader(blob)); err == nil {
t.Fatal("expected error, got nil")
}
if nn, err := rw.WriteBlobAt("a", "b", 0, bytes.NewReader(blob)); err != nil {
t.Fatal(err)
} else if expected := int64(len(blob)); expected != nn {
t.Fatalf("wrong written bytes count: %v, expected: %v", nn, expected)
}
if out, err := rw.bs.GetBlob("a", "b"); err != nil {
t.Fatal(err)
} else {
assertBlobContents(t, out, blob)
}
if bx, err := rw.bs.GetBlockList("a", "b", azure.BlockListTypeCommitted); err != nil {
t.Fatal(err)
} else if len(bx.CommittedBlocks) != 3 {
t.Fatalf("got wrong number of committed blocks: %v", len(bx.CommittedBlocks))
}
// Replace first 512 bytes
leftChunk := randomContents(512)
blob = append(leftChunk, blob[512:]...)
if nn, err := rw.WriteBlobAt("a", "b", 0, bytes.NewReader(leftChunk)); err != nil {
t.Fatal(err)
} else if expected := int64(len(leftChunk)); expected != nn {
t.Fatalf("wrong written bytes count: %v, expected: %v", nn, expected)
}
if out, err := rw.bs.GetBlob("a", "b"); err != nil {
t.Fatal(err)
} else {
assertBlobContents(t, out, blob)
}
if bx, err := rw.bs.GetBlockList("a", "b", azure.BlockListTypeCommitted); err != nil {
t.Fatal(err)
} else if expected := 4; len(bx.CommittedBlocks) != expected {
t.Fatalf("got wrong number of committed blocks: %v, expected: %v", len(bx.CommittedBlocks), expected)
}
// Replace last 512 bytes with 1024 bytes
rightChunk := randomContents(1024)
offset := int64(len(blob) - 512)
blob = append(blob[:offset], rightChunk...)
if nn, err := rw.WriteBlobAt("a", "b", offset, bytes.NewReader(rightChunk)); err != nil {
t.Fatal(err)
} else if expected := int64(len(rightChunk)); expected != nn {
t.Fatalf("wrong written bytes count: %v, expected: %v", nn, expected)
}
if out, err := rw.bs.GetBlob("a", "b"); err != nil {
t.Fatal(err)
} else {
assertBlobContents(t, out, blob)
}
if bx, err := rw.bs.GetBlockList("a", "b", azure.BlockListTypeCommitted); err != nil {
t.Fatal(err)
} else if expected := 5; len(bx.CommittedBlocks) != expected {
t.Fatalf("got wrong number of committed blocks: %v, expected: %v", len(bx.CommittedBlocks), expected)
}
// Replace 2K-4K (overlaps 2 blocks from L/R)
newChunk := randomContents(1024 * 2)
offset = 1024 * 2
blob = append(append(blob[:offset], newChunk...), blob[offset+int64(len(newChunk)):]...)
if nn, err := rw.WriteBlobAt("a", "b", offset, bytes.NewReader(newChunk)); err != nil {
t.Fatal(err)
} else if expected := int64(len(newChunk)); expected != nn {
t.Fatalf("wrong written bytes count: %v, expected: %v", nn, expected)
}
if out, err := rw.bs.GetBlob("a", "b"); err != nil {
t.Fatal(err)
} else {
assertBlobContents(t, out, blob)
}
if bx, err := rw.bs.GetBlockList("a", "b", azure.BlockListTypeCommitted); err != nil {
t.Fatal(err)
} else if expected := 6; len(bx.CommittedBlocks) != expected {
t.Fatalf("got wrong number of committed blocks: %v, expected: %v\n%v", len(bx.CommittedBlocks), expected, bx.CommittedBlocks)
}
// Replace the entire blob
newBlob := randomContents(1024 * 30)
if nn, err := rw.WriteBlobAt("a", "b", 0, bytes.NewReader(newBlob)); err != nil {
t.Fatal(err)
} else if expected := int64(len(newBlob)); expected != nn {
t.Fatalf("wrong written bytes count: %v, expected: %v", nn, expected)
}
if out, err := rw.bs.GetBlob("a", "b"); err != nil {
t.Fatal(err)
} else {
assertBlobContents(t, out, newBlob)
}
if bx, err := rw.bs.GetBlockList("a", "b", azure.BlockListTypeCommitted); err != nil {
t.Fatal(err)
} else if expected := 10; len(bx.CommittedBlocks) != expected {
t.Fatalf("got wrong number of committed blocks: %v, expected: %v\n%v", len(bx.CommittedBlocks), expected, bx.CommittedBlocks)
} else if expected, size := int64(1024*30), getBlobSize(bx); size != expected {
t.Fatalf("committed block size does not indicate blob size")
}
}
func Test_getBlobSize(t *testing.T) {
// with some committed blocks
if expected, size := int64(151), getBlobSize(azure.BlockListResponse{
CommittedBlocks: []azure.BlockResponse{
{"A", 100},
{"B", 50},
{"C", 1},
},
UncommittedBlocks: []azure.BlockResponse{
{"D", 200},
}}); expected != size {
t.Fatalf("wrong blob size: %v, expected: %v", size, expected)
}
// with no committed blocks
if expected, size := int64(0), getBlobSize(azure.BlockListResponse{
UncommittedBlocks: []azure.BlockResponse{
{"A", 100},
{"B", 50},
{"C", 1},
{"D", 200},
}}); expected != size {
t.Fatalf("wrong blob size: %v, expected: %v", size, expected)
}
}
func assertBlobContents(t *testing.T, r io.Reader, expected []byte) {
out, err := ioutil.ReadAll(r)
if err != nil {
t.Fatal(err)
}
if !reflect.DeepEqual(out, expected) {
t.Fatalf("wrong blob contents. size: %v, expected: %v", len(out), len(expected))
}
}
func randomContents(length int64) []byte {
b := make([]byte, length)
for i := range b {
b[i] = byte(rand.Intn(2 << 8))
}
return b
}

49
docs/storage/driver/azure/zerofillwriter.go
View file

@ -1,49 +0,0 @@
package azure
import (
"bytes"
"io"
)
type blockBlobWriter interface {
GetSize(container, blob string) (int64, error)
WriteBlobAt(container, blob string, offset int64, chunk io.Reader) (int64, error)
}
// zeroFillWriter enables writing to an offset outside a block blob's size
// by offering the chunk to the underlying writer as a contiguous data with
// the gap in between filled with NUL (zero) bytes.
type zeroFillWriter struct {
blockBlobWriter
}
func newZeroFillWriter(b blockBlobWriter) zeroFillWriter {
w := zeroFillWriter{}
w.blockBlobWriter = b
return w
}
// Write writes the given chunk to the specified existing blob even though
// offset is out of blob's size. The gaps are filled with zeros. Returned
// written number count does not include zeros written.
func (z *zeroFillWriter) Write(container, blob string, offset int64, chunk io.Reader) (int64, error) {
size, err := z.blockBlobWriter.GetSize(container, blob)
if err != nil {
return 0, err
}
var reader io.Reader
var zeroPadding int64
if offset <= size {
reader = chunk
} else {
zeroPadding = offset - size
offset = size // adjust offset to be the append index
zeros := bytes.NewReader(make([]byte, zeroPadding))
reader = io.MultiReader(zeros, chunk)
}
nn, err := z.blockBlobWriter.WriteBlobAt(container, blob, offset, reader)
nn -= zeroPadding
return nn, err
}

126
docs/storage/driver/azure/zerofillwriter_test.go
View file

@ -1,126 +0,0 @@
package azure
import (
"bytes"
"testing"
)
func Test_zeroFillWrite_AppendNoGap(t *testing.T) {
s := NewStorageSimulator()
bw := newRandomBlobWriter(&s, 1024*1)
zw := newZeroFillWriter(&bw)
if err := s.CreateBlockBlob("a", "b"); err != nil {
t.Fatal(err)
}
firstChunk := randomContents(1024*3 + 512)
if nn, err := zw.Write("a", "b", 0, bytes.NewReader(firstChunk)); err != nil {
t.Fatal(err)
} else if expected := int64(len(firstChunk)); expected != nn {
t.Fatalf("wrong written bytes count: %v, expected: %v", nn, expected)
}
if out, err := s.GetBlob("a", "b"); err != nil {
t.Fatal(err)
} else {
assertBlobContents(t, out, firstChunk)
}
secondChunk := randomContents(256)
if nn, err := zw.Write("a", "b", int64(len(firstChunk)), bytes.NewReader(secondChunk)); err != nil {
t.Fatal(err)
} else if expected := int64(len(secondChunk)); expected != nn {
t.Fatalf("wrong written bytes count: %v, expected: %v", nn, expected)
}
if out, err := s.GetBlob("a", "b"); err != nil {
t.Fatal(err)
} else {
assertBlobContents(t, out, append(firstChunk, secondChunk...))
}
}
func Test_zeroFillWrite_StartWithGap(t *testing.T) {
s := NewStorageSimulator()
bw := newRandomBlobWriter(&s, 1024*2)
zw := newZeroFillWriter(&bw)
if err := s.CreateBlockBlob("a", "b"); err != nil {
t.Fatal(err)
}
chunk := randomContents(1024 * 5)
padding := int64(1024*2 + 256)
if nn, err := zw.Write("a", "b", padding, bytes.NewReader(chunk)); err != nil {
t.Fatal(err)
} else if expected := int64(len(chunk)); expected != nn {
t.Fatalf("wrong written bytes count: %v, expected: %v", nn, expected)
}
if out, err := s.GetBlob("a", "b"); err != nil {
t.Fatal(err)
} else {
assertBlobContents(t, out, append(make([]byte, padding), chunk...))
}
}
func Test_zeroFillWrite_AppendWithGap(t *testing.T) {
s := NewStorageSimulator()
bw := newRandomBlobWriter(&s, 1024*2)
zw := newZeroFillWriter(&bw)
if err := s.CreateBlockBlob("a", "b"); err != nil {
t.Fatal(err)
}
firstChunk := randomContents(1024*3 + 512)
if _, err := zw.Write("a", "b", 0, bytes.NewReader(firstChunk)); err != nil {
t.Fatal(err)
}
if out, err := s.GetBlob("a", "b"); err != nil {
t.Fatal(err)
} else {
assertBlobContents(t, out, firstChunk)
}
secondChunk := randomContents(256)
padding := int64(1024 * 4)
if nn, err := zw.Write("a", "b", int64(len(firstChunk))+padding, bytes.NewReader(secondChunk)); err != nil {
t.Fatal(err)
} else if expected := int64(len(secondChunk)); expected != nn {
t.Fatalf("wrong written bytes count: %v, expected: %v", nn, expected)
}
if out, err := s.GetBlob("a", "b"); err != nil {
t.Fatal(err)
} else {
assertBlobContents(t, out, append(firstChunk, append(make([]byte, padding), secondChunk...)...))
}
}
func Test_zeroFillWrite_LiesWithinSize(t *testing.T) {
s := NewStorageSimulator()
bw := newRandomBlobWriter(&s, 1024*2)
zw := newZeroFillWriter(&bw)
if err := s.CreateBlockBlob("a", "b"); err != nil {
t.Fatal(err)
}
firstChunk := randomContents(1024 * 3)
if _, err := zw.Write("a", "b", 0, bytes.NewReader(firstChunk)); err != nil {
t.Fatal(err)
}
if out, err := s.GetBlob("a", "b"); err != nil {
t.Fatal(err)
} else {
assertBlobContents(t, out, firstChunk)
}
// in this case, zerofill won't be used
secondChunk := randomContents(256)
if nn, err := zw.Write("a", "b", 0, bytes.NewReader(secondChunk)); err != nil {
t.Fatal(err)
} else if expected := int64(len(secondChunk)); expected != nn {
t.Fatalf("wrong written bytes count: %v, expected: %v", nn, expected)
}
if out, err := s.GetBlob("a", "b"); err != nil {
t.Fatal(err)
} else {
assertBlobContents(t, out, append(secondChunk, firstChunk[len(secondChunk):]...))
}
}

24
docs/storage/driver/base/base.go
View file

@ -102,10 +102,10 @@ func (base *Base) PutContent(ctx context.Context, path string, content []byte) e
return base.setDriverName(base.StorageDriver.PutContent(ctx, path, content))
}
// ReadStream wraps ReadStream of underlying storage driver.
func (base *Base) ReadStream(ctx context.Context, path string, offset int64) (io.ReadCloser, error) {
// Reader wraps Reader of underlying storage driver.
func (base *Base) Reader(ctx context.Context, path string, offset int64) (io.ReadCloser, error) {
ctx, done := context.WithTrace(ctx)
defer done("%s.ReadStream(%q, %d)", base.Name(), path, offset)
defer done("%s.Reader(%q, %d)", base.Name(), path, offset)
if offset < 0 {
return nil, storagedriver.InvalidOffsetError{Path: path, Offset: offset, DriverName: base.StorageDriver.Name()}
@ -115,25 +115,21 @@ func (base *Base) ReadStream(ctx context.Context, path string, offset int64) (io
return nil, storagedriver.InvalidPathError{Path: path, DriverName: base.StorageDriver.Name()}
}
rc, e := base.StorageDriver.ReadStream(ctx, path, offset)
rc, e := base.StorageDriver.Reader(ctx, path, offset)
return rc, base.setDriverName(e)
}
// WriteStream wraps WriteStream of underlying storage driver.
func (base *Base) WriteStream(ctx context.Context, path string, offset int64, reader io.Reader) (nn int64, err error) {
// Writer wraps Writer of underlying storage driver.
func (base *Base) Writer(ctx context.Context, path string, append bool) (storagedriver.FileWriter, error) {
ctx, done := context.WithTrace(ctx)
defer done("%s.WriteStream(%q, %d)", base.Name(), path, offset)
if offset < 0 {
return 0, storagedriver.InvalidOffsetError{Path: path, Offset: offset, DriverName: base.StorageDriver.Name()}
}
defer done("%s.Writer(%q, %v)", base.Name(), path, append)
if !storagedriver.PathRegexp.MatchString(path) {
return 0, storagedriver.InvalidPathError{Path: path, DriverName: base.StorageDriver.Name()}
return nil, storagedriver.InvalidPathError{Path: path, DriverName: base.StorageDriver.Name()}
}
i64, e := base.StorageDriver.WriteStream(ctx, path, offset, reader)
return i64, base.setDriverName(e)
writer, e := base.StorageDriver.Writer(ctx, path, append)
return writer, base.setDriverName(e)
}
// Stat wraps Stat of underlying storage driver.

144
docs/storage/driver/filesystem/driver.go
View file

@ -1,6 +1,7 @@
package filesystem
import (
"bufio"
"bytes"
"fmt"
"io"
@ -78,7 +79,7 @@ func (d *driver) Name() string {
// GetContent retrieves the content stored at "path" as a []byte.
func (d *driver) GetContent(ctx context.Context, path string) ([]byte, error) {
rc, err := d.ReadStream(ctx, path, 0)
rc, err := d.Reader(ctx, path, 0)
if err != nil {
return nil, err
}
@ -94,16 +95,22 @@ func (d *driver) GetContent(ctx context.Context, path string) ([]byte, error) {
// PutContent stores the []byte content at a location designated by "path".
func (d *driver) PutContent(ctx context.Context, subPath string, contents []byte) error {
if _, err := d.WriteStream(ctx, subPath, 0, bytes.NewReader(contents)); err != nil {
writer, err := d.Writer(ctx, subPath, false)
if err != nil {
return err
}
return os.Truncate(d.fullPath(subPath), int64(len(contents)))
defer writer.Close()
_, err = io.Copy(writer, bytes.NewReader(contents))
if err != nil {
writer.Cancel()
return err
}
return writer.Commit()
}
// ReadStream retrieves an io.ReadCloser for the content stored at "path" with a
// Reader retrieves an io.ReadCloser for the content stored at "path" with a
// given byte offset.
func (d *driver) ReadStream(ctx context.Context, path string, offset int64) (io.ReadCloser, error) {
func (d *driver) Reader(ctx context.Context, path string, offset int64) (io.ReadCloser, error) {
file, err := os.OpenFile(d.fullPath(path), os.O_RDONLY, 0644)
if err != nil {
if os.IsNotExist(err) {
@ -125,40 +132,36 @@ func (d *driver) ReadStream(ctx context.Context, path string, offset int64) (io.
return file, nil
}
// WriteStream stores the contents of the provided io.Reader at a location
// designated by the given path.
func (d *driver) WriteStream(ctx context.Context, subPath string, offset int64, reader io.Reader) (nn int64, err error) {
// TODO(stevvooe): This needs to be a requirement.
// if !path.IsAbs(subPath) {
// return fmt.Errorf("absolute path required: %q", subPath)
// }
func (d *driver) Writer(ctx context.Context, subPath string, append bool) (storagedriver.FileWriter, error) {
fullPath := d.fullPath(subPath)
parentDir := path.Dir(fullPath)
if err := os.MkdirAll(parentDir, 0777); err != nil {
return 0, err
return nil, err
}
fp, err := os.OpenFile(fullPath, os.O_WRONLY|os.O_CREATE, 0666)
if err != nil {
// TODO(stevvooe): A few missing conditions in storage driver:
// 1. What if the path is already a directory?
// 2. Should number 1 be exposed explicitly in storagedriver?
// 2. Can this path not exist, even if we create above?
return 0, err
return nil, err
}
defer fp.Close()
nn, err = fp.Seek(offset, os.SEEK_SET)
var offset int64
if !append {
err := fp.Truncate(0)
if err != nil {
return 0, err
fp.Close()
return nil, err
}
} else {
n, err := fp.Seek(0, os.SEEK_END)
if err != nil {
fp.Close()
return nil, err
}
offset = int64(n)
}
if nn != offset {
return 0, fmt.Errorf("bad seek to %v, expected %v in fp=%v", offset, nn, fp)
}
return io.Copy(fp, reader)
return newFileWriter(fp, offset), nil
}
// Stat retrieves the FileInfo for the given path, including the current size
@ -286,3 +289,88 @@ func (fi fileInfo) ModTime() time.Time {
func (fi fileInfo) IsDir() bool {
return fi.FileInfo.IsDir()
}
type fileWriter struct {
file *os.File
size int64
bw *bufio.Writer
closed bool
committed bool
cancelled bool
}
func newFileWriter(file *os.File, size int64) *fileWriter {
return &fileWriter{
file: file,
size: size,
bw: bufio.NewWriter(file),
}
}
func (fw *fileWriter) Write(p []byte) (int, error) {
if fw.closed {
return 0, fmt.Errorf("already closed")
} else if fw.committed {
return 0, fmt.Errorf("already committed")
} else if fw.cancelled {
return 0, fmt.Errorf("already cancelled")
}
n, err := fw.bw.Write(p)
fw.size += int64(n)
return n, err
}
func (fw *fileWriter) Size() int64 {
return fw.size
}
func (fw *fileWriter) Close() error {
if fw.closed {
return fmt.Errorf("already closed")
}
if err := fw.bw.Flush(); err != nil {
return err
}
if err := fw.file.Sync(); err != nil {
return err
}
if err := fw.file.Close(); err != nil {
return err
}
fw.closed = true
return nil
}
func (fw *fileWriter) Cancel() error {
if fw.closed {
return fmt.Errorf("already closed")
}
fw.cancelled = true
fw.file.Close()
return os.Remove(fw.file.Name())
}
func (fw *fileWriter) Commit() error {
if fw.closed {
return fmt.Errorf("already closed")
} else if fw.committed {
return fmt.Errorf("already committed")
} else if fw.cancelled {
return fmt.Errorf("already cancelled")
}
if err := fw.bw.Flush(); err != nil {
return err
}
if err := fw.file.Sync(); err != nil {
return err
}
fw.committed = true
return nil
}

126
docs/storage/driver/inmemory/driver.go
View file

@ -1,7 +1,6 @@
package inmemory
import (
"bytes"
"fmt"
"io"
"io/ioutil"
@ -74,7 +73,7 @@ func (d *driver) GetContent(ctx context.Context, path string) ([]byte, error) {
d.mutex.RLock()
defer d.mutex.RUnlock()
rc, err := d.ReadStream(ctx, path, 0)
rc, err := d.Reader(ctx, path, 0)
if err != nil {
return nil, err
}
@ -88,7 +87,9 @@ func (d *driver) PutContent(ctx context.Context, p string, contents []byte) erro
d.mutex.Lock()
defer d.mutex.Unlock()
f, err := d.root.mkfile(p)
normalized := normalize(p)
f, err := d.root.mkfile(normalized)
if err != nil {
// TODO(stevvooe): Again, we need to clarify when this is not a
// directory in StorageDriver API.
@ -101,9 +102,9 @@ func (d *driver) PutContent(ctx context.Context, p string, contents []byte) erro
return nil
}
// ReadStream retrieves an io.ReadCloser for the content stored at "path" with a
// Reader retrieves an io.ReadCloser for the content stored at "path" with a
// given byte offset.
func (d *driver) ReadStream(ctx context.Context, path string, offset int64) (io.ReadCloser, error) {
func (d *driver) Reader(ctx context.Context, path string, offset int64) (io.ReadCloser, error) {
d.mutex.RLock()
defer d.mutex.RUnlock()
@ -111,10 +112,10 @@ func (d *driver) ReadStream(ctx context.Context, path string, offset int64) (io.
return nil, storagedriver.InvalidOffsetError{Path: path, Offset: offset}
}
path = normalize(path)
found := d.root.find(path)
normalized := normalize(path)
found := d.root.find(normalized)
if found.path() != path {
if found.path() != normalized {
return nil, storagedriver.PathNotFoundError{Path: path}
}
@ -125,46 +126,24 @@ func (d *driver) ReadStream(ctx context.Context, path string, offset int64) (io.
return ioutil.NopCloser(found.(*file).sectionReader(offset)), nil
}
// WriteStream stores the contents of the provided io.ReadCloser at a location
// designated by the given path.
func (d *driver) WriteStream(ctx context.Context, path string, offset int64, reader io.Reader) (nn int64, err error) {
// Writer returns a FileWriter which will store the content written to it
// at the location designated by "path" after the call to Commit.
func (d *driver) Writer(ctx context.Context, path string, append bool) (storagedriver.FileWriter, error) {
d.mutex.Lock()
defer d.mutex.Unlock()
if offset < 0 {
return 0, storagedriver.InvalidOffsetError{Path: path, Offset: offset}
}
normalized := normalize(path)
f, err := d.root.mkfile(normalized)
if err != nil {
return 0, fmt.Errorf("not a file")
return nil, fmt.Errorf("not a file")
}
// Unlock while we are reading from the source, in case we are reading
// from the same mfs instance. This can be fixed by a more granular
// locking model.
d.mutex.Unlock()
d.mutex.RLock() // Take the readlock to block other writers.
var buf bytes.Buffer
nn, err = buf.ReadFrom(reader)
if err != nil {
// TODO(stevvooe): This condition is odd and we may need to clarify:
// we've read nn bytes from reader but have written nothing to the
// backend. What is the correct return value? Really, the caller needs
// to know that the reader has been advanced and reattempting the
// operation is incorrect.
d.mutex.RUnlock()
d.mutex.Lock()
return nn, err
if !append {
f.truncate()
}
d.mutex.RUnlock()
d.mutex.Lock()
f.WriteAt(buf.Bytes(), offset)
return nn, err
return d.newWriter(f), nil
}
// Stat returns info about the provided path.
@ -173,7 +152,7 @@ func (d *driver) Stat(ctx context.Context, path string) (storagedriver.FileInfo,
defer d.mutex.RUnlock()
normalized := normalize(path)
found := d.root.find(path)
found := d.root.find(normalized)
if found.path() != normalized {
return nil, storagedriver.PathNotFoundError{Path: path}
@ -260,3 +239,74 @@ func (d *driver) Delete(ctx context.Context, path string) error {
func (d *driver) URLFor(ctx context.Context, path string, options map[string]interface{}) (string, error) {
return "", storagedriver.ErrUnsupportedMethod{}
}
type writer struct {
d *driver
f *file
closed bool
committed bool
cancelled bool
}
func (d *driver) newWriter(f *file) storagedriver.FileWriter {
return &writer{
d: d,
f: f,
}
}
func (w *writer) Write(p []byte) (int, error) {
if w.closed {
return 0, fmt.Errorf("already closed")
} else if w.committed {
return 0, fmt.Errorf("already committed")
} else if w.cancelled {
return 0, fmt.Errorf("already cancelled")
}
w.d.mutex.Lock()
defer w.d.mutex.Unlock()
return w.f.WriteAt(p, int64(len(w.f.data)))
}
func (w *writer) Size() int64 {
w.d.mutex.RLock()
defer w.d.mutex.RUnlock()
return int64(len(w.f.data))
}
func (w *writer) Close() error {
if w.closed {
return fmt.Errorf("already closed")
}
w.closed = true
return nil
}
func (w *writer) Cancel() error {
if w.closed {
return fmt.Errorf("already closed")
} else if w.committed {
return fmt.Errorf("already committed")
}
w.cancelled = true
w.d.mutex.Lock()
defer w.d.mutex.Unlock()
return w.d.root.delete(w.f.path())
}
func (w *writer) Commit() error {
if w.closed {
return fmt.Errorf("already closed")
} else if w.committed {
return fmt.Errorf("already committed")
} else if w.cancelled {
return fmt.Errorf("already cancelled")
}
w.committed = true
return nil
}

648
docs/storage/driver/s3-aws/s3.go
View file

@ -20,10 +20,8 @@ import (
"reflect"
"strconv"
"strings"
"sync"
"time"
"github.com/Sirupsen/logrus"
"github.com/aws/aws-sdk-go/aws"
"github.com/aws/aws-sdk-go/aws/awserr"
"github.com/aws/aws-sdk-go/aws/credentials"
@ -103,9 +101,6 @@ type driver struct {
Encrypt bool
RootDirectory string
StorageClass string
pool sync.Pool // pool []byte buffers used for WriteStream
zeros []byte // shared, zero-valued buffer used for WriteStream
}
type baseEmbed struct {
@ -302,11 +297,6 @@ func New(params DriverParameters) (*Driver, error) {
Encrypt: params.Encrypt,
RootDirectory: params.RootDirectory,
StorageClass: params.StorageClass,
zeros: make([]byte, params.ChunkSize),
}
d.pool.New = func() interface{} {
return make([]byte, d.ChunkSize)
}
return &Driver{
@ -326,7 +316,7 @@ func (d *driver) Name() string {
// GetContent retrieves the content stored at "path" as a []byte.
func (d *driver) GetContent(ctx context.Context, path string) ([]byte, error) {
reader, err := d.ReadStream(ctx, path, 0)
reader, err := d.Reader(ctx, path, 0)
if err != nil {
return nil, err
}
@ -347,9 +337,9 @@ func (d *driver) PutContent(ctx context.Context, path string, contents []byte) e
return parseError(path, err)
}
// ReadStream retrieves an io.ReadCloser for the content stored at "path" with a
// Reader retrieves an io.ReadCloser for the content stored at "path" with a
// given byte offset.
func (d *driver) ReadStream(ctx context.Context, path string, offset int64) (io.ReadCloser, error) {
func (d *driver) Reader(ctx context.Context, path string, offset int64) (io.ReadCloser, error) {
resp, err := d.S3.GetObject(&s3.GetObjectInput{
Bucket: aws.String(d.Bucket),
Key: aws.String(d.s3Path(path)),
@ -366,372 +356,52 @@ func (d *driver) ReadStream(ctx context.Context, path string, offset int64) (io.
return resp.Body, nil
}
// WriteStream stores the contents of the provided io.Reader at a
// location designated by the given path. The driver will know it has
// received the full contents when the reader returns io.EOF. The number
// of successfully READ bytes will be returned, even if an error is
// returned. May be used to resume writing a stream by providing a nonzero
// offset. Offsets past the current size will write from the position
// beyond the end of the file.
func (d *driver) WriteStream(ctx context.Context, path string, offset int64, reader io.Reader) (totalRead int64, err error) {
var partNumber int64 = 1
bytesRead := 0
var putErrChan chan error
parts := []*s3.CompletedPart{}
done := make(chan struct{}) // stopgap to free up waiting goroutines
// Writer returns a FileWriter which will store the content written to it
// at the location designated by "path" after the call to Commit.
func (d *driver) Writer(ctx context.Context, path string, append bool) (storagedriver.FileWriter, error) {
key := d.s3Path(path)
if !append {
// TODO (brianbland): cancel other uploads at this path
resp, err := d.S3.CreateMultipartUpload(&s3.CreateMultipartUploadInput{
Bucket: aws.String(d.Bucket),
Key: aws.String(d.s3Path(path)),
Key: aws.String(key),
ContentType: d.getContentType(),
ACL: d.getACL(),
ServerSideEncryption: d.getEncryptionMode(),
StorageClass: d.getStorageClass(),
})
if err != nil {
return 0, err
return nil, err
}
uploadID := resp.UploadId
buf := d.getbuf()
// We never want to leave a dangling multipart upload, our only consistent state is
// when there is a whole object at path. This is in order to remain consistent with
// the stat call.
//
// Note that if the machine dies before executing the defer, we will be left with a dangling
// multipart upload, which will eventually be cleaned up, but we will lose all of the progress
// made prior to the machine crashing.
defer func() {
if putErrChan != nil {
if putErr := <-putErrChan; putErr != nil {
err = putErr
return d.newWriter(key, *resp.UploadId, nil), nil
}
}
if len(parts) > 0 {
_, err := d.S3.CompleteMultipartUpload(&s3.CompleteMultipartUploadInput{
resp, err := d.S3.ListMultipartUploads(&s3.ListMultipartUploadsInput{
Bucket: aws.String(d.Bucket),
Key: aws.String(d.s3Path(path)),
UploadId: uploadID,
MultipartUpload: &s3.CompletedMultipartUpload{
Parts: parts,
},
Prefix: aws.String(key),
})
if err != nil {
// TODO (brianbland): log errors here
d.S3.AbortMultipartUpload(&s3.AbortMultipartUploadInput{
return nil, parseError(path, err)
}
for _, multi := range resp.Uploads {
if key != *multi.Key {
continue
}
resp, err := d.S3.ListParts(&s3.ListPartsInput{
Bucket: aws.String(d.Bucket),
Key: aws.String(d.s3Path(path)),
UploadId: uploadID,
})
}
}
d.putbuf(buf) // needs to be here to pick up new buf value
close(done) // free up any waiting goroutines
}()
// Fills from 0 to total from current
fromSmallCurrent := func(total int64) error {
current, err := d.ReadStream(ctx, path, 0)
if err != nil {
return err
}
bytesRead = 0
for int64(bytesRead) < total {
//The loop should very rarely enter a second iteration
nn, err := current.Read(buf[bytesRead:total])
bytesRead += nn
if err != nil {
if err != io.EOF {
return err
}
break
}
}
return nil
}
// Fills from parameter to chunkSize from reader
fromReader := func(from int64) error {
bytesRead = 0
for from+int64(bytesRead) < d.ChunkSize {
nn, err := reader.Read(buf[from+int64(bytesRead):])
totalRead += int64(nn)
bytesRead += nn
if err != nil {
if err != io.EOF {
return err
}
break
}
}
if putErrChan == nil {
putErrChan = make(chan error)
} else {
if putErr := <-putErrChan; putErr != nil {
putErrChan = nil
return putErr
}
}
go func(bytesRead int, from int64, buf []byte) {
defer d.putbuf(buf) // this buffer gets dropped after this call
// DRAGONS(stevvooe): There are few things one might want to know
// about this section. First, the putErrChan is expecting an error
// and a nil or just a nil to come through the channel. This is
// covered by the silly defer below. The other aspect is the s3
// retry backoff to deal with RequestTimeout errors. Even though
// the underlying s3 library should handle it, it doesn't seem to
// be part of the shouldRetry function (see AdRoll/goamz/s3).
defer func() {
select {
case putErrChan <- nil: // for some reason, we do this no matter what.
case <-done:
return // ensure we don't leak the goroutine
}
}()
if bytesRead <= 0 {
return
}
resp, err := d.S3.UploadPart(&s3.UploadPartInput{
Bucket: aws.String(d.Bucket),
Key: aws.String(d.s3Path(path)),
PartNumber: aws.Int64(partNumber),
UploadId: uploadID,
Body: bytes.NewReader(buf[0 : int64(bytesRead)+from]),
Key: aws.String(key),
UploadId: multi.UploadId,
})
if err != nil {
logrus.Errorf("error putting part, aborting: %v", err)
select {
case putErrChan <- err:
case <-done:
return // don't leak the goroutine
return nil, parseError(path, err)
}
var multiSize int64
for _, part := range resp.Parts {
multiSize += *part.Size
}
// parts and partNumber are safe, because this function is the
// only one modifying them and we force it to be executed
// serially.
parts = append(parts, &s3.CompletedPart{
ETag: resp.ETag,
PartNumber: aws.Int64(partNumber),
})
partNumber++
}(bytesRead, from, buf)
buf = d.getbuf() // use a new buffer for the next call
return nil
return d.newWriter(key, *multi.UploadId, resp.Parts), nil
}
if offset > 0 {
resp, err := d.S3.HeadObject(&s3.HeadObjectInput{
Bucket: aws.String(d.Bucket),
Key: aws.String(d.s3Path(path)),
})
if err != nil {
if s3Err, ok := err.(awserr.Error); !ok || s3Err.Code() != "NoSuchKey" {
return 0, err
}
}
currentLength := int64(0)
if err == nil && resp.ContentLength != nil {
currentLength = *resp.ContentLength
}
if currentLength >= offset {
if offset < d.ChunkSize {
// chunkSize > currentLength >= offset
if err = fromSmallCurrent(offset); err != nil {
return totalRead, err
}
if err = fromReader(offset); err != nil {
return totalRead, err
}
if totalRead+offset < d.ChunkSize {
return totalRead, nil
}
} else {
// currentLength >= offset >= chunkSize
resp, err := d.S3.UploadPartCopy(&s3.UploadPartCopyInput{
Bucket: aws.String(d.Bucket),
Key: aws.String(d.s3Path(path)),
PartNumber: aws.Int64(partNumber),
UploadId: uploadID,
CopySource: aws.String(d.Bucket + "/" + d.s3Path(path)),
CopySourceRange: aws.String("bytes=0-" + strconv.FormatInt(offset-1, 10)),
})
if err != nil {
return 0, err
}
parts = append(parts, &s3.CompletedPart{
ETag: resp.CopyPartResult.ETag,
PartNumber: aws.Int64(partNumber),
})
partNumber++
}
} else {
// Fills between parameters with 0s but only when to - from <= chunkSize
fromZeroFillSmall := func(from, to int64) error {
bytesRead = 0
for from+int64(bytesRead) < to {
nn, err := bytes.NewReader(d.zeros).Read(buf[from+int64(bytesRead) : to])
bytesRead += nn
if err != nil {
return err
}
}
return nil
}
// Fills between parameters with 0s, making new parts
fromZeroFillLarge := func(from, to int64) error {
bytesRead64 := int64(0)
for to-(from+bytesRead64) >= d.ChunkSize {
resp, err := d.S3.UploadPart(&s3.UploadPartInput{
Bucket: aws.String(d.Bucket),
Key: aws.String(d.s3Path(path)),
PartNumber: aws.Int64(partNumber),
UploadId: uploadID,
Body: bytes.NewReader(d.zeros),
})
if err != nil {
return err
}
bytesRead64 += d.ChunkSize
parts = append(parts, &s3.CompletedPart{
ETag: resp.ETag,
PartNumber: aws.Int64(partNumber),
})
partNumber++
}
return fromZeroFillSmall(0, (to-from)%d.ChunkSize)
}
// currentLength < offset
if currentLength < d.ChunkSize {
if offset < d.ChunkSize {
// chunkSize > offset > currentLength
if err = fromSmallCurrent(currentLength); err != nil {
return totalRead, err
}
if err = fromZeroFillSmall(currentLength, offset); err != nil {
return totalRead, err
}
if err = fromReader(offset); err != nil {
return totalRead, err
}
if totalRead+offset < d.ChunkSize {
return totalRead, nil
}
} else {
// offset >= chunkSize > currentLength
if err = fromSmallCurrent(currentLength); err != nil {
return totalRead, err
}
if err = fromZeroFillSmall(currentLength, d.ChunkSize); err != nil {
return totalRead, err
}
resp, err := d.S3.UploadPart(&s3.UploadPartInput{
Bucket: aws.String(d.Bucket),
Key: aws.String(d.s3Path(path)),
PartNumber: aws.Int64(partNumber),
UploadId: uploadID,
Body: bytes.NewReader(buf),
})
if err != nil {
return totalRead, err
}
parts = append(parts, &s3.CompletedPart{
ETag: resp.ETag,
PartNumber: aws.Int64(partNumber),
})
partNumber++
//Zero fill from chunkSize up to offset, then some reader
if err = fromZeroFillLarge(d.ChunkSize, offset); err != nil {
return totalRead, err
}
if err = fromReader(offset % d.ChunkSize); err != nil {
return totalRead, err
}
if totalRead+(offset%d.ChunkSize) < d.ChunkSize {
return totalRead, nil
}
}
} else {
// offset > currentLength >= chunkSize
resp, err := d.S3.UploadPartCopy(&s3.UploadPartCopyInput{
Bucket: aws.String(d.Bucket),
Key: aws.String(d.s3Path(path)),
PartNumber: aws.Int64(partNumber),
UploadId: uploadID,
CopySource: aws.String(d.Bucket + "/" + d.s3Path(path)),
})
if err != nil {
return 0, err
}
parts = append(parts, &s3.CompletedPart{
ETag: resp.CopyPartResult.ETag,
PartNumber: aws.Int64(partNumber),
})
partNumber++
//Zero fill from currentLength up to offset, then some reader
if err = fromZeroFillLarge(currentLength, offset); err != nil {
return totalRead, err
}
if err = fromReader((offset - currentLength) % d.ChunkSize); err != nil {
return totalRead, err
}
if totalRead+((offset-currentLength)%d.ChunkSize) < d.ChunkSize {
return totalRead, nil
}
}
}
}
for {
if err = fromReader(0); err != nil {
return totalRead, err
}
if int64(bytesRead) < d.ChunkSize {
break
}
}
return totalRead, nil
return nil, storagedriver.PathNotFoundError{Path: path}
}
// Stat retrieves the FileInfo for the given path, including the current size
@ -971,12 +641,258 @@ func (d *driver) getStorageClass() *string {
return aws.String(d.StorageClass)
}
// getbuf returns a buffer from the driver's pool with length d.ChunkSize.
func (d *driver) getbuf() []byte {
return d.pool.Get().([]byte)
// writer attempts to upload parts to S3 in a buffered fashion where the last
// part is at least as large as the chunksize, so the multipart upload could be
// cleanly resumed in the future. This is violated if Close is called after less
// than a full chunk is written.
type writer struct {
driver *driver
key string
uploadID string
parts []*s3.Part
size int64
readyPart []byte
pendingPart []byte
closed bool
committed bool
cancelled bool
}
func (d *driver) putbuf(p []byte) {
copy(p, d.zeros)
d.pool.Put(p)
func (d *driver) newWriter(key, uploadID string, parts []*s3.Part) storagedriver.FileWriter {
var size int64
for _, part := range parts {
size += *part.Size
}
return &writer{
driver: d,
key: key,
uploadID: uploadID,
parts: parts,
size: size,
}
}
func (w *writer) Write(p []byte) (int, error) {
if w.closed {
return 0, fmt.Errorf("already closed")
} else if w.committed {
return 0, fmt.Errorf("already committed")
} else if w.cancelled {
return 0, fmt.Errorf("already cancelled")
}
// If the last written part is smaller than minChunkSize, we need to make a
// new multipart upload :sadface:
if len(w.parts) > 0 && int(*w.parts[len(w.parts)-1].Size) < minChunkSize {
var completedParts []*s3.CompletedPart
for _, part := range w.parts {
completedParts = append(completedParts, &s3.CompletedPart{
ETag: part.ETag,
PartNumber: part.PartNumber,
})
}
_, err := w.driver.S3.CompleteMultipartUpload(&s3.CompleteMultipartUploadInput{
Bucket: aws.String(w.driver.Bucket),
Key: aws.String(w.key),
UploadId: aws.String(w.uploadID),
MultipartUpload: &s3.CompletedMultipartUpload{
Parts: completedParts,
},
})
if err != nil {
w.driver.S3.AbortMultipartUpload(&s3.AbortMultipartUploadInput{
Bucket: aws.String(w.driver.Bucket),
Key: aws.String(w.key),
UploadId: aws.String(w.uploadID),
})
return 0, err
}
resp, err := w.driver.S3.CreateMultipartUpload(&s3.CreateMultipartUploadInput{
Bucket: aws.String(w.driver.Bucket),
Key: aws.String(w.key),
ContentType: w.driver.getContentType(),
ACL: w.driver.getACL(),
ServerSideEncryption: w.driver.getEncryptionMode(),
StorageClass: w.driver.getStorageClass(),
})
if err != nil {
return 0, err
}
w.uploadID = *resp.UploadId
// If the entire written file is smaller than minChunkSize, we need to make
// a new part from scratch :double sad face:
if w.size < minChunkSize {
resp, err := w.driver.S3.GetObject(&s3.GetObjectInput{
Bucket: aws.String(w.driver.Bucket),
Key: aws.String(w.key),
})
defer resp.Body.Close()
if err != nil {
return 0, err
}
w.parts = nil
w.readyPart, err = ioutil.ReadAll(resp.Body)
if err != nil {
return 0, err
}
} else {
// Otherwise we can use the old file as the new first part
copyPartResp, err := w.driver.S3.UploadPartCopy(&s3.UploadPartCopyInput{
Bucket: aws.String(w.driver.Bucket),
CopySource: aws.String(w.driver.Bucket + "/" + w.key),
Key: aws.String(w.key),
PartNumber: aws.Int64(1),
UploadId: resp.UploadId,
})
if err != nil {
return 0, err
}
w.parts = []*s3.Part{
{
ETag: copyPartResp.CopyPartResult.ETag,
PartNumber: aws.Int64(1),
Size: aws.Int64(w.size),
},
}
}
}
var n int
for len(p) > 0 {
// If no parts are ready to write, fill up the first part
if neededBytes := int(w.driver.ChunkSize) - len(w.readyPart); neededBytes > 0 {
if len(p) >= neededBytes {
w.readyPart = append(w.readyPart, p[:neededBytes]...)
n += neededBytes
p = p[neededBytes:]
} else {
w.readyPart = append(w.readyPart, p...)
n += len(p)
p = nil
}
}
if neededBytes := int(w.driver.ChunkSize) - len(w.pendingPart); neededBytes > 0 {
if len(p) >= neededBytes {
w.pendingPart = append(w.pendingPart, p[:neededBytes]...)
n += neededBytes
p = p[neededBytes:]
err := w.flushPart()
if err != nil {
w.size += int64(n)
return n, err
}
} else {
w.pendingPart = append(w.pendingPart, p...)
n += len(p)
p = nil
}
}
}
w.size += int64(n)
return n, nil
}
func (w *writer) Size() int64 {
return w.size
}
func (w *writer) Close() error {
if w.closed {
return fmt.Errorf("already closed")
}
w.closed = true
return w.flushPart()
}
func (w *writer) Cancel() error {
if w.closed {
return fmt.Errorf("already closed")
} else if w.committed {
return fmt.Errorf("already committed")
}
w.cancelled = true
_, err := w.driver.S3.AbortMultipartUpload(&s3.AbortMultipartUploadInput{
Bucket: aws.String(w.driver.Bucket),
Key: aws.String(w.key),
UploadId: aws.String(w.uploadID),
})
return err
}
func (w *writer) Commit() error {
if w.closed {
return fmt.Errorf("already closed")
} else if w.committed {
return fmt.Errorf("already committed")
} else if w.cancelled {
return fmt.Errorf("already cancelled")
}
err := w.flushPart()
if err != nil {
return err
}
w.committed = true
var completedParts []*s3.CompletedPart
for _, part := range w.parts {
completedParts = append(completedParts, &s3.CompletedPart{
ETag: part.ETag,
PartNumber: part.PartNumber,
})
}
_, err = w.driver.S3.CompleteMultipartUpload(&s3.CompleteMultipartUploadInput{
Bucket: aws.String(w.driver.Bucket),
Key: aws.String(w.key),
UploadId: aws.String(w.uploadID),
MultipartUpload: &s3.CompletedMultipartUpload{
Parts: completedParts,
},
})
if err != nil {
w.driver.S3.AbortMultipartUpload(&s3.AbortMultipartUploadInput{
Bucket: aws.String(w.driver.Bucket),
Key: aws.String(w.key),
UploadId: aws.String(w.uploadID),
})
return err
}
return nil
}
// flushPart flushes buffers to write a part to S3.
// Only called by Write (with both buffers full) and Close/Commit (always)
func (w *writer) flushPart() error {
if len(w.readyPart) == 0 && len(w.pendingPart) == 0 {
// nothing to write
return nil
}
if len(w.pendingPart) < int(w.driver.ChunkSize) {
// closing with a small pending part
// combine ready and pending to avoid writing a small part
w.readyPart = append(w.readyPart, w.pendingPart...)
w.pendingPart = nil
}
partNumber := aws.Int64(int64(len(w.parts) + 1))
resp, err := w.driver.S3.UploadPart(&s3.UploadPartInput{
Bucket: aws.String(w.driver.Bucket),
Key: aws.String(w.key),
PartNumber: partNumber,
UploadId: aws.String(w.uploadID),
Body: bytes.NewReader(w.readyPart),
})
if err != nil {
return err
}
w.parts = append(w.parts, &s3.Part{
ETag: resp.ETag,
PartNumber: partNumber,
Size: aws.Int64(int64(len(w.readyPart))),
})
w.readyPart = w.pendingPart
w.pendingPart = nil
return nil
}

545
docs/storage/driver/s3-goamz/s3.go
View file

@ -21,10 +21,8 @@ import (
"reflect"
"strconv"
"strings"
"sync"
"time"
"github.com/Sirupsen/logrus"
"github.com/docker/goamz/aws"
"github.com/docker/goamz/s3"
@ -79,9 +77,6 @@ type driver struct {
Encrypt bool
RootDirectory string
StorageClass s3.StorageClass
pool sync.Pool // pool []byte buffers used for WriteStream
zeros []byte // shared, zero-valued buffer used for WriteStream
}
type baseEmbed struct {
@ -301,11 +296,6 @@ func New(params DriverParameters) (*Driver, error) {
Encrypt: params.Encrypt,
RootDirectory: params.RootDirectory,
StorageClass: params.StorageClass,
zeros: make([]byte, params.ChunkSize),
}
d.pool.New = func() interface{} {
return make([]byte, d.ChunkSize)
}
return &Driver{
@ -337,9 +327,9 @@ func (d *driver) PutContent(ctx context.Context, path string, contents []byte) e
return parseError(path, d.Bucket.Put(d.s3Path(path), contents, d.getContentType(), getPermissions(), d.getOptions()))
}
// ReadStream retrieves an io.ReadCloser for the content stored at "path" with a
// Reader retrieves an io.ReadCloser for the content stored at "path" with a
// given byte offset.
func (d *driver) ReadStream(ctx context.Context, path string, offset int64) (io.ReadCloser, error) {
func (d *driver) Reader(ctx context.Context, path string, offset int64) (io.ReadCloser, error) {
headers := make(http.Header)
headers.Add("Range", "bytes="+strconv.FormatInt(offset, 10)+"-")
@ -354,343 +344,37 @@ func (d *driver) ReadStream(ctx context.Context, path string, offset int64) (io.
return resp.Body, nil
}
// WriteStream stores the contents of the provided io.Reader at a
// location designated by the given path. The driver will know it has
// received the full contents when the reader returns io.EOF. The number
// of successfully READ bytes will be returned, even if an error is
// returned. May be used to resume writing a stream by providing a nonzero
// offset. Offsets past the current size will write from the position
// beyond the end of the file.
func (d *driver) WriteStream(ctx context.Context, path string, offset int64, reader io.Reader) (totalRead int64, err error) {
partNumber := 1
bytesRead := 0
var putErrChan chan error
parts := []s3.Part{}
var part s3.Part
done := make(chan struct{}) // stopgap to free up waiting goroutines
multi, err := d.Bucket.InitMulti(d.s3Path(path), d.getContentType(), getPermissions(), d.getOptions())
// Writer returns a FileWriter which will store the content written to it
// at the location designated by "path" after the call to Commit.
func (d *driver) Writer(ctx context.Context, path string, append bool) (storagedriver.FileWriter, error) {
key := d.s3Path(path)
if !append {
// TODO (brianbland): cancel other uploads at this path
multi, err := d.Bucket.InitMulti(key, d.getContentType(), getPermissions(), d.getOptions())
if err != nil {
return 0, err
return nil, err
}
buf := d.getbuf()
// We never want to leave a dangling multipart upload, our only consistent state is
// when there is a whole object at path. This is in order to remain consistent with
// the stat call.
//
// Note that if the machine dies before executing the defer, we will be left with a dangling
// multipart upload, which will eventually be cleaned up, but we will lose all of the progress
// made prior to the machine crashing.
defer func() {
if putErrChan != nil {
if putErr := <-putErrChan; putErr != nil {
err = putErr
return d.newWriter(key, multi, nil), nil
}
}
if len(parts) > 0 {
if multi == nil {
// Parts should be empty if the multi is not initialized
panic("Unreachable")
} else {
if multi.Complete(parts) != nil {
multi.Abort()
}
}
}
d.putbuf(buf) // needs to be here to pick up new buf value
close(done) // free up any waiting goroutines
}()
// Fills from 0 to total from current
fromSmallCurrent := func(total int64) error {
current, err := d.ReadStream(ctx, path, 0)
multis, _, err := d.Bucket.ListMulti(key, "")
if err != nil {
return err
return nil, parseError(path, err)
}
bytesRead = 0
for int64(bytesRead) < total {
//The loop should very rarely enter a second iteration
nn, err := current.Read(buf[bytesRead:total])
bytesRead += nn
for _, multi := range multis {
if key != multi.Key {
continue
}
parts, err := multi.ListParts()
if err != nil {
if err != io.EOF {
return err
return nil, parseError(path, err)
}
break
var multiSize int64
for _, part := range parts {
multiSize += part.Size
}
return d.newWriter(key, multi, parts), nil
}
return nil
}
// Fills from parameter to chunkSize from reader
fromReader := func(from int64) error {
bytesRead = 0
for from+int64(bytesRead) < d.ChunkSize {
nn, err := reader.Read(buf[from+int64(bytesRead):])
totalRead += int64(nn)
bytesRead += nn
if err != nil {
if err != io.EOF {
return err
}
break
}
}
if putErrChan == nil {
putErrChan = make(chan error)
} else {
if putErr := <-putErrChan; putErr != nil {
putErrChan = nil
return putErr
}
}
go func(bytesRead int, from int64, buf []byte) {
defer d.putbuf(buf) // this buffer gets dropped after this call
// DRAGONS(stevvooe): There are few things one might want to know
// about this section. First, the putErrChan is expecting an error
// and a nil or just a nil to come through the channel. This is
// covered by the silly defer below. The other aspect is the s3
// retry backoff to deal with RequestTimeout errors. Even though
// the underlying s3 library should handle it, it doesn't seem to
// be part of the shouldRetry function (see AdRoll/goamz/s3).
defer func() {
select {
case putErrChan <- nil: // for some reason, we do this no matter what.
case <-done:
return // ensure we don't leak the goroutine
}
}()
if bytesRead <= 0 {
return
}
var err error
var part s3.Part
loop:
for retries := 0; retries < 5; retries++ {
part, err = multi.PutPart(int(partNumber), bytes.NewReader(buf[0:int64(bytesRead)+from]))
if err == nil {
break // success!
}
// NOTE(stevvooe): This retry code tries to only retry under
// conditions where the s3 package does not. We may add s3
// error codes to the below if we see others bubble up in the
// application. Right now, the most troubling is
// RequestTimeout, which seems to only triggered when a tcp
// connection to s3 slows to a crawl. If the RequestTimeout
// ends up getting added to the s3 library and we don't see
// other errors, this retry loop can be removed.
switch err := err.(type) {
case *s3.Error:
switch err.Code {
case "RequestTimeout":
// allow retries on only this error.
default:
break loop
}
}
backoff := 100 * time.Millisecond * time.Duration(retries+1)
logrus.Errorf("error putting part, retrying after %v: %v", err, backoff.String())
time.Sleep(backoff)
}
if err != nil {
logrus.Errorf("error putting part, aborting: %v", err)
select {
case putErrChan <- err:
case <-done:
return // don't leak the goroutine
}
}
// parts and partNumber are safe, because this function is the
// only one modifying them and we force it to be executed
// serially.
parts = append(parts, part)
partNumber++
}(bytesRead, from, buf)
buf = d.getbuf() // use a new buffer for the next call
return nil
}
if offset > 0 {
resp, err := d.Bucket.Head(d.s3Path(path), nil)
if err != nil {
if s3Err, ok := err.(*s3.Error); !ok || s3Err.Code != "NoSuchKey" {
return 0, err
}
}
currentLength := int64(0)
if err == nil {
currentLength = resp.ContentLength
}
if currentLength >= offset {
if offset < d.ChunkSize {
// chunkSize > currentLength >= offset
if err = fromSmallCurrent(offset); err != nil {
return totalRead, err
}
if err = fromReader(offset); err != nil {
return totalRead, err
}
if totalRead+offset < d.ChunkSize {
return totalRead, nil
}
} else {
// currentLength >= offset >= chunkSize
_, part, err = multi.PutPartCopy(partNumber,
s3.CopyOptions{CopySourceOptions: "bytes=0-" + strconv.FormatInt(offset-1, 10)},
d.Bucket.Name+"/"+d.s3Path(path))
if err != nil {
return 0, err
}
parts = append(parts, part)
partNumber++
}
} else {
// Fills between parameters with 0s but only when to - from <= chunkSize
fromZeroFillSmall := func(from, to int64) error {
bytesRead = 0
for from+int64(bytesRead) < to {
nn, err := bytes.NewReader(d.zeros).Read(buf[from+int64(bytesRead) : to])
bytesRead += nn
if err != nil {
return err
}
}
return nil
}
// Fills between parameters with 0s, making new parts
fromZeroFillLarge := func(from, to int64) error {
bytesRead64 := int64(0)
for to-(from+bytesRead64) >= d.ChunkSize {
part, err := multi.PutPart(int(partNumber), bytes.NewReader(d.zeros))
if err != nil {
return err
}
bytesRead64 += d.ChunkSize
parts = append(parts, part)
partNumber++
}
return fromZeroFillSmall(0, (to-from)%d.ChunkSize)
}
// currentLength < offset
if currentLength < d.ChunkSize {
if offset < d.ChunkSize {
// chunkSize > offset > currentLength
if err = fromSmallCurrent(currentLength); err != nil {
return totalRead, err
}
if err = fromZeroFillSmall(currentLength, offset); err != nil {
return totalRead, err
}
if err = fromReader(offset); err != nil {
return totalRead, err
}
if totalRead+offset < d.ChunkSize {
return totalRead, nil
}
} else {
// offset >= chunkSize > currentLength
if err = fromSmallCurrent(currentLength); err != nil {
return totalRead, err
}
if err = fromZeroFillSmall(currentLength, d.ChunkSize); err != nil {
return totalRead, err
}
part, err = multi.PutPart(int(partNumber), bytes.NewReader(buf))
if err != nil {
return totalRead, err
}
parts = append(parts, part)
partNumber++
//Zero fill from chunkSize up to offset, then some reader
if err = fromZeroFillLarge(d.ChunkSize, offset); err != nil {
return totalRead, err
}
if err = fromReader(offset % d.ChunkSize); err != nil {
return totalRead, err
}
if totalRead+(offset%d.ChunkSize) < d.ChunkSize {
return totalRead, nil
}
}
} else {
// offset > currentLength >= chunkSize
_, part, err = multi.PutPartCopy(partNumber,
s3.CopyOptions{},
d.Bucket.Name+"/"+d.s3Path(path))
if err != nil {
return 0, err
}
parts = append(parts, part)
partNumber++
//Zero fill from currentLength up to offset, then some reader
if err = fromZeroFillLarge(currentLength, offset); err != nil {
return totalRead, err
}
if err = fromReader((offset - currentLength) % d.ChunkSize); err != nil {
return totalRead, err
}
if totalRead+((offset-currentLength)%d.ChunkSize) < d.ChunkSize {
return totalRead, nil
}
}
}
}
for {
if err = fromReader(0); err != nil {
return totalRead, err
}
if int64(bytesRead) < d.ChunkSize {
break
}
}
return totalRead, nil
return nil, storagedriver.PathNotFoundError{Path: path}
}
// Stat retrieves the FileInfo for the given path, including the current size
@ -882,12 +566,181 @@ func (d *driver) getContentType() string {
return "application/octet-stream"
}
// getbuf returns a buffer from the driver's pool with length d.ChunkSize.
func (d *driver) getbuf() []byte {
return d.pool.Get().([]byte)
// writer attempts to upload parts to S3 in a buffered fashion where the last
// part is at least as large as the chunksize, so the multipart upload could be
// cleanly resumed in the future. This is violated if Close is called after less
// than a full chunk is written.
type writer struct {
driver *driver
key string
multi *s3.Multi
parts []s3.Part
size int64
readyPart []byte
pendingPart []byte
closed bool
committed bool
cancelled bool
}
func (d *driver) putbuf(p []byte) {
copy(p, d.zeros)
d.pool.Put(p)
func (d *driver) newWriter(key string, multi *s3.Multi, parts []s3.Part) storagedriver.FileWriter {
var size int64
for _, part := range parts {
size += part.Size
}
return &writer{
driver: d,
key: key,
multi: multi,
parts: parts,
size: size,
}
}
func (w *writer) Write(p []byte) (int, error) {
if w.closed {
return 0, fmt.Errorf("already closed")
} else if w.committed {
return 0, fmt.Errorf("already committed")
} else if w.cancelled {
return 0, fmt.Errorf("already cancelled")
}
// If the last written part is smaller than minChunkSize, we need to make a
// new multipart upload :sadface:
if len(w.parts) > 0 && int(w.parts[len(w.parts)-1].Size) < minChunkSize {
err := w.multi.Complete(w.parts)
if err != nil {
w.multi.Abort()
return 0, err
}
multi, err := w.driver.Bucket.InitMulti(w.key, w.driver.getContentType(), getPermissions(), w.driver.getOptions())
if err != nil {
return 0, err
}
w.multi = multi
// If the entire written file is smaller than minChunkSize, we need to make
// a new part from scratch :double sad face:
if w.size < minChunkSize {
contents, err := w.driver.Bucket.Get(w.key)
if err != nil {
return 0, err
}
w.parts = nil
w.readyPart = contents
} else {
// Otherwise we can use the old file as the new first part
_, part, err := multi.PutPartCopy(1, s3.CopyOptions{}, w.driver.Bucket.Name+"/"+w.key)
if err != nil {
return 0, err
}
w.parts = []s3.Part{part}
}
}
var n int
for len(p) > 0 {
// If no parts are ready to write, fill up the first part
if neededBytes := int(w.driver.ChunkSize) - len(w.readyPart); neededBytes > 0 {
if len(p) >= neededBytes {
w.readyPart = append(w.readyPart, p[:neededBytes]...)
n += neededBytes
p = p[neededBytes:]
} else {
w.readyPart = append(w.readyPart, p...)
n += len(p)
p = nil
}
}
if neededBytes := int(w.driver.ChunkSize) - len(w.pendingPart); neededBytes > 0 {
if len(p) >= neededBytes {
w.pendingPart = append(w.pendingPart, p[:neededBytes]...)
n += neededBytes
p = p[neededBytes:]
err := w.flushPart()
if err != nil {
w.size += int64(n)
return n, err
}
} else {
w.pendingPart = append(w.pendingPart, p...)
n += len(p)
p = nil
}
}
}
w.size += int64(n)
return n, nil
}
func (w *writer) Size() int64 {
return w.size
}
func (w *writer) Close() error {
if w.closed {
return fmt.Errorf("already closed")
}
w.closed = true
return w.flushPart()
}
func (w *writer) Cancel() error {
if w.closed {
return fmt.Errorf("already closed")
} else if w.committed {
return fmt.Errorf("already committed")
}
w.cancelled = true
err := w.multi.Abort()
return err
}
func (w *writer) Commit() error {
if w.closed {
return fmt.Errorf("already closed")
} else if w.committed {
return fmt.Errorf("already committed")
} else if w.cancelled {
return fmt.Errorf("already cancelled")
}
err := w.flushPart()
if err != nil {
return err
}
w.committed = true
err = w.multi.Complete(w.parts)
if err != nil {
w.multi.Abort()
return err
}
return nil
}
// flushPart flushes buffers to write a part to S3.
// Only called by Write (with both buffers full) and Close/Commit (always)
func (w *writer) flushPart() error {
if len(w.readyPart) == 0 && len(w.pendingPart) == 0 {
// nothing to write
return nil
}
if len(w.pendingPart) < int(w.driver.ChunkSize) {
// closing with a small pending part
// combine ready and pending to avoid writing a small part
w.readyPart = append(w.readyPart, w.pendingPart...)
w.pendingPart = nil
}
part, err := w.multi.PutPart(len(w.parts)+1, bytes.NewReader(w.readyPart))
if err != nil {
return err
}
w.parts = append(w.parts, part)
w.readyPart = w.pendingPart
w.pendingPart = nil
return nil
}

30
docs/storage/driver/storagedriver.go
View file

@ -49,15 +49,14 @@ type StorageDriver interface {
// This should primarily be used for small objects.
PutContent(ctx context.Context, path string, content []byte) error
// ReadStream retrieves an io.ReadCloser for the content stored at "path"
// Reader retrieves an io.ReadCloser for the content stored at "path"
// with a given byte offset.
// May be used to resume reading a stream by providing a nonzero offset.
ReadStream(ctx context.Context, path string, offset int64) (io.ReadCloser, error)
Reader(ctx context.Context, path string, offset int64) (io.ReadCloser, error)
// WriteStream stores the contents of the provided io.ReadCloser at a
// location designated by the given path.
// May be used to resume writing a stream by providing a nonzero offset.
WriteStream(ctx context.Context, path string, offset int64, reader io.Reader) (nn int64, err error)
// Writer returns a FileWriter which will store the content written to it
// at the location designated by "path" after the call to Commit.
Writer(ctx context.Context, path string, append bool) (FileWriter, error)
// Stat retrieves the FileInfo for the given path, including the current
// size in bytes and the creation time.
@ -83,6 +82,25 @@ type StorageDriver interface {
URLFor(ctx context.Context, path string, options map[string]interface{}) (string, error)
}
// FileWriter provides an abstraction for an opened writable file-like object in
// the storage backend. The FileWriter must flush all content written to it on
// the call to Close, but is only required to make its content readable on a
// call to Commit.
type FileWriter interface {
io.WriteCloser
// Size returns the number of bytes written to this FileWriter.
Size() int64
// Cancel removes any written content from this FileWriter.
Cancel() error
// Commit flushes all content written to this FileWriter and makes it
// available for future calls to StorageDriver.GetContent and
// StorageDriver.Reader.
Commit() error
}
// PathRegexp is the regular expression which each file path must match. A
// file path is absolute, beginning with a slash and containing a positive
// number of path components separated by slashes, where each component is

247
docs/storage/driver/testsuites/testsuites.go
View file

@ -282,11 +282,19 @@ func (suite *DriverSuite) TestWriteReadLargeStreams(c *check.C) {
var fileSize int64 = 5 * 1024 * 1024 * 1024
contents := newRandReader(fileSize)
written, err := suite.StorageDriver.WriteStream(suite.ctx, filename, 0, io.TeeReader(contents, checksum))
writer, err := suite.StorageDriver.Writer(suite.ctx, filename, false)
c.Assert(err, check.IsNil)
written, err := io.Copy(writer, io.TeeReader(contents, checksum))
c.Assert(err, check.IsNil)
c.Assert(written, check.Equals, fileSize)
reader, err := suite.StorageDriver.ReadStream(suite.ctx, filename, 0)
err = writer.Commit()
c.Assert(err, check.IsNil)
err = writer.Close()
c.Assert(err, check.IsNil)
reader, err := suite.StorageDriver.Reader(suite.ctx, filename, 0)
c.Assert(err, check.IsNil)
defer reader.Close()
@ -296,9 +304,9 @@ func (suite *DriverSuite) TestWriteReadLargeStreams(c *check.C) {
c.Assert(writtenChecksum.Sum(nil), check.DeepEquals, checksum.Sum(nil))
}
// TestReadStreamWithOffset tests that the appropriate data is streamed when
// TestReaderWithOffset tests that the appropriate data is streamed when
// reading with a given offset.
func (suite *DriverSuite) TestReadStreamWithOffset(c *check.C) {
func (suite *DriverSuite) TestReaderWithOffset(c *check.C) {
filename := randomPath(32)
defer suite.deletePath(c, firstPart(filename))
@ -311,7 +319,7 @@ func (suite *DriverSuite) TestReadStreamWithOffset(c *check.C) {
err := suite.StorageDriver.PutContent(suite.ctx, filename, append(append(contentsChunk1, contentsChunk2...), contentsChunk3...))
c.Assert(err, check.IsNil)
reader, err := suite.StorageDriver.ReadStream(suite.ctx, filename, 0)
reader, err := suite.StorageDriver.Reader(suite.ctx, filename, 0)
c.Assert(err, check.IsNil)
defer reader.Close()
@ -320,7 +328,7 @@ func (suite *DriverSuite) TestReadStreamWithOffset(c *check.C) {
c.Assert(readContents, check.DeepEquals, append(append(contentsChunk1, contentsChunk2...), contentsChunk3...))
reader, err = suite.StorageDriver.ReadStream(suite.ctx, filename, chunkSize)
reader, err = suite.StorageDriver.Reader(suite.ctx, filename, chunkSize)
c.Assert(err, check.IsNil)
defer reader.Close()
@ -329,7 +337,7 @@ func (suite *DriverSuite) TestReadStreamWithOffset(c *check.C) {
c.Assert(readContents, check.DeepEquals, append(contentsChunk2, contentsChunk3...))
reader, err = suite.StorageDriver.ReadStream(suite.ctx, filename, chunkSize*2)
reader, err = suite.StorageDriver.Reader(suite.ctx, filename, chunkSize*2)
c.Assert(err, check.IsNil)
defer reader.Close()
@ -338,7 +346,7 @@ func (suite *DriverSuite) TestReadStreamWithOffset(c *check.C) {
c.Assert(readContents, check.DeepEquals, contentsChunk3)
// Ensure we get invalid offest for negative offsets.
reader, err = suite.StorageDriver.ReadStream(suite.ctx, filename, -1)
reader, err = suite.StorageDriver.Reader(suite.ctx, filename, -1)
c.Assert(err, check.FitsTypeOf, storagedriver.InvalidOffsetError{})
c.Assert(err.(storagedriver.InvalidOffsetError).Offset, check.Equals, int64(-1))
c.Assert(err.(storagedriver.InvalidOffsetError).Path, check.Equals, filename)
@ -347,7 +355,7 @@ func (suite *DriverSuite) TestReadStreamWithOffset(c *check.C) {
// Read past the end of the content and make sure we get a reader that
// returns 0 bytes and io.EOF
reader, err = suite.StorageDriver.ReadStream(suite.ctx, filename, chunkSize*3)
reader, err = suite.StorageDriver.Reader(suite.ctx, filename, chunkSize*3)
c.Assert(err, check.IsNil)
defer reader.Close()
@ -357,7 +365,7 @@ func (suite *DriverSuite) TestReadStreamWithOffset(c *check.C) {
c.Assert(n, check.Equals, 0)
// Check the N-1 boundary condition, ensuring we get 1 byte then io.EOF.
reader, err = suite.StorageDriver.ReadStream(suite.ctx, filename, chunkSize*3-1)
reader, err = suite.StorageDriver.Reader(suite.ctx, filename, chunkSize*3-1)
c.Assert(err, check.IsNil)
defer reader.Close()
@ -395,78 +403,51 @@ func (suite *DriverSuite) testContinueStreamAppend(c *check.C, chunkSize int64)
contentsChunk1 := randomContents(chunkSize)
contentsChunk2 := randomContents(chunkSize)
contentsChunk3 := randomContents(chunkSize)
contentsChunk4 := randomContents(chunkSize)
zeroChunk := make([]byte, int64(chunkSize))
fullContents := append(append(contentsChunk1, contentsChunk2...), contentsChunk3...)
nn, err := suite.StorageDriver.WriteStream(suite.ctx, filename, 0, bytes.NewReader(contentsChunk1))
writer, err := suite.StorageDriver.Writer(suite.ctx, filename, false)
c.Assert(err, check.IsNil)
nn, err := io.Copy(writer, bytes.NewReader(contentsChunk1))
c.Assert(err, check.IsNil)
c.Assert(nn, check.Equals, int64(len(contentsChunk1)))
fi, err := suite.StorageDriver.Stat(suite.ctx, filename)
c.Assert(err, check.IsNil)
c.Assert(fi, check.NotNil)
c.Assert(fi.Size(), check.Equals, int64(len(contentsChunk1)))
curSize := writer.Size()
c.Assert(curSize, check.Equals, int64(len(contentsChunk1)))
nn, err = suite.StorageDriver.WriteStream(suite.ctx, filename, fi.Size(), bytes.NewReader(contentsChunk2))
err = writer.Close()
c.Assert(err, check.IsNil)
writer, err = suite.StorageDriver.Writer(suite.ctx, filename, true)
c.Assert(err, check.IsNil)
c.Assert(writer.Size(), check.Equals, curSize)
nn, err = io.Copy(writer, bytes.NewReader(contentsChunk2))
c.Assert(err, check.IsNil)
c.Assert(nn, check.Equals, int64(len(contentsChunk2)))
fi, err = suite.StorageDriver.Stat(suite.ctx, filename)
c.Assert(err, check.IsNil)
c.Assert(fi, check.NotNil)
c.Assert(fi.Size(), check.Equals, 2*chunkSize)
curSize = writer.Size()
c.Assert(curSize, check.Equals, 2*chunkSize)
// Test re-writing the last chunk
nn, err = suite.StorageDriver.WriteStream(suite.ctx, filename, fi.Size()-chunkSize, bytes.NewReader(contentsChunk2))
err = writer.Close()
c.Assert(err, check.IsNil)
c.Assert(nn, check.Equals, int64(len(contentsChunk2)))
fi, err = suite.StorageDriver.Stat(suite.ctx, filename)
writer, err = suite.StorageDriver.Writer(suite.ctx, filename, true)
c.Assert(err, check.IsNil)
c.Assert(fi, check.NotNil)
c.Assert(fi.Size(), check.Equals, 2*chunkSize)
c.Assert(writer.Size(), check.Equals, curSize)
nn, err = suite.StorageDriver.WriteStream(suite.ctx, filename, fi.Size(), bytes.NewReader(fullContents[fi.Size():]))
nn, err = io.Copy(writer, bytes.NewReader(fullContents[curSize:]))
c.Assert(err, check.IsNil)
c.Assert(nn, check.Equals, int64(len(fullContents[curSize:])))
err = writer.Commit()
c.Assert(err, check.IsNil)
err = writer.Close()
c.Assert(err, check.IsNil)
c.Assert(nn, check.Equals, int64(len(fullContents[fi.Size():])))
received, err := suite.StorageDriver.GetContent(suite.ctx, filename)
c.Assert(err, check.IsNil)
c.Assert(received, check.DeepEquals, fullContents)
// Writing past size of file extends file (no offset error). We would like
// to write chunk 4 one chunk length past chunk 3. It should be successful
// and the resulting file will be 5 chunks long, with a chunk of all
// zeros.
fullContents = append(fullContents, zeroChunk...)
fullContents = append(fullContents, contentsChunk4...)
nn, err = suite.StorageDriver.WriteStream(suite.ctx, filename, int64(len(fullContents))-chunkSize, bytes.NewReader(contentsChunk4))
c.Assert(err, check.IsNil)
c.Assert(nn, check.Equals, chunkSize)
fi, err = suite.StorageDriver.Stat(suite.ctx, filename)
c.Assert(err, check.IsNil)
c.Assert(fi, check.NotNil)
c.Assert(fi.Size(), check.Equals, int64(len(fullContents)))
received, err = suite.StorageDriver.GetContent(suite.ctx, filename)
c.Assert(err, check.IsNil)
c.Assert(len(received), check.Equals, len(fullContents))
c.Assert(received[chunkSize*3:chunkSize*4], check.DeepEquals, zeroChunk)
c.Assert(received[chunkSize*4:chunkSize*5], check.DeepEquals, contentsChunk4)
c.Assert(received, check.DeepEquals, fullContents)
// Ensure that negative offsets return correct error.
nn, err = suite.StorageDriver.WriteStream(suite.ctx, filename, -1, bytes.NewReader(zeroChunk))
c.Assert(err, check.NotNil)
c.Assert(err, check.FitsTypeOf, storagedriver.InvalidOffsetError{})
c.Assert(err.(storagedriver.InvalidOffsetError).Path, check.Equals, filename)
c.Assert(err.(storagedriver.InvalidOffsetError).Offset, check.Equals, int64(-1))
c.Assert(strings.Contains(err.Error(), suite.Name()), check.Equals, true)
}
// TestReadNonexistentStream tests that reading a stream for a nonexistent path
@ -474,12 +455,12 @@ func (suite *DriverSuite) testContinueStreamAppend(c *check.C, chunkSize int64)
func (suite *DriverSuite) TestReadNonexistentStream(c *check.C) {
filename := randomPath(32)
_, err := suite.StorageDriver.ReadStream(suite.ctx, filename, 0)
_, err := suite.StorageDriver.Reader(suite.ctx, filename, 0)
c.Assert(err, check.NotNil)
c.Assert(err, check.FitsTypeOf, storagedriver.PathNotFoundError{})
c.Assert(strings.Contains(err.Error(), suite.Name()), check.Equals, true)
_, err = suite.StorageDriver.ReadStream(suite.ctx, filename, 64)
_, err = suite.StorageDriver.Reader(suite.ctx, filename, 64)
c.Assert(err, check.NotNil)
c.Assert(err, check.FitsTypeOf, storagedriver.PathNotFoundError{})
c.Assert(strings.Contains(err.Error(), suite.Name()), check.Equals, true)
@ -800,7 +781,7 @@ func (suite *DriverSuite) TestStatCall(c *check.C) {
// TestPutContentMultipleTimes checks that if storage driver can overwrite the content
// in the subsequent puts. Validates that PutContent does not have to work
// with an offset like WriteStream does and overwrites the file entirely
// with an offset like Writer does and overwrites the file entirely
// rather than writing the data to the [0,len(data)) of the file.
func (suite *DriverSuite) TestPutContentMultipleTimes(c *check.C) {
filename := randomPath(32)
@ -842,7 +823,7 @@ func (suite *DriverSuite) TestConcurrentStreamReads(c *check.C) {
readContents := func() {
defer wg.Done()
offset := rand.Int63n(int64(len(contents)))
reader, err := suite.StorageDriver.ReadStream(suite.ctx, filename, offset)
reader, err := suite.StorageDriver.Reader(suite.ctx, filename, offset)
c.Assert(err, check.IsNil)
readContents, err := ioutil.ReadAll(reader)
@ -858,7 +839,7 @@ func (suite *DriverSuite) TestConcurrentStreamReads(c *check.C) {
}
// TestConcurrentFileStreams checks that multiple *os.File objects can be passed
// in to WriteStream concurrently without hanging.
// in to Writer concurrently without hanging.
func (suite *DriverSuite) TestConcurrentFileStreams(c *check.C) {
numStreams := 32
@ -882,53 +863,54 @@ func (suite *DriverSuite) TestConcurrentFileStreams(c *check.C) {
wg.Wait()
}
// TODO (brianbland): evaluate the relevancy of this test
// TestEventualConsistency checks that if stat says that a file is a certain size, then
// you can freely read from the file (this is the only guarantee that the driver needs to provide)
func (suite *DriverSuite) TestEventualConsistency(c *check.C) {
if testing.Short() {
c.Skip("Skipping test in short mode")
}
filename := randomPath(32)
defer suite.deletePath(c, firstPart(filename))
var offset int64
var misswrites int
var chunkSize int64 = 32
for i := 0; i < 1024; i++ {
contents := randomContents(chunkSize)
read, err := suite.StorageDriver.WriteStream(suite.ctx, filename, offset, bytes.NewReader(contents))
c.Assert(err, check.IsNil)
fi, err := suite.StorageDriver.Stat(suite.ctx, filename)
c.Assert(err, check.IsNil)
// We are most concerned with being able to read data as soon as Stat declares
// it is uploaded. This is the strongest guarantee that some drivers (that guarantee
// at best eventual consistency) absolutely need to provide.
if fi.Size() == offset+chunkSize {
reader, err := suite.StorageDriver.ReadStream(suite.ctx, filename, offset)
c.Assert(err, check.IsNil)
readContents, err := ioutil.ReadAll(reader)
c.Assert(err, check.IsNil)
c.Assert(readContents, check.DeepEquals, contents)
reader.Close()
offset += read
} else {
misswrites++
}
}
if misswrites > 0 {
c.Log("There were " + string(misswrites) + " occurrences of a write not being instantly available.")
}
c.Assert(misswrites, check.Not(check.Equals), 1024)
}
// func (suite *DriverSuite) TestEventualConsistency(c *check.C) {
// if testing.Short() {
// c.Skip("Skipping test in short mode")
// }
//
// filename := randomPath(32)
// defer suite.deletePath(c, firstPart(filename))
//
// var offset int64
// var misswrites int
// var chunkSize int64 = 32
//
// for i := 0; i < 1024; i++ {
// contents := randomContents(chunkSize)
// read, err := suite.StorageDriver.Writer(suite.ctx, filename, offset, bytes.NewReader(contents))
// c.Assert(err, check.IsNil)
//
// fi, err := suite.StorageDriver.Stat(suite.ctx, filename)
// c.Assert(err, check.IsNil)
//
// // We are most concerned with being able to read data as soon as Stat declares
// // it is uploaded. This is the strongest guarantee that some drivers (that guarantee
// // at best eventual consistency) absolutely need to provide.
// if fi.Size() == offset+chunkSize {
// reader, err := suite.StorageDriver.Reader(suite.ctx, filename, offset)
// c.Assert(err, check.IsNil)
//
// readContents, err := ioutil.ReadAll(reader)
// c.Assert(err, check.IsNil)
//
// c.Assert(readContents, check.DeepEquals, contents)
//
// reader.Close()
// offset += read
// } else {
// misswrites++
// }
// }
//
// if misswrites > 0 {
// c.Log("There were " + string(misswrites) + " occurrences of a write not being instantly available.")
// }
//
// c.Assert(misswrites, check.Not(check.Equals), 1024)
// }
// BenchmarkPutGetEmptyFiles benchmarks PutContent/GetContent for 0B files
func (suite *DriverSuite) BenchmarkPutGetEmptyFiles(c *check.C) {
@ -968,22 +950,22 @@ func (suite *DriverSuite) benchmarkPutGetFiles(c *check.C, size int64) {
}
}
// BenchmarkStreamEmptyFiles benchmarks WriteStream/ReadStream for 0B files
// BenchmarkStreamEmptyFiles benchmarks Writer/Reader for 0B files
func (suite *DriverSuite) BenchmarkStreamEmptyFiles(c *check.C) {
suite.benchmarkStreamFiles(c, 0)
}
// BenchmarkStream1KBFiles benchmarks WriteStream/ReadStream for 1KB files
// BenchmarkStream1KBFiles benchmarks Writer/Reader for 1KB files
func (suite *DriverSuite) BenchmarkStream1KBFiles(c *check.C) {
suite.benchmarkStreamFiles(c, 1024)
}
// BenchmarkStream1MBFiles benchmarks WriteStream/ReadStream for 1MB files
// BenchmarkStream1MBFiles benchmarks Writer/Reader for 1MB files
func (suite *DriverSuite) BenchmarkStream1MBFiles(c *check.C) {
suite.benchmarkStreamFiles(c, 1024*1024)
}
// BenchmarkStream1GBFiles benchmarks WriteStream/ReadStream for 1GB files
// BenchmarkStream1GBFiles benchmarks Writer/Reader for 1GB files
func (suite *DriverSuite) BenchmarkStream1GBFiles(c *check.C) {
suite.benchmarkStreamFiles(c, 1024*1024*1024)
}
@ -998,11 +980,18 @@ func (suite *DriverSuite) benchmarkStreamFiles(c *check.C, size int64) {
for i := 0; i < c.N; i++ {
filename := path.Join(parentDir, randomPath(32))
written, err := suite.StorageDriver.WriteStream(suite.ctx, filename, 0, bytes.NewReader(randomContents(size)))
writer, err := suite.StorageDriver.Writer(suite.ctx, filename, false)
c.Assert(err, check.IsNil)
written, err := io.Copy(writer, bytes.NewReader(randomContents(size)))
c.Assert(err, check.IsNil)
c.Assert(written, check.Equals, size)
rc, err := suite.StorageDriver.ReadStream(suite.ctx, filename, 0)
err = writer.Commit()
c.Assert(err, check.IsNil)
err = writer.Close()
c.Assert(err, check.IsNil)
rc, err := suite.StorageDriver.Reader(suite.ctx, filename, 0)
c.Assert(err, check.IsNil)
rc.Close()
}
@ -1083,11 +1072,18 @@ func (suite *DriverSuite) testFileStreams(c *check.C, size int64) {
tf.Sync()
tf.Seek(0, os.SEEK_SET)
nn, err := suite.StorageDriver.WriteStream(suite.ctx, filename, 0, tf)
writer, err := suite.StorageDriver.Writer(suite.ctx, filename, false)
c.Assert(err, check.IsNil)
nn, err := io.Copy(writer, tf)
c.Assert(err, check.IsNil)
c.Assert(nn, check.Equals, size)
reader, err := suite.StorageDriver.ReadStream(suite.ctx, filename, 0)
err = writer.Commit()
c.Assert(err, check.IsNil)
err = writer.Close()
c.Assert(err, check.IsNil)
reader, err := suite.StorageDriver.Reader(suite.ctx, filename, 0)
c.Assert(err, check.IsNil)
defer reader.Close()
@ -1112,11 +1108,18 @@ func (suite *DriverSuite) writeReadCompare(c *check.C, filename string, contents
func (suite *DriverSuite) writeReadCompareStreams(c *check.C, filename string, contents []byte) {
defer suite.deletePath(c, firstPart(filename))
nn, err := suite.StorageDriver.WriteStream(suite.ctx, filename, 0, bytes.NewReader(contents))
writer, err := suite.StorageDriver.Writer(suite.ctx, filename, false)
c.Assert(err, check.IsNil)
nn, err := io.Copy(writer, bytes.NewReader(contents))
c.Assert(err, check.IsNil)
c.Assert(nn, check.Equals, int64(len(contents)))
reader, err := suite.StorageDriver.ReadStream(suite.ctx, filename, 0)
err = writer.Commit()
c.Assert(err, check.IsNil)
err = writer.Close()
c.Assert(err, check.IsNil)
reader, err := suite.StorageDriver.Reader(suite.ctx, filename, 0)
c.Assert(err, check.IsNil)
defer reader.Close()

2
docs/storage/filereader.go
View file

@ -119,7 +119,7 @@ func (fr *fileReader) reader() (io.Reader, error) {
}
// If we don't have a reader, open one up.
rc, err := fr.driver.ReadStream(fr.ctx, fr.path, fr.offset)
rc, err := fr.driver.Reader(fr.ctx, fr.path, fr.offset)
if err != nil {
switch err := err.(type) {
case storagedriver.PathNotFoundError:

135
docs/storage/filewriter.go
View file

@ -1,135 +0,0 @@
package storage
import (
"bytes"
"fmt"
"io"
"os"
"github.com/docker/distribution/context"
storagedriver "github.com/docker/distribution/registry/storage/driver"
)
// fileWriter implements a remote file writer backed by a storage driver.
type fileWriter struct {
driver storagedriver.StorageDriver
ctx context.Context
// identifying fields
path string
// mutable fields
size int64 // size of the file, aka the current end
offset int64 // offset is the current write offset
err error // terminal error, if set, reader is closed
}
// fileWriterInterface makes the desired io compliant interface that the
// filewriter should implement.
type fileWriterInterface interface {
io.WriteSeeker
io.ReaderFrom
io.Closer
}
var _ fileWriterInterface = &fileWriter{}
// newFileWriter returns a prepared fileWriter for the driver and path. This
// could be considered similar to an "open" call on a regular filesystem.
func newFileWriter(ctx context.Context, driver storagedriver.StorageDriver, path string) (*fileWriter, error) {
fw := fileWriter{
driver: driver,
path: path,
ctx: ctx,
}
if fi, err := driver.Stat(ctx, path); err != nil {
switch err := err.(type) {
case storagedriver.PathNotFoundError:
// ignore, offset is zero
default:
return nil, err
}
} else {
if fi.IsDir() {
return nil, fmt.Errorf("cannot write to a directory")
}
fw.size = fi.Size()
}
return &fw, nil
}
// Write writes the buffer p at the current write offset.
func (fw *fileWriter) Write(p []byte) (n int, err error) {
nn, err := fw.ReadFrom(bytes.NewReader(p))
return int(nn), err
}
// ReadFrom reads reader r until io.EOF writing the contents at the current
// offset.
func (fw *fileWriter) ReadFrom(r io.Reader) (n int64, err error) {
if fw.err != nil {
return 0, fw.err
}
nn, err := fw.driver.WriteStream(fw.ctx, fw.path, fw.offset, r)
// We should forward the offset, whether or not there was an error.
// Basically, we keep the filewriter in sync with the reader's head. If an
// error is encountered, the whole thing should be retried but we proceed
// from an expected offset, even if the data didn't make it to the
// backend.
fw.offset += nn
if fw.offset > fw.size {
fw.size = fw.offset
}
return nn, err
}
// Seek moves the write position do the requested offest based on the whence
// argument, which can be os.SEEK_CUR, os.SEEK_END, or os.SEEK_SET.
func (fw *fileWriter) Seek(offset int64, whence int) (int64, error) {
if fw.err != nil {
return 0, fw.err
}
var err error
newOffset := fw.offset
switch whence {
case os.SEEK_CUR:
newOffset += int64(offset)
case os.SEEK_END:
newOffset = fw.size + int64(offset)
case os.SEEK_SET:
newOffset = int64(offset)
}
if newOffset < 0 {
err = fmt.Errorf("cannot seek to negative position")
} else {
// No problems, set the offset.
fw.offset = newOffset
}
return fw.offset, err
}
// Close closes the fileWriter for writing.
// Calling it once is valid and correct and it will
// return a nil error. Calling it subsequent times will
// detect that fw.err has been set and will return the error.
func (fw *fileWriter) Close() error {
if fw.err != nil {
return fw.err
}
fw.err = fmt.Errorf("filewriter@%v: closed", fw.path)
return nil
}

226
docs/storage/filewriter_test.go
View file

@ -1,226 +0,0 @@
package storage
import (
"bytes"
"crypto/rand"
"io"
"os"
"testing"
"github.com/docker/distribution/context"
"github.com/docker/distribution/digest"
storagedriver "github.com/docker/distribution/registry/storage/driver"
"github.com/docker/distribution/registry/storage/driver/inmemory"
)
// TestSimpleWrite takes the fileWriter through common write operations
// ensuring data integrity.
func TestSimpleWrite(t *testing.T) {
content := make([]byte, 1<<20)
n, err := rand.Read(content)
if err != nil {
t.Fatalf("unexpected error building random data: %v", err)
}
if n != len(content) {
t.Fatalf("random read did't fill buffer")
}
dgst, err := digest.FromReader(bytes.NewReader(content))
if err != nil {
t.Fatalf("unexpected error digesting random content: %v", err)
}
driver := inmemory.New()
path := "/random"
ctx := context.Background()
fw, err := newFileWriter(ctx, driver, path)
if err != nil {
t.Fatalf("unexpected error creating fileWriter: %v", err)
}
defer fw.Close()
n, err = fw.Write(content)
if err != nil {
t.Fatalf("unexpected error writing content: %v", err)
}
if n != len(content) {
t.Fatalf("unexpected write length: %d != %d", n, len(content))
}
fr, err := newFileReader(ctx, driver, path, int64(len(content)))
if err != nil {
t.Fatalf("unexpected error creating fileReader: %v", err)
}
defer fr.Close()
verifier, err := digest.NewDigestVerifier(dgst)
if err != nil {
t.Fatalf("unexpected error getting digest verifier: %s", err)
}
io.Copy(verifier, fr)
if !verifier.Verified() {
t.Fatalf("unable to verify write data")
}
// Check the seek position is equal to the content length
end, err := fw.Seek(0, os.SEEK_END)
if err != nil {
t.Fatalf("unexpected error seeking: %v", err)
}
if end != int64(len(content)) {
t.Fatalf("write did not advance offset: %d != %d", end, len(content))
}
// Double the content
doubled := append(content, content...)
doubledgst, err := digest.FromReader(bytes.NewReader(doubled))
if err != nil {
t.Fatalf("unexpected error digesting doubled content: %v", err)
}
nn, err := fw.ReadFrom(bytes.NewReader(content))
if err != nil {
t.Fatalf("unexpected error doubling content: %v", err)
}
if nn != int64(len(content)) {
t.Fatalf("writeat was short: %d != %d", n, len(content))
}
fr, err = newFileReader(ctx, driver, path, int64(len(doubled)))
if err != nil {
t.Fatalf("unexpected error creating fileReader: %v", err)
}
defer fr.Close()
verifier, err = digest.NewDigestVerifier(doubledgst)
if err != nil {
t.Fatalf("unexpected error getting digest verifier: %s", err)
}
io.Copy(verifier, fr)
if !verifier.Verified() {
t.Fatalf("unable to verify write data")
}
// Check that Write updated the offset.
end, err = fw.Seek(0, os.SEEK_END)
if err != nil {
t.Fatalf("unexpected error seeking: %v", err)
}
if end != int64(len(doubled)) {
t.Fatalf("write did not advance offset: %d != %d", end, len(doubled))
}
// Now, we copy from one path to another, running the data through the
// fileReader to fileWriter, rather than the driver.Move command to ensure
// everything is working correctly.
fr, err = newFileReader(ctx, driver, path, int64(len(doubled)))
if err != nil {
t.Fatalf("unexpected error creating fileReader: %v", err)
}
defer fr.Close()
fw, err = newFileWriter(ctx, driver, "/copied")
if err != nil {
t.Fatalf("unexpected error creating fileWriter: %v", err)
}
defer fw.Close()
nn, err = io.Copy(fw, fr)
if err != nil {
t.Fatalf("unexpected error copying data: %v", err)
}
if nn != int64(len(doubled)) {
t.Fatalf("unexpected copy length: %d != %d", nn, len(doubled))
}
fr, err = newFileReader(ctx, driver, "/copied", int64(len(doubled)))
if err != nil {
t.Fatalf("unexpected error creating fileReader: %v", err)
}
defer fr.Close()
verifier, err = digest.NewDigestVerifier(doubledgst)
if err != nil {
t.Fatalf("unexpected error getting digest verifier: %s", err)
}
io.Copy(verifier, fr)
if !verifier.Verified() {
t.Fatalf("unable to verify write data")
}
}
func BenchmarkFileWriter(b *testing.B) {
b.StopTimer() // not sure how long setup above will take
for i := 0; i < b.N; i++ {
// Start basic fileWriter initialization
fw := fileWriter{
driver: inmemory.New(),
path: "/random",
}
ctx := context.Background()
if fi, err := fw.driver.Stat(ctx, fw.path); err != nil {
switch err := err.(type) {
case storagedriver.PathNotFoundError:
// ignore, offset is zero
default:
b.Fatalf("Failed to initialize fileWriter: %v", err.Error())
}
} else {
if fi.IsDir() {
b.Fatalf("Cannot write to a directory")
}
fw.size = fi.Size()
}
randomBytes := make([]byte, 1<<20)
_, err := rand.Read(randomBytes)
if err != nil {
b.Fatalf("unexpected error building random data: %v", err)
}
// End basic file writer initialization
b.StartTimer()
for j := 0; j < 100; j++ {
fw.Write(randomBytes)
}
b.StopTimer()
}
}
func BenchmarkfileWriter(b *testing.B) {
b.StopTimer() // not sure how long setup above will take
ctx := context.Background()
for i := 0; i < b.N; i++ {
bfw, err := newFileWriter(ctx, inmemory.New(), "/random")
if err != nil {
b.Fatalf("Failed to initialize fileWriter: %v", err.Error())
}
randomBytes := make([]byte, 1<<20)
_, err = rand.Read(randomBytes)
if err != nil {
b.Fatalf("unexpected error building random data: %v", err)
}
b.StartTimer()
for j := 0; j < 100; j++ {
bfw.Write(randomBytes)
}
b.StopTimer()
}
}

13
docs/storage/linkedblobstore.go
View file

@ -179,7 +179,7 @@ func (lbs *linkedBlobStore) Create(ctx context.Context, options ...distribution.
return nil, err
}
return lbs.newBlobUpload(ctx, uuid, path, startedAt)
return lbs.newBlobUpload(ctx, uuid, path, startedAt, false)
}
func (lbs *linkedBlobStore) Resume(ctx context.Context, id string) (distribution.BlobWriter, error) {
@ -218,7 +218,7 @@ func (lbs *linkedBlobStore) Resume(ctx context.Context, id string) (distribution
return nil, err
}
return lbs.newBlobUpload(ctx, id, path, startedAt)
return lbs.newBlobUpload(ctx, id, path, startedAt, true)
}
func (lbs *linkedBlobStore) Delete(ctx context.Context, dgst digest.Digest) error {
@ -312,18 +312,21 @@ func (lbs *linkedBlobStore) mount(ctx context.Context, sourceRepo reference.Name
}
// newBlobUpload allocates a new upload controller with the given state.
func (lbs *linkedBlobStore) newBlobUpload(ctx context.Context, uuid, path string, startedAt time.Time) (distribution.BlobWriter, error) {
fw, err := newFileWriter(ctx, lbs.driver, path)
func (lbs *linkedBlobStore) newBlobUpload(ctx context.Context, uuid, path string, startedAt time.Time, append bool) (distribution.BlobWriter, error) {
fw, err := lbs.driver.Writer(ctx, path, append)
if err != nil {
return nil, err
}
bw := &blobWriter{
ctx: ctx,
blobStore: lbs,
id: uuid,
startedAt: startedAt,
digester: digest.Canonical.New(),
fileWriter: *fw,
fileWriter: fw,
driver: lbs.driver,
path: path,
resumableDigestEnabled: lbs.resumableDigestEnabled,
}