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Support FileWriter interface for OSS storage driver

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Change-Id: Ie5533ad85f944800499ca1040fd67bf1378815e0
Signed-off-by: Li Yi <denverdino@gmail.com>
This commit is contained in:
Li Yi 2016-02-21 08:54:32 +08:00 committed by Brian Bland
parent 307504713f
commit a9bf7a2aae
2 changed files with 203 additions and 322 deletions
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2
cmd/registry/main.go
View file

@ -13,7 +13,7 @@ import (
_ "github.com/docker/distribution/registry/storage/driver/gcs" _ "github.com/docker/distribution/registry/storage/driver/gcs"
_ "github.com/docker/distribution/registry/storage/driver/inmemory" _ "github.com/docker/distribution/registry/storage/driver/inmemory"
_ "github.com/docker/distribution/registry/storage/driver/middleware/cloudfront" _ "github.com/docker/distribution/registry/storage/driver/middleware/cloudfront"
// _ "github.com/docker/distribution/registry/storage/driver/oss" _ "github.com/docker/distribution/registry/storage/driver/oss"
_ "github.com/docker/distribution/registry/storage/driver/s3-aws" _ "github.com/docker/distribution/registry/storage/driver/s3-aws"
_ "github.com/docker/distribution/registry/storage/driver/s3-goamz" _ "github.com/docker/distribution/registry/storage/driver/s3-goamz"
// _ "github.com/docker/distribution/registry/storage/driver/swift" // _ "github.com/docker/distribution/registry/storage/driver/swift"

519
registry/storage/driver/oss/oss.go
View file

@ -20,7 +20,6 @@ import (
"reflect" "reflect"
"strconv" "strconv"
"strings" "strings"
"sync"
"time" "time"
"github.com/docker/distribution/context" "github.com/docker/distribution/context"
@ -75,9 +74,6 @@ type driver struct {
ChunkSize int64 ChunkSize int64
Encrypt bool Encrypt bool
RootDirectory string RootDirectory string
pool sync.Pool // pool []byte buffers used for WriteStream
zeros []byte // shared, zero-valued buffer used for WriteStream
} }
type baseEmbed struct { type baseEmbed struct {
@ -99,8 +95,7 @@ type Driver struct {
// - encrypt // - encrypt
func FromParameters(parameters map[string]interface{}) (*Driver, error) { func FromParameters(parameters map[string]interface{}) (*Driver, error) {
// Providing no values for these is valid in case the user is authenticating // Providing no values for these is valid in case the user is authenticating
// with an IAM on an ec2 instance (in which case the instance credentials will
// be summoned when GetAuth is called)
accessKey, ok := parameters["accesskeyid"] accessKey, ok := parameters["accesskeyid"]
if !ok { if !ok {
return nil, fmt.Errorf("No accesskeyid parameter provided") return nil, fmt.Errorf("No accesskeyid parameter provided")
@ -220,11 +215,6 @@ func New(params DriverParameters) (*Driver, error) {
ChunkSize: params.ChunkSize, ChunkSize: params.ChunkSize,
Encrypt: params.Encrypt, Encrypt: params.Encrypt,
RootDirectory: params.RootDirectory, RootDirectory: params.RootDirectory,
zeros: make([]byte, params.ChunkSize),
}
d.pool.New = func() interface{} {
return make([]byte, d.ChunkSize)
} }
return &Driver{ return &Driver{
@ -256,9 +246,9 @@ func (d *driver) PutContent(ctx context.Context, path string, contents []byte) e
return parseError(path, d.Bucket.Put(d.ossPath(path), contents, d.getContentType(), getPermissions(), d.getOptions())) return parseError(path, d.Bucket.Put(d.ossPath(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. // 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 := make(http.Header)
headers.Add("Range", "bytes="+strconv.FormatInt(offset, 10)+"-") headers.Add("Range", "bytes="+strconv.FormatInt(offset, 10)+"-")
@ -279,315 +269,37 @@ func (d *driver) ReadStream(ctx context.Context, path string, offset int64) (io.
return resp.Body, nil return resp.Body, nil
} }
// WriteStream stores the contents of the provided io.Reader at a // Writer returns a FileWriter which will store the content written to it
// location designated by the given path. The driver will know it has // at the location designated by "path" after the call to Commit.
// received the full contents when the reader returns io.EOF. The number func (d *driver) Writer(ctx context.Context, path string, append bool) (storagedriver.FileWriter, error) {
// of successfully READ bytes will be returned, even if an error is key := d.ossPath(path)
// returned. May be used to resume writing a stream by providing a nonzero if !append {
// offset. Offsets past the current size will write from the position // TODO (brianbland): cancel other uploads at this path
// beyond the end of the file. multi, err := d.Bucket.InitMulti(key, d.getContentType(), getPermissions(), d.getOptions())
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 := []oss.Part{}
var part oss.Part
done := make(chan struct{}) // stopgap to free up waiting goroutines
multi, err := d.Bucket.InitMulti(d.ossPath(path), d.getContentType(), getPermissions(), d.getOptions())
if err != nil { if err != nil {
return 0, err return nil, err
} }
return d.newWriter(key, multi, nil), nil
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
} }
} multis, _, err := d.Bucket.ListMulti(key, "")
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)
if err != nil { if err != nil {
return err return nil, parseError(path, err)
} }
for _, multi := range multis {
bytesRead = 0 if key != multi.Key {
for int64(bytesRead) < total { continue
//The loop should very rarely enter a second iteration }
nn, err := current.Read(buf[bytesRead:total]) parts, err := multi.ListParts()
bytesRead += nn
if err != nil { if err != nil {
if err != io.EOF { return nil, parseError(path, err)
return err
} }
var multiSize int64
break for _, part := range parts {
multiSize += part.Size
} }
return d.newWriter(key, multi, parts), nil
} }
return nil return nil, storagedriver.PathNotFoundError{Path: path}
}
// 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 OSS
// retry backoff to deal with RequestTimeout errors. Even though
// the underlying OSS library should handle it, it doesn't seem to
// be part of the shouldRetry function (see denverdino/aliyungo/oss).
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 oss.Part
part, err = multi.PutPartWithTimeout(int(partNumber), bytes.NewReader(buf[0:int64(bytesRead)+from]), defaultTimeout)
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.ossPath(path), nil)
if err != nil {
if ossErr, ok := err.(*oss.Error); !ok || ossErr.StatusCode != http.StatusNotFound {
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,
oss.CopyOptions{CopySourceOptions: "bytes=0-" + strconv.FormatInt(offset-1, 10)},
d.Bucket.Path(d.ossPath(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.PutPartWithTimeout(int(partNumber), bytes.NewReader(d.zeros), defaultTimeout)
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.PutPartWithTimeout(int(partNumber), bytes.NewReader(buf), defaultTimeout)
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,
oss.CopyOptions{},
d.Bucket.Path(d.ossPath(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
} }
// Stat retrieves the FileInfo for the given path, including the current size // Stat retrieves the FileInfo for the given path, including the current size
@ -778,12 +490,181 @@ func (d *driver) getContentType() string {
return "application/octet-stream" return "application/octet-stream"
} }
// getbuf returns a buffer from the driver's pool with length d.ChunkSize. // writer attempts to upload parts to S3 in a buffered fashion where the last
func (d *driver) getbuf() []byte { // part is at least as large as the chunksize, so the multipart upload could be
return d.pool.Get().([]byte) // 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 *oss.Multi
parts []oss.Part
size int64
readyPart []byte
pendingPart []byte
closed bool
committed bool
cancelled bool
} }
func (d *driver) putbuf(p []byte) { func (d *driver) newWriter(key string, multi *oss.Multi, parts []oss.Part) storagedriver.FileWriter {
copy(p, d.zeros) var size int64
d.pool.Put(p) 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, oss.CopyOptions{}, w.driver.Bucket.Name+"/"+w.key)
if err != nil {
return 0, err
}
w.parts = []oss.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
} }