219 lines
6.3 KiB
Go
219 lines
6.3 KiB
Go
|
// Copyright 2014 Google Inc. All Rights Reserved.
|
||
|
|
//
|
||
|
|
// Licensed under the Apache License, Version 2.0 (the "License");
|
||
|
|
// you may not use this file except in compliance with the License.
|
||
|
|
// You may obtain a copy of the License at
|
||
|
|
//
|
||
|
|
// http://www.apache.org/licenses/LICENSE-2.0
|
||
|
|
//
|
||
|
|
// Unless required by applicable law or agreed to in writing, software
|
||
|
|
// distributed under the License is distributed on an "AS IS" BASIS,
|
||
|
|
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
||
|
|
// See the License for the specific language governing permissions and
|
||
|
|
// limitations under the License.
|
||
|
|
|
||
|
|
package storage
|
||
|
|
|
||
|
|
import (
|
||
|
|
"encoding/base64"
|
||
|
|
"errors"
|
||
|
|
"fmt"
|
||
|
|
"io"
|
||
|
|
"sync"
|
||
|
|
"unicode/utf8"
|
||
|
|
|
||
|
|
"golang.org/x/net/context"
|
||
|
|
"google.golang.org/api/googleapi"
|
||
|
|
raw "google.golang.org/api/storage/v1"
|
||
|
|
)
|
||
|
|
|
||
|
|
// A Writer writes a Cloud Storage object.
|
||
|
|
type Writer struct {
|
||
|
|
// ObjectAttrs are optional attributes to set on the object. Any attributes
|
||
|
|
// must be initialized before the first Write call. Nil or zero-valued
|
||
|
|
// attributes are ignored.
|
||
|
|
ObjectAttrs
|
||
|
|
|
||
|
|
// SendCRC specifies whether to transmit a CRC32C field. It should be set
|
||
|
|
// to true in addition to setting the Writer's CRC32C field, because zero
|
||
|
|
// is a valid CRC and normally a zero would not be transmitted.
|
||
|
|
// If a CRC32C is sent, and the data written does not match the checksum,
|
||
|
|
// the write will be rejected.
|
||
|
|
SendCRC32C bool
|
||
|
|
|
||
|
|
// ChunkSize controls the maximum number of bytes of the object that the
|
||
|
|
// Writer will attempt to send to the server in a single request. Objects
|
||
|
|
// smaller than the size will be sent in a single request, while larger
|
||
|
|
// objects will be split over multiple requests. The size will be rounded up
|
||
|
|
// to the nearest multiple of 256K. If zero, chunking will be disabled and
|
||
|
|
// the object will be uploaded in a single request.
|
||
|
|
//
|
||
|
|
// ChunkSize will default to a reasonable value. If you perform many concurrent
|
||
|
|
// writes of small objects, you may wish set ChunkSize to a value that matches
|
||
|
|
// your objects' sizes to avoid consuming large amounts of memory.
|
||
|
|
//
|
||
|
|
// ChunkSize must be set before the first Write call.
|
||
|
|
ChunkSize int
|
||
|
|
|
||
|
|
// ProgressFunc can be used to monitor the progress of a large write.
|
||
|
|
// operation. If ProgressFunc is not nil and writing requires multiple
|
||
|
|
// calls to the underlying service (see
|
||
|
|
// https://cloud.google.com/storage/docs/json_api/v1/how-tos/resumable-upload),
|
||
|
|
// then ProgressFunc will be invoked after each call with the number of bytes of
|
||
|
|
// content copied so far.
|
||
|
|
//
|
||
|
|
// ProgressFunc should return quickly without blocking.
|
||
|
|
ProgressFunc func(int64)
|
||
|
|
|
||
|
|
ctx context.Context
|
||
|
|
o *ObjectHandle
|
||
|
|
|
||
|
|
opened bool
|
||
|
|
pw *io.PipeWriter
|
||
|
|
|
||
|
|
donec chan struct{} // closed after err and obj are set.
|
||
|
|
obj *ObjectAttrs
|
||
|
|
|
||
|
|
mu sync.Mutex
|
||
|
|
err error
|
||
|
|
}
|
||
|
|
|
||
|
|
func (w *Writer) open() error {
|
||
|
|
attrs := w.ObjectAttrs
|
||
|
|
// Check the developer didn't change the object Name (this is unfortunate, but
|
||
|
|
// we don't want to store an object under the wrong name).
|
||
|
|
if attrs.Name != w.o.object {
|
||
|
|
return fmt.Errorf("storage: Writer.Name %q does not match object name %q", attrs.Name, w.o.object)
|
||
|
|
}
|
||
|
|
if !utf8.ValidString(attrs.Name) {
|
||
|
|
return fmt.Errorf("storage: object name %q is not valid UTF-8", attrs.Name)
|
||
|
|
}
|
||
|
|
pr, pw := io.Pipe()
|
||
|
|
w.pw = pw
|
||
|
|
w.opened = true
|
||
|
|
|
||
|
|
if w.ChunkSize < 0 {
|
||
|
|
return errors.New("storage: Writer.ChunkSize must be non-negative")
|
||
|
|
}
|
||
|
|
mediaOpts := []googleapi.MediaOption{
|
||
|
|
googleapi.ChunkSize(w.ChunkSize),
|
||
|
|
}
|
||
|
|
if c := attrs.ContentType; c != "" {
|
||
|
|
mediaOpts = append(mediaOpts, googleapi.ContentType(c))
|
||
|
|
}
|
||
|
|
|
||
|
|
go func() {
|
||
|
|
defer close(w.donec)
|
||
|
|
|
||
|
|
rawObj := attrs.toRawObject(w.o.bucket)
|
||
|
|
if w.SendCRC32C {
|
||
|
|
rawObj.Crc32c = encodeUint32(attrs.CRC32C)
|
||
|
|
}
|
||
|
|
if w.MD5 != nil {
|
||
|
|
rawObj.Md5Hash = base64.StdEncoding.EncodeToString(w.MD5)
|
||
|
|
}
|
||
|
|
call := w.o.c.raw.Objects.Insert(w.o.bucket, rawObj).
|
||
|
|
Media(pr, mediaOpts...).
|
||
|
|
Projection("full").
|
||
|
|
Context(w.ctx)
|
||
|
|
if w.ProgressFunc != nil {
|
||
|
|
call.ProgressUpdater(func(n, _ int64) { w.ProgressFunc(n) })
|
||
|
|
}
|
||
|
|
if err := setEncryptionHeaders(call.Header(), w.o.encryptionKey, false); err != nil {
|
||
|
|
w.mu.Lock()
|
||
|
|
w.err = err
|
||
|
|
w.mu.Unlock()
|
||
|
|
pr.CloseWithError(err)
|
||
|
|
return
|
||
|
|
}
|
||
|
|
var resp *raw.Object
|
||
|
|
err := applyConds("NewWriter", w.o.gen, w.o.conds, call)
|
||
|
|
if err == nil {
|
||
|
|
if w.o.userProject != "" {
|
||
|
|
call.UserProject(w.o.userProject)
|
||
|
|
}
|
||
|
|
setClientHeader(call.Header())
|
||
|
|
// If the chunk size is zero, then no chunking is done on the Reader,
|
||
|
|
// which means we cannot retry: the first call will read the data, and if
|
||
|
|
// it fails, there is no way to re-read.
|
||
|
|
if w.ChunkSize == 0 {
|
||
|
|
resp, err = call.Do()
|
||
|
|
} else {
|
||
|
|
// We will only retry here if the initial POST, which obtains a URI for
|
||
|
|
// the resumable upload, fails with a retryable error. The upload itself
|
||
|
|
// has its own retry logic.
|
||
|
|
err = runWithRetry(w.ctx, func() error {
|
||
|
|
var err2 error
|
||
|
|
resp, err2 = call.Do()
|
||
|
|
return err2
|
||
|
|
})
|
||
|
|
}
|
||
|
|
}
|
||
|
|
if err != nil {
|
||
|
|
w.mu.Lock()
|
||
|
|
w.err = err
|
||
|
|
w.mu.Unlock()
|
||
|
|
pr.CloseWithError(err)
|
||
|
|
return
|
||
|
|
}
|
||
|
|
w.obj = newObject(resp)
|
||
|
|
}()
|
||
|
|
return nil
|
||
|
|
}
|
||
|
|
|
||
|
|
// Write appends to w. It implements the io.Writer interface.
|
||
|
|
//
|
||
|
|
// Since writes happen asynchronously, Write may return a nil
|
||
|
|
// error even though the write failed (or will fail). Always
|
||
|
|
// use the error returned from Writer.Close to determine if
|
||
|
|
// the upload was successful.
|
||
|
|
func (w *Writer) Write(p []byte) (n int, err error) {
|
||
|
|
w.mu.Lock()
|
||
|
|
werr := w.err
|
||
|
|
w.mu.Unlock()
|
||
|
|
if werr != nil {
|
||
|
|
return 0, werr
|
||
|
|
}
|
||
|
|
if !w.opened {
|
||
|
|
if err := w.open(); err != nil {
|
||
|
|
return 0, err
|
||
|
|
}
|
||
|
|
}
|
||
|
|
return w.pw.Write(p)
|
||
|
|
}
|
||
|
|
|
||
|
|
// Close completes the write operation and flushes any buffered data.
|
||
|
|
// If Close doesn't return an error, metadata about the written object
|
||
|
|
// can be retrieved by calling Attrs.
|
||
|
|
func (w *Writer) Close() error {
|
||
|
|
if !w.opened {
|
||
|
|
if err := w.open(); err != nil {
|
||
|
|
return err
|
||
|
|
}
|
||
|
|
}
|
||
|
|
if err := w.pw.Close(); err != nil {
|
||
|
|
return err
|
||
|
|
}
|
||
|
|
<-w.donec
|
||
|
|
w.mu.Lock()
|
||
|
|
defer w.mu.Unlock()
|
||
|
|
return w.err
|
||
|
|
}
|
||
|
|
|
||
|
|
// CloseWithError aborts the write operation with the provided error.
|
||
|
|
// CloseWithError always returns nil.
|
||
|
|
//
|
||
|
|
// Deprecated: cancel the context passed to NewWriter instead.
|
||
|
|
func (w *Writer) CloseWithError(err error) error {
|
||
|
|
if !w.opened {
|
||
|
|
return nil
|
||
|
|
}
|
||
|
|
return w.pw.CloseWithError(err)
|
||
|
|
}
|
||
|
|
|
||
|
|
// Attrs returns metadata about a successfully-written object.
|
||
|
|
// It's only valid to call it after Close returns nil.
|
||
|
|
func (w *Writer) Attrs() *ObjectAttrs {
|
||
|
|
return w.obj
|
||
|
|
}
|