aboutsummaryrefslogtreecommitdiff
path: root/vendor/google.golang.org/api/gensupport/resumable.go
diff options
context:
space:
mode:
Diffstat (limited to 'vendor/google.golang.org/api/gensupport/resumable.go')
-rw-r--r--vendor/google.golang.org/api/gensupport/resumable.go198
1 files changed, 198 insertions, 0 deletions
diff --git a/vendor/google.golang.org/api/gensupport/resumable.go b/vendor/google.golang.org/api/gensupport/resumable.go
new file mode 100644
index 0000000..ad16943
--- /dev/null
+++ b/vendor/google.golang.org/api/gensupport/resumable.go
@@ -0,0 +1,198 @@
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package gensupport
+
+import (
+ "fmt"
+ "io"
+ "net/http"
+ "sync"
+ "time"
+
+ "golang.org/x/net/context"
+ "golang.org/x/net/context/ctxhttp"
+)
+
+const (
+ // statusResumeIncomplete is the code returned by the Google uploader
+ // when the transfer is not yet complete.
+ statusResumeIncomplete = 308
+
+ // statusTooManyRequests is returned by the storage API if the
+ // per-project limits have been temporarily exceeded. The request
+ // should be retried.
+ // https://cloud.google.com/storage/docs/json_api/v1/status-codes#standardcodes
+ statusTooManyRequests = 429
+)
+
+// ResumableUpload is used by the generated APIs to provide resumable uploads.
+// It is not used by developers directly.
+type ResumableUpload struct {
+ Client *http.Client
+ // URI is the resumable resource destination provided by the server after specifying "&uploadType=resumable".
+ URI string
+ UserAgent string // User-Agent for header of the request
+ // Media is the object being uploaded.
+ Media *MediaBuffer
+ // MediaType defines the media type, e.g. "image/jpeg".
+ MediaType string
+
+ mu sync.Mutex // guards progress
+ progress int64 // number of bytes uploaded so far
+
+ // Callback is an optional function that will be periodically called with the cumulative number of bytes uploaded.
+ Callback func(int64)
+
+ // If not specified, a default exponential backoff strategy will be used.
+ Backoff BackoffStrategy
+}
+
+// Progress returns the number of bytes uploaded at this point.
+func (rx *ResumableUpload) Progress() int64 {
+ rx.mu.Lock()
+ defer rx.mu.Unlock()
+ return rx.progress
+}
+
+// doUploadRequest performs a single HTTP request to upload data.
+// off specifies the offset in rx.Media from which data is drawn.
+// size is the number of bytes in data.
+// final specifies whether data is the final chunk to be uploaded.
+func (rx *ResumableUpload) doUploadRequest(ctx context.Context, data io.Reader, off, size int64, final bool) (*http.Response, error) {
+ req, err := http.NewRequest("POST", rx.URI, data)
+ if err != nil {
+ return nil, err
+ }
+
+ req.ContentLength = size
+ var contentRange string
+ if final {
+ if size == 0 {
+ contentRange = fmt.Sprintf("bytes */%v", off)
+ } else {
+ contentRange = fmt.Sprintf("bytes %v-%v/%v", off, off+size-1, off+size)
+ }
+ } else {
+ contentRange = fmt.Sprintf("bytes %v-%v/*", off, off+size-1)
+ }
+ req.Header.Set("Content-Range", contentRange)
+ req.Header.Set("Content-Type", rx.MediaType)
+ req.Header.Set("User-Agent", rx.UserAgent)
+ return ctxhttp.Do(ctx, rx.Client, req)
+
+}
+
+// reportProgress calls a user-supplied callback to report upload progress.
+// If old==updated, the callback is not called.
+func (rx *ResumableUpload) reportProgress(old, updated int64) {
+ if updated-old == 0 {
+ return
+ }
+ rx.mu.Lock()
+ rx.progress = updated
+ rx.mu.Unlock()
+ if rx.Callback != nil {
+ rx.Callback(updated)
+ }
+}
+
+// transferChunk performs a single HTTP request to upload a single chunk from rx.Media.
+func (rx *ResumableUpload) transferChunk(ctx context.Context) (*http.Response, error) {
+ chunk, off, size, err := rx.Media.Chunk()
+
+ done := err == io.EOF
+ if !done && err != nil {
+ return nil, err
+ }
+
+ res, err := rx.doUploadRequest(ctx, chunk, off, int64(size), done)
+ if err != nil {
+ return res, err
+ }
+
+ if res.StatusCode == statusResumeIncomplete || res.StatusCode == http.StatusOK {
+ rx.reportProgress(off, off+int64(size))
+ }
+
+ if res.StatusCode == statusResumeIncomplete {
+ rx.Media.Next()
+ }
+ return res, nil
+}
+
+func contextDone(ctx context.Context) bool {
+ select {
+ case <-ctx.Done():
+ return true
+ default:
+ return false
+ }
+}
+
+// Upload starts the process of a resumable upload with a cancellable context.
+// It retries using the provided back off strategy until cancelled or the
+// strategy indicates to stop retrying.
+// It is called from the auto-generated API code and is not visible to the user.
+// rx is private to the auto-generated API code.
+// Exactly one of resp or err will be nil. If resp is non-nil, the caller must call resp.Body.Close.
+func (rx *ResumableUpload) Upload(ctx context.Context) (resp *http.Response, err error) {
+ var pause time.Duration
+ backoff := rx.Backoff
+ if backoff == nil {
+ backoff = DefaultBackoffStrategy()
+ }
+
+ for {
+ // Ensure that we return in the case of cancelled context, even if pause is 0.
+ if contextDone(ctx) {
+ return nil, ctx.Err()
+ }
+ select {
+ case <-ctx.Done():
+ return nil, ctx.Err()
+ case <-time.After(pause):
+ }
+
+ resp, err = rx.transferChunk(ctx)
+
+ var status int
+ if resp != nil {
+ status = resp.StatusCode
+ }
+
+ // Check if we should retry the request.
+ if shouldRetry(status, err) {
+ var retry bool
+ pause, retry = backoff.Pause()
+ if retry {
+ if resp != nil && resp.Body != nil {
+ resp.Body.Close()
+ }
+ continue
+ }
+ }
+
+ // If the chunk was uploaded successfully, but there's still
+ // more to go, upload the next chunk without any delay.
+ if status == statusResumeIncomplete {
+ pause = 0
+ backoff.Reset()
+ resp.Body.Close()
+ continue
+ }
+
+ // It's possible for err and resp to both be non-nil here, but we expose a simpler
+ // contract to our callers: exactly one of resp and err will be non-nil. This means
+ // that any response body must be closed here before returning a non-nil error.
+ if err != nil {
+ if resp != nil && resp.Body != nil {
+ resp.Body.Close()
+ }
+ return nil, err
+ }
+
+ return resp, nil
+ }
+}