// Upload starts the process of a resumable upload with a cancellable context.
// It retries indefinitely (with a pause of uploadPause between attempts) until cancelled.
// 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.
func (rx *ResumableUpload) Upload(ctx context.Context) (*http.Response, error) {
var res *http.Response
var err error
for {
res, err = rx.transferChunks(ctx)
if err != nil || res.StatusCode == http.StatusCreated || res.StatusCode == http.StatusOK {
return res, err
}
select { // Check for cancellation
case <-ctx.Done():
res.StatusCode = http.StatusRequestTimeout
return res, ctx.Err()
default:
}
sleep(uploadPause)
}
return res, err
}
func (rx *ResumableUpload) transferChunks(ctx context.Context) (*http.Response, error) {
start, res, err := rx.transferStatus()
if err != nil || res.StatusCode != statusResumeIncomplete {
return res, err
}
for {
select { // Check for cancellation
case <-ctx.Done():
res.StatusCode = http.StatusRequestTimeout
return res, ctx.Err()
default:
}
reqSize := rx.ContentLength - start
if reqSize > chunkSize {
reqSize = chunkSize
}
r := io.NewSectionReader(rx.Media, start, reqSize)
req, _ := http.NewRequest("POST", rx.URI, r)
req.ContentLength = reqSize
req.Header.Set("Content-Range", fmt.Sprintf("bytes %v-%v/%v", start, start+reqSize-1, rx.ContentLength))
req.Header.Set("Content-Type", rx.MediaType)
req.Header.Set("User-Agent", rx.UserAgent)
res, err = rx.Client.Do(req)
start += reqSize
if err == nil && (res.StatusCode == statusResumeIncomplete || res.StatusCode == http.StatusOK) {
rx.mu.Lock()
rx.progress = start // keep track of number of bytes sent so far
rx.mu.Unlock()
if rx.Callback != nil {
rx.Callback(start, rx.ContentLength)
}
}
if err != nil || res.StatusCode != statusResumeIncomplete {
break
}
}
return res, err
}