Function splitHTTP200ResponseToPartial

docker/docker_image_src.go:275–312

splitHTTP200ResponseToPartial splits a 200 response in multiple streams as specified by the chunks

(streams chan io.ReadCloser, errs chan error, body io.ReadCloser, chunks []private.ImageSourceChunk)

// splitHTTP200ResponseToPartial splits a 200 response in multiple streams as specified by the chunks
func splitHTTP200ResponseToPartial(streams chan io.ReadCloser, errs chan error, body io.ReadCloser, chunks []private.ImageSourceChunk) {
	defer close(streams)
	defer close(errs)
	currentOffset := uint64(0)

	body = makeBufferedNetworkReader(body, 64, 16384)
	defer body.Close()
	for _, c := range chunks {
		if c.Offset != currentOffset {
			if c.Offset < currentOffset {
				errs <- fmt.Errorf("invalid chunk offset specified %v (expected >= %v)", c.Offset, currentOffset)
				break
			}
			toSkip := c.Offset - currentOffset
			if _, err := io.Copy(io.Discard, io.LimitReader(body, int64(toSkip))); err != nil {
				errs <- err
				break
			}
			currentOffset += toSkip
		}
		var reader io.Reader
		if c.Length == math.MaxUint64 {
			reader = body
		} else {
			reader = io.LimitReader(body, int64(c.Length))
		}
		s := signalCloseReader{
			closed:        make(chan struct{}),
			stream:        io.NopCloser(reader),
			consumeStream: true,
		}
		streams <- s

		// Wait until the stream is closed before going to the next chunk
		<-s.closed
		currentOffset += c.Length
	}
}

// handle206Response reads a 206 response and send each part as a separate ReadCloser to the streams chan.
func handle206Response(streams chan io.ReadCloser, errs chan error, body io.ReadCloser, chunks []private.ImageSourceChunk, mediaType string, params map[string]string) {