Function getBlobSize

docker/docker_client.go:1018–1032

(resp *http.Response)

}

func getBlobSize(resp *http.Response) (int64, error) {
	hdrs := resp.Header.Values("Content-Length")
	if len(hdrs) == 0 {
		return -1, errors.New(`Missing "Content-Length" header in response`)
	}
	hdr := hdrs[0] // Equivalent to resp.Header.Get(…)
	size, err := strconv.ParseInt(hdr, 10, 64)
	if err != nil { // Go’s response reader should already reject such values.
		return -1, err
	}
	if size < 0 { // '-' is not a valid character in Content-Length, so negative values are invalid. Go’s response reader should already reject such values.
		return -1, fmt.Errorf(`Invalid negative "Content-Length" %q`, hdr)
	}
	return size, nil
}

// getBlob returns a stream for the specified blob in ref, and the blob’s size (or -1 if unknown).
// The Digest field in BlobInfo is guaranteed to be provided, Size may be -1 and MediaType may be optionally provided.