Method compressedStream

copy/compression.go:426–434

compressedStream returns a stream the input reader compressed using format, and a metadata map. The caller must close the returned reader. AFTER the stream is consumed, metadata will be updated with annotations to use on the data.

(reader io.Reader, algorithm compressiontypes.Algorithm)

// The caller must close the returned reader.
// AFTER the stream is consumed, metadata will be updated with annotations to use on the data.
func (ic *imageCopier) compressedStream(reader io.Reader, algorithm compressiontypes.Algorithm) (io.ReadCloser, map[string]string) {
	pipeReader, pipeWriter := io.Pipe()
	annotations := map[string]string{}
	// If this fails while writing data, it will do pipeWriter.CloseWithError(); if it fails otherwise,
	// e.g. because we have exited and due to pipeReader.Close() above further writing to the pipe has failed,
	// we don’t care.
	go ic.compressGoroutine(pipeWriter, reader, annotations, algorithm) // Closes pipeWriter
	return pipeReader, annotations
}