Method writeCompressedFrame

write.go:141–188

writeCompressedFrame compresses and writes p as a single frame.

(ctx context.Context, p []byte)

// writeCompressedFrame compresses and writes p as a single frame.
func (mw *msgWriter) writeCompressedFrame(ctx context.Context, p []byte) (int, error) {
	err := mw.writeMu.lock(mw.ctx)
	if err != nil {
		return 0, fmt.Errorf("failed to write: %w", err)
	}
	defer mw.writeMu.unlock()

	if mw.closed {
		return 0, errors.New("cannot use closed writer")
	}

	mw.ensureFlate()

	buf := bpool.Get()
	defer bpool.Put(buf)

	// Buffer compressed output so we can write as
	// a single frame instead of chunked frames.
	origWriter := mw.trimWriter.w
	mw.trimWriter.w = buf
	defer func() {
		mw.trimWriter.w = origWriter
	}()

	_, err = mw.flateWriter.Write(p)
	if err != nil {
		return 0, fmt.Errorf("failed to compress: %w", err)
	}

	err = mw.flateWriter.Flush()
	if err != nil {
		return 0, fmt.Errorf("failed to flush compression: %w", err)
	}

	mw.trimWriter.reset()

	if !mw.flateContextTakeover() {
		mw.putFlateWriter()
	}

	mw.closed = true

	_, err = mw.c.writeFrame(ctx, true, true, mw.opcode, buf.Bytes())
	if err != nil {
		return 0, err
	}
	return len(p), nil
}

// Write writes the given bytes to the WebSocket connection.
func (mw *msgWriter) Write(p []byte) (_ int, err error) {