Method frame

prepared.go:62–94

(key prepareKey)

}

func (pm *PreparedMessage) frame(key prepareKey) (int, []byte, error) {
	pm.mu.Lock()
	frame, ok := pm.frames[key]
	if !ok {
		frame = &preparedFrame{}
		pm.frames[key] = frame
	}
	pm.mu.Unlock()

	var err error
	frame.once.Do(func() {
		// Prepare a frame using a 'fake' connection.
		// TODO: Refactor code in conn.go to allow more direct construction of
		// the frame.
		mu := make(chan struct{}, 1)
		mu <- struct{}{}
		var nc prepareConn
		c := &Conn{
			conn:                   &nc,
			mu:                     mu,
			isServer:               key.isServer,
			compressionLevel:       key.compressionLevel,
			enableWriteCompression: true,
			writeBuf:               make([]byte, defaultWriteBufferSize+maxFrameHeaderSize),
		}
		if key.compress {
			c.newCompressionWriter = compressNoContextTakeover
		}
		err = c.WriteMessage(pm.messageType, pm.data)
		frame.data = nc.buf.Bytes()
	})
	return pm.messageType, frame.data, err
}

type prepareConn struct {
	buf bytes.Buffer