Method peekMessage

pgconn/pgconn.go:625–661

peekMessage peeks at the next message without setting up context cancellation.

()

// peekMessage peeks at the next message without setting up context cancellation.
func (pgConn *PgConn) peekMessage() (pgproto3.BackendMessage, error) {
	if pgConn.peekedMsg != nil {
		return pgConn.peekedMsg, nil
	}

	var msg pgproto3.BackendMessage
	var err error
	if pgConn.bufferingReceive {
		pgConn.bufferingReceiveMux.Lock()
		msg = pgConn.bufferingReceiveMsg
		err = pgConn.bufferingReceiveErr
		pgConn.bufferingReceiveMux.Unlock()
		pgConn.bufferingReceive = false

		// If a timeout error happened in the background try the read again.
		var netErr net.Error
		if errors.As(err, &netErr) && netErr.Timeout() {
			msg, err = pgConn.frontend.Receive()
		}
	} else {
		msg, err = pgConn.frontend.Receive()
	}

	if err != nil {
		// Close on anything other than timeout error - everything else is fatal
		var netErr net.Error
		isNetErr := errors.As(err, &netErr)
		if !(isNetErr && netErr.Timeout()) {
			pgConn.asyncClose()
		}

		return nil, err
	}

	pgConn.peekedMsg = msg
	return msg, nil
}

// receiveMessage receives a message without setting up context cancellation
func (pgConn *PgConn) receiveMessage() (pgproto3.BackendMessage, error) {