Method heartbeat

conn.go:345–366

heartbeat sends a heartbeat message required by consumer groups See http://kafka.apache.org/protocol.html#The_Messages_Heartbeat

(request heartbeatRequestV0)

//
// See http://kafka.apache.org/protocol.html#The_Messages_Heartbeat
func (c *Conn) heartbeat(request heartbeatRequestV0) (heartbeatResponseV0, error) {
	var response heartbeatResponseV0

	err := c.writeOperation(
		func(deadline time.Time, id int32) error {
			return c.writeRequest(heartbeat, v0, id, request)
		},
		func(deadline time.Time, size int) error {
			return expectZeroSize(func() (remain int, err error) {
				return (&response).readFrom(&c.rbuf, size)
			}())
		},
	)
	if err != nil {
		return heartbeatResponseV0{}, err
	}
	if response.ErrorCode != 0 {
		return heartbeatResponseV0{}, Error(response.ErrorCode)
	}

	return response, nil
}

// joinGroup attempts to join a consumer group
//