// Internal goroutine that reads from the socket and writes events to // the channel func (mc *Client) runFeed(ch chan TapEvent, feed *TapFeed) { defer close(ch) var headerBuf [transport.HDR_LEN]byte loop: for { // Read the next request from the server. // // (Can't call mc.Receive() because it reads a // _response_ not a request.) var pkt transport.MCRequest n, err := pkt.Receive(mc.conn, headerBuf[:]) if TapRecvHook != nil { TapRecvHook(&pkt, n, err) } if err != nil { if err != io.EOF { feed.Error = err } break loop } //logging.Warnf("** TapFeed received %#v : %q", pkt, pkt.Body) if pkt.Opcode == transport.TAP_CONNECT { // This is not an event from the server; it's // an error response to my connect request. feed.Error = fmt.Errorf("tap connection failed: %s", pkt.Body) break loop } event := makeTapEvent(pkt) if event != nil { if event.Opcode == tapEndStream { break loop } select { case ch <- *event: case <-feed.closer: break loop } } if len(pkt.Extras) >= 4 { reqFlags := binary.BigEndian.Uint16(pkt.Extras[2:]) if reqFlags&transport.TAP_ACK != 0 { if _, err := mc.sendAck(&pkt); err != nil { feed.Error = err break loop } } } } if err := mc.Close(); err != nil { logging.Warnf("Error closing memcached client: %v", err) } }
// receive loop func (feed *DcpFeed) doReceive(rcvch chan []interface{}, conn *Client) { defer close(rcvch) var headerBuf [transport.HDR_LEN]byte var duration time.Duration var start time.Time var blocked bool epoc := time.Now() tick := time.Tick(time.Minute * 5) // log every 5 minutes. for { pkt := transport.MCRequest{} // always a new instance. bytes, err := pkt.Receive(conn.conn, headerBuf[:]) if err != nil && err == io.EOF { logging.Infof("%v EOF received\n", feed.logPrefix) break } else if feed.isClosed() { logging.Infof("%v doReceive(): connection closed\n", feed.logPrefix) break } else if err != nil { logging.Errorf("%v doReceive(): %v\n", feed.logPrefix, err) break } logging.Tracef("%v packet received %#v", feed.logPrefix, pkt) if len(rcvch) == cap(rcvch) { start, blocked = time.Now(), true } rcvch <- []interface{}{&pkt, bytes} if blocked { duration += time.Since(start) blocked = false select { case <-tick: percent := float64(duration) / float64(time.Since(epoc)) fmsg := "%v DCP-socket -> projector %f%% blocked" logging.Infof(fmsg, feed.logPrefix, percent) default: } } } }