// 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:
}
}
}
}
