// 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)
}
}
func TestTransmitReq(t *testing.T) {
b := bytes.NewBuffer([]byte{})
buf := bufio.NewWriter(b)
req := transport.MCRequest{
Opcode: transport.SET,
Cas: 938424885,
Opaque: 7242,
VBucket: 824,
Extras: []byte{},
Key: []byte("somekey"),
Body: []byte("somevalue"),
}
// Verify nil transmit is OK
_, err := transmitRequest(nil, &req)
if err != errNoConn {
t.Errorf("Expected errNoConn with no conn, got %v", err)
}
_, err = transmitRequest(buf, &req)
if err != nil {
t.Fatalf("Error transmitting request: %v", err)
}
buf.Flush()
expected := []byte{
transport.REQ_MAGIC, byte(transport.SET),
0x0, 0x7, // length of key
0x0, // extra length
0x0, // reserved
0x3, 0x38, // vbucket
0x0, 0x0, 0x0, 0x10, // Length of value
0x0, 0x0, 0x1c, 0x4a, // opaque
0x0, 0x0, 0x0, 0x0, 0x37, 0xef, 0x3a, 0x35, // CAS
's', 'o', 'm', 'e', 'k', 'e', 'y',
's', 'o', 'm', 'e', 'v', 'a', 'l', 'u', 'e'}
if len(b.Bytes()) != req.Size() {
t.Fatalf("Expected %v bytes, got %v", req.Size(),
len(b.Bytes()))
}
if !reflect.DeepEqual(b.Bytes(), expected) {
t.Fatalf("Expected:\n%#v\n -- got -- \n%#v",
expected, b.Bytes())
}
}
// 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:
}
}
}
}
func BenchmarkTransmitReqNull(b *testing.B) {
req := transport.MCRequest{
Opcode: transport.SET,
Cas: 938424885,
Opaque: 7242,
VBucket: 824,
Extras: []byte{},
Key: []byte("somekey"),
Body: []byte("somevalue"),
}
b.SetBytes(int64(req.Size()))
for i := 0; i < b.N; i++ {
_, err := transmitRequest(ioutil.Discard, &req)
if err != nil {
b.Fatalf("Error transmitting request: %v", err)
}
}
}
func BenchmarkTransmitReqLarge(b *testing.B) {
bout := bytes.NewBuffer([]byte{})
req := transport.MCRequest{
Opcode: transport.SET,
Cas: 938424885,
Opaque: 7242,
VBucket: 824,
Extras: []byte{},
Key: []byte("somekey"),
Body: make([]byte, 24*1024),
}
b.SetBytes(int64(req.Size()))
for i := 0; i < b.N; i++ {
bout.Reset()
buf := bufio.NewWriterSize(bout, req.Size()*2)
_, err := transmitRequest(buf, &req)
if err != nil {
b.Fatalf("Error transmitting request: %v", err)
}
}
}
