Add expvars integration for stream packet size metrics in czar protocol

Author: mohanson

protocol/czar/engine.go

@@ -10,6 +10,7 @@ import (
 	"time"
 
 	"github.com/libraries/daze"
+	"github.com/libraries/daze/lib/expvpp"
 	"github.com/libraries/daze/lib/rate"
 	"github.com/libraries/daze/protocol/ashe"
 )
@@ -55,6 +56,13 @@ var Conf = struct {
 	StreamPool:        256,
 }
 
+// Expv is a simple wrapper around the expvars package.
+var Expv = struct {
+	StreamWriteSize *expvpp.Average
+}{
+	StreamWriteSize: expvpp.NewAverage("Protocol.Czar.Stream.WriteSize", 64),
+}
+
 // Server implemented the czar protocol.
 type Server struct {
 	Cipher []byte

protocol/czar/mux.go

@@ -90,6 +90,7 @@ func (s *Stream) Read(p []byte) (int, error) {
 
 // Write implements io.Writer.
 func (s *Stream) Write(p []byte) (int, error) {
+	Expv.StreamWriteSize.Append(float64(len(p)))
 	var (
 		buf []byte
 		l   = 0
@@ -248,10 +249,6 @@ func (m *Mux) Recv() {
 			m.ach <- stm
 		case 0x01:
 			bsz = binary.BigEndian.Uint16(buf[2:4])
-			if int(bsz) > Conf.PacketSize-4 {
-				m.con.Close()
-				break
-			}
 			msg = make([]byte, bsz)
 			_, err = io.ReadFull(m.con, msg)
 			if err != nil {