Introduce a postWrite hook

evio.go

@@ -115,6 +115,8 @@ type Events struct {
 	Detached func(c Conn, rwc io.ReadWriteCloser) (action Action)
 	// PreWrite fires just before any data is written to any client socket.
 	PreWrite func()
+	// PostWrite fires just after any data is written to any client socket.
+	PostWrite func(c Conn)
 	// Data fires when a connection sends the server data.
 	// The in parameter is the incoming data.
 	// Use the out return value to write data to the connection.

evio_std.go

@@ -384,6 +384,9 @@ func stdloopRead(s *stdserver, l *stdloop, c *stdconn, in []byte) error {
 				s.events.PreWrite()
 			}
 			c.conn.Write(out)
+			if s.events.PostWrite != nil {
+				s.events.PostWrite(c)
+			}
 		}
 		switch action {
 		case Shutdown:
@@ -405,6 +408,9 @@ func stdloopReadUDP(s *stdserver, l *stdloop, c *stdudpconn) error {
 				s.events.PreWrite()
 			}
 			s.lns[c.addrIndex].pconn.WriteTo(out, c.remoteAddr)
+			if s.events.PostWrite != nil {
+				s.events.PostWrite(c)
+			}
 		}
 		switch action {
 		case Shutdown:
@@ -439,6 +445,9 @@ func stdloopAccept(s *stdserver, l *stdloop, c *stdconn) error {
 				s.events.PreWrite()
 			}
 			c.conn.Write(out)
+			if s.events.PostWrite != nil {
+				s.events.PostWrite(c)
+			}
 		}
 		if opts.TCPKeepAlive > 0 {
 			if c, ok := c.conn.(*net.TCPConn); ok {

evio_unix.go

@@ -333,6 +333,9 @@ func loopUDPRead(s *server, l *loop, lnidx, fd int) error {
 				s.events.PreWrite()
 			}
 			syscall.Sendto(fd, out, 0, sa)
+			if s.events.PostWrite != nil {
+				s.events.PostWrite(c)
+			}
 		}
 		switch action {
 		case Shutdown:
@@ -391,6 +394,9 @@ func loopWrite(s *server, l *loop, c *conn) error {
 	if len(c.out) == 0 && c.action == None {
 		l.poll.ModRead(c.fd)
 	}
+	if len(c.out) == 0 && s.events.PostWrite != nil {
+		s.events.PostWrite(c)
+	}
 	return nil
 }