add error return for OnOpen

README.md

@@ -11,6 +11,13 @@
 ## develop history ##
 ---
 
+- 2016/09/06
+	> 1 codec.go:(Reader)Read(*Session, []byte) (interface{}, error)  -> codec.go:(Reader)Read(*Session, []byte) (interface{}, int, error) 
+	>
+    > 2 codec.go:(EventListener)OnOpen(*Session) -> codec.go:(EventListener)OnOpen(*Session) error
+	>
+    > 3 version: 0.3.04
+
 - 2016/09/05
 	> 1 add 'errFlag = true' when got err in pkgHandler.Read loop clause in session.go:(Session)handlePackage
 	>
@@ -41,7 +48,7 @@
 - 2016/09/02
 	> 1 add session.go:(gettyConn)close and session.go:(Session)dispose
 	>
-    > 2 modify return value of server.go:SessionCallback from void to err
+    > 2 modify return value of server.go:NewSessionCallback from void to err
 	>
     > 3 add client.go:Client
     >

client.go

@@ -33,7 +33,7 @@ type Client struct {
 	number     int
 	interval   time.Duration
 	addr       string
-	newSession SessionCallback
+	newSession NewSessionCallback
 	sessionMap map[*Session]empty
 
 	sync.Once
@@ -100,9 +100,9 @@ func (this *Client) sessionNum() int {
 
 func (this *Client) connect() {
 	var (
-		err  error
-		conn net.Conn
-		ss   *Session
+		err     error
+		conn    net.Conn
+		session *Session
 	)
 
 	for {
@@ -111,12 +111,12 @@ func (this *Client) connect() {
 			// client has been closed
 			break
 		}
-		ss = NewSession(conn)
-		err = this.newSession(ss)
+		session = NewSession(conn)
+		err = this.newSession(session)
 		if err == nil {
-			ss.RunEventloop()
+			session.RunEventLoop()
 			this.Lock()
-			this.sessionMap[ss] = empty{}
+			this.sessionMap[session] = empty{}
 			this.Unlock()
 			break
 		}
@@ -124,7 +124,7 @@ func (this *Client) connect() {
 	}
 }
 
-func (this *Client) RunEventLoop(newSession SessionCallback) {
+func (this *Client) RunEventLoop(newSession NewSessionCallback) {
 	this.Lock()
 	this.newSession = newSession
 	this.Unlock()

codec.go

@@ -9,16 +9,17 @@
 
 package getty
 
-// SessionCallback will be invoked when server accepts a new client connection or client connects to server successfully.
+// NewSessionCallback will be invoked when server accepts a new client connection or client connects to server successfully.
 // if there are too many client connections or u do not want to connect a server again, u can return non-nil error. And
 // then getty will close the new session.
-type SessionCallback func(*Session) error
+type NewSessionCallback func(*Session) error
 
 // Reader is used to unmarshal a complete pkg from buffer
 type Reader interface {
 	// Parse pkg from buffer and if possible return a complete pkg
-	// If length of buf is not long enough, u should return {nil, nil}
-	Read(*Session, []byte) (interface{}, error)
+	// If length of buf is not long enough, u should return {nil,0, nil}
+	// The second return value is the length of the pkg.
+	Read(*Session, []byte) (interface{}, int, error)
 }
 
 // Writer is used to marshal pkg and write to session
@@ -35,7 +36,7 @@ type ReadWriter interface {
 // EventListener is used to process pkg that recved from remote session
 type EventListener interface {
 	// invoked when session opened
-	OnOpen(*Session)
+	OnOpen(*Session) error
 
 	// invoked when session closed
 	OnClose(*Session)

server.go

@@ -77,7 +77,7 @@ func (this *Server) Listen(network string, addr string) error {
 	return nil
 }
 
-func (this *Server) RunEventloop(newSession SessionCallback) {
+func (this *Server) RunEventloop(newSession NewSessionCallback) {
 	this.wg.Add(1)
 	go func() {
 		defer this.wg.Done()
@@ -111,7 +111,7 @@ func (this *Server) RunEventloop(newSession SessionCallback) {
 				continue
 			}
 			delay = 0
-			client.RunEventloop()
+			client.RunEventLoop()
 		}
 	}()
 }
@@ -120,7 +120,7 @@ func (this *Server) Listener() net.Listener {
 	return this.listener
 }
 
-func (this *Server) Accept(newSession SessionCallback) (*Session, error) {
+func (this *Server) Accept(newSession NewSessionCallback) (*Session, error) {
 	conn, err := this.listener.Accept()
 	if err != nil {
 		return nil, err

session.go

@@ -17,7 +17,9 @@ import (
 	"sync"
 	"sync/atomic"
 	"time"
+)
 
+import (
 	log "github.com/AlexStocks/log4go"
 )
 
@@ -30,6 +32,10 @@ const (
 	outputFormat       = "session %s, Read Count: %d, Write Count: %d, Read Pkg Count: %d, Write Pkg Count: %d"
 )
 
+var (
+	ErrInvalidConnection = errors.New("connection has been closed.")
+)
+
 /////////////////////////////////////////
 // getty connection
 /////////////////////////////////////////
@@ -52,12 +58,19 @@ func newGettyConn(conn net.Conn) gettyConn {
 }
 
 func (this *gettyConn) read(p []byte) (int, error) {
+	// if this.conn == nil {
+	//	return 0, ErrInvalidConnection
+	// }
 	// atomic.AddUint32(&this.readCount, 1)
 	atomic.AddUint32(&this.readCount, (uint32)(len(p)))
 	return this.conn.Read(p)
 }
 
 func (this *gettyConn) write(p []byte) (int, error) {
+	// if this.conn == nil {
+	//	return 0, ErrInvalidConnection
+	// }
+
 	// atomic.AddUint32(&this.writeCount, 1)
 	atomic.AddUint32(&this.writeCount, (uint32)(len(p)))
 	return this.conn.Write(p)
@@ -67,8 +80,11 @@ func (this *gettyConn) close(waitSec int) {
 	// if tcpConn, ok := this.conn.(*net.TCPConn); ok {
 	// tcpConn.SetLinger(0)
 	// }
-	this.conn.(*net.TCPConn).SetLinger(waitSec)
-	this.conn.Close()
+	if this.conn != nil {
+		this.conn.(*net.TCPConn).SetLinger(waitSec)
+		this.conn.Close()
+		this.conn = nil
+	}
 }
 
 func (this *gettyConn) incReadPkgCount() {
@@ -141,6 +157,7 @@ func (this *Session) Reset() {
 func (this *Session) SetConn(conn net.Conn) { this.gettyConn = newGettyConn(conn) }
 func (this *Session) Conn() net.Conn        { return this.conn }
 
+// return the connect statistic data
 func (this *Session) Stat() string {
 	return fmt.Sprintf(
 		outputFormat,
@@ -152,6 +169,7 @@ func (this *Session) Stat() string {
 	)
 }
 
+// check whether the session has been closed.
 func (this *Session) IsClosed() bool {
 	select {
 	case <-this.done:
@@ -205,6 +223,7 @@ func (this *Session) SetWQLen(writeQLen int) {
 	this.lock.Unlock()
 }
 
+// SetReadDeadline sets deadline for the future read calls.
 func (this *Session) SetReadDeadline(rDeadline time.Duration) {
 	if rDeadline < 1 {
 		panic("@rDeadline < 1")
@@ -218,6 +237,7 @@ func (this *Session) SetReadDeadline(rDeadline time.Duration) {
 	this.lock.Unlock()
 }
 
+// SetWriteDeadlile sets deadline for the future read calls.
 func (this *Session) SetWriteDeadline(wDeadline time.Duration) {
 	if wDeadline < 1 {
 		panic("@wDeadline < 1")
@@ -259,25 +279,6 @@ func (this *Session) RemoveAttribute(key string) {
 	this.lock.Unlock()
 }
 
-func (this *Session) stop() {
-	select {
-	case <-this.done:
-		return
-	default:
-		// defeat "panic: close of closed channel"
-		this.once.Do(func() { close(this.done) })
-	}
-}
-
-func (this *Session) Close() error {
-	this.stop()
-	this.attrs = nil
-	log.Info("%s closed now, its current gr num %d",
-		this.sessionToken(), atomic.LoadInt32(&(this.grNum)))
-
-	return nil
-}
-
 func (this *Session) sessionToken() string {
 	return fmt.Sprintf(
 		"{%s, %d, %s <-> %s}",
@@ -317,27 +318,26 @@ func (this *Session) WriteBytes(pkg []byte) error {
 	return err
 }
 
-func (this *Session) dispose() {
-	this.lock.Lock()
-	// this.conn.Close()
-	this.gettyConn.close((int)((int64)(this.wait)))
-	this.lock.Unlock()
-}
-
-func (this *Session) RunEventloop() {
+func (this *Session) RunEventLoop() {
 	if this.rQ == nil || this.wQ == nil {
 		errStr := fmt.Sprintf("Session{name:%s, rQ:%#v, wQ:%#v}",
 			this.name, this.rQ, this.wQ)
 		log.Error(errStr)
 		panic(errStr)
 	}
-	if this.conn == nil || this.pkgHandler == nil {
-		errStr := fmt.Sprintf("Session{name:%s, conn:%#v, pkgHandler:%#v}",
-			this.name, this.conn, this.pkgHandler)
+	if this.conn == nil || this.listener == nil || this.pkgHandler == nil {
+		errStr := fmt.Sprintf("Session{name:%s, conn:%#v, listener:%#v, pkgHandler:%#v}",
+			this.name, this.conn, this.listener, this.pkgHandler)
 		log.Error(errStr)
 		panic(errStr)
 	}
 
+	// call session opened
+	if err := this.listener.OnOpen(this); err != nil {
+		this.Close()
+		return
+	}
+
 	atomic.AddInt32(&(this.grNum), 2)
 	go this.handleLoop()
 	go this.handlePackage()
@@ -357,22 +357,13 @@ func (this *Session) handleLoop() {
 		if err := recover(); err != nil {
 			log.Error("%s, [session.handleLoop] err=%+v\n", this.sessionToken(), err)
 		}
-		close(this.wQ)
-		close(this.rQ)
+
 		grNum = atomic.AddInt32(&(this.grNum), -1)
-		if this.listener != nil {
-			this.listener.OnClose(this)
-		}
-		// real close connection, dispose会调用(conn)Close,
-		this.dispose()
+		this.listener.OnClose(this)
 		log.Info("statistic{%s}, [session.handleLoop] goroutine exit now, left gr num %d", this.Stat(), grNum)
+		this.Close()
 	}()
 
-	// call session opened
-	if this.listener != nil {
-		this.listener.OnOpen(this)
-	}
-
 	ticker = time.NewTicker(this.peroid)
 LOOP:
 	for {
@@ -381,10 +372,10 @@ LOOP:
 			log.Info("%s, [session.handleLoop] got done signal ", this.Stat())
 			break LOOP
 		case inPkg = <-this.rQ:
-			if this.listener != nil {
-				this.listener.OnMessage(this, inPkg)
-				this.incReadPkgCount()
-			}
+
+			this.listener.OnMessage(this, inPkg)
+			this.incReadPkgCount()
+
 		case outPkg = <-this.wQ:
 			if err = this.pkgHandler.Write(this, outPkg); err != nil {
 				log.Error("%s, [session.handleLoop] = error{%+v}", this.sessionToken(), err)
@@ -392,9 +383,7 @@ LOOP:
 			}
 			this.incWritePkgCount()
 		case <-ticker.C:
-			if this.listener != nil {
-				this.listener.OnCron(this)
-			}
+			this.listener.OnCron(this)
 		}
 	}
 	ticker.Stop()
@@ -418,10 +407,10 @@ LAST:
 			}
 			this.incWritePkgCount()
 		case inPkg = <-this.rQ:
-			if this.listener != nil {
-				this.listener.OnMessage(this, inPkg)
-				this.incReadPkgCount()
-			}
+
+			this.listener.OnMessage(this, inPkg)
+			this.incReadPkgCount()
+
 		default:
 			log.Info("%s, [session.handleLoop] default", this.sessionToken())
 			break LAST
@@ -452,7 +441,7 @@ func (this *Session) handlePackage() {
 		close(this.readerDone)
 		grNum = atomic.AddInt32(&(this.grNum), -1)
 		log.Info("%s, [session.handlePackage] gr will exit now, left gr num %d", this.sessionToken(), grNum)
-		if errFlag && this.listener != nil {
+		if errFlag {
 			log.Info("%s, [session.handlePackage] errFlag", this.sessionToken())
 			this.listener.OnError(this, err)
 		}
@@ -492,7 +481,7 @@ func (this *Session) handlePackage() {
 				break
 			}
 			// pkg, err = this.pkgHandler.Read(this, pktBuf)
-			pkg, err = this.pkgHandler.Read(this, pktBuf.Bytes())
+			pkg, len, err = this.pkgHandler.Read(this, pktBuf.Bytes())
 			if err != nil {
 				log.Info("%s, [session.pkgHandler.Read] = error{%+v}", this.sessionToken(), err)
 				errFlag = true
@@ -503,9 +492,44 @@ func (this *Session) handlePackage() {
 				break
 			}
 			this.rQ <- pkg
+			pktBuf.Next(len)
 		}
 		if exit {
 			break
 		}
 	}
 }
+
+func (this *Session) stop() {
+	select {
+	case <-this.done:
+		return
+	default:
+		this.once.Do(func() { close(this.done) })
+	}
+}
+
+// this function will be invoked by NewSessionCallback(if return error is not nil) or (Session)handleLoop automatically.
+// It is goroutine-safe to be invoked many times.
+func (this *Session) Close() error {
+	this.stop()
+	log.Info("%s closed now, its current gr num %d",
+		this.sessionToken(), atomic.LoadInt32(&(this.grNum)))
+	this.lock.Lock()
+	if this.attrs != nil {
+		this.attrs = nil
+		select {
+		case <-this.readerDone:
+		default:
+			close(this.readerDone)
+		}
+		close(this.wQ)
+		this.wQ = nil
+		close(this.rQ)
+		this.rQ = nil
+		this.gettyConn.close((int)((int64)(this.wait)))
+	}
+	this.lock.Unlock()
+
+	return nil
+}

utils.go

@@ -10,8 +10,6 @@
 package getty
 
 import (
-	"bytes"
-	"encoding/binary"
 	"net"
 	"strconv"
 )
@@ -20,23 +18,3 @@ import (
 func HostAddress(host string, port int) string {
 	return net.JoinHostPort(host, strconv.Itoa(port))
 }
-
-////////////////////////////////////////
-// enc/dec
-////////////////////////////////////////
-
-func Int2Bytes(x int32) []byte {
-	var buf = bytes.NewBuffer([]byte{})
-	binary.Write(buf, binary.BigEndian, x)
-	return buf.Bytes()
-}
-
-func Bytes2Int(b []byte) int32 {
-	var (
-		x   int32
-		buf *bytes.Buffer
-	)
-	buf = bytes.NewBuffer(b)
-	binary.Read(buf, binary.BigEndian, &x)
-	return x
-}

version.go

@@ -10,5 +10,5 @@
 package getty
 
 var (
-	Version = "0.3.03"
+	Version = "0.3.04"
 )