// persistence endpoints into db
func (s *server) persistence_task() {
timer := time.After(CHECK_INTERVAL)
db := s.open_db()
changes := make(map[uint64]bool)
sig := make(chan os.Signal, 1)
signal.Notify(sig, syscall.SIGTERM, syscall.SIGINT)
for {
select {
case key := <-s.pending:
changes[key] = true
case <-timer:
s.dump(db, changes)
if len(changes) > 0 {
log.Infof("perisisted %v endpoints:", len(changes))
}
changes = make(map[uint64]bool)
timer = time.After(CHECK_INTERVAL)
case nr := <-sig:
s.dump(db, changes)
db.Close()
log.Info(nr)
os.Exit(0)
}
}
}
func (s *server) restore() {
// restore data from db file
db := s.open_db()
defer db.Close()
count := 0
db.View(func(tx *bolt.Tx) error {
b := tx.Bucket([]byte(BOLTDB_BUCKET))
b.ForEach(func(k, v []byte) error {
var msg []Chat_Message
err := msgpack.Unmarshal(v, &msg)
if err != nil {
log.Critical("chat data corrupted:", err)
os.Exit(-1)
}
id, err := strconv.ParseUint(string(k), 0, 64)
if err != nil {
log.Critical("chat data corrupted:", err)
os.Exit(-1)
}
ep := NewEndPoint()
ep.inbox = msg
s.eps[id] = ep
count++
return nil
})
return nil
})
log.Infof("restored %v chats", count)
}
// start a goroutine when a new connection is accepted
func handleClient(conn *net.TCPConn) {
defer utils.PrintPanicStack()
// set per-connection socket buffer
conn.SetReadBuffer(SO_RCVBUF)
// set initial socket buffer
conn.SetWriteBuffer(SO_SNDBUF)
// initial network control struct
header := make([]byte, 2)
in := make(chan []byte)
defer func() {
close(in) // session will close
}()
// create a new session object for the connection
var sess Session
host, port, err := net.SplitHostPort(conn.RemoteAddr().String())
if err != nil {
log.Error("cannot get remote address:", err)
return
}
sess.IP = net.ParseIP(host)
log.Infof("new connection from:%v port:%v", host, port)
// session die signal
sess.Die = make(chan struct{})
// create a write buffer
out := new_buffer(conn, sess.Die)
go out.start()
// start one agent for handling packet
wg.Add(1)
go agent(&sess, in, out)
// network loop
for {
// solve dead link problem
conn.SetReadDeadline(time.Now().Add(TCP_READ_DEADLINE * time.Second))
n, err := io.ReadFull(conn, header)
if err != nil {
log.Warningf("read header failed, ip:%v reason:%v size:%v", sess.IP, err, n)
return
}
size := binary.BigEndian.Uint16(header)
// alloc a byte slice for reading
payload := make([]byte, size)
// read msg
n, err = io.ReadFull(conn, payload)
if err != nil {
log.Warningf("read payload failed, ip:%v reason:%v size:%v", sess.IP, err, n)
return
}
select {
case in <- payload: // payload queued
case <-sess.Die:
log.Warningf("connection closed by logic, flag:%v ip:%v", sess.Flag, sess.IP)
return
}
}
}
// PIPELINE #1: handleClient
// the goroutine is used for reading incoming PACKETS
// each packet is defined as :
// | 2B size | DATA |
//
func handleClient(conn *net.TCPConn) {
defer utils.PrintPanicStack()
// set socket read buffer
conn.SetReadBuffer(SO_RCVBUF)
// set socket write buffer
conn.SetWriteBuffer(SO_SNDBUF)
// for reading the 2-Byte header
header := make([]byte, 2)
// the input channel for agent()
in := make(chan []byte)
defer func() {
close(in) // session will close
}()
// create a new session object for the connection
// and record it's IP address
var sess Session
host, port, err := net.SplitHostPort(conn.RemoteAddr().String())
if err != nil {
log.Error("cannot get remote address:", err)
return
}
sess.IP = net.ParseIP(host)
log.Infof("new connection from:%v port:%v", host, port)
// session die signal, will be triggered by agent()
sess.Die = make(chan struct{})
// create a write buffer
out := new_buffer(conn, sess.Die)
go out.start()
// start agent for PACKET processing
wg.Add(1)
go agent(&sess, in, out)
// read loop
for {
// solve dead link problem:
// physical disconnection without any communcation between client and server
// will cause the read to block FOREVER, so a timeout is a rescue.
conn.SetReadDeadline(time.Now().Add(TCP_READ_DEADLINE * time.Second))
// read 2B header
n, err := io.ReadFull(conn, header)
if err != nil {
log.Warningf("read header failed, ip:%v reason:%v size:%v", sess.IP, err, n)
return
}
size := binary.BigEndian.Uint16(header)
// alloc a byte slice of the size defined in the header for reading data
payload := make([]byte, size)
n, err = io.ReadFull(conn, payload)
if err != nil {
log.Warningf("read payload failed, ip:%v reason:%v size:%v", sess.IP, err, n)
return
}
// deliver the data to the input queue of agent()
select {
case in <- payload: // payload queued
case <-sess.Die:
log.Warningf("connection closed by logic, flag:%v ip:%v", sess.Flag, sess.IP)
return
}
}
}