+ FIX : add the ping/ack msg to session.Pingack

[ljy2010a]

for fix #27 #29
add the ping/ack msg to session.Pingack for panics with slice bounds out of range.

[suyashkumar]

Hi there @ljy2010a! Thanks so much for this PR, just applied it on my fork of this repo. However keeping the server alive via PINGREQs seems to throw this error a lot. From what I can tell since it's a ping this is not a problem, correct? Figured I'd ask someone like you who knows MQTT better than I :)

[suyashkumar]

If it's not an issue, I'll probably just make it:

if (len(ackmsg.Msgbuf) == 0 || len(ackmsg.Ackbuf) == 0) && ackmsg.Mtype!="PINGREQ"

But so far I have not had the i/o timeout issues I was having before, so I really like this (thanks for this PR!)

[ljy2010a]

i/o timeout issues is case by the server setTimeout , when you have a heartbeat or send message interval less than timeout,it should not apper

the code here is just check the buffer len more than 0,that the message library
miss

you should not get the 0 buffer , so I fill the PINGRESP it in ackqueue.go like below

but if you get the 0 buffer , you should check the message that client send ,
or the server get message
, it may have a bug

by the way , i did not use this in Industrial env

[ljy2010a]

here is my test example

package main

import (
    "flag"
    "log"
    "os"
    "time"

    mqtt "github.com/eclipse/paho.mqtt.golang"
    "github.com/surge/glog"
    "github.com/surgemq/message"
    "github.com/surgemq/surgemq/service"
)

var addr = "tcp://127.0.0.1:12345"

func main() {

    flag.Parse()
    defer glog.Flush()

    go func() {
        srv := service.Server{}
        glog.Info("starting MQTT server at :12345")
        glog.Fatal(srv.ListenAndServe(addr))
    }()

    // wait a bit, the internal MQTT server is still starting up
    time.Sleep(time.Second)
    surgemqClient()
    // pahoClient()
}

func surgemqClient() {
    client := &service.Client{}
    msg := message.NewConnectMessage()
    msg.SetVersion(4)
    KeepAlive := 40
    msg.SetKeepAlive(uint16(KeepAlive))
    msg.SetCleanSession(true)
    // make the byte like Paho
    msg.SetClientId([]byte("Paho"))
    if err := client.Connect(addr, msg); err != nil {
        glog.Fatal(err)
    }

    go heartbeatProcess(client, KeepAlive)

    glog.Infoln("connected to port 12345")

    i := 0
    for _ = range time.Tick(time.Second * 1) {
        i++
        glog.Info(i)
    }
}

func pahoClient() {
    mqtt.ERROR = log.New(os.Stdout, "", 0)
    opts := mqtt.NewClientOptions().AddBroker(addr).SetClientID("Paho")
    opts.SetKeepAlive(2 * time.Second)
    opts.SetPingTimeout(1 * time.Second)

    c := mqtt.NewClient(opts)
    if token := c.Connect(); token.Wait() && token.Error() != nil {
        panic(token.Error())
    }

    i := 0
    for _ = range time.Tick(time.Second * 1) {
        i++
        glog.Info(i)
    }
}

func heartbeatProcess(c *service.Client, KeepAlive int) {
    for _ = range time.Tick(time.Duration(KeepAlive) * time.Second) {
        c.Ping(func(msg, ack message.Message, err error) error {
            glog.Infof("Ping \n")
            return nil
        })
    }
}