topserve

golang topic server and client package

what is topic?

topic is a something that use to connect some programs together with events a topic have this parts: *Event: >event is thing that happens and it have some values *Publisher: >this will notify Subscribers that event happens and give them values *Subscriber: >this will listen to Publisher and when publisher notify that event happened it will give values and proccess them for example imagine you have a program that will fetch data when a server sends it so here we have a event (fetchdata) and event value (data that comes from server) on the other side you have two programs one will show values to user and the other one will process values you need to connect this three programs together using topic first all of the programs need to be client in topic server in this case the data fetcher program is a publisher for "fetched data" event and other two programs are subscribers now lets see how to do it with topserve

Server Code

    var server topserve.Server
	server, err := server.New(":7777") //create a new topic server on port :7777 using tcp connection
	if err != nil {
		fmt.Println(err)
		os.Exit(-1)
	}
	for {
		c, err := server.AcceptConnection()  //accepting new connection to clients
		if err != nil {
			fmt.Println(err)
		} else {
			go server.HandleConnection(c)//handle and procces the client messages this need to be routine
		}
	}

when you want server to stop service just do this

	server.End()

this is server code now lets see client

Client Code

first you should make new client for the port that server run on it to recive server messages

    var client topserve.Client
    client = client.New(":7777") // my server run at port :7777 so i connect client to that port
    go client.HandleIncomings()  //this will give messages from server and procces them

so we have connected now we need to register our client as "test:test" event publisher in server

    err = client.RegisterPublisher("test:test")
	if err != nil {
		t.Log(err)
		t.Fail()
	}

so now our first client is publisher for "test:test" event so now we need another client for our second program to subscribe the "test:test" event

    var client2 topserve.Client
    client2 = client2.New(":7777") // my server run at port :7777 so i connect client2 to that port
    go client2.HandleIncomings()  //this will give messages from server and procces them

    err = client2.RegisterSubscriber("test:test")//register as subscriber of "test:test" event in server
	if err != nil {
		t.Log(err)
		t.Fail()
	}

    err = client2.Subscribe("test:test", func(v interface{}, unixTime int64) {
		fmt.Println("test:test happens in ",unixTime," and the value is",v)
	})

now you will notify when "test:test" happens but you need to some jobs to do when event happens

    err = client2.Subscribe("test:test", func(v interface{}, unixTime int64) {
		fmt.Println("test:test happens in ",unixTime," and the value is",v)
	})//this function will run when "test:test" happens
    err = client2.Subscribe("test:test", func(v interface{}, unixTime int64) {
		fmt.Println("test:test happens in ",unixTime," and the value is",v)
	})//this function will run when "test:test" happens

now return to first client now imagine that "test:test" happens you need to message server that event happens to publish the event

    err = client.PublishServer("test:test", value)//this will notify server "test:test" happens 
	if err != nil {
		t.Log(err)
		t.Fail()
	}

now server will notify subscriber clients of "test:test" and they will run subscribed functions of event

now you are tired of subscribing "test:test" event and you dont want to recive event any more so you can deRegister your subscriber from "test:test" event in server

    err = client2.DeRegisterSubscriber("test:test")// remove you from "test:test" subscribers you wil not notify any more
	if err != nil {
		t.Log(err)
		t.Fail()
	}

now you dont want to publish "test:test" any more so you can deregister your publisher from server and the subscriber will automaticly delete

    err = client.DeRegisterPublisher("test:test")
	if err != nil {
		t.Log(err)
		t.Fail()
	}

when you want to delete your client and all of it publishers and subscribers use this

	client.End()

you can see good example at topserve_test.go

at the end please help me to imporve this library special thanks from @ahmdrz