Support streaming(push)

[defool]

Draft1: Support streaming api like this: https://grpc.io/docs/languages/go/basics/#server-side-streaming-rpc。

proto.tars:

module ServerTest {
	interface RPCServant {  // RPC API
	    string Echo(string in); 
	};

	stream PushServant { // Stream API
	    string Message(string in);
	};
};

Client:

streamCli := &ServerTest.PushServant{}
comm.StringToProxy("App.ServerTest.PushServantObj", streamCli)

msg1, err := streamCli.RecvMessage() // block if no message
msg2, err = streamCli.RecvMessage() // block if no message
err := streamCli.SendMessage("abc") // block if no message

Server Start:

ServerTest.AddStreamSevant("App.ServerTest.PushServantObj", serverImp)

Server Implement:

type serverImp struct{}

func (s *serverImp) Messsage(ctx context.Context, stream ServerTest.MesssageStream) error {
	for {
		msg, err := stream.RecvMessage() // block if no message
		err = stream.SendMessage("hello") // block if no message
	}
}

[defool]

Draft2: Support low level push API like this: https://github.com/TarsCloud/TarsCpp/tree/master/examples/PushDemo

client:

package main

import (
	"fmt"
	"time"

	"github.com/TarsCloud/TarsGo/tars"
	"github.com/TarsCloud/TarsGo/tars/protocol/push"
)

func callback(data []byte) {
	fmt.Println("recv message:", string(data))
}

func main() {
	comm := tars.NewCommunicator()
	obj := fmt.Sprintf("TestApp.PushServer.MessageObj@tcp -h 127.0.0.1 -p 10015 -t 60000")
	client := push.NewClient()
	comm.StringToProxy(obj, client)
	err := client.Connect("pushFunc", []byte("hello"), callback)
	if err != nil {
		panic(err)
	}
	// Wait for receving message
	time.Sleep(time.Second * 1)
}

server:

package main

import (
	"context"
	"fmt"
	"time"

	"github.com/TarsCloud/TarsGo/tars"
	"github.com/TarsCloud/TarsGo/tars/protocol/push"
	"github.com/TarsCloud/TarsGo/tars/util/current"
)

var (
	logger = tars.GetLogger("")
)

type pushImp struct{}

func (p *pushImp) OnConnect(ctx context.Context, req []byte) []byte {
	logger.Debugf("push client: ", current.GetClientIPFromContext(ctx))
	go func() {
		for i := 0; i < 3; i++ {
			time.Sleep(time.Millisecond * 100)
			push.Send(ctx, []byte("msg"+fmt.Sprint(i)))
		}
	}()
	return req
}

func main() {
	cfg := tars.GetServerConfig()
	proto := push.NewServer(&pushImp{})
	tars.AddServantWithProtocol(proto, cfg.App+"."+cfg.Server+".MessageObj")
	tars.Run()
}