rsocket

rsocket-go

rsocket-go is an implementation of the RSocket protocol in Go. It is still under development, APIs are unstable and maybe change at any time until release of v1.0.0. Please do not use it in a production environment.

Features

• Design For Golang.
• Thin reactive-streams implementation.
• Simulate Java SDK API.
• Fast CLI (Compatible with https://github.com/rsocket/rsocket-cli).
  • Installation: go get github.com/rsocket/rsocket-go/cmd/rsocket-cli
  • Example: rsocket-cli --request -i hello_world --setup setup_me tcp://127.0.0.1:7878

Getting started

Start an echo server

package main

import (
	"context"

	"github.com/rsocket/rsocket-go"
	"github.com/rsocket/rsocket-go/payload"
	"github.com/rsocket/rsocket-go/rx/mono"
)

func main() {
	err := rsocket.Receive().
		Resume().
		Fragment(1024).
		Acceptor(func(setup payload.SetupPayload, sendingSocket rsocket.CloseableRSocket) rsocket.RSocket {
			// bind responder
			return rsocket.NewAbstractSocket(
				rsocket.RequestResponse(func(msg payload.Payload) mono.Mono {
					return mono.Just(msg)
				}),
			)
		}).
		Transport("tcp://127.0.0.1:7878").
		Serve(context.Background())
	panic(err)
}

Connect to echo server

package main

import (
	"context"
	"log"

	"github.com/rsocket/rsocket-go"
	"github.com/rsocket/rsocket-go/payload"
)

func main() {
	// Connect to server
	cli, err := rsocket.Connect().
		Resume().
		Fragment(1024).
		SetupPayload(payload.NewString("Hello", "World")).
		Transport("tcp://127.0.0.1:7878").
		Start(context.Background())
	if err != nil {
		panic(err)
	}
	defer cli.Close()
	// Send request
	result, err := cli.RequestResponse(payload.NewString("你好", "世界")).Block(context.Background())
	if err != nil {
		panic(err)
	}
	log.Println("response:", result)
}

NOTICE: more server examples are Here

Advanced

Load Balance

Basic load balance feature, see here.

Reactor API

Mono and Flux are two parts of Reactor API. They are based on my another project reactor-go.

Mono

Mono completes successfully by emitting an element, or with an error. Here is a tiny example:

package main

import (
	"context"
	"fmt"

	"github.com/jjeffcaii/reactor-go/scheduler"
	"github.com/rsocket/rsocket-go/payload"
	"github.com/rsocket/rsocket-go/rx"
	"github.com/rsocket/rsocket-go/rx/mono"
)

func main() {
	// Create a Mono using Just.
	m := mono.Just(payload.NewString("Hello World!", "text/plain"))

	// More create
	//m := mono.Create(func(i context.Context, sink mono.Sink) {
	//	sink.Success(payload.NewString("Hello World!", "text/plain"))
	//})

	done := make(chan struct{})

	m.
		DoFinally(func(s rx.SignalType) {
			close(done)
		}).
		DoOnSuccess(func(input payload.Payload) {
			// Handle and consume payload.
			// Do something here...
			fmt.Println("bingo:", input)
		}).
		SubscribeOn(scheduler.Elastic()).
		Subscribe(context.Background())

	<-done
}

Flux

Flux emits 0 to N elements, and then completes (successfully or with an error). Here is tiny example:

package main

import (
	"context"
	"fmt"

	flxx "github.com/jjeffcaii/reactor-go/flux"
	"github.com/rsocket/rsocket-go/extension"
	"github.com/rsocket/rsocket-go/payload"
	"github.com/rsocket/rsocket-go/rx/flux"
)

func main() {
	// Create a Flux and produce 10 elements.
	f := flux.Create(func(ctx context.Context, sink flux.Sink) {
		for i := 0; i < 10; i++ {
			sink.Next(payload.NewString(fmt.Sprintf("Hello@%d", i), extension.TextPlain.String()))
		}
		sink.Complete()
	})

	// Or use Just.
	//f := flux.Just(
	//	payload.NewString("foo", extension.TextPlain.String()),
	//	payload.NewString("bar", extension.TextPlain.String()),
	//	payload.NewString("qux", extension.TextPlain.String()),
	//)

	f.
		DoOnNext(func(elem payload.Payload) {
			// Handle and consume elements
			// Do something here...
			fmt.Println("bingo:", elem)
		}).
		Subscribe(context.Background())

	// Or you can use Raw reactor-go API. :-D
	f2 := flux.Raw(flxx.Range(0, 10).Map(func(i interface{}) interface{} {
		return payload.NewString(fmt.Sprintf("Hello@%d", i.(int)), extension.TextPlain.String())
	}))
	f2.
		DoOnNext(func(input payload.Payload) {
			fmt.Println("bingo:", input)
		}).
		BlockLast(context.Background())
}

Backpressure & RequestN

Flux support backpressure.

You can call func Request in Subscription or use LimitRate before subscribe.

package main

import (
	"context"
	"fmt"

	"github.com/rsocket/rsocket-go/extension"
	"github.com/rsocket/rsocket-go/payload"
	"github.com/rsocket/rsocket-go/rx"
	"github.com/rsocket/rsocket-go/rx/flux"
)

func main() {
	// Here is an example which consume Payload one by one.
	f := flux.Create(func(ctx context.Context, s flux.Sink) {
		for i := 0; i < 5; i++ {
			s.Next(payload.NewString(fmt.Sprintf("Hello@%d", i), extension.TextPlain.String()))
		}
		s.Complete()
	})

	var su rx.Subscription
	f.
		DoOnRequest(func(n int) {
			fmt.Printf("requesting next %d element......\n", n)
		}).
		Subscribe(
			context.Background(),
			rx.OnSubscribe(func(s rx.Subscription) {
				// Init Request 1 element.
				su = s
				su.Request(1)
			}),
			rx.OnNext(func(elem payload.Payload) {
				// Consume element, do something...
				fmt.Println("bingo:", elem)
				// Request for next one manually.
				su.Request(1)
			}),
		)
}

Dependencies

• reactor-go
• bytebufferpool
• testify
• websocket

TODO

Transport

• TCP
• Websocket

Duplex Socket

• MetadataPush
• RequestFNF
• RequestResponse
• RequestStream
• RequestChannel

• Resume
• Keepalive
• Fragmentation
• Thin Reactor
• Cancel
• Error
• Flow Control: RequestN
• Flow Control: Lease
• Load Balance