rsocket-java小试牛刀

序

本文主要研究一下rsocket-java

RSocket

rsocket-core-0.12.1-sources.jar!/io/rsocket/RSocket.java

public interface RSocket extends Availability, Closeable {

  /**
   * Fire and Forget interaction model of {@code RSocket}.
   *
   * @param payload Request payload.
   * @return {@code Publisher} that completes when the passed {@code payload} is successfully
   *     handled, otherwise errors.
   */
  Mono<Void> fireAndForget(Payload payload);

  /**
   * Request-Response interaction model of {@code RSocket}.
   *
   * @param payload Request payload.
   * @return {@code Publisher} containing at most a single {@code Payload} representing the
   *     response.
   */
  Mono<Payload> requestResponse(Payload payload);

  /**
   * Request-Stream interaction model of {@code RSocket}.
   *
   * @param payload Request payload.
   * @return {@code Publisher} containing the stream of {@code Payload}s representing the response.
   */
  Flux<Payload> requestStream(Payload payload);

  /**
   * Request-Channel interaction model of {@code RSocket}.
   *
   * @param payloads Stream of request payloads.
   * @return Stream of response payloads.
   */
  Flux<Payload> requestChannel(Publisher<Payload> payloads);

  /**
   * Metadata-Push interaction model of {@code RSocket}.
   *
   * @param payload Request payloads.
   * @return {@code Publisher} that completes when the passed {@code payload} is successfully
   *     handled, otherwise errors.
   */
  Mono<Void> metadataPush(Payload payload);

  @Override
  default double availability() {
    return isDisposed() ? 0.0 : 1.0;
  }
}

• RSocket接口继承了Availability(定义double availability()方法)及Closeable(定义了Mono<Void> onClose()方法)接口
• RSocket定义了fireAndForget、requestResponse、requestStream、requestChannel方法分别对应4种Interaction Model
• RSocket的Frame包含metadata及data payload，其中metadata可选，可以用于描述data payload，因而RSocket还定义了metadataPush方法用于push metadata

Interaction Model

fireAndForget

    @Test
    public void testFireAndForget() throws InterruptedException {
        //SERVER
        RSocketFactory.receive()
                .acceptor(
                        (setupPayload, reactiveSocket) ->
                                Mono.just(
                                        new AbstractRSocket() {
                                            @Override
                                            public Mono<Void> fireAndForget(Payload payload) {
                                                System.out.printf("fire-forget: %s%n", payload.getDataUtf8());
                                                return Mono.empty();
                                            }
                                        }))
                .transport(TcpServerTransport.create("localhost", 8080))
                .start()
                .subscribe();

        //CLIENT
        RSocket socket =
                RSocketFactory.connect()
                        .transport(TcpClientTransport.create("localhost", 8080))
                        .start()
                        .block();

        socket
                .fireAndForget(DefaultPayload.create("Hello"))
                .block();

        socket.dispose();

        TimeUnit.SECONDS.sleep(5);
    }

类似udp，无需ack，比较适合metrics上报、访问日志上报等

requestResponse

    @Test
    public void testRequestResponse(){
        //SERVER
        RSocketFactory.receive()
                .acceptor(
                        (setupPayload, reactiveSocket) ->
                                Mono.just(
                                        new AbstractRSocket() {
                                            @Override
                                            public Mono<Payload> requestResponse(Payload p) {
                                                return Mono.just(p);
                                            }
                                        }))
                .transport(TcpServerTransport.create("localhost", 8080))
                .start()
                .subscribe();

        //CLIENT
        RSocket socket =
                RSocketFactory.connect()
                        .transport(TcpClientTransport.create("localhost", 8080))
                        .start()
                        .block();

        socket
                .requestResponse(DefaultPayload.create("Hello"))
                .map(Payload::getDataUtf8)
                .onErrorReturn("error")
                .doOnNext(System.out::println)
                .block();

        socket.dispose();
    }

类似http，但是优于http，因为它是异步的，而且是multiplexed

requestStream

    @Test
    public void testRequestStream(){
        //SERVER
        RSocketFactory.receive()
                .acceptor(new SocketAcceptor() {
                    @Override
                    public Mono<RSocket> accept(ConnectionSetupPayload connectionSetupPayload, RSocket rSocket) {
                        return Mono.just(
                                new AbstractRSocket() {
                                    @Override
                                    public Flux<Payload> requestStream(Payload payload) {
                                        return Flux.interval(Duration.ofMillis(100))
                                                .map(aLong -> DefaultPayload.create("Interval: " + aLong));
                                    }
                                });
                    }
                })
                .transport(TcpServerTransport.create("localhost", 8080))
                .start()
                .subscribe();

        //CLIENT
        RSocket socket =
                RSocketFactory.connect()
                        .transport(TcpClientTransport.create("localhost", 8080))
                        .start()
                        .block();

        socket
                .requestStream(DefaultPayload.create("Hello"))
                .map(Payload::getDataUtf8)
                .doOnNext(System.out::println)
                .take(10)
                .then()
                .doFinally(signalType -> socket.dispose())
                .then()
                .block();
    }

类似Request-Response(返回Mono)，只不过返回的是Flux

requestChannel

    @Test
    public void testRequestChannel(){
        //SERVER
        RSocketFactory.receive()
                .acceptor(new SocketAcceptor(){
                    @Override
                    public Mono<RSocket> accept(ConnectionSetupPayload setup, RSocket sendingSocket) {
                        return Mono.just(
                                new AbstractRSocket() {
                                    @Override
                                    public Flux<Payload> requestChannel(Publisher<Payload> payloads) {
                                        return Flux.from(payloads)
                                                .map(Payload::getDataUtf8)
                                                .map(s -> "Echo: " + s)
                                                .map(DefaultPayload::create);
                                    }
                                });
                    }
                })
                .transport(TcpServerTransport.create("localhost", 8080))
                .start()
                .subscribe();

        //CLIENT
        RSocket socket =
                RSocketFactory.connect()
                        .transport(TcpClientTransport.create("localhost", 8080))
                        .start()
                        .block();

        socket
                .requestChannel(
                        Flux.interval(Duration.ofMillis(1000)).map(i -> DefaultPayload.create("Hello")))
                .map(Payload::getDataUtf8)
                .doOnNext(System.out::println)
                .take(10)
                .doFinally(signalType -> socket.dispose())
                .then()
                .block();
    }

类似websocket，可以双向通信

MetadataPush

    @Test
    public void testMetadataPush() throws InterruptedException {
        //SERVER
        RSocketFactory.receive()
                .acceptor(
                        (setupPayload, reactiveSocket) ->
                                Mono.just(
                                        new AbstractRSocket() {

                                            @Override
                                            public Mono<Void> metadataPush(Payload payload) {
                                                System.out.printf("metadataPush: %s%n", payload.getDataUtf8());
                                                return Mono.empty();
                                            }
                                        }))
                .transport(TcpServerTransport.create("localhost", 8080))
                .start()
                .subscribe();

        //CLIENT
        RSocket socket =
                RSocketFactory.connect()
                        .transport(TcpClientTransport.create("localhost", 8080))
                        .start()
                        .block();

        socket
                .metadataPush(DefaultPayload.create("hello","version=1.0.0+"))
                .block();

        socket.dispose();

        TimeUnit.SECONDS.sleep(5);
    }

• RSocket还定义了metadataPush方法，与fireAndForget方法不同的是metadataPush方法会等待data pushed成功，然后在接收到对方发送的complete signal时complete

小结

• RSocket是一种bi-directional、multiplexed、message-based的二进制协议
• RSocket有四种Interaction Model，分别是Request-Response、Fire-and-Forget、Request-Stream、Channel
• RSocket的Frame包含metadata及data payload，其中metadata可选，可以用于描述data payload；除了可以在4种Interaction Model对应方法的Payload参数中设置metadata外，还可以使用RSocket定义的metadataPush方法来专门push metadata

doc

• rsocket.io