org.springframework.cloud.gateway.rsocket.server.PendingRequestRSocket.java Source code

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Here is the source code for org.springframework.cloud.gateway.rsocket.server.PendingRequestRSocket.java

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/*
 * Copyright 2018-2019 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.cloud.gateway.rsocket.server;

import java.util.function.Consumer;
import java.util.function.Function;
import java.util.logging.Level;

import io.rsocket.AbstractRSocket;
import io.rsocket.Payload;
import io.rsocket.RSocket;
import io.rsocket.ResponderRSocket;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.reactivestreams.Publisher;
import reactor.core.Disposable;
import reactor.core.publisher.Flux;
import reactor.core.publisher.Mono;
import reactor.core.publisher.MonoProcessor;
import reactor.util.function.Tuple2;

import org.springframework.cloud.gateway.rsocket.filter.RSocketFilter.Success;
import org.springframework.cloud.gateway.rsocket.registry.Registry.RegisteredEvent;
import org.springframework.cloud.gateway.rsocket.route.Route;
import org.springframework.cloud.gateway.rsocket.support.Metadata;

import static org.springframework.cloud.gateway.rsocket.server.GatewayExchange.ROUTE_ATTR;
import static org.springframework.cloud.gateway.rsocket.server.GatewayExchange.Type.REQUEST_STREAM;
import static org.springframework.cloud.gateway.rsocket.server.GatewayFilterChain.executeFilterChain;

public class PendingRequestRSocket extends AbstractRSocket implements ResponderRSocket, Consumer<RegisteredEvent> {

    private static final Log log = LogFactory.getLog(PendingRequestRSocket.class);

    private final Function<RegisteredEvent, Mono<Route>> routeFinder;

    private final Consumer<Metadata> metadataCallback;

    private final MonoProcessor<RSocket> rSocketProcessor;

    private Disposable subscriptionDisposable;

    private Route route;

    public PendingRequestRSocket(Function<RegisteredEvent, Mono<Route>> routeFinder,
            Consumer<Metadata> metadataCallback) {
        this(routeFinder, metadataCallback, MonoProcessor.create());
    }

    /* for testing */ PendingRequestRSocket(Function<RegisteredEvent, Mono<Route>> routeFinder,
            Consumer<Metadata> metadataCallback, MonoProcessor<RSocket> rSocketProcessor) {
        this.routeFinder = routeFinder;
        this.metadataCallback = metadataCallback;
        this.rSocketProcessor = rSocketProcessor;
    }

    /**
     * Find route (if needed) using pendingExchange. If found, see if the route target
     * matches the registered service. If it matches, send registered RSocket to
     * processor. Then execute normal filter chain. If filter chain is successful, execute
     * request.
     * @param registeredEvent the RegisteredEvent
     */
    @Override
    public void accept(RegisteredEvent registeredEvent) {
        this.routeFinder.apply(registeredEvent).subscribe(route -> {
            this.route = route;
            this.metadataCallback.accept(registeredEvent.getRoutingMetadata());
            this.rSocketProcessor.onNext(registeredEvent.getRSocket());
            this.rSocketProcessor.onComplete();
            if (this.subscriptionDisposable != null) {
                this.subscriptionDisposable.dispose();
            }
        });
    }

    @Override
    public Mono<Void> fireAndForget(Payload payload) {
        return processor("pending-request-faf", payload).flatMap(tuple -> tuple.getT1().fireAndForget(payload));
    }

    @Override
    public Mono<Payload> requestResponse(Payload payload) {
        return processor("pending-request-rr", payload).flatMap(tuple -> tuple.getT1().requestResponse(payload));
    }

    @Override
    public Flux<Payload> requestStream(Payload payload) {
        return processor("pending-request-rs", payload).flatMapMany(tuple -> tuple.getT1().requestStream(payload));
    }

    @Override
    public Flux<Payload> requestChannel(Payload payload, Publisher<Payload> payloads) {
        return processor("pending-request-rc", payload).flatMapMany(tuple -> {
            RSocket rSocket = tuple.getT1();
            if (rSocket instanceof ResponderRSocket) {
                ResponderRSocket socket = (ResponderRSocket) rSocket;
                return socket.requestChannel(payload, payloads);
            }
            return rSocket.requestChannel(payloads);
        });
    }

    /**
     * After processor receives onNext signal, get route from exchange attrs, create a new
     * exchange from payload. Copy exchange attrs. Execute filter chain, if successful,
     * execute request.
     * @param logCategory log category
     * @param payload payload.
     * @return
     */
    protected Mono<Tuple2<RSocket, Success>> processor(String logCategory, Payload payload) {
        return rSocketProcessor.log(PendingRequestRSocket.class.getName() + "." + logCategory, Level.FINEST)
                .flatMap(rSocket -> {
                    GatewayExchange exchange = GatewayExchange.fromPayload(REQUEST_STREAM, payload);
                    exchange.getAttributes().put(ROUTE_ATTR, route);
                    // exchange.getAttributes().putAll(pendingExchange.getAttributes());
                    return Mono.just(rSocket).zipWith(executeFilterChain(route.getFilters(), exchange));
                });

    }

    public void setSubscriptionDisposable(Disposable subscriptionDisposable) {
        this.subscriptionDisposable = subscriptionDisposable;
    }

}