org.apache.beam.runners.fnexecution.GrpcFnServer.java Source code

Introduction

Here is the source code for org.apache.beam.runners.fnexecution.GrpcFnServer.java

Source

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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
 *
 *     http://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.apache.beam.runners.fnexecution;

import com.google.common.collect.ImmutableList;
import java.io.IOException;
import java.util.concurrent.TimeUnit;
import org.apache.beam.model.pipeline.v1.Endpoints.ApiServiceDescriptor;
import org.apache.beam.vendor.grpc.v1p13p1.io.grpc.Server;

/**
 * A {@link Server gRPC Server} which manages a single {@link FnService}. The lifetime of the
 * service is bound to the {@link GrpcFnServer}.
 */
public class GrpcFnServer<ServiceT extends FnService> implements AutoCloseable {
    /**
     * Create a {@link GrpcFnServer} for the provided {@link FnService} running on an arbitrary port.
     */
    public static <ServiceT extends FnService> GrpcFnServer<ServiceT> allocatePortAndCreateFor(ServiceT service,
            ServerFactory factory) throws IOException {
        ApiServiceDescriptor.Builder apiServiceDescriptor = ApiServiceDescriptor.newBuilder();
        Server server = factory.allocateAddressAndCreate(ImmutableList.of(service), apiServiceDescriptor);
        return new GrpcFnServer<>(server, service, apiServiceDescriptor.build());
    }

    /**
     * Create a {@link GrpcFnServer} for the provided {@link FnService} which will run at the endpoint
     * specified in the {@link ApiServiceDescriptor}.
     */
    public static <ServiceT extends FnService> GrpcFnServer<ServiceT> create(ServiceT service,
            ApiServiceDescriptor endpoint, ServerFactory factory) throws IOException {
        return new GrpcFnServer<>(factory.create(ImmutableList.of(service), endpoint), service, endpoint);
    }

    /** @deprecated This create function is used for Dataflow migration purpose only. */
    @Deprecated
    public static <ServiceT extends FnService> GrpcFnServer<ServiceT> create(ServiceT service,
            ApiServiceDescriptor endpoint) {
        return new GrpcFnServer(null, service, endpoint) {
            @Override
            public void close() throws Exception {
            }
        };
    }

    private final Server server;
    private final ServiceT service;
    private final ApiServiceDescriptor apiServiceDescriptor;

    private GrpcFnServer(Server server, ServiceT service, ApiServiceDescriptor apiServiceDescriptor) {
        this.server = server;
        this.service = service;
        this.apiServiceDescriptor = apiServiceDescriptor;
    }

    /**
     * Get an {@link ApiServiceDescriptor} describing the endpoint this {@link GrpcFnServer} is bound
     * to.
     */
    public ApiServiceDescriptor getApiServiceDescriptor() {
        return apiServiceDescriptor;
    }

    /** Get the service exposed by this {@link GrpcFnServer}. */
    public ServiceT getService() {
        return service;
    }

    /** Get the underlying {@link Server} contained by this {@link GrpcFnServer}. */
    public Server getServer() {
        return server;
    }

    @Override
    public void close() throws Exception {
        try {
            // The server has been closed, and should not respond to any new incoming calls.
            server.shutdown();
            service.close();
            server.awaitTermination(60, TimeUnit.SECONDS);
        } finally {
            server.shutdownNow();
            server.awaitTermination();
        }
    }
}