content: /*
   * The Alluxio Open Foundation licenses this work under the Apache License, version 2.0
   * (the "License"). You may not use this work except in compliance with the License, which is
   * available at www.apache.org/licenses/LICENSE-2.0
   *
   * This software is distributed on an "AS IS" basis, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
   * either express or implied, as more fully set forth in the License.
   *
   * See the NOTICE file distributed with this work for information regarding copyright ownership.
   */
  
  package alluxio.master.transport;
  
  import alluxio.conf.AlluxioConfiguration;
  import alluxio.security.user.UserState;
  import alluxio.util.ThreadFactoryUtils;
  
  import com.google.common.base.Preconditions;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import java.util.LinkedList;
  import java.util.List;
  import java.util.concurrent.CompletableFuture;
  import java.util.concurrent.ExecutorService;
  import java.util.concurrent.Executors;
  
  /**
   * Transport implementation based on Alluxio gRPC messaging.
   */
  public class GrpcMessagingTransport {
    private static final Logger LOG = LoggerFactory.getLogger(GrpcMessagingTransport.class);
  
    /** Alluxio configuration for clients. */
    private final AlluxioConfiguration mClientConf;
    /** Alluxio configuration for servers. */
    private final AlluxioConfiguration mServerConf;
    /** User for clients. */
    private final UserState mClientUser;
    /** User for servers. */
    private final UserState mServerUser;
    /** Used to distinguish between multiple users of the transport. */
    private final String mClientType;
  
    /** List of created clients. */
    private final List<GrpcMessagingClient> mClients;
    /** List of created servers. */
    private final List<GrpcMessagingServer> mServers;
  
    /** External proxy configuration for servers. */
    private GrpcMessagingProxy mServerProxy = new GrpcMessagingProxy();
  
    /** Executor that is used by clients/servers for building connections. */
    private final ExecutorService mExecutor;
  
    /** Whether the transport is closed. */
    private boolean mClosed;
  
    /**
     * Creates {@link GrpcMessagingTransport} based on Alluxio gRPC messaging.
     *
     * @param conf Alluxio configuration
     * @param user Alluxio user
     * @param clientType Transport client type
     */
    public GrpcMessagingTransport(AlluxioConfiguration conf, UserState user, String clientType) {
      this(conf, conf, user, user, clientType);
    }
  
    /**
     * Creates {@link GrpcMessagingTransport} based on Alluxio gRPC messaging.
     *
     * @param clientConf Alluxio configuration for clients
     * @param serverConf Alluxio configuration for servers
     * @param clientUser User for clients
     * @param serverUser User for servers
     * @param clientType Transport client type
     */
    public GrpcMessagingTransport(AlluxioConfiguration clientConf, AlluxioConfiguration serverConf,
        UserState clientUser, UserState serverUser, String clientType) {
      mClientConf = clientConf;
      mServerConf = serverConf;
      mClientUser = clientUser;
      mServerUser = serverUser;
      mClientType = clientType;
  
      mClients = new LinkedList<>();
      mServers = new LinkedList<>();
      mExecutor = Executors
          .newCachedThreadPool(ThreadFactoryUtils.build("grpc-messaging-transport-worker-%d", true));
    }
  
    /**
     * Sets external proxy configuration for servers.
     *
     * @param proxy external proxy configuration
     * @return the updated transport instance
     */
    public synchronized GrpcMessagingTransport withServerProxy(GrpcMessagingProxy proxy) {
      Preconditions.checkNotNull(proxy, "Server proxy reference cannot be null.");
      mServerProxy = proxy;
      return this;
    }
  
    /**
     * Creates a new Grpc messaging client.
     *
     * @return the created client
     */
    public synchronized GrpcMessagingClient client() {
      if (mClosed) {
        throw new RuntimeException("Messaging transport closed");
      }
      GrpcMessagingClient client =
          new GrpcMessagingClient(mClientConf, mClientUser, mExecutor);
      mClients.add(client);
      return client;
    }
  
    /**
     * Creates a new Grpc messaging server.
     *
     * @return the created server
     */
    public synchronized GrpcMessagingServer server() {
      if (mClosed) {
        throw new RuntimeException("Messaging transport closed");
      }
      GrpcMessagingServer server =
          new GrpcMessagingServer(mServerConf, mServerUser, mExecutor, mServerProxy);
      mServers.add(server);
      return server;
    }
  
    /**
     * Closes the opened clients and servers.
     */
    public synchronized void close() {
      if (!mClosed) {
        mClosed = true;
  
        // Close created clients.
        int index = 0;
        CompletableFuture<Void>[] clientCloseFutures = new CompletableFuture[mClients.size()];
        for (GrpcMessagingClient client : mClients) {
          clientCloseFutures[index] = client.close();
          index++;
        }
        mClients.clear();
        try {
          CompletableFuture.allOf(clientCloseFutures).get();
        } catch (Exception e) {
          LOG.warn("Failed to close messaging transport clients.", e);
        }
  
        // Close created servers.
        index = 0;
        CompletableFuture<Void>[] serverCloseFutures = new CompletableFuture[mServers.size()];
        for (GrpcMessagingServer server : mServers) {
          serverCloseFutures[index] = server.close();
          index++;
        }
        mServers.clear();
        try {
          CompletableFuture.allOf(serverCloseFutures).get();
        } catch (Exception e) {
          LOG.warn("Failed to close messaging transport servers.", e);
        }
  
        // Shut down transport executor.
        mExecutor.shutdownNow();
      }
    }
  }
  