content: /*
   * Tencent is pleased to support the open source community by making Angel available.
   *
   * Copyright (C) 2017-2018 THL A29 Limited, a Tencent company. All rights reserved.
   *
   * 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://opensource.org/licenses/Apache-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 com.tencent.angel.ipc;
  
  import com.tencent.angel.master.MasterProtocol;
  import com.tencent.angel.ps.server.control.PSProtocol;
  import com.tencent.angel.worker.WorkerProtocol;
  
  import java.util.List;
  
  import org.apache.hadoop.conf.Configuration;
  
  import java.io.Closeable;
  import java.io.IOException;
  
  /**
   * {@link com.tencent.angel.ipc.TConnectionManager} manages instances of this class.
   * <p>
   * <p>
   * TConnection instances can be shared. Sharing is usually what you want because rather than each
   * TConnection instance having to do its own cache of partition locations. Sharing makes cleanup of
   * TConnections awkward. See {@link TConnectionManager} for cleanup discussion.
   *
   * @see com.tencent.angel.ipc.TConnectionManager
   */
  public interface TConnection extends Closeable {
  
    /**
     * @return Configuration instance being used by this TConnection instance.
     */
    public Configuration getConfiguration();
  
    /**
     * @return true if this connection is closed
     */
    public boolean isClosed();
  
    /**
     * Get ps rpc client with sync mode.
     *
     * @param hostname ps host name
     * @param port     ps listening port
     * @return ps rpc client
     * @throws IOException
     */
    public PSProtocol getPSService(String hostname, int port) throws IOException;
  
    /**
     * Get ps rpc client with async mode.
     *
     * @param hostname ps host name
     * @param port     ps listening port
     * @return ps rpc client
     * @throws IOException
     */
    public PSProtocol.AsyncProtocol getAsyncPSService(String hostname, int port) throws IOException;
  
    /**
     * Get worker rpc client with sync mode.
     *
     * @param hostname worker host name
     * @param port     worker listening port
     * @return worker rpc client
     * @throws IOException
     */
    public WorkerProtocol getWorkerService(String hostname, int port) throws IOException;
  
    /**
     * Get master rpc client with sync mode.
     *
     * @param hostname master host name
     * @param port     master listening port
     * @return master rpc client
     * @throws IOException
     */
    public MasterProtocol getMasterService(String hostname, int port) throws IOException;
  
  
    VersionedProtocol getProtocol(final String hostname, final int port,
      final Class<? extends VersionedProtocol> protocolClass, final long version,
      List<String> addrList4Failover) throws IOException;
  }
  