content: /*
   * 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.cassandra.streaming;
  
  import java.io.IOException;
  import java.net.InetSocketAddress;
  import java.util.function.IntFunction;
  
  import io.netty.util.concurrent.Future; //checkstyle: permit this import
  import org.apache.cassandra.streaming.async.NettyStreamingConnectionFactory;
  import org.apache.cassandra.utils.Shared;
  
  import static org.apache.cassandra.utils.Shared.Recursive.INTERFACES;
  import static org.apache.cassandra.utils.Shared.Scope.SIMULATION;
  
  @Shared(scope = SIMULATION, inner = INTERFACES)
  public interface StreamingChannel
  {
      public interface Factory
      {
          public static class Global
          {
              private static StreamingChannel.Factory FACTORY = new NettyStreamingConnectionFactory();
              public static StreamingChannel.Factory streamingFactory()
              {
                  return FACTORY;
              }
  
              public static void unsafeSet(StreamingChannel.Factory factory)
              {
                  FACTORY = factory;
              }
          }
  
          StreamingChannel create(InetSocketAddress to, int messagingVersion, Kind kind) throws IOException;
  
          default StreamingChannel create(InetSocketAddress to,
                                          InetSocketAddress preferred,
                                          int messagingVersion,
                                          StreamingChannel.Kind kind) throws IOException
          {
              // Implementations can decide whether or not to do something with the preferred address.
              return create(to, messagingVersion, kind);
          }
  
          /** Provide way to disable getPreferredIP() for tools without access to the system keyspace
           *
           * CASSANDRA-17663 moves calls to SystemKeyspace.getPreferredIP() outside of any threads
           * that are regularly interrupted.  However the streaming subsystem is also used
           * by the bulk loader tool, which does not have direct access to the local tables
           * and uses the client metadata/queries to retrieve it.
           *
           * @return true if SystemKeyspace.getPreferredIP() should be used when connecting
           */
          default boolean supportsPreferredIp()
          {
              return true;
          }
      }
  
      public enum Kind { CONTROL, FILE }
  
      public interface Send
      {
          void send(IntFunction<StreamingDataOutputPlus> outSupplier) throws IOException;
      }
  
      Object id();
      String description();
  
      InetSocketAddress peer();
      InetSocketAddress connectedTo();
      boolean connected();
  
      StreamingDataInputPlus in();
  
      /**
       * until closed, cannot invoke {@link #send(Send)}
       */
      StreamingDataOutputPlus acquireOut();
      Future<?> send(Send send) throws IOException;
  
      Future<?> close();
      void onClose(Runnable runOnClose);
  }
  