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.kafka.common.network;
  
  
  import org.apache.kafka.common.memory.MemoryPool;
  
  import java.io.IOException;
  import java.net.InetSocketAddress;
  import java.util.Collection;
  import java.util.List;
  import java.util.Map;
  
  /**
   * An interface for asynchronous, multi-channel network I/O
   */
  public interface Selectable {
  
      /**
       * See {@link #connect(String, InetSocketAddress, int, int) connect()}
       */
      int USE_DEFAULT_BUFFER_SIZE = -1;
  
      /**
       * Begin establishing a socket connection to the given address identified by the given address
       * @param id The id for this connection
       * @param address The address to connect to
       * @param sendBufferSize The send buffer for the socket
       * @param receiveBufferSize The receive buffer for the socket
       * @throws IOException If we cannot begin connecting
       */
      void connect(String id, InetSocketAddress address, int sendBufferSize, int receiveBufferSize) throws IOException;
  
      /**
       * Wakeup this selector if it is blocked on I/O
       */
      void wakeup();
  
      /**
       * Close this selector
       */
      void close();
  
      /**
       * Close the connection identified by the given id
       */
      void close(String id);
  
      /**
       * Queue the given request for sending in the subsequent {@link #poll(long) poll()} calls
       * @param send The request to send
       */
      void send(NetworkSend send);
  
      /**
       * Do I/O. Reads, writes, connection establishment, etc.
       * @param timeout The amount of time to block if there is nothing to do
       * @throws IOException
       */
      void poll(long timeout) throws IOException;
  
      /**
       * The list of sends that completed on the last {@link #poll(long) poll()} call.
       */
      List<NetworkSend> completedSends();
  
      /**
       * The collection of receives that completed on the last {@link #poll(long) poll()} call.
       *
       * Note that the caller of this method assumes responsibility to close the NetworkReceive resources which may be
       * backed by a {@link MemoryPool}. In such scenarios (when NetworkReceive uses a {@link MemoryPool}), it is necessary
       * to close the {@link NetworkReceive} to prevent any memory leaks.
       */
      Collection<NetworkReceive> completedReceives();
  
      /**
       * The connections that finished disconnecting on the last {@link #poll(long) poll()}
       * call. Channel state indicates the local channel state at the time of disconnection.
       */
      Map<String, ChannelState> disconnected();
  
      /**
       * The list of connections that completed their connection on the last {@link #poll(long) poll()}
       * call.
       */
      List<String> connected();
  
      /**
       * Disable reads from the given connection
       * @param id The id for the connection
       */
      void mute(String id);
  
      /**
       * Re-enable reads from the given connection
       * @param id The id for the connection
       */
      void unmute(String id);
  
      /**
       * Disable reads from all connections
       */
      void muteAll();
  
      /**
       * Re-enable reads from all connections
       */
      void unmuteAll();
  
      /**
       * returns true  if a channel is ready
       * @param id The id for the connection
       */
      boolean isChannelReady(String id);
  }
  