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.raft;
  
  import org.apache.kafka.common.network.ListenerName;
  import org.apache.kafka.common.protocol.ApiKeys;
  
  import java.util.ArrayList;
  import java.util.HashMap;
  import java.util.Iterator;
  import java.util.List;
  import java.util.Map;
  import java.util.Optional;
  import java.util.concurrent.atomic.AtomicInteger;
  
  public class MockNetworkChannel implements NetworkChannel {
      public static final ListenerName LISTENER_NAME = VoterSetTest.DEFAULT_LISTENER_NAME;
  
      private final AtomicInteger correlationIdCounter;
      private final List<RaftRequest.Outbound> sendQueue = new ArrayList<>();
      private final Map<Integer, RaftRequest.Outbound> awaitingResponse = new HashMap<>();
  
      public MockNetworkChannel(AtomicInteger correlationIdCounter) {
          this.correlationIdCounter = correlationIdCounter;
      }
  
      public MockNetworkChannel() {
          this(new AtomicInteger(0));
      }
  
      @Override
      public int newCorrelationId() {
          return correlationIdCounter.getAndIncrement();
      }
  
      @Override
      public void send(RaftRequest.Outbound request) {
          sendQueue.add(request);
      }
  
      @Override
      public ListenerName listenerName() {
          return LISTENER_NAME;
      }
  
      public List<RaftRequest.Outbound> drainSendQueue() {
          return drainSentRequests(Optional.empty());
      }
  
      public List<RaftRequest.Outbound> drainSentRequests(Optional<ApiKeys> apiKeyFilter) {
          List<RaftRequest.Outbound> requests = new ArrayList<>();
          Iterator<RaftRequest.Outbound> iterator = sendQueue.iterator();
          while (iterator.hasNext()) {
              RaftRequest.Outbound request = iterator.next();
              if (apiKeyFilter.isEmpty() || request.data().apiKey() == apiKeyFilter.get().id) {
                  awaitingResponse.put(request.correlationId(), request);
                  requests.add(request);
                  iterator.remove();
              }
          }
          return requests;
      }
  
      public boolean hasSentRequests() {
          return !sendQueue.isEmpty();
      }
  
      public void mockReceive(RaftResponse.Inbound response) {
          RaftRequest.Outbound request = awaitingResponse.get(response.correlationId());
          if (request == null) {
              throw new IllegalStateException("Received response for a request which is not being awaited");
          }
          request.completion.complete(response);
      }
  }
  