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 java.util.ArrayDeque;
  import java.util.OptionalLong;
  import java.util.Queue;
  import java.util.concurrent.atomic.AtomicBoolean;
  import java.util.concurrent.atomic.AtomicLong;
  
  /**
   * Mocked implementation which does not block in {@link #poll(long)}..
   */
  public class MockMessageQueue implements RaftMessageQueue {
      private final Queue<RaftMessage> messages = new ArrayDeque<>();
      private final AtomicBoolean wakeupRequested = new AtomicBoolean(false);
      private final AtomicLong lastPollTimeout = new AtomicLong(-1);
  
      @Override
      public RaftMessage poll(long timeoutMs) {
          wakeupRequested.set(false);
          lastPollTimeout.set(timeoutMs);
          return messages.poll();
      }
  
      @Override
      public void add(RaftMessage message) {
          messages.offer(message);
      }
  
      public OptionalLong lastPollTimeoutMs() {
          long lastTimeoutMs = lastPollTimeout.get();
          if (lastTimeoutMs < 0) {
              return OptionalLong.empty();
          } else {
              return OptionalLong.of(lastTimeoutMs);
          }
      }
  
      public boolean wakeupRequested() {
          return wakeupRequested.get();
      }
  
      @Override
      public boolean isEmpty() {
          return messages.isEmpty();
      }
  
      @Override
      public void wakeup() {
          wakeupRequested.set(true);
      }
  }
  