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.errors.TimeoutException;
  import org.apache.kafka.common.utils.MockTime;
  
  import java.util.PriorityQueue;
  import java.util.concurrent.CompletableFuture;
  import java.util.concurrent.atomic.AtomicLong;
  
  public final class MockExpirationService implements ExpirationService, MockTime.Listener {
      private final AtomicLong idGenerator = new AtomicLong(0);
      private final MockTime time;
      private final PriorityQueue<ExpirationFuture<?>> queue = new PriorityQueue<>();
  
      public MockExpirationService(MockTime time) {
          this.time = time;
          time.addListener(this);
      }
  
      @Override
      public <T> CompletableFuture<T> failAfter(long timeoutMs) {
          long deadlineMs = time.milliseconds() + timeoutMs;
          long id = idGenerator.incrementAndGet();
          ExpirationFuture<T> future = new ExpirationFuture<>(id, deadlineMs);
          queue.add(future);
          return future;
      }
  
      @Override
      public void onTimeUpdated() {
          long currentTimeMs = time.milliseconds();
          while (true) {
              ExpirationFuture<?> future = queue.peek();
              if (future == null || future.deadlineMs > currentTimeMs) {
                  break;
              }
              ExpirationFuture<?> polled = queue.poll();
              polled.completeExceptionally(new TimeoutException());
          }
      }
  
      private static class ExpirationFuture<T> extends CompletableFuture<T> implements Comparable<ExpirationFuture<?>> {
          private final long id;
          private final long deadlineMs;
  
          private ExpirationFuture(long id, long deadlineMs) {
              this.id = id;
              this.deadlineMs = deadlineMs;
          }
  
          @Override
          public int compareTo(ExpirationFuture<?> o) {
              int res = Long.compare(this.deadlineMs, o.deadlineMs);
              if (res != 0) {
                  return res;
              } else {
                  return Long.compare(this.id, o.id);
              }
          }
      }
  
  }
  