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.service.paxos.v1;
  
  import org.apache.cassandra.config.DatabaseDescriptor;
  import org.apache.cassandra.db.ConsistencyLevel;
  import org.apache.cassandra.db.WriteType;
  import org.apache.cassandra.exceptions.WriteTimeoutException;
  import org.apache.cassandra.net.RequestCallback;
  import org.apache.cassandra.transport.Dispatcher;
  import org.apache.cassandra.utils.concurrent.UncheckedInterruptedException;
  import org.apache.cassandra.utils.Clock;
  import org.apache.cassandra.utils.concurrent.CountDownLatch;
  
  import static java.util.concurrent.TimeUnit.NANOSECONDS;
  import static org.apache.cassandra.utils.concurrent.CountDownLatch.newCountDownLatch;
  
  public abstract class AbstractPaxosCallback<T> implements RequestCallback<T>
  {
      protected final CountDownLatch latch;
      protected final int targets;
      private final ConsistencyLevel consistency;
      private final Dispatcher.RequestTime requestTime;
  
      public AbstractPaxosCallback(int targets, ConsistencyLevel consistency, Dispatcher.RequestTime requestTime)
      {
          this.targets = targets;
          this.consistency = consistency;
          latch = newCountDownLatch(targets);
          this.requestTime = requestTime;
      }
  
      public int getResponseCount()
      {
          return targets - latch.count();
      }
  
      public void await() throws WriteTimeoutException
      {
          try
          {
              long now = Clock.Global.nanoTime();
              long timeout = requestTime.computeTimeout(now, DatabaseDescriptor.getWriteRpcTimeout(NANOSECONDS));
  
              if (!latch.await(timeout, NANOSECONDS))
                  throw new WriteTimeoutException(WriteType.CAS, consistency, getResponseCount(), targets);
          }
          catch (InterruptedException e)
          {
              throw new UncheckedInterruptedException(e);
          }
      }
  }
  