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;
  
  import java.util.AbstractMap;
  import java.util.AbstractSet;
  import java.util.Iterator;
  import java.util.Map;
  import java.util.Set;
  import java.util.concurrent.atomic.AtomicReferenceFieldUpdater;
  
  import org.apache.cassandra.exceptions.RequestFailure;
  import org.apache.cassandra.exceptions.RequestFailureReason;
  import org.apache.cassandra.locator.InetAddressAndPort;
  import org.apache.cassandra.net.RequestCallbackWithFailure;
  import org.apache.cassandra.utils.concurrent.IntrusiveStack;
  
  import static org.apache.cassandra.exceptions.RequestFailureReason.TIMEOUT;
  
  public abstract class FailureRecordingCallback<T> implements RequestCallbackWithFailure<T>
  {
      public static class FailureResponses extends IntrusiveStack<FailureResponses> implements Map.Entry<InetAddressAndPort, RequestFailureReason>
      {
          final InetAddressAndPort from;
          final RequestFailureReason reason;
  
          public FailureResponses(InetAddressAndPort from, RequestFailureReason reason)
          {
              this.from = from;
              this.reason = reason;
          }
  
          @Override
          public InetAddressAndPort getKey()
          {
              return from;
          }
  
          @Override
          public RequestFailureReason getValue()
          {
              return reason;
          }
  
          @Override
          public RequestFailureReason setValue(RequestFailureReason value)
          {
              throw new UnsupportedOperationException();
          }
  
          public static <O> void push(AtomicReferenceFieldUpdater<O, FailureResponses> headUpdater, O owner, InetAddressAndPort from, RequestFailureReason reason)
          {
              getAndPush(headUpdater, owner, new FailureResponses(from, reason));
          }
  
          public static <O> void pushExclusive(AtomicReferenceFieldUpdater<O, FailureResponses> headUpdater, O owner, InetAddressAndPort from, RequestFailureReason reason)
          {
              pushExclusive(headUpdater, owner, new FailureResponses(from, reason));
          }
  
          public static FailureResponses pushExclusive(FailureResponses head, InetAddressAndPort from, RequestFailureReason reason)
          {
              return IntrusiveStack.pushExclusive(head, new FailureResponses(from, reason));
          }
  
          public static int size(FailureResponses head)
          {
              return IntrusiveStack.size(head);
          }
  
          public static Iterator<FailureResponses> iterator(FailureResponses head)
          {
              return IntrusiveStack.iterator(head);
          }
  
          public static int failureCount(FailureResponses head)
          {
              return (int)IntrusiveStack.accumulate(head, (f, v) -> f.reason == TIMEOUT ? v : v + 1, 0);
          }
      }
  
      public static class AsMap extends AbstractMap<InetAddressAndPort, RequestFailureReason>
      {
          final FailureResponses head;
          int size = -1;
  
          AsMap(FailureResponses head)
          {
              this.head = head;
          }
  
          @Override
          public Set<Map.Entry<InetAddressAndPort, RequestFailureReason>> entrySet()
          {
              return new AbstractSet<Map.Entry<InetAddressAndPort, RequestFailureReason>>()
              {
                  @Override
                  public Iterator<Map.Entry<InetAddressAndPort, RequestFailureReason>> iterator()
                  {
                      return (Iterator<Map.Entry<InetAddressAndPort, RequestFailureReason>>)
                              (Iterator<?>) FailureResponses.iterator(head);
                  }
  
                  @Override
                  public int size()
                  {
                      if (size < 0)
                          size = FailureResponses.size(head);
                      return size;
                  }
              };
          }
  
          public int failureCount()
          {
              return FailureResponses.failureCount(head);
          }
      }
  
      private volatile FailureResponses failureResponses;
      private static final AtomicReferenceFieldUpdater<FailureRecordingCallback, FailureResponses> responsesUpdater = AtomicReferenceFieldUpdater.newUpdater(FailureRecordingCallback.class, FailureResponses.class, "failureResponses");
  
      @Override
      public void onFailure(InetAddressAndPort from, RequestFailure failure)
      {
          FailureResponses.push(responsesUpdater, this, from, failure.reason);
      }
  
      protected void onFailureWithMutex(InetAddressAndPort from, RequestFailureReason failureReason)
      {
          FailureResponses.pushExclusive(responsesUpdater, this, from, failureReason);
      }
  
      protected AsMap failureReasonsAsMap()
      {
          return new AsMap(failureResponses);
      }
  }
  