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.net;
  
  import java.util.Map;
  
  import org.apache.cassandra.exceptions.RequestFailure;
  import org.apache.cassandra.exceptions.RequestFailureReason;
  import org.apache.cassandra.locator.InetAddressAndPort;
  
  /**
   * implementors of {@link RequestCallback} need to make sure that any public methods
   * are threadsafe with respect to {@link #onResponse} being called from the message
   * service.  In particular, if any shared state is referenced, making
   * response alone synchronized will not suffice.
   */
  public interface RequestCallback<T>
  {
      /**
       * @param msg response received.
       */
      void onResponse(Message<T> msg);
  
      /**
       * Called when there is an exception on the remote node or timeout happens
       */
      default void onFailure(InetAddressAndPort from, RequestFailure failure)
      {
      }
  
      /**
       * Returns true if the callback handles failure reporting - in which case the remove host will be asked to
       * report failures to us in the event of a problem processing the request.
       *
       * TODO: this is an error prone method, and we should be handling failures everywhere
       *       so we should probably just start doing that, and remove this method
       *
       * @return true if the callback should be invoked on failure
       */
      default boolean invokeOnFailure()
      {
          return false;
      }
  
      /**
       * @return true if this callback is on the read path and its latency should be
       * given as input to the dynamic snitch.
       */
      default boolean trackLatencyForSnitch()
      {
          return false;
      }
  
      static boolean isTimeout(Map<InetAddressAndPort, RequestFailureReason> failureReasonByEndpoint)
      {
          // The reason that all must be timeout to be called a timeout is as follows
          // Assume RF=6, QUORUM, and failureReasonByEndpoint.size() == 3
          // R1 -> TIMEOUT
          // R2 -> TIMEOUT
          // R3 -> READ_TOO_MANY_TOMBSTONES
          // Since we got a reply back, and that was a failure, we should return a failure letting the user know.
          // When all failures are a timeout, then this is a race condition with
          // org.apache.cassandra.utils.concurrent.Awaitable.await(long, java.util.concurrent.TimeUnit)
          // The race is that the message expire path runs and expires all messages, this then casues the condition
          // to signal telling the caller "got all replies!".
          return failureReasonByEndpoint.values().stream().allMatch(RequestFailureReason.TIMEOUT::equals);
      }
  
  }
  