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.auth;
  
  import java.util.Set;
  import java.util.concurrent.CopyOnWriteArraySet;
  
  import com.google.common.annotations.VisibleForTesting;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import org.apache.cassandra.cql3.QueryEvents;
  import org.apache.cassandra.service.QueryState;
  
  public class AuthEvents
  {
      private static final Logger logger = LoggerFactory.getLogger(QueryEvents.class);
  
      public static final AuthEvents instance = new AuthEvents();
  
      private final Set<Listener> listeners = new CopyOnWriteArraySet<>();
  
      @VisibleForTesting
      public int listenerCount()
      {
          return listeners.size();
      }
  
      public void registerListener(Listener listener)
      {
          listeners.add(listener);
      }
  
      public void unregisterListener(Listener listener)
      {
          listeners.remove(listener);
      }
  
      public void notifyAuthSuccess(QueryState state)
      {
          try
          {
              for (Listener listener : listeners)
                  listener.authSuccess(state);
          }
          catch (Exception e)
          {
              logger.error("Failed notifying listeners", e);
          }
      }
  
      public void notifyAuthFailure(QueryState state, Exception cause)
      {
          try
          {
              for (Listener listener : listeners)
                  listener.authFailure(state, cause);
          }
          catch (Exception e)
          {
              logger.error("Failed notifying listeners", e);
          }
      }
  
      public static interface Listener
      {
          void authSuccess(QueryState state);
          void authFailure(QueryState state, Exception cause);
      }
  }
  