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.ambari.server.events.publishers;
  
  import java.util.ArrayList;
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  
  import org.apache.ambari.server.EagerSingleton;
  import org.apache.ambari.server.controller.utilities.ServiceCalculatedStateFactory;
  import org.apache.ambari.server.controller.utilities.state.ServiceCalculatedState;
  import org.apache.ambari.server.events.STOMPEvent;
  import org.apache.ambari.server.events.ServiceUpdateEvent;
  import org.apache.ambari.server.state.State;
  
  import com.google.common.eventbus.EventBus;
  import com.google.inject.Inject;
  
  @EagerSingleton
  public class ServiceUpdateEventPublisher extends BufferedUpdateEventPublisher<ServiceUpdateEvent> {
    private Map<String, Map<String, State>> states = new HashMap<>();
  
    @Inject
    public ServiceUpdateEventPublisher(STOMPUpdatePublisher stompUpdatePublisher) {
      super(stompUpdatePublisher);
    }
  
  
    @Override
    public STOMPEvent.Type getType() {
      return STOMPEvent.Type.SERVICE;
    }
  
    @Override
    public void mergeBufferAndPost(List<ServiceUpdateEvent> events, EventBus eventBus) {
      List<ServiceUpdateEvent> filtered = new ArrayList<>();
      for (ServiceUpdateEvent event : events) {
        int pos = filtered.indexOf(event);
        if (pos != -1) {
          if (event.isStateChanged()) {
            filtered.get(pos).setStateChanged(true);
          }
          if (event.getMaintenanceState() != null) {
            filtered.get(pos).setMaintenanceState(event.getMaintenanceState());
          }
        } else {
          filtered.add(event);
        }
      }
      for (ServiceUpdateEvent serviceUpdateEvent : filtered) {
        // calc state
        if (serviceUpdateEvent.isStateChanged()) {
          ServiceCalculatedState serviceCalculatedState =
              ServiceCalculatedStateFactory.getServiceStateProvider(serviceUpdateEvent.getServiceName());
          State serviceState =
              serviceCalculatedState.getState(serviceUpdateEvent.getClusterName(), serviceUpdateEvent.getServiceName());
  
          String serviceName = serviceUpdateEvent.getServiceName();
          String clusterName = serviceUpdateEvent.getClusterName();
  
          // retrieve state from cache
          // don't send update when state was not changed and update doesn't have maintenance info
          if (states.containsKey(clusterName) && states.get(clusterName).containsKey(serviceName)
              && states.get(clusterName).get(serviceName).equals(serviceState)
              && serviceUpdateEvent.getMaintenanceState() == null) {
            continue;
          }
          states.computeIfAbsent(clusterName, c -> new HashMap<>()).put(serviceName, serviceState);
          serviceUpdateEvent.setState(serviceState);
        }
  
        eventBus.post(serviceUpdateEvent);
      }
    }
  }
  