slider-core/src/main/java/org/apache/slider/server/appmaster/web/rest/application/resources/LiveContainersRefresher.java

/*
 * 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.slider.server.appmaster.web.rest.application.resources;

import org.apache.slider.api.types.SerializedContainerInformation;
import org.apache.slider.server.appmaster.state.RoleInstance;
import org.apache.slider.server.appmaster.state.StateAccessForProviders;

import java.util.HashMap;
import java.util.List;
import java.util.Map;

/**
 * Refresh the container list.
 */
public class LiveContainersRefresher implements ResourceRefresher<Map<String, SerializedContainerInformation>> {

  private final StateAccessForProviders state;

  public LiveContainersRefresher(StateAccessForProviders state) {
    this.state = state;
  }

  @Override
  public Map<String, SerializedContainerInformation> refresh() {
    List<RoleInstance> containerList = state.cloneOwnedContainerList();

    Map<String, SerializedContainerInformation> map = new HashMap<String, SerializedContainerInformation>();
    for (RoleInstance instance : containerList) {
      SerializedContainerInformation serialized = instance.serialize();
      map.put(serialized.containerId, serialized);
    }
    return map;
  }
}