Source code

001/*
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *   http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing,
013 * software distributed under the License is distributed on an
014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015 * KIND, either express or implied.  See the License for the
016 * specific language governing permissions and limitations
017 * under the License.
018 */
019package org.apache.reef.driver.restart;
020
021import org.apache.reef.annotations.Unstable;
022import org.apache.reef.annotations.audience.DriverSide;
023import org.apache.reef.annotations.audience.Private;
024import org.apache.reef.util.BuilderUtils;
025
026import java.util.Collections;
027import java.util.HashMap;
028import java.util.Map;
029import java.util.Set;
030
031/**
032 * Represents holds the set of Evaluator information needed to recover EvaluatorManagers
033 * on the restarted Driver.
034 */
035@Private
036@DriverSide
037@Unstable
038public final class RestartEvaluators {
039  private final Map<String, EvaluatorRestartInfo> restartEvaluatorsMap;
040
041  private RestartEvaluators(final Map<String, EvaluatorRestartInfo> restartEvaluatorsMap){
042    this.restartEvaluatorsMap = BuilderUtils.notNull(restartEvaluatorsMap);
043  }
044
045  /**
046   * @return true if Evaluator with evaluatorId can be an Evaluator from
047   * previous application attempts.
048   */
049  boolean contains(final String evaluatorId) {
050    return restartEvaluatorsMap.containsKey(evaluatorId);
051  }
052
053  /**
054   * @return The {@link EvaluatorRestartInfo} of an Evaluator from
055   * previous application attempts.
056   */
057  EvaluatorRestartInfo get(final String evaluatorId) {
058    return restartEvaluatorsMap.get(evaluatorId);
059  }
060
061  /**
062   * @return The set of Evaluator IDs of Evaluators from previous
063   * application attempts.
064   */
065  Set<String> getEvaluatorIds() {
066    return restartEvaluatorsMap.keySet();
067  }
068
069  /**
070   * @return a new Builder to build an instance of {@link RestartEvaluators}.
071   */
072  public static Builder newBuilder() {
073    return new Builder();
074  }
075
076  /**
077   * Builder to build {@link RestartEvaluators}.
078   */
079  public static final class Builder implements org.apache.reef.util.Builder<RestartEvaluators>{
080    private final Map<String, EvaluatorRestartInfo> restartInfoMap = new HashMap<>();
081
082    private Builder(){
083    }
084
085    public boolean addRestartEvaluator(final EvaluatorRestartInfo evaluatorRestartInfo) {
086      if (evaluatorRestartInfo == null) {
087        return false;
088      }
089
090      final String evaluatorId = evaluatorRestartInfo.getResourceRecoverEvent().getIdentifier();
091      if (evaluatorId == null || restartInfoMap.containsKey(evaluatorId)) {
092        return false;
093      }
094
095      restartInfoMap.put(evaluatorId, evaluatorRestartInfo);
096      return true;
097    }
098
099    @Override
100    public RestartEvaluators build() {
101      return new RestartEvaluators(Collections.unmodifiableMap(restartInfoMap));
102    }
103  }
104}