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.examples.group.bgd.utils;
020
021import org.apache.reef.driver.task.TaskConfiguration;
022import org.apache.reef.driver.task.TaskConfigurationOptions;
023import org.apache.reef.examples.group.bgd.MasterTask;
024import org.apache.reef.tang.Configuration;
025import org.apache.reef.tang.Injector;
026import org.apache.reef.tang.JavaConfigurationBuilder;
027import org.apache.reef.tang.Tang;
028import org.apache.reef.tang.annotations.Name;
029import org.apache.reef.tang.exceptions.InjectionException;
030import org.apache.reef.tang.formats.AvroConfigurationSerializer;
031import org.apache.reef.tang.formats.ConfigurationSerializer;
032
033import java.util.logging.Level;
034import java.util.logging.Logger;
035
036/**
037 * Subconfiguration: limit given configuration to a given list of classes.
038 */
039public final class SubConfiguration {
040
041  private static final Logger LOG = Logger.getLogger(SubConfiguration.class.getName());
042
043  @SafeVarargs
044  public static Configuration from(
045      final Configuration baseConf, final Class<? extends Name<?>>... classes) {
046
047    final Injector injector = Tang.Factory.getTang().newInjector(baseConf);
048    final JavaConfigurationBuilder confBuilder = Tang.Factory.getTang().newConfigurationBuilder();
049
050    for (final Class<? extends Name<?>> clazz : classes) {
051      try {
052        confBuilder.bindNamedParameter(clazz,
053            injector.getNamedInstance((Class<? extends Name<Object>>) clazz).toString());
054      } catch (final InjectionException ex) {
055        final String msg = "Exception while creating subconfiguration";
056        LOG.log(Level.WARNING, msg, ex);
057        throw new RuntimeException(msg, ex);
058      }
059    }
060
061    return confBuilder.build();
062  }
063
064  public static void main(final String[] args) throws InjectionException {
065
066    final Configuration conf = TaskConfiguration.CONF
067        .set(TaskConfiguration.IDENTIFIER, "TASK")
068        .set(TaskConfiguration.TASK, MasterTask.class)
069        .build();
070
071    final ConfigurationSerializer confSerizalizer = new AvroConfigurationSerializer();
072    final Configuration subConf = SubConfiguration.from(conf, TaskConfigurationOptions.Identifier.class);
073    LOG.log(Level.INFO, "OUT: Base conf:\n{0}", confSerizalizer.toString(conf));
074    LOG.log(Level.INFO, "OUT: Sub conf:\n{0}", confSerizalizer.toString(subConf));
075  }
076
077  /**
078   * Empty private constructor to prohibit instantiation of utility class.
079   */
080  private SubConfiguration() {
081  }
082}