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.wake.remote.impl;
020
021import com.google.protobuf.InvalidProtocolBufferException;
022import org.apache.reef.wake.remote.Decoder;
023import org.apache.reef.wake.remote.exception.RemoteRuntimeException;
024import org.apache.reef.wake.remote.proto.WakeRemoteProtos.WakeTuplePBuf;
025
026import java.util.Map;
027
028/**
029 * Decoder using the WakeTuple protocol buffer.
030 * (class name and bytes)
031 *
032 * @param <T> type
033 */
034public class MultiDecoder<T> implements Decoder<T> {
035  private final Map<Class<? extends T>, Decoder<? extends T>> clazzToDecoderMap;
036
037  /**
038   * Constructs a decoder that decodes bytes based on the class name.
039   *
040   * @param clazzToDecoderMap a map of decoder for class
041   */
042  public MultiDecoder(final Map<Class<? extends T>, Decoder<? extends T>> clazzToDecoderMap) {
043    this.clazzToDecoderMap = clazzToDecoderMap;
044  }
045
046  /**
047   * Decodes byte array.
048   *
049   * @param data class name and byte payload
050   */
051  @Override
052  public T decode(final byte[] data) {
053    final WakeTuplePBuf tuple;
054    try {
055      tuple = WakeTuplePBuf.parseFrom(data);
056    } catch (final InvalidProtocolBufferException e) {
057      e.printStackTrace();
058      throw new RemoteRuntimeException(e);
059    }
060
061    final String className = tuple.getClassName();
062    final byte[] message = tuple.getData().toByteArray();
063    final Class<?> clazz;
064    try {
065      clazz = Class.forName(className);
066    } catch (final ClassNotFoundException e) {
067      e.printStackTrace();
068      throw new RemoteRuntimeException(e);
069    }
070    return clazzToDecoderMap.get(clazz).decode(message);
071  }
072}