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.ByteString;
022import org.apache.reef.wake.remote.Encoder;
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 * Encoder using the WakeTuple protocol buffer.
030 * (class name and bytes)
031 *
032 * @param <T> type
033 */
034public class MultiEncoder<T> implements Encoder<T> {
035
036  private final Map<Class<? extends T>, Encoder<? extends T>> clazzToEncoderMap;
037
038  /**
039   * Constructs an encoder that encodes an object to bytes based on the class name.
040   *
041   * @param clazzToEncoderMap a map of encoder for class
042   */
043  public MultiEncoder(final Map<Class<? extends T>, Encoder<? extends T>> clazzToEncoderMap) {
044    this.clazzToEncoderMap = clazzToEncoderMap;
045  }
046
047  /**
048   * Encodes an object to a byte array.
049   *
050   * @param obj an object to be encoded
051   */
052  @Override
053  public byte[] encode(final T obj) {
054    final Encoder<T> encoder = (Encoder<T>) clazzToEncoderMap.get(obj.getClass());
055    if (encoder == null) {
056      throw new RemoteRuntimeException("Encoder for " + obj.getClass() + " not known.");
057    }
058
059    final WakeTuplePBuf.Builder tupleBuilder = WakeTuplePBuf.newBuilder();
060    tupleBuilder.setClassName(obj.getClass().getName());
061    tupleBuilder.setData(ByteString.copyFrom(encoder.encode(obj)));
062    return tupleBuilder.build().toByteArray();
063  }
064
065}