lang/java/reef-wake/wake/src/main/java/org/apache/reef/wake/remote/impl/RemoteEventDecoder.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.reef.wake.remote.impl;

import com.google.protobuf.InvalidProtocolBufferException;
import org.apache.reef.wake.remote.Decoder;
import org.apache.reef.wake.remote.exception.RemoteRuntimeException;
import org.apache.reef.wake.remote.proto.WakeRemoteProtos.WakeMessagePBuf;

/**
 * Remote event decoder using the WakeMessage protocol buffer.
 *
 * @param <T> type
 */
public class RemoteEventDecoder<T> implements Decoder<RemoteEvent<T>> {

  private final Decoder<T> decoder;

  /**
   * Constructs a remote event decoder.
   *
   * @param decoder the decoder of the event
   */
  public RemoteEventDecoder(final Decoder<T> decoder) {
    this.decoder = decoder;
  }

  /**
   * Decodes a remote event from the byte array data.
   *
   * @param data the byte array data
   * @return a remote event object
   * @throws RemoteRuntimeException
   */
  @Override
  public RemoteEvent<T> decode(final byte[] data) {
    final WakeMessagePBuf pbuf;
    try {
      pbuf = WakeMessagePBuf.parseFrom(data);
      return new RemoteEvent<T>(null, null, pbuf.getSeq(), decoder.decode(pbuf.getData().toByteArray()));
    } catch (final InvalidProtocolBufferException e) {
      throw new RemoteRuntimeException(e);
    }
  }

  @Override
  public String toString() {
    return String.format("RemoteEventDecoder: { decoder: %s }", this.decoder);
  }
}