giraph-core/src/main/java/org/apache/giraph/comm/requests/SendWorkerAggregatorsRequest.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.giraph.comm.requests;

import java.io.IOException;

import org.apache.giraph.comm.GlobalCommType;
import org.apache.giraph.comm.ServerData;
import org.apache.giraph.comm.aggregators.OwnerAggregatorServerData;
import org.apache.giraph.utils.UnsafeByteArrayInputStream;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.Writable;

/**
 * Request to send partial aggregated values for current superstep (values
 * which were computed by one worker's vertices)
 */
public class SendWorkerAggregatorsRequest extends
    ByteArrayWithSenderTaskIdRequest implements WorkerRequest {

  /**
   * Constructor
   *
   * @param data Serialized aggregator data
   * @param senderTaskId Sender task id
   */
  public SendWorkerAggregatorsRequest(byte[] data, int senderTaskId) {
    super(data, senderTaskId);
  }

  /**
   * Constructor used for reflection only
   */
  public SendWorkerAggregatorsRequest() {
  }

  @Override
  public void doRequest(ServerData serverData) {
    UnsafeByteArrayInputStream input = getUnsafeByteArrayInput();
    OwnerAggregatorServerData aggregatorData =
        serverData.getOwnerAggregatorData();
    try {
      int num = input.readInt();
      for (int i = 0; i < num; i++) {
        String name = input.readUTF();
        GlobalCommType type = GlobalCommType.values()[input.readByte()];
        if (type == GlobalCommType.SPECIAL_COUNT) {
          LongWritable value = new LongWritable();
          value.readFields(input);
          aggregatorData.receivedRequestCountFromWorker(
              value.get(),
              getSenderTaskId());
        } else if (type == GlobalCommType.REDUCED_VALUE) {
          Writable value = aggregatorData.createInitialValue(name);
          value.readFields(input);
          aggregatorData.reduce(name, value);
        } else {
          throw new IllegalStateException(
              "SendWorkerAggregatorsRequest received " + type);
        }
      }
    } catch (IOException e) {
      throw new IllegalStateException("doRequest: " +
          "IOException occurred while processing request", e);
    }
    aggregatorData.receivedRequestFromWorker();
  }

  @Override
  public RequestType getType() {
    return RequestType.SEND_WORKER_AGGREGATORS_REQUEST;
  }
}