lang/java/mapred/src/main/java/org/apache/avro/mapred/tether/TetherKeySerialization.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.avro.mapred.tether;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

import org.apache.hadoop.io.serializer.Serialization;
import org.apache.hadoop.io.serializer.Deserializer;
import org.apache.hadoop.io.serializer.Serializer;
import org.apache.hadoop.conf.Configured;

import org.apache.avro.io.BinaryEncoder;
import org.apache.avro.io.BinaryDecoder;
import org.apache.avro.io.DecoderFactory;
import org.apache.avro.io.EncoderFactory;

/** A {@link Serialization} for {@link TetherData}. */
class TetherKeySerialization
  extends Configured implements Serialization<TetherData> {

  public boolean accept(Class<?> c) {
    return TetherData.class.isAssignableFrom(c);
  }

  public Deserializer<TetherData> getDeserializer(Class<TetherData> c) {
    return new TetherDataDeserializer();
  }

  private static final DecoderFactory FACTORY = DecoderFactory.get();

  private class TetherDataDeserializer implements Deserializer<TetherData> {
    private BinaryDecoder decoder;

    public void open(InputStream in) {
      this.decoder = FACTORY.directBinaryDecoder(in, decoder);
    }

    public TetherData deserialize(TetherData datum) throws IOException {
      if (datum == null) datum = new TetherData();
      datum.buffer(decoder.readBytes(datum.buffer()));
      return datum;
    }

    public void close() throws IOException {
      decoder.inputStream().close();
    }
  }

  public Serializer<TetherData> getSerializer(Class<TetherData> c) {
    return new TetherDataSerializer();
  }

  private class TetherDataSerializer implements Serializer<TetherData> {

    private OutputStream out;
    private BinaryEncoder encoder;

    public void open(OutputStream out) {
      this.out = out;
      this.encoder = EncoderFactory.get().directBinaryEncoder(out, encoder);
    }

    public void serialize(TetherData datum) throws IOException {
      encoder.writeBytes(datum.buffer());
      encoder.flush(); //Flush shouldn't be required. Might be a bug in AVRO.
    }

    public void close() throws IOException {
      encoder.flush();
      out.close();
    }

  }

}