ReduceContextImpl.java 文件源码

/**
 * This method is called to write the record that was most recently
 * served (before a call to the mark). Since the framework reads one
 * record in advance, to get this record, we serialize the current key
 * and value
 * @param out
 * @throws IOException
 */
private void writeFirstKeyValueBytes(DataOutputStream out) 
throws IOException {
  assert (getCurrentKey() != null && getCurrentValue() != null);
  WritableUtils.writeVInt(out, currentKeyLength);
  WritableUtils.writeVInt(out, currentValueLength);
  Serializer<KEYIN> keySerializer = 
    serializationFactory.getSerializer(keyClass);
  keySerializer.open(out);
  keySerializer.serialize(getCurrentKey());

  Serializer<VALUEIN> valueSerializer = 
    serializationFactory.getSerializer(valueClass);
  valueSerializer.open(out);
  valueSerializer.serialize(getCurrentValue());
}