| /* |
| * 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.nemo.runtime.executor.datatransfer; |
| |
| import org.apache.commons.lang.SerializationUtils; |
| import org.apache.nemo.common.coder.DecoderFactory; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| import java.io.EOFException; |
| import java.io.IOException; |
| import java.io.InputStream; |
| |
| /** |
| * A factory for NemoEventDecoder. |
| */ |
| public final class NemoEventDecoderFactory implements DecoderFactory { |
| private static final Logger LOG = LoggerFactory.getLogger(NemoEventDecoderFactory.class.getName()); |
| |
| private final DecoderFactory valueDecoderFactory; |
| |
| public NemoEventDecoderFactory(final DecoderFactory valueDecoderFactory) { |
| this.valueDecoderFactory = valueDecoderFactory; |
| } |
| |
| @Override |
| public Decoder create(final InputStream inputStream) throws IOException { |
| return new NemoEventDecoder(valueDecoderFactory.create(inputStream), inputStream); |
| } |
| |
| @Override |
| public String toString() { |
| return "NemoEventDecoderFactory{" |
| + "valueDecoderFactory=" + valueDecoderFactory |
| + '}'; |
| } |
| |
| /** |
| * This class decodes receive data into two types. |
| * - normal data |
| * - WatermarkWithIndex |
| */ |
| private final class NemoEventDecoder implements DecoderFactory.Decoder { |
| |
| private final Decoder valueDecoder; |
| private final InputStream inputStream; |
| |
| NemoEventDecoder(final Decoder valueDecoder, |
| final InputStream inputStream) { |
| this.valueDecoder = valueDecoder; |
| this.inputStream = inputStream; |
| } |
| |
| @Override |
| public Object decode() throws IOException { |
| |
| final byte isWatermark = (byte) inputStream.read(); |
| if (isWatermark == -1) { |
| // end of the input stream |
| throw new EOFException(); |
| } |
| |
| if (isWatermark == 0x00) { |
| // this is not a watermark |
| return valueDecoder.decode(); |
| } else if (isWatermark == 0x01) { |
| // this is a watermark |
| final WatermarkWithIndex watermarkWithIndex = |
| (WatermarkWithIndex) SerializationUtils.deserialize(inputStream); |
| return watermarkWithIndex; |
| } else { |
| throw new RuntimeException("Watermark decoding failure: " + isWatermark); |
| } |
| } |
| |
| @Override |
| public String toString() { |
| final StringBuilder stringBuilder = new StringBuilder("NemoDecoder{"); |
| stringBuilder.append(valueDecoder.toString()); |
| stringBuilder.append("}"); |
| return stringBuilder.toString(); |
| } |
| } |
| } |