| /** |
| * 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.hadoop.mapreduce.task.reduce; |
| |
| import java.io.InputStream; |
| import java.io.IOException; |
| |
| import org.apache.hadoop.classification.InterfaceAudience; |
| import org.apache.hadoop.classification.InterfaceStability; |
| |
| import org.apache.commons.logging.Log; |
| import org.apache.commons.logging.LogFactory; |
| |
| import org.apache.hadoop.conf.Configuration; |
| |
| import org.apache.hadoop.io.BoundedByteArrayOutputStream; |
| import org.apache.hadoop.io.IOUtils; |
| |
| import org.apache.hadoop.io.compress.CodecPool; |
| import org.apache.hadoop.io.compress.CompressionCodec; |
| import org.apache.hadoop.io.compress.Decompressor; |
| |
| import org.apache.hadoop.mapred.IFileInputStream; |
| import org.apache.hadoop.mapred.Reporter; |
| |
| import org.apache.hadoop.mapreduce.TaskAttemptID; |
| |
| @InterfaceAudience.Private |
| @InterfaceStability.Unstable |
| class InMemoryMapOutput<K, V> extends MapOutput<K, V> { |
| private static final Log LOG = LogFactory.getLog(InMemoryMapOutput.class); |
| private Configuration conf; |
| private final MergeManagerImpl<K, V> merger; |
| private final byte[] memory; |
| private BoundedByteArrayOutputStream byteStream; |
| // Decompression of map-outputs |
| private final CompressionCodec codec; |
| private final Decompressor decompressor; |
| |
| public InMemoryMapOutput(Configuration conf, TaskAttemptID mapId, |
| MergeManagerImpl<K, V> merger, |
| int size, CompressionCodec codec, |
| boolean primaryMapOutput) { |
| super(mapId, (long)size, primaryMapOutput); |
| this.conf = conf; |
| this.merger = merger; |
| this.codec = codec; |
| byteStream = new BoundedByteArrayOutputStream(size); |
| memory = byteStream.getBuffer(); |
| if (codec != null) { |
| decompressor = CodecPool.getDecompressor(codec); |
| } else { |
| decompressor = null; |
| } |
| } |
| |
| public byte[] getMemory() { |
| return memory; |
| } |
| |
| public BoundedByteArrayOutputStream getArrayStream() { |
| return byteStream; |
| } |
| |
| @Override |
| public void shuffle(MapHost host, InputStream input, |
| long compressedLength, long decompressedLength, |
| ShuffleClientMetrics metrics, |
| Reporter reporter) throws IOException { |
| IFileInputStream checksumIn = |
| new IFileInputStream(input, compressedLength, conf); |
| |
| input = checksumIn; |
| |
| // Are map-outputs compressed? |
| if (codec != null) { |
| decompressor.reset(); |
| input = codec.createInputStream(input, decompressor); |
| } |
| |
| try { |
| IOUtils.readFully(input, memory, 0, memory.length); |
| metrics.inputBytes(memory.length); |
| reporter.progress(); |
| LOG.info("Read " + memory.length + " bytes from map-output for " + |
| getMapId()); |
| } catch (IOException ioe) { |
| // Close the streams |
| IOUtils.cleanup(LOG, input); |
| |
| // Re-throw |
| throw ioe; |
| } finally { |
| CodecPool.returnDecompressor(decompressor); |
| } |
| } |
| |
| @Override |
| public void commit() throws IOException { |
| merger.closeInMemoryFile(this); |
| } |
| |
| @Override |
| public void abort() { |
| merger.unreserve(memory.length); |
| } |
| |
| @Override |
| public String getDescription() { |
| return "MEMORY"; |
| } |
| } |