| /** |
| * 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.mapred.gridmix; |
| |
| import java.io.IOException; |
| import java.util.ArrayList; |
| import java.util.Collections; |
| import java.util.Comparator; |
| import java.util.HashMap; |
| import java.util.List; |
| import java.util.Map.Entry; |
| |
| import org.apache.hadoop.conf.Configuration; |
| import org.apache.hadoop.fs.BlockLocation; |
| import org.apache.hadoop.fs.FileStatus; |
| import org.apache.hadoop.fs.Path; |
| import org.apache.hadoop.io.compress.CompressionCodec; |
| import org.apache.hadoop.io.compress.CompressionCodecFactory; |
| import org.apache.hadoop.mapreduce.lib.input.CombineFileSplit; |
| |
| import org.apache.commons.logging.Log; |
| import org.apache.commons.logging.LogFactory; |
| |
| /** |
| * Given a {@link #FilePool}, obtain a set of files capable of satisfying |
| * a full set of splits, then iterate over each source to fill the request. |
| */ |
| class InputStriper { |
| public static final Log LOG = LogFactory.getLog(InputStriper.class); |
| int idx; |
| long currentStart; |
| FileStatus current; |
| final List<FileStatus> files = new ArrayList<FileStatus>(); |
| final Configuration conf = new Configuration(); |
| |
| /** |
| * @param inputDir Pool from which files are requested. |
| * @param mapBytes Sum of all expected split requests. |
| */ |
| InputStriper(FilePool inputDir, long mapBytes) |
| throws IOException { |
| final long inputBytes = inputDir.getInputFiles(mapBytes, files); |
| if (mapBytes > inputBytes) { |
| LOG.warn("Using " + inputBytes + "/" + mapBytes + " bytes"); |
| } |
| if (files.isEmpty() && mapBytes > 0) { |
| throw new IOException("Failed to satisfy request for " + mapBytes); |
| } |
| current = files.isEmpty() ? null : files.get(0); |
| } |
| |
| /** |
| * @param inputDir Pool used to resolve block locations. |
| * @param bytes Target byte count |
| * @param nLocs Number of block locations per split. |
| * @return A set of files satisfying the byte count, with locations weighted |
| * to the dominating proportion of input bytes. |
| */ |
| CombineFileSplit splitFor(FilePool inputDir, long bytes, int nLocs) |
| throws IOException { |
| final ArrayList<Path> paths = new ArrayList<Path>(); |
| final ArrayList<Long> start = new ArrayList<Long>(); |
| final ArrayList<Long> length = new ArrayList<Long>(); |
| final HashMap<String,Double> sb = new HashMap<String,Double>(); |
| do { |
| paths.add(current.getPath()); |
| start.add(currentStart); |
| final long fromFile = Math.min(bytes, current.getLen() - currentStart); |
| length.add(fromFile); |
| for (BlockLocation loc : |
| inputDir.locationsFor(current, currentStart, fromFile)) { |
| final double tedium = loc.getLength() / (1.0 * bytes); |
| for (String l : loc.getHosts()) { |
| Double j = sb.get(l); |
| if (null == j) { |
| sb.put(l, tedium); |
| } else { |
| sb.put(l, j.doubleValue() + tedium); |
| } |
| } |
| } |
| currentStart += fromFile; |
| bytes -= fromFile; |
| // Switch to a new file if |
| // - the current file is uncompressed and completely used |
| // - the current file is compressed |
| |
| CompressionCodecFactory compressionCodecs = |
| new CompressionCodecFactory(conf); |
| CompressionCodec codec = compressionCodecs.getCodec(current.getPath()); |
| if (current.getLen() - currentStart == 0 |
| || codec != null) { |
| current = files.get(++idx % files.size()); |
| currentStart = 0; |
| } |
| } while (bytes > 0); |
| final ArrayList<Entry<String,Double>> sort = |
| new ArrayList<Entry<String,Double>>(sb.entrySet()); |
| Collections.sort(sort, hostRank); |
| final String[] hosts = new String[Math.min(nLocs, sort.size())]; |
| for (int i = 0; i < nLocs && i < sort.size(); ++i) { |
| hosts[i] = sort.get(i).getKey(); |
| } |
| return new CombineFileSplit(paths.toArray(new Path[0]), |
| toLongArray(start), toLongArray(length), hosts); |
| } |
| |
| private long[] toLongArray(final ArrayList<Long> sigh) { |
| final long[] ret = new long[sigh.size()]; |
| for (int i = 0; i < ret.length; ++i) { |
| ret[i] = sigh.get(i); |
| } |
| return ret; |
| } |
| |
| static final Comparator<Entry<String,Double>> hostRank = |
| new Comparator<Entry<String,Double>>() { |
| public int compare(Entry<String,Double> a, Entry<String,Double> b) { |
| final double va = a.getValue(); |
| final double vb = b.getValue(); |
| return va > vb ? -1 : va < vb ? 1 : 0; |
| } |
| }; |
| } |