| /** |
| * 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.io.InputStream; |
| |
| import org.apache.hadoop.conf.Configuration; |
| import org.apache.hadoop.fs.Path; |
| import org.apache.hadoop.io.IOUtils; |
| import org.apache.hadoop.mapreduce.lib.input.CombineFileSplit; |
| |
| /** |
| * Given a {@link org.apache.hadoop.mapreduce.lib.input.CombineFileSplit}, |
| * circularly read through each input source. |
| */ |
| class FileQueue extends InputStream { |
| |
| private int idx = -1; |
| private long curlen = -1L; |
| private InputStream input; |
| private final byte[] z = new byte[1]; |
| private final Path[] paths; |
| private final long[] lengths; |
| private final long[] startoffset; |
| private final Configuration conf; |
| |
| /** |
| * @param split Description of input sources. |
| * @param conf Used to resolve FileSystem instances. |
| */ |
| public FileQueue(CombineFileSplit split, Configuration conf) |
| throws IOException { |
| this.conf = conf; |
| paths = split.getPaths(); |
| startoffset = split.getStartOffsets(); |
| lengths = split.getLengths(); |
| nextSource(); |
| } |
| |
| protected void nextSource() throws IOException { |
| if (0 == paths.length) { |
| return; |
| } |
| if (input != null) { |
| input.close(); |
| } |
| idx = (idx + 1) % paths.length; |
| curlen = lengths[idx]; |
| final Path file = paths[idx]; |
| input = |
| CompressionEmulationUtil.getPossiblyDecompressedInputStream(file, |
| conf, startoffset[idx]); |
| } |
| |
| @Override |
| public int read() throws IOException { |
| final int tmp = read(z); |
| return tmp == -1 ? -1 : (0xFF & z[0]); |
| } |
| |
| @Override |
| public int read(byte[] b) throws IOException { |
| return read(b, 0, b.length); |
| } |
| |
| @Override |
| public int read(byte[] b, int off, int len) throws IOException { |
| int kvread = 0; |
| while (kvread < len) { |
| if (curlen <= 0) { |
| nextSource(); |
| continue; |
| } |
| final int srcRead = (int) Math.min(len - kvread, curlen); |
| IOUtils.readFully(input, b, kvread, srcRead); |
| curlen -= srcRead; |
| kvread += srcRead; |
| } |
| return kvread; |
| } |
| |
| @Override |
| public void close() throws IOException { |
| input.close(); |
| } |
| |
| } |