| /** |
| * 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; |
| |
| import java.io.IOException; |
| import java.util.regex.PatternSyntaxException; |
| |
| import org.apache.hadoop.classification.InterfaceAudience; |
| import org.apache.hadoop.classification.InterfaceStability; |
| import org.apache.hadoop.conf.Configuration; |
| import org.apache.hadoop.util.ReflectionUtils; |
| |
| /** |
| * A class that allows a map/red job to work on a sample of sequence files. |
| * The sample is decided by the filter class set by the job. |
| */ |
| @InterfaceAudience.Public |
| @InterfaceStability.Stable |
| public class SequenceFileInputFilter<K, V> |
| extends SequenceFileInputFormat<K, V> { |
| |
| final private static String FILTER_CLASS = org.apache.hadoop.mapreduce.lib. |
| input.SequenceFileInputFilter.FILTER_CLASS; |
| |
| public SequenceFileInputFilter() { |
| } |
| |
| /** Create a record reader for the given split |
| * @param split file split |
| * @param job job configuration |
| * @param reporter reporter who sends report to task tracker |
| * @return RecordReader |
| */ |
| public RecordReader<K, V> getRecordReader(InputSplit split, |
| JobConf job, Reporter reporter) |
| throws IOException { |
| |
| reporter.setStatus(split.toString()); |
| |
| return new FilterRecordReader<K, V>(job, (FileSplit) split); |
| } |
| |
| |
| /** set the filter class |
| * |
| * @param conf application configuration |
| * @param filterClass filter class |
| */ |
| public static void setFilterClass(Configuration conf, Class filterClass) { |
| conf.set(FILTER_CLASS, filterClass.getName()); |
| } |
| |
| |
| /** |
| * filter interface |
| */ |
| public interface Filter extends |
| org.apache.hadoop.mapreduce.lib.input.SequenceFileInputFilter.Filter { |
| } |
| |
| /** |
| * base class for Filters |
| */ |
| public static abstract class FilterBase extends org.apache.hadoop.mapreduce. |
| lib.input.SequenceFileInputFilter.FilterBase |
| implements Filter { |
| } |
| |
| /** Records filter by matching key to regex |
| */ |
| public static class RegexFilter extends FilterBase { |
| org.apache.hadoop.mapreduce.lib.input.SequenceFileInputFilter. |
| RegexFilter rf; |
| public static void setPattern(Configuration conf, String regex) |
| throws PatternSyntaxException { |
| org.apache.hadoop.mapreduce.lib.input.SequenceFileInputFilter. |
| RegexFilter.setPattern(conf, regex); |
| } |
| |
| public RegexFilter() { |
| rf = new org.apache.hadoop.mapreduce.lib.input.SequenceFileInputFilter. |
| RegexFilter(); |
| } |
| |
| /** configure the Filter by checking the configuration |
| */ |
| public void setConf(Configuration conf) { |
| rf.setConf(conf); |
| } |
| |
| |
| /** Filtering method |
| * If key matches the regex, return true; otherwise return false |
| * @see org.apache.hadoop.mapred.SequenceFileInputFilter.Filter#accept(Object) |
| */ |
| public boolean accept(Object key) { |
| return rf.accept(key); |
| } |
| } |
| |
| /** This class returns a percentage of records |
| * The percentage is determined by a filtering frequency <i>f</i> using |
| * the criteria record# % f == 0. |
| * For example, if the frequency is 10, one out of 10 records is returned. |
| */ |
| public static class PercentFilter extends FilterBase { |
| org.apache.hadoop.mapreduce.lib.input.SequenceFileInputFilter. |
| PercentFilter pf; |
| /** set the frequency and stores it in conf |
| * @param conf configuration |
| * @param frequency filtering frequencey |
| */ |
| public static void setFrequency(Configuration conf, int frequency) { |
| org.apache.hadoop.mapreduce.lib.input.SequenceFileInputFilter. |
| PercentFilter.setFrequency(conf, frequency); |
| } |
| |
| public PercentFilter() { |
| pf = new org.apache.hadoop.mapreduce.lib.input.SequenceFileInputFilter. |
| PercentFilter(); |
| } |
| |
| /** configure the filter by checking the configuration |
| * |
| * @param conf configuration |
| */ |
| public void setConf(Configuration conf) { |
| pf.setConf(conf); |
| } |
| |
| /** Filtering method |
| * If record# % frequency==0, return true; otherwise return false |
| * @see org.apache.hadoop.mapred.SequenceFileInputFilter.Filter#accept(Object) |
| */ |
| public boolean accept(Object key) { |
| return pf.accept(key); |
| } |
| } |
| |
| /** This class returns a set of records by examing the MD5 digest of its |
| * key against a filtering frequency <i>f</i>. The filtering criteria is |
| * MD5(key) % f == 0. |
| */ |
| public static class MD5Filter extends FilterBase { |
| public static final int MD5_LEN = org.apache.hadoop.mapreduce.lib. |
| input.SequenceFileInputFilter.MD5Filter.MD5_LEN; |
| org.apache.hadoop.mapreduce.lib.input.SequenceFileInputFilter.MD5Filter mf; |
| /** set the filtering frequency in configuration |
| * |
| * @param conf configuration |
| * @param frequency filtering frequency |
| */ |
| public static void setFrequency(Configuration conf, int frequency) { |
| org.apache.hadoop.mapreduce.lib.input.SequenceFileInputFilter.MD5Filter. |
| setFrequency(conf, frequency); |
| } |
| |
| public MD5Filter() { |
| mf = new org.apache.hadoop.mapreduce.lib.input. |
| SequenceFileInputFilter.MD5Filter(); |
| } |
| |
| /** configure the filter according to configuration |
| * |
| * @param conf configuration |
| */ |
| public void setConf(Configuration conf) { |
| mf.setConf(conf); |
| } |
| |
| /** Filtering method |
| * If MD5(key) % frequency==0, return true; otherwise return false |
| * @see org.apache.hadoop.mapred.SequenceFileInputFilter.Filter#accept(Object) |
| */ |
| public boolean accept(Object key) { |
| return mf.accept(key); |
| } |
| } |
| |
| private static class FilterRecordReader<K, V> |
| extends SequenceFileRecordReader<K, V> { |
| |
| private Filter filter; |
| |
| public FilterRecordReader(Configuration conf, FileSplit split) |
| throws IOException { |
| super(conf, split); |
| // instantiate filter |
| filter = (Filter)ReflectionUtils.newInstance( |
| conf.getClass(FILTER_CLASS, PercentFilter.class), |
| conf); |
| } |
| |
| public synchronized boolean next(K key, V value) throws IOException { |
| while (next(key)) { |
| if (filter.accept(key)) { |
| getCurrentValue(value); |
| return true; |
| } |
| } |
| |
| return false; |
| } |
| } |
| } |