| /** |
| * 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.lib.aggregate; |
| |
| import java.util.ArrayList; |
| import java.util.Map.Entry; |
| |
| import org.apache.hadoop.classification.InterfaceAudience; |
| import org.apache.hadoop.classification.InterfaceStability; |
| import org.apache.hadoop.conf.Configuration; |
| import org.apache.hadoop.io.Text; |
| import org.apache.hadoop.mapreduce.MRJobConfig; |
| |
| /** |
| * This class implements the common functionalities of |
| * the subclasses of ValueAggregatorDescriptor class. |
| */ |
| @InterfaceAudience.Public |
| @InterfaceStability.Stable |
| public class ValueAggregatorBaseDescriptor |
| implements ValueAggregatorDescriptor { |
| |
| static public final String UNIQ_VALUE_COUNT = "UniqValueCount"; |
| |
| static public final String LONG_VALUE_SUM = "LongValueSum"; |
| |
| static public final String DOUBLE_VALUE_SUM = "DoubleValueSum"; |
| |
| static public final String VALUE_HISTOGRAM = "ValueHistogram"; |
| |
| static public final String LONG_VALUE_MAX = "LongValueMax"; |
| |
| static public final String LONG_VALUE_MIN = "LongValueMin"; |
| |
| static public final String STRING_VALUE_MAX = "StringValueMax"; |
| |
| static public final String STRING_VALUE_MIN = "StringValueMin"; |
| |
| public String inputFile = null; |
| |
| private static class MyEntry implements Entry<Text, Text> { |
| Text key; |
| |
| Text val; |
| |
| public Text getKey() { |
| return key; |
| } |
| |
| public Text getValue() { |
| return val; |
| } |
| |
| public Text setValue(Text val) { |
| this.val = val; |
| return val; |
| } |
| |
| public MyEntry(Text key, Text val) { |
| this.key = key; |
| this.val = val; |
| } |
| } |
| |
| /** |
| * |
| * @param type the aggregation type |
| * @param id the aggregation id |
| * @param val the val associated with the id to be aggregated |
| * @return an Entry whose key is the aggregation id prefixed with |
| * the aggregation type. |
| */ |
| public static Entry<Text, Text> generateEntry(String type, |
| String id, Text val) { |
| Text key = new Text(type + TYPE_SEPARATOR + id); |
| return new MyEntry(key, val); |
| } |
| |
| /** |
| * |
| * @param type the aggregation type |
| * @param uniqCount the limit in the number of unique values to keep, |
| * if type is UNIQ_VALUE_COUNT |
| * @return a value aggregator of the given type. |
| */ |
| static public ValueAggregator generateValueAggregator(String type, long uniqCount) { |
| if (type.compareToIgnoreCase(LONG_VALUE_SUM) == 0) { |
| return new LongValueSum(); |
| } if (type.compareToIgnoreCase(LONG_VALUE_MAX) == 0) { |
| return new LongValueMax(); |
| } else if (type.compareToIgnoreCase(LONG_VALUE_MIN) == 0) { |
| return new LongValueMin(); |
| } else if (type.compareToIgnoreCase(STRING_VALUE_MAX) == 0) { |
| return new StringValueMax(); |
| } else if (type.compareToIgnoreCase(STRING_VALUE_MIN) == 0) { |
| return new StringValueMin(); |
| } else if (type.compareToIgnoreCase(DOUBLE_VALUE_SUM) == 0) { |
| return new DoubleValueSum(); |
| } else if (type.compareToIgnoreCase(UNIQ_VALUE_COUNT) == 0) { |
| return new UniqValueCount(uniqCount); |
| } else if (type.compareToIgnoreCase(VALUE_HISTOGRAM) == 0) { |
| return new ValueHistogram(); |
| } |
| return null; |
| } |
| |
| /** |
| * Generate 1 or 2 aggregation-id/value pairs for the given key/value pair. |
| * The first id will be of type LONG_VALUE_SUM, with "record_count" as |
| * its aggregation id. If the input is a file split, |
| * the second id of the same type will be generated too, with the file name |
| * as its aggregation id. This achieves the behavior of counting the total |
| * number of records in the input data, and the number of records |
| * in each input file. |
| * |
| * @param key |
| * input key |
| * @param val |
| * input value |
| * @return a list of aggregation id/value pairs. An aggregation id encodes an |
| * aggregation type which is used to guide the way to aggregate the |
| * value in the reduce/combiner phrase of an Aggregate based job. |
| */ |
| public ArrayList<Entry<Text, Text>> generateKeyValPairs(Object key, |
| Object val) { |
| ArrayList<Entry<Text, Text>> retv = new ArrayList<Entry<Text, Text>>(); |
| String countType = LONG_VALUE_SUM; |
| String id = "record_count"; |
| Entry<Text, Text> e = generateEntry(countType, id, ONE); |
| if (e != null) { |
| retv.add(e); |
| } |
| if (this.inputFile != null) { |
| e = generateEntry(countType, this.inputFile, ONE); |
| if (e != null) { |
| retv.add(e); |
| } |
| } |
| return retv; |
| } |
| |
| /** |
| * get the input file name. |
| * |
| * @param conf a configuration object |
| */ |
| public void configure(Configuration conf) { |
| this.inputFile = conf.get(MRJobConfig.MAP_INPUT_FILE); |
| } |
| } |