001/** 002 * Licensed to the Apache Software Foundation (ASF) under one 003 * or more contributor license agreements. See the NOTICE file 004 * distributed with this work for additional information 005 * regarding copyright ownership. The ASF licenses this file 006 * to you under the Apache License, Version 2.0 (the 007 * "License"); you may not use this file except in compliance 008 * with the License. You may obtain a copy of the License at 009 * 010 * http://www.apache.org/licenses/LICENSE-2.0 011 * 012 * Unless required by applicable law or agreed to in writing, software 013 * distributed under the License is distributed on an "AS IS" BASIS, 014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 015 * See the License for the specific language governing permissions and 016 * limitations under the License. 017 */ 018 019package org.apache.hadoop.mapred.lib.aggregate; 020 021import org.apache.hadoop.classification.InterfaceAudience; 022import org.apache.hadoop.classification.InterfaceStability; 023 024/** 025 * This class implements a value aggregator that dedupes a sequence of objects. 026 */ 027@InterfaceAudience.Public 028@InterfaceStability.Stable 029public class UniqValueCount 030 extends org.apache.hadoop.mapreduce.lib.aggregate.UniqValueCount 031 implements ValueAggregator<Object> { 032 /** 033 * the default constructor 034 * 035 */ 036 public UniqValueCount() { 037 super(); 038 } 039 040 /** 041 * constructor 042 * @param maxNum the limit in the number of unique values to keep. 043 * 044 */ 045 public UniqValueCount(long maxNum) { 046 super(maxNum); 047 } 048}