com.metamx.common.collect.AggregatingMap Maven / Gradle / Ivy
/*
* Copyright 2011,2012 Metamarkets Group Inc.
*
* Licensed 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 com.metamx.common.collect;
import java.util.HashMap;
// Can't find a good way to abstract over which aggregator representation is used,
// so I just pick Double/MutableDouble.
public class AggregatingMap extends HashMap
{
public void add(K k, double n)
{
final Double value = get(k);
if (value == null) {
put(k, n);
return;
}
put(k, value + n);
}
}