storm-client/src/jvm/org/apache/storm/metric/api/CombinedMetric.java

/**
 * 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.storm.metric.api;

public class CombinedMetric implements IMetric {
    private final ICombiner combiner;
    private Object value;

    public CombinedMetric(ICombiner combiner) {
        this.combiner = combiner;
        value = this.combiner.identity();
    }

    public void update(Object value) {
        this.value = combiner.combine(this.value, value);
    }

    @Override
    public Object getValueAndReset() {
        Object ret = value;
        value = combiner.identity();
        return ret;
    }
}