org.apache.kafka.common.metrics.stats.Max Maven / Gradle / Ivy
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* 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.kafka.common.metrics.stats;
import java.util.List;
import org.apache.kafka.common.metrics.MetricConfig;
/**
* A {@link SampledStat} that gives the max over its samples.
*/
public final class Max extends SampledStat {
public Max() {
super(Double.NEGATIVE_INFINITY);
}
@Override
protected void update(Sample sample, MetricConfig config, double value, long now) {
sample.value = Math.max(sample.value, value);
}
@Override
public double combine(List samples, MetricConfig config, long now) {
double max = Double.NEGATIVE_INFINITY;
long count = 0;
for (Sample sample : samples) {
max = Math.max(max, sample.value);
count += sample.eventCount;
}
return count == 0 ? Double.NaN : max;
}
}