| /** |
| * 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.bookkeeper.stats.prometheus; |
| |
| import java.util.Map; |
| import java.util.concurrent.atomic.LongAdder; |
| |
| import org.apache.bookkeeper.stats.Counter; |
| |
| /** |
| * {@link Counter} implementation based on {@link LongAdder}. |
| * |
| * <p>LongAdder keeps a counter per-thread and then aggregates to get the result, in order to avoid contention between |
| * multiple threads. |
| */ |
| public class LongAdderCounter implements Counter { |
| private final LongAdder counter = new LongAdder(); |
| |
| private final Map<String, String> labels; |
| |
| public LongAdderCounter(Map<String, String> labels) { |
| this.labels = labels; |
| } |
| |
| @Override |
| public void clear() { |
| counter.reset(); |
| } |
| |
| @Override |
| public void inc() { |
| counter.increment(); |
| } |
| |
| @Override |
| public void dec() { |
| counter.decrement(); |
| } |
| |
| @Override |
| public void add(long delta) { |
| counter.add(delta); |
| } |
| |
| @Override |
| public Long get() { |
| return counter.sum(); |
| } |
| |
| public Map<String, String> getLabels() { |
| return labels; |
| } |
| } |