| /** |
| * 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; |
| |
| import java.util.concurrent.TimeUnit; |
| |
| /** |
| * A <i>no-op</i> {@code StatsLogger}. |
| * |
| * <p>Metrics are not recorded, making this receiver useful in unit tests and as defaults in |
| * situations where metrics are not strictly required. |
| */ |
| public class NullStatsLogger implements StatsLogger { |
| |
| public static final NullStatsLogger INSTANCE = new NullStatsLogger(); |
| |
| /** |
| * A <i>no-op</i> {@code OpStatsLogger}. |
| */ |
| static class NullOpStatsLogger implements OpStatsLogger { |
| final OpStatsData nullOpStats = new OpStatsData(0, 0, 0, new long[6]); |
| |
| @Override |
| public void registerFailedEvent(long eventLatency, TimeUnit unit) { |
| // nop |
| } |
| |
| @Override |
| public void registerSuccessfulEvent(long eventLatency, TimeUnit unit) { |
| // nop |
| } |
| |
| @Override |
| public void registerSuccessfulValue(long value) { |
| // nop |
| } |
| |
| @Override |
| public void registerFailedValue(long value) { |
| // nop |
| } |
| |
| @Override |
| public OpStatsData toOpStatsData() { |
| return nullOpStats; |
| } |
| |
| @Override |
| public void clear() { |
| // nop |
| } |
| } |
| static NullOpStatsLogger nullOpStatsLogger = new NullOpStatsLogger(); |
| |
| /** |
| * A <i>no-op</i> {@code Counter}. |
| */ |
| static class NullCounter implements Counter { |
| @Override |
| public void clear() { |
| // nop |
| } |
| |
| @Override |
| public void inc() { |
| // nop |
| } |
| |
| @Override |
| public void dec() { |
| // nop |
| } |
| |
| @Override |
| public void add(long delta) { |
| // nop |
| } |
| |
| @Override |
| public Long get() { |
| return 0L; |
| } |
| } |
| static NullCounter nullCounter = new NullCounter(); |
| |
| @Override |
| public OpStatsLogger getOpStatsLogger(String name) { |
| return nullOpStatsLogger; |
| } |
| |
| @Override |
| public Counter getCounter(String name) { |
| return nullCounter; |
| } |
| |
| @Override |
| public <T extends Number> void registerGauge(String name, Gauge<T> gauge) { |
| // nop |
| } |
| |
| @Override |
| public <T extends Number> void unregisterGauge(String name, Gauge<T> gauge) { |
| // nop |
| } |
| |
| @Override |
| public StatsLogger scope(String name) { |
| return this; |
| } |
| |
| @Override |
| public void removeScope(String name, StatsLogger statsLogger) { |
| // nop |
| } |
| } |