| /* |
| * 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.sling.commons.metrics; |
| |
| |
| import org.osgi.annotation.versioning.ProviderType; |
| |
| /** |
| * The {@code MetricsService} enables creation of various types of {@code Metric}. |
| */ |
| @ProviderType |
| public interface MetricsService { |
| /** |
| * Dummy variant of MetricsService which does not |
| * collect any metric |
| */ |
| MetricsService NOOP = new MetricsService() { |
| @Override |
| public Timer timer(String name) { |
| return NoopMetric.INSTANCE; |
| } |
| |
| @Override |
| public Histogram histogram(String name) { |
| return NoopMetric.INSTANCE; |
| } |
| |
| @Override |
| public Counter counter(String name) { |
| return NoopMetric.INSTANCE; |
| } |
| |
| @Override |
| public Meter meter(String name) { |
| return NoopMetric.INSTANCE; |
| } |
| |
| @Override |
| public <A> A adaptTo(Class<A> type) { |
| return null; |
| } |
| }; |
| |
| /** |
| * Creates a new {@link Timer} and registers it under the given name. |
| * If a timer with same name exists then same instance is returned |
| * |
| * @param name the name of the metric |
| * @return a new {@link Timer} |
| */ |
| Timer timer(String name); |
| |
| /** |
| * Creates a new {@link Histogram} and registers it under the given name. |
| * If a histogram with same name exists then same instance is returned. |
| * |
| * @param name the name of the metric |
| * @return a new {@link Histogram} |
| */ |
| Histogram histogram(String name); |
| |
| /** |
| * Creates a new {@link Counter} and registers it under the given name. |
| * If a counter with same name exists then same instance is returned |
| * |
| * @param name the name of the metric |
| * @return a new {@link Counter} |
| */ |
| Counter counter(String name); |
| |
| /** |
| * Creates a new {@link Meter} and registers it under the given name. |
| * If a meter with same name exists then same instance is returned |
| * |
| * @param name the name of the metric |
| * @return a new {@link Meter} |
| */ |
| Meter meter(String name); |
| |
| /** |
| * Adapts the service to the specified type. This can be used to |
| * get instance to underlying {@code MetricRegistry} |
| * |
| * @param <A> The type to which this metric is to be adapted. |
| * @param type Class object for the type to which this metric is to be adapted. |
| * @return The object, of the specified type, to which this metric has been adapted |
| * or null if this metric cannot be adapted to the specified type. |
| */ |
| <A> A adaptTo(Class<A> type); |
| } |