001/*
002 * Licensed to DuraSpace under one or more contributor license agreements.
003 * See the NOTICE file distributed with this work for additional information
004 * regarding copyright ownership.
005 *
006 * DuraSpace licenses this file to you under the Apache License,
007 * Version 2.0 (the "License"); you may not use this file except in
008 * compliance with the License.  You may obtain a copy of the License at
009 *
010 *     http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018package org.fcrepo.metrics;
019
020import static com.codahale.metrics.SharedMetricRegistries.getOrCreate;
021
022import com.codahale.metrics.MetricRegistry;
023
024/**
025 * Provide helpers for working with the Metrics registry
026 *
027 * @author cbeer
028 * @since Mar 22, 2013
029 */
030public final class RegistryService {
031
032    private static final MetricRegistry METRICS = getOrCreate("fcrepo-metrics");
033
034    private static volatile RegistryService instance = null;
035
036    private RegistryService() {
037      // New instances should come from the singleton
038    }
039
040    /**
041     * Create the instance
042     * @return the local object
043     */
044    public synchronized static RegistryService getInstance() {
045        RegistryService local = instance;
046        if (null == local) {
047             instance = local = new RegistryService();
048        }
049        return local;
050    }
051
052    /**
053     * Get the current registry service
054     *
055     * TODO the new upstream SharedMetricRegistries may make this obsolete
056     * @return the current registry service
057     */
058    @SuppressWarnings("static-method")
059    public MetricRegistry getMetrics() {
060        return METRICS;
061    }
062
063}