001/**
002 * Copyright 2015 DuraSpace, Inc.
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 *     http://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016package org.fcrepo.metrics;
017
018import static com.codahale.metrics.SharedMetricRegistries.getOrCreate;
019
020import com.codahale.metrics.MetricRegistry;
021
022/**
023 * Provide helpers for working with the Metrics registry
024 * 
025 * @author cbeer
026 * @since Mar 22, 2013
027 */
028public final class RegistryService {
029
030    private static final MetricRegistry METRICS = getOrCreate("fcrepo-metrics");
031
032    private static volatile RegistryService instance = null;
033
034    private RegistryService() {
035      // New instances should come from the singleton
036    }
037
038    /**
039     * Create the instance
040     * @return the local object
041     */
042    public synchronized static RegistryService getInstance() {
043        RegistryService local = instance;
044        if (null == local) {
045             instance = local = new RegistryService();
046        }
047        return local;
048    }
049
050    /**
051     * Get the current registry service
052     * 
053     * TODO the new upstream SharedMetricRegistries may make this obsolete
054     * @return the current registry service
055     */
056    public MetricRegistry getMetrics() {
057        return METRICS;
058    }
059
060}