| /* |
| * 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.resourceresolver.impl.observation; |
| |
| import java.util.Collections; |
| import java.util.List; |
| import java.util.Map; |
| import java.util.concurrent.ConcurrentHashMap; |
| |
| import org.apache.sling.api.resource.observation.ResourceChange; |
| import org.apache.sling.api.resource.observation.ResourceChangeListener; |
| import org.apache.sling.api.resource.path.Path; |
| import org.apache.sling.api.resource.path.PathSet; |
| import org.apache.sling.resourceresolver.impl.providers.ResourceProviderTracker; |
| import org.apache.sling.resourceresolver.impl.providers.ResourceProviderTracker.ObservationReporterGenerator; |
| import org.apache.sling.spi.resource.provider.ObservationReporter; |
| import org.apache.sling.spi.resource.provider.ObserverConfiguration; |
| import org.osgi.framework.BundleContext; |
| import org.osgi.framework.ServiceReference; |
| import org.osgi.util.tracker.ServiceTracker; |
| import org.osgi.util.tracker.ServiceTrackerCustomizer; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| /** |
| * Tracker component for the resource change listeners. |
| */ |
| public class ResourceChangeListenerWhiteboard implements ResourceProviderTracker.ObservationReporterGenerator { |
| |
| private final Logger logger = LoggerFactory.getLogger(this.getClass()); |
| |
| private final Map<ServiceReference<ResourceChangeListener>, ResourceChangeListenerInfo> listeners = new ConcurrentHashMap<>(); |
| |
| private volatile ResourceProviderTracker resourceProviderTracker; |
| |
| private volatile ServiceTracker<ResourceChangeListener, ServiceReference<ResourceChangeListener>> tracker; |
| |
| private volatile List<String> searchPath; |
| |
| public void activate(final BundleContext bundleContext, |
| final ResourceProviderTracker resourceProviderTracker, |
| final List<String> searchPath) { |
| this.searchPath = searchPath; |
| this.resourceProviderTracker = resourceProviderTracker; |
| this.resourceProviderTracker.setObservationReporterGenerator(this); |
| this.tracker = new ServiceTracker<>(bundleContext, |
| ResourceChangeListener.class, |
| new ServiceTrackerCustomizer<ResourceChangeListener, ServiceReference<ResourceChangeListener>>() { |
| |
| @Override |
| public void removedService(final ServiceReference<ResourceChangeListener> reference, final ServiceReference<ResourceChangeListener> service) { |
| final ResourceChangeListenerInfo info = listeners.remove(reference); |
| if ( info != null ) { |
| updateProviderTracker(); |
| } |
| } |
| |
| @Override |
| public void modifiedService(final ServiceReference<ResourceChangeListener> reference, final ServiceReference<ResourceChangeListener> service) { |
| removedService(reference, service); |
| addingService(reference); |
| } |
| |
| @Override |
| public ServiceReference<ResourceChangeListener> addingService(final ServiceReference<ResourceChangeListener> reference) { |
| final ResourceChangeListenerInfo info = new ResourceChangeListenerInfo(reference, searchPath); |
| if ( info.isValid() ) { |
| final ResourceChangeListener listener = bundleContext.getService(reference); |
| if ( listener != null ) { |
| info.setListener(listener); |
| listeners.put(reference, info); |
| updateProviderTracker(); |
| } |
| } else { |
| logger.warn("Ignoring invalid resource change listener {}", reference); |
| } |
| return reference; |
| } |
| }); |
| this.tracker.open(); |
| } |
| |
| public void deactivate() { |
| if ( this.tracker != null ) { |
| this.tracker.close(); |
| this.tracker = null; |
| } |
| this.resourceProviderTracker.setObservationReporterGenerator(NOP_GENERATOR); |
| this.resourceProviderTracker = null; |
| } |
| |
| private void updateProviderTracker() { |
| this.resourceProviderTracker.setObservationReporterGenerator(this); |
| } |
| |
| @Override |
| public ObservationReporter create(final Path path, final PathSet excludes) { |
| return new BasicObservationReporter(this.searchPath, this.listeners.values(), path, excludes); |
| } |
| |
| @Override |
| public ObservationReporter createProviderReporter() { |
| return new BasicObservationReporter(this.searchPath, this.listeners.values()); |
| } |
| |
| private static final ObservationReporter EMPTY_REPORTER = new ObservationReporter() { |
| |
| @Override |
| public void reportChanges(Iterable<ResourceChange> changes, boolean distribute) { |
| // ignore |
| } |
| |
| @Override |
| public void reportChanges(ObserverConfiguration config, Iterable<ResourceChange> changes, boolean distribute) { |
| // ignore |
| } |
| |
| @Override |
| public List<ObserverConfiguration> getObserverConfigurations() { |
| return Collections.emptyList(); |
| } |
| }; |
| |
| private static final ObservationReporterGenerator NOP_GENERATOR = new ObservationReporterGenerator() { |
| |
| @Override |
| public ObservationReporter create(Path path, PathSet excludes) { |
| return EMPTY_REPORTER; |
| } |
| |
| @Override |
| public ObservationReporter createProviderReporter() { |
| return EMPTY_REPORTER; |
| } |
| }; |
| } |