| /* |
| * 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.felix.cm.impl.persistence; |
| |
| |
| import java.util.ArrayList; |
| import java.util.Collections; |
| import java.util.List; |
| |
| import org.apache.felix.cm.NotCachablePersistenceManager; |
| import org.apache.felix.cm.PersistenceManager; |
| import org.apache.felix.cm.impl.ActivatorWorkerQueue; |
| import org.apache.felix.cm.impl.ConfigurationAdminStarter; |
| import org.osgi.framework.BundleContext; |
| import org.osgi.framework.BundleException; |
| import org.osgi.framework.Constants; |
| import org.osgi.framework.InvalidSyntaxException; |
| import org.osgi.framework.ServiceReference; |
| import org.osgi.util.tracker.ServiceTracker; |
| import org.osgi.util.tracker.ServiceTrackerCustomizer; |
| |
| /** |
| * This tracker tracks registered persistence managers and |
| * if the required PM becomes available, configuration admin |
| * is registered. |
| * Service ranking of registered persistence managers |
| * is respected. |
| */ |
| public class PersistenceManagerTracker |
| implements ServiceTrackerCustomizer<PersistenceManager, PersistenceManagerTracker.Holder> |
| { |
| private final List<Holder> holders = new ArrayList<>(); |
| |
| private final ServiceTracker<PersistenceManager, Holder> persistenceManagerTracker; |
| |
| private final BundleContext bundleContext; |
| |
| private final ActivatorWorkerQueue workerQueue; |
| |
| private final ConfigurationAdminStarter starter; |
| |
| public PersistenceManagerTracker(final BundleContext bundleContext, |
| final ActivatorWorkerQueue workerQueue, |
| final ConfigurationAdminStarter starter, |
| final String pmName) |
| throws BundleException, InvalidSyntaxException |
| { |
| this.workerQueue = workerQueue; |
| this.starter = starter; |
| this.bundleContext = bundleContext; |
| this.persistenceManagerTracker = new ServiceTracker<>(bundleContext, |
| bundleContext.createFilter("(&(" + Constants.OBJECTCLASS + "=" + PersistenceManager.class.getName() + ")(name=" + pmName + "))"), |
| this ); |
| this.persistenceManagerTracker.open(); |
| } |
| |
| /** |
| * Stop the tracker |
| */ |
| public void stop( ) |
| { |
| this.persistenceManagerTracker.close(); |
| } |
| |
| public static ExtPersistenceManager createPersistenceManagerProxy(final PersistenceManager pm) |
| { |
| final ExtPersistenceManager extPM; |
| if ( pm instanceof NotCachablePersistenceManager ) |
| { |
| extPM = new PersistenceManagerProxy( pm ); |
| } |
| else |
| { |
| extPM = new CachingPersistenceManagerProxy( pm ); |
| } |
| return extPM; |
| } |
| |
| @Override |
| public Holder addingService(final ServiceReference<PersistenceManager> reference) |
| { |
| final PersistenceManager pm = this.bundleContext.getService(reference); |
| if ( pm != null ) |
| { |
| final ExtPersistenceManager extPM = createPersistenceManagerProxy(pm); |
| final Holder holder = new Holder(reference, extPM); |
| |
| synchronized ( this.holders ) |
| { |
| final Holder oldHolder = this.holders.isEmpty() ? null : this.holders.get(0); |
| this.holders.add(holder); |
| Collections.sort(holders); |
| if ( holders.get(0) == holder ) |
| { |
| this.workerQueue.enqueue(new Runnable() |
| { |
| |
| @Override |
| public void run() |
| { |
| if ( oldHolder != null ) |
| { |
| starter.unsetPersistenceManager(); |
| } |
| if (!holder.isActivated()) { |
| starter.setPersistenceManager(holder.getPersistenceManager()); |
| holder.activate(); |
| } |
| } |
| }); |
| } |
| } |
| return holder; |
| } |
| return null; |
| } |
| |
| |
| @Override |
| public void modifiedService(final ServiceReference<PersistenceManager> reference, final Holder holder) |
| { |
| // find the old holder, remove, add new holder, sort |
| synchronized ( this.holders ) |
| { |
| final Holder oldHolder = this.holders.isEmpty() ? null : this.holders.get(0); |
| |
| this.holders.remove(holder); |
| this.holders.add(new Holder(reference, holder.getPersistenceManager())); |
| Collections.sort(this.holders); |
| if ( holders.get(0) == holder && oldHolder != null && oldHolder.compareTo(holder) != 0 ) |
| { |
| this.workerQueue.enqueue(new Runnable() |
| { |
| |
| @Override |
| public void run() |
| { |
| starter.unsetPersistenceManager(); |
| if (!holder.isActivated()) { |
| starter.setPersistenceManager(holder.getPersistenceManager()); |
| holder.activate(); |
| } |
| } |
| }); |
| } |
| } |
| |
| } |
| |
| |
| @Override |
| public void removedService(final ServiceReference<PersistenceManager> reference, |
| final Holder holder) |
| { |
| synchronized ( this.holders ) |
| { |
| final boolean deactivate = holders.get(0) == holder; |
| this.holders.remove(holder); |
| if ( deactivate ) |
| { |
| this.workerQueue.enqueue(new Runnable() |
| { |
| |
| @Override |
| public void run() |
| { |
| starter.unsetPersistenceManager(); |
| if ( !holders.isEmpty() ) |
| { |
| Holder h = holders.get(0); |
| if (!h.isActivated()) { |
| starter.setPersistenceManager(h.getPersistenceManager()); |
| h.activate(); |
| } |
| } |
| } |
| }); |
| } |
| } |
| } |
| |
| public static final class Holder implements Comparable<Holder> |
| { |
| private final ServiceReference<PersistenceManager> reference; |
| |
| private final ExtPersistenceManager manager; |
| |
| // no need to synchronize, as it's changed only in WorkQueue tasks |
| private boolean activated; |
| |
| public Holder(final ServiceReference<PersistenceManager> ref, final ExtPersistenceManager epm) |
| { |
| this.reference = ref; |
| this.manager = epm; |
| } |
| |
| public ExtPersistenceManager getPersistenceManager() |
| { |
| return this.manager; |
| } |
| |
| @Override |
| public int compareTo(final Holder o) |
| { |
| // sort, highest first |
| return -reference.compareTo(o.reference); |
| } |
| |
| public boolean isActivated() { |
| return activated; |
| } |
| |
| public void activate() { |
| this.activated = true; |
| } |
| |
| @Override |
| public int hashCode() |
| { |
| return this.reference.hashCode(); |
| } |
| |
| @Override |
| public boolean equals(final Object obj) |
| { |
| if (this == obj) |
| { |
| return true; |
| } |
| if (obj == null || getClass() != obj.getClass()) |
| { |
| return false; |
| } |
| final Holder other = (Holder) obj; |
| return this.reference.equals(other.reference); |
| } |
| } |
| } |
| |