/*
* 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.jackrabbit.spi2jcr;
import org.apache.jackrabbit.spi.EventBundle;
import org.apache.jackrabbit.spi.EventFilter;
import org.apache.jackrabbit.spi.Event;
import org.apache.jackrabbit.spi.IdFactory;
import org.apache.jackrabbit.spi.Subscription;
import org.apache.jackrabbit.spi.QValueFactory;
import org.apache.jackrabbit.spi.commons.EventBundleImpl;
import org.apache.jackrabbit.spi.commons.EventFilterImpl;
import org.slf4j.LoggerFactory;
import org.slf4j.Logger;
import javax.jcr.observation.EventListener;
import javax.jcr.observation.ObservationManager;
import javax.jcr.RepositoryException;
import java.util.ArrayList;
import java.util.List;
import java.util.Iterator;
import java.util.Arrays;
import java.util.Collections;
/**
* <code>EventSubscription</code> listens for JCR events and creates SPI event
* bundles for them.
*/
class EventSubscription implements Subscription, EventListener {
/**
* Logger instance for this class.
*/
private static final Logger log = LoggerFactory.getLogger(EventSubscription.class);
/**
* Mask for all events.
*/
static final int ALL_EVENTS = javax.jcr.observation.Event.NODE_ADDED
| javax.jcr.observation.Event.NODE_REMOVED
| javax.jcr.observation.Event.PROPERTY_ADDED
| javax.jcr.observation.Event.PROPERTY_CHANGED
| javax.jcr.observation.Event.PROPERTY_REMOVED
| javax.jcr.observation.Event.NODE_MOVED
| javax.jcr.observation.Event.PERSIST;
private final List<EventBundle> eventBundles = new ArrayList<EventBundle>();
private final SessionInfoImpl sessionInfo;
/**
* Current list of filters. Copy on write is performed on this list.
*/
private volatile List<EventFilter> filters;
/**
* Set to <code>true</code> if this subscription has been disposed.
*/
private volatile boolean disposed = false;
/**
* The event factory.
*/
private final EventFactory eventFactory;
/**
* Creates a new subscription for the passed session.
*
* @param idFactory the id factory.
* @param qValueFactory the QValueFactory.
* @param sessionInfo the session info.
* @param filters the filters that should be applied to the generated
* events.
* @throws RepositoryException if an error occurs while an event listener is
* registered with the session.
*/
EventSubscription(IdFactory idFactory,
QValueFactory qValueFactory,
SessionInfoImpl sessionInfo,
EventFilter[] filters) throws RepositoryException {
this.sessionInfo = sessionInfo;
this.eventFactory = new EventFactory(sessionInfo.getSession(),
sessionInfo.getNamePathResolver(), idFactory, qValueFactory);
setFilters(filters);
ObservationManager obsMgr = sessionInfo.getSession().getWorkspace().getObservationManager();
obsMgr.addEventListener(this, EventSubscription.ALL_EVENTS, "/", true, null, null, true);
}
/**
* Sets a new list of event filters for this subscription.
*
* @param filters the new filters.
* @throws RepositoryException if the filters array contains a unknown
* implementation of EventFilters.
*/
void setFilters(EventFilter[] filters) throws RepositoryException {
// check type
for (EventFilter filter : filters) {
if (!(filter instanceof EventFilterImpl)) {
throw new RepositoryException("Unknown filter implementation");
}
}
List<EventFilter> tmp = new ArrayList<EventFilter>(Arrays.asList(filters));
this.filters = Collections.unmodifiableList(tmp);
}
/**
* Removes this subscription as a listener from the observation manager and
* marks itself as disposed.
*/
void dispose() throws RepositoryException {
sessionInfo.removeSubscription(this);
sessionInfo.getSession().getWorkspace().getObservationManager().removeEventListener(this);
disposed = true;
synchronized (eventBundles) {
eventBundles.notify();
}
}
//--------------------------< EventListener >-------------------------------
/**
* Adds the events to the list of pending event bundles.
*
* @param events the events that occurred.
*/
public void onEvent(javax.jcr.observation.EventIterator events) {
createEventBundle(events, false);
}
/**
* @return a temporary event listener that will create local event bundles
* for delivered events.
*/
EventListener getLocalEventListener() {
return new EventListener() {
public void onEvent(javax.jcr.observation.EventIterator events) {
createEventBundle(events, true);
}
};
}
/**
* @return all the pending event bundles.
*/
EventBundle[] getEventBundles(long timeout) {
EventBundle[] bundles;
synchronized (eventBundles) {
if (eventBundles.isEmpty()) {
try {
eventBundles.wait(timeout);
} catch (InterruptedException e) {
// continue
}
}
bundles = eventBundles.toArray(new EventBundle[eventBundles.size()]);
eventBundles.clear();
}
EventFilter[] eventFilters = filters.toArray(new EventFilter[filters.size()]);
// apply filters to bundles
for (int i = 0; i < bundles.length; i++) {
List<Event> filteredEvents = new ArrayList<Event>();
for (Iterator<Event> it = bundles[i].getEvents(); it.hasNext(); ) {
Event e = it.next();
// TODO: this is actually not correct. if filters are empty no event should go out
if (eventFilters == null || eventFilters.length == 0) {
filteredEvents.add(e);
} else {
for (EventFilter eventFilter : eventFilters) {
if (eventFilter.accept(e, bundles[i].isLocal())) {
filteredEvents.add(e);
break;
}
}
}
}
bundles[i] = new EventBundleImpl(filteredEvents, bundles[i].isLocal());
}
return bundles;
}
//--------------------------------< internal >------------------------------
private void createEventBundle(javax.jcr.observation.EventIterator events,
boolean isLocal) {
// do not create events when disposed
if (disposed) {
return;
}
List<Event> spiEvents = new ArrayList<Event>();
while (events.hasNext()) {
try {
Event spiEvent = eventFactory.fromJCREvent(events.nextEvent());
spiEvents.add(spiEvent);
} catch (Exception ex) {
log.warn("Unable to create SPI Event: " + ex);
}
}
EventBundle bundle = new EventBundleImpl(spiEvents, isLocal);
synchronized (eventBundles) {
eventBundles.add(bundle);
eventBundles.notify();
}
}
}