/*
* 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.ItemId;
import org.apache.jackrabbit.spi.NodeId;
import org.apache.jackrabbit.spi.IdFactory;
import org.apache.jackrabbit.spi.Name;
import org.apache.jackrabbit.spi.Path;
import org.apache.jackrabbit.spi.Subscription;
import org.apache.jackrabbit.spi.commons.EventImpl;
import org.apache.jackrabbit.spi.commons.EventBundleImpl;
import org.apache.jackrabbit.spi.commons.EventFilterImpl;
import org.apache.jackrabbit.spi.commons.conversion.NameException;
import org.apache.jackrabbit.spi.commons.conversion.NameResolver;
import org.apache.jackrabbit.spi.commons.conversion.NamePathResolver;
import org.slf4j.LoggerFactory;
import org.slf4j.Logger;
import javax.jcr.observation.EventListener;
import javax.jcr.observation.ObservationManager;
import javax.jcr.Session;
import javax.jcr.Node;
import javax.jcr.UnsupportedRepositoryOperationException;
import javax.jcr.NamespaceException;
import javax.jcr.RepositoryException;
import javax.jcr.nodetype.NodeType;
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;
private final List eventBundles = new ArrayList();
private final IdFactory idFactory;
private final SessionInfoImpl sessionInfo;
/**
* Current list of filters. Copy on write is performed on this list.
*/
private volatile List filters;
/**
* The resolver of the underlying session.
*/
private final NamePathResolver resolver;
/**
* Set to <code>true</code> if this subscription has been disposed.
*/
private volatile boolean disposed = false;
/**
* Creates a new subscription for the passed session.
*
* @param idFactory the id factory.
* @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,
SessionInfoImpl sessionInfo,
EventFilter[] filters) throws RepositoryException {
this.idFactory = idFactory;
this.sessionInfo = sessionInfo;
this.resolver = sessionInfo.getNamePathResolver();
setFilters(filters);
ObservationManager obsMgr = sessionInfo.getSession().getWorkspace().getObservationManager();
obsMgr.addEventListener(this, EventSubscription.ALL_EVENTS,
"/", true, null, null, true);
}
/**
* @return the session info associated with this event subscription.
*/
SessionInfoImpl getSessionInfo() {
return sessionInfo;
}
/**
* 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 (int i = 0; i < filters.length; i++) {
if (!(filters[i] instanceof EventFilterImpl)) {
throw new RepositoryException("Unknown filter implementation");
}
}
List tmp = new ArrayList(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 = (EventBundle[]) eventBundles.toArray(new EventBundle[eventBundles.size()]);
eventBundles.clear();
}
EventFilter[] eventFilters = (EventFilter[]) filters.toArray(
new EventFilter[filters.size()]);
// apply filters to bundles
for (int i = 0; i < bundles.length; i++) {
List filteredEvents = new ArrayList();
for (Iterator it = bundles[i].getEvents(); it.hasNext(); ) {
Event e = (Event) 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 (int j = 0; j < eventFilters.length; j++) {
if (eventFilters[j].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 spiEvents = new ArrayList();
while (events.hasNext()) {
try {
Session session = sessionInfo.getSession();
javax.jcr.observation.Event e = events.nextEvent();
Path p = resolver.getQPath(e.getPath());
Path parent = p.getAncestor(1);
NodeId parentId = idFactory.createNodeId((String) null, parent);
ItemId itemId = null;
Node node = null;
switch (e.getType()) {
case Event.NODE_ADDED:
node = session.getItem(e.getPath()).getParent();
case Event.NODE_REMOVED:
itemId = idFactory.createNodeId((String) null, p);
break;
case Event.PROPERTY_ADDED:
case Event.PROPERTY_CHANGED:
node = session.getItem(e.getPath()).getParent();
case Event.PROPERTY_REMOVED:
itemId = idFactory.createPropertyId(parentId,
p.getNameElement().getName());
break;
}
Name nodeTypeName = null;
Name[] mixinTypes = new Name[0];
if (node != null) {
try {
parentId = idFactory.createNodeId(node.getUUID(), null);
} catch (UnsupportedRepositoryOperationException ex) {
// not referenceable
}
nodeTypeName = resolver.getQName(node.getPrimaryNodeType().getName());
mixinTypes = getNodeTypeNames(node.getMixinNodeTypes(), resolver);
}
Event spiEvent = new EventImpl(e.getType(), p, itemId, parentId,
nodeTypeName, mixinTypes, e.getUserID());
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();
}
}
/**
* Returns the qualified names of the passed node types using the namespace
* resolver to parse the names.
*
* @param nt the node types
* @param resolver
* @return the qualified names of the node types.
* @throws NameException if a node type returns an illegal name.
* @throws NamespaceException if the name of a node type contains a
* prefix that is not known to <code>resolver</code>.
*/
private static Name[] getNodeTypeNames(NodeType[] nt, NameResolver resolver)
throws NameException, NamespaceException {
Name[] names = new Name[nt.length];
for (int i = 0; i < nt.length; i++) {
Name ntName = resolver.getQName(nt[i].getName());
names[i] = ntName;
}
return names;
}
}