/*
* 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.oak.plugins.observation;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.ScheduledFuture;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicReference;
import javax.jcr.observation.Event;
import javax.jcr.observation.EventListener;
import com.google.common.base.Function;
import com.google.common.base.Predicate;
import com.google.common.collect.Iterators;
import org.apache.jackrabbit.commons.iterator.EventIteratorAdapter;
import org.apache.jackrabbit.oak.api.PropertyState;
import org.apache.jackrabbit.oak.commons.PathUtils;
import org.apache.jackrabbit.oak.namepath.NamePathMapper;
import org.apache.jackrabbit.oak.spi.observation.ChangeExtractor;
import org.apache.jackrabbit.oak.spi.state.ChildNodeEntry;
import org.apache.jackrabbit.oak.spi.state.NodeState;
import org.apache.jackrabbit.oak.spi.state.NodeStateDiff;
import org.apache.jackrabbit.oak.spi.state.NodeStateUtils;
import org.apache.jackrabbit.oak.util.TODO;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.slf4j.Marker;
import org.slf4j.MarkerFactory;
/**
* TODO document
*/
class ChangeProcessor implements Runnable {
private static final Logger log =
LoggerFactory.getLogger(ChangeProcessor.class);
private static final Marker DEPRECATED =
MarkerFactory.getMarker("deprecated");
private static final String DUMMY_USER_ID = TODO.dummyImplementation().returnValueOrNull("oak:unknown");
private final ObservationManagerImpl observationManager;
private final NamePathMapper namePathMapper;
private final ChangeExtractor changeExtractor;
private final EventListener listener;
private final AtomicReference<ChangeFilter> filterRef;
private volatile boolean running;
private volatile boolean stopping;
private ScheduledFuture<?> future;
private boolean userIDAccessed = false;
private boolean userDataAccessed = false;
private boolean isExternalAccessed = false;
private boolean userInfoAccessedWithoutExternalsCheck = false;
private boolean userInfoAccessedFromExternalEvent = false;
public ChangeProcessor(ObservationManagerImpl observationManager, EventListener listener, ChangeFilter filter) {
this.observationManager = observationManager;
this.namePathMapper = observationManager.getNamePathMapper();
this.changeExtractor = observationManager.getChangeExtractor();
this.listener = listener;
filterRef = new AtomicReference<ChangeFilter>(filter);
}
public void setFilter(ChangeFilter filter) {
filterRef.set(filter);
}
/**
* Stop this change processor if running. After returning from this methods no further
* events will be delivered.
* @throws IllegalStateException if not yet started or stopped already
*/
public synchronized void stop() {
if (future == null) {
throw new IllegalStateException("Change processor not started");
}
try {
stopping = true;
future.cancel(true);
while (running) {
wait();
}
} catch (InterruptedException e) {
Thread.currentThread().interrupt();
}
finally {
future = null;
}
}
/**
* Start the change processor on the passed {@code executor}.
* @param executor
* @throws IllegalStateException if started already
*/
public synchronized void start(ScheduledExecutorService executor) {
if (future != null) {
throw new IllegalStateException("Change processor started already");
}
stopping = false;
future = executor.scheduleWithFixedDelay(this, 100, 1000, TimeUnit.MILLISECONDS);
}
@Override
public void run() {
running = true;
try{
EventGeneratingNodeStateDiff diff = new EventGeneratingNodeStateDiff();
changeExtractor.getChanges(diff);
if (!stopping) {
diff.sendEvents();
}
} catch (Exception e) {
log.error("Unable to generate or send events", e);
} finally {
synchronized (this) {
running = false;
notifyAll();
}
}
}
synchronized void userIDAccessed() {
userIDAccessed = true;
}
synchronized void userDataAccessed() {
userDataAccessed = true;
}
synchronized void externalAccessed() {
isExternalAccessed = true;
}
synchronized void userInfoAccessedWithoutExternalCheck() {
if (!userInfoAccessedWithoutExternalsCheck) {
log.warn(DEPRECATED,
"Event listener " + listener + " is trying to access"
+ " event user information without checking for whether"
+ " the event is external");
userInfoAccessedWithoutExternalsCheck = true;
}
}
synchronized void userInfoAccessedFromExternalEvent() {
if (!userInfoAccessedFromExternalEvent) {
log.warn(DEPRECATED,
"Event listener " + listener + " is trying to access"
+ " event user information from an external event");
userInfoAccessedFromExternalEvent = true;
}
}
//------------------------------------------------------------< private >---
private class EventGeneratingNodeStateDiff implements NodeStateDiff {
public static final int PURGE_LIMIT = 8192;
private final String path;
private final NodeState associatedParentNode;
private int childNodeCount;
private List<Iterator<Event>> events;
EventGeneratingNodeStateDiff(String path, List<Iterator<Event>> events, NodeState associatedParentNode) {
this.path = path;
this.associatedParentNode = associatedParentNode;
this.events = events;
}
public EventGeneratingNodeStateDiff() {
this("/", new ArrayList<Iterator<Event>>(PURGE_LIMIT), null);
}
public void sendEvents() {
Iterator<Event> eventIt = Iterators.concat(events.iterator());
if (eventIt.hasNext()) {
observationManager.setHasEvents();
listener.onEvent(new EventIteratorAdapter(eventIt) {
@Override
public boolean hasNext() {
return !stopping && super.hasNext();
}
});
events = new ArrayList<Iterator<Event>>(PURGE_LIMIT);
}
}
private String jcrPath() {
return namePathMapper.getJcrPath(path);
}
@Override
public boolean propertyAdded(PropertyState after) {
if (!NodeStateUtils.isHidden(after.getName())
&& filterRef.get().include(Event.PROPERTY_ADDED, jcrPath(), associatedParentNode)) {
Event event = generatePropertyEvent(Event.PROPERTY_ADDED, path, after);
events.add(Iterators.singletonIterator(event));
}
return !stopping;
}
@Override
public boolean propertyChanged(PropertyState before, PropertyState after) {
if (!NodeStateUtils.isHidden(before.getName())
&& filterRef.get().include(Event.PROPERTY_CHANGED, jcrPath(), associatedParentNode)) {
Event event = generatePropertyEvent(Event.PROPERTY_CHANGED, path, after);
events.add(Iterators.singletonIterator(event));
}
return !stopping;
}
@Override
public boolean propertyDeleted(PropertyState before) {
if (!NodeStateUtils.isHidden(before.getName())
&& filterRef.get().include(Event.PROPERTY_REMOVED, jcrPath(), associatedParentNode)) {
Event event = generatePropertyEvent(Event.PROPERTY_REMOVED, path, before);
events.add(Iterators.singletonIterator(event));
}
return !stopping;
}
@Override
public boolean childNodeAdded(String name, NodeState after) {
if (!NodeStateUtils.isHidden(name)
&& filterRef.get().includeChildren(jcrPath())) {
Iterator<Event> events = generateNodeEvents(Event.NODE_ADDED, path, name, after);
this.events.add(events);
if (++childNodeCount > PURGE_LIMIT) {
sendEvents();
}
}
return !stopping;
}
@Override
public boolean childNodeDeleted(String name, NodeState before) {
if (!NodeStateUtils.isHidden(name)
&& filterRef.get().includeChildren(jcrPath())) {
Iterator<Event> events = generateNodeEvents(Event.NODE_REMOVED, path, name, before);
this.events.add(events);
}
return !stopping;
}
@Override
public boolean childNodeChanged(String name, NodeState before, NodeState after) {
if (!NodeStateUtils.isHidden(name)
&& filterRef.get().includeChildren(jcrPath())) {
EventGeneratingNodeStateDiff diff = new EventGeneratingNodeStateDiff(
PathUtils.concat(path, name), events, after);
if (!after.compareAgainstBaseState(before, diff)) {
return false;
}
if (events.size() > PURGE_LIMIT) {
diff.sendEvents();
}
}
return !stopping;
}
private Event generatePropertyEvent(int eventType, String parentPath, PropertyState property) {
String jcrPath = namePathMapper.getJcrPath(PathUtils.concat(parentPath, property.getName()));
// TODO support userId, identifier, info, date
return new EventImpl(ChangeProcessor.this, eventType, jcrPath, DUMMY_USER_ID, null, null, 0, null, false);
}
private Iterator<Event> generateNodeEvents(int eventType, String parentPath, String name, NodeState node) {
ChangeFilter filter = filterRef.get();
final String path = PathUtils.concat(parentPath, name);
String jcrParentPath = namePathMapper.getJcrPath(parentPath);
String jcrPath = namePathMapper.getJcrPath(path);
Iterator<Event> nodeEvent;
if (filter.include(eventType, jcrParentPath, associatedParentNode)) {
// TODO support userId, identifier, info, date
Event event = new EventImpl(ChangeProcessor.this, eventType, jcrPath, DUMMY_USER_ID, null, null, 0, null, false);
nodeEvent = Iterators.singletonIterator(event);
} else {
nodeEvent = Iterators.emptyIterator();
}
final int propertyEventType = eventType == Event.NODE_ADDED
? Event.PROPERTY_ADDED
: Event.PROPERTY_REMOVED;
Iterator<Event> propertyEvents;
if (filter.include(propertyEventType, jcrPath, associatedParentNode)) {
propertyEvents = Iterators.transform(
Iterators.filter(
node.getProperties().iterator(),
new Predicate<PropertyState>() {
@Override
public boolean apply(PropertyState propertyState) {
return !NodeStateUtils.isHidden(propertyState.getName());
}
}),
new Function<PropertyState, Event>() {
@Override
public Event apply(PropertyState property) {
return generatePropertyEvent(propertyEventType, path, property);
}
});
} else {
propertyEvents = Iterators.emptyIterator();
}
Iterator<Event> childNodeEvents = filter.includeChildren(jcrPath)
? Iterators.concat(generateChildEvents(eventType, path, node))
: Iterators.<Event>emptyIterator();
return Iterators.concat(nodeEvent, propertyEvents, childNodeEvents);
}
private Iterator<Iterator<Event>> generateChildEvents(final int eventType, final String parentPath, NodeState node) {
return Iterators.transform(
Iterators.filter(node.getChildNodeEntries().iterator(),
new Predicate<ChildNodeEntry>() {
@Override
public boolean apply(ChildNodeEntry entry) {
return !NodeStateUtils.isHidden(entry.getName());
}
}),
new Function<ChildNodeEntry, Iterator<Event>>() {
@Override
public Iterator<Event> apply(ChildNodeEntry entry) {
return generateNodeEvents(eventType, parentPath, entry.getName(), entry.getNodeState());
}
});
}
}
}