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* 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
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package org.apache.cayenne;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
import java.util.Map;
import org.apache.cayenne.event.EventManager;
import org.apache.cayenne.event.EventSubject;
import org.apache.cayenne.graph.ArcCreateOperation;
import org.apache.cayenne.graph.ArcDeleteOperation;
import org.apache.cayenne.graph.GraphChangeHandler;
import org.apache.cayenne.graph.GraphDiff;
import org.apache.cayenne.graph.GraphEvent;
import org.apache.cayenne.graph.GraphMap;
import org.apache.cayenne.graph.NodeCreateOperation;
import org.apache.cayenne.graph.NodeDeleteOperation;
import org.apache.cayenne.graph.NodeIdChangeOperation;
import org.apache.cayenne.graph.NodePropertyChangeOperation;
import org.apache.cayenne.map.EntityResolver;
import org.apache.cayenne.reflect.ArcProperty;
import org.apache.cayenne.reflect.ClassDescriptor;
import org.apache.cayenne.reflect.PropertyException;
import org.apache.cayenne.reflect.ToManyMapProperty;
/**
* A GraphMap extension that works together with ObjectContext to track persistent object
* changes and send events.
*
* @since 1.2
*/
final class CayenneContextGraphManager extends GraphMap {
static final String COMMIT_MARKER = "commit";
static final String FLUSH_MARKER = "flush";
CayenneContext context;
Collection<Object> deadIds;
boolean changeEventsEnabled;
boolean lifecycleEventsEnabled;
ObjectContextStateLog stateLog;
ObjectContextChangeLog changeLog;
CayenneContextGraphManager(CayenneContext context, boolean changeEventsEnabled,
boolean lifecycleEventsEnabled) {
this.context = context;
this.changeEventsEnabled = changeEventsEnabled;
this.lifecycleEventsEnabled = lifecycleEventsEnabled;
this.stateLog = new ObjectContextStateLog(this);
this.changeLog = new ObjectContextChangeLog();
}
boolean hasChanges() {
return changeLog.size() > 0;
}
boolean hasChangesSinceLastFlush() {
int size = changeLog.hasMarker(FLUSH_MARKER) ? changeLog
.sizeAfterMarker(FLUSH_MARKER) : changeLog.size();
return size > 0;
}
GraphDiff getDiffs() {
return changeLog.getDiffs();
}
GraphDiff getDiffsSinceLastFlush() {
return changeLog.hasMarker(FLUSH_MARKER) ? changeLog
.getDiffsAfterMarker(FLUSH_MARKER) : changeLog.getDiffs();
}
Collection<Object> dirtyNodes() {
return stateLog.dirtyNodes();
}
Collection<Object> dirtyNodes(int state) {
return stateLog.dirtyNodes(state);
}
@Override
public synchronized Object unregisterNode(Object nodeId) {
Object node = super.unregisterNode(nodeId);
// remove node from other collections...
if (node != null) {
stateLog.unregisterNode(nodeId);
changeLog.unregisterNode(nodeId);
return node;
}
return null;
}
// ****** Sync Events API *****
/**
* Clears commit marker, but keeps all recorded operations.
*/
void graphCommitAborted() {
changeLog.removeMarker(COMMIT_MARKER);
}
/**
* Sets commit start marker in the change log. If events are enabled, posts commit
* start event.
*/
void graphCommitStarted() {
changeLog.setMarker(COMMIT_MARKER);
}
void graphCommitted(GraphDiff parentSyncDiff) {
if (parentSyncDiff != null) {
new CayenneContextMergeHandler(context).merge(parentSyncDiff);
}
remapTargets();
stateLog.graphCommitted();
reset();
if (lifecycleEventsEnabled) {
// include all diffs after the commit start marker.
// We fire event as if it was posted by parent channel, so that
// nested contexts could catch it
context.fireDataChannelCommitted(context.getChannel(), parentSyncDiff);
}
}
/**
* Remaps keys in to-many map relationships that contain dirty objects with
* potentially modified properties.
*/
private void remapTargets() {
Iterator<Object> it = stateLog.dirtyIds().iterator();
EntityResolver resolver = context.getEntityResolver();
// avoid processing callbacks when updating the map...
PropertyChangeProcessingStrategy oldChangeStrategy = context
.getPropertyChangeProcessingStrategy();
context
.setPropertyChangeProcessingStrategy(PropertyChangeProcessingStrategy.IGNORE);
try {
while (it.hasNext()) {
ObjectId id = (ObjectId) it.next();
ClassDescriptor descriptor = resolver.getClassDescriptor(id
.getEntityName());
Iterator<ArcProperty> mapArcProperties = descriptor.getMapArcProperties();
if (mapArcProperties.hasNext()) {
Object object = getNode(id);
while (mapArcProperties.hasNext()) {
ArcProperty arc = mapArcProperties.next();
ToManyMapProperty reverseArc = (ToManyMapProperty) arc
.getComplimentaryReverseArc();
Object source = arc.readPropertyDirectly(object);
if (source != null && !reverseArc.isFault(source)) {
remapTarget(reverseArc, source, object);
}
}
}
}
}
finally {
context.setPropertyChangeProcessingStrategy(oldChangeStrategy);
}
}
// clone of DataDomainSyncBucket.remapTarget
private final void remapTarget(
ToManyMapProperty property,
Object source,
Object target) throws PropertyException {
Map<Object, Object> map = (Map<Object, Object>) property.readProperty(source);
Object newKey = property.getMapKey(target);
Object currentValue = map.get(newKey);
if (currentValue == target) {
// nothing to do
return;
}
// else - do not check for conflicts here (i.e. another object mapped for the same
// key), as we have no control of the order in which this method is called, so
// another object may be remapped later by the caller
// must do a slow map scan to ensure the object is not mapped under a different
// key...
Iterator<?> it = map.entrySet().iterator();
while (it.hasNext()) {
Map.Entry<?, ?> e = (Map.Entry<?, ?>) it.next();
if (e.getValue() == target) {
it.remove();
break;
}
}
map.put(newKey, target);
}
void graphFlushed() {
changeLog.setMarker(FLUSH_MARKER);
}
void graphReverted() {
GraphDiff diff = changeLog.getDiffs();
diff.undo(new RollbackChangeHandler());
stateLog.graphReverted();
reset();
if (lifecycleEventsEnabled) {
context.fireDataChannelRolledback(context, diff);
}
}
// ****** GraphChangeHandler API ******
// =====================================================
@Override
public synchronized void nodeIdChanged(Object nodeId, Object newId) {
stateLog.nodeIdChanged(nodeId, newId);
processChange(new NodeIdChangeOperation(nodeId, newId));
}
@Override
public synchronized void nodeCreated(Object nodeId) {
stateLog.nodeCreated(nodeId);
processChange(new NodeCreateOperation(nodeId));
}
@Override
public synchronized void nodeRemoved(Object nodeId) {
stateLog.nodeRemoved(nodeId);
processChange(new NodeDeleteOperation(nodeId));
}
@Override
public synchronized void nodePropertyChanged(
Object nodeId,
String property,
Object oldValue,
Object newValue) {
stateLog.nodePropertyChanged(nodeId, property, oldValue, newValue);
processChange(new NodePropertyChangeOperation(
nodeId,
property,
oldValue,
newValue));
}
@Override
public synchronized void arcCreated(Object nodeId, Object targetNodeId, Object arcId) {
stateLog.arcCreated(nodeId, targetNodeId, arcId);
processChange(new ArcCreateOperation(nodeId, targetNodeId, arcId));
}
@Override
public synchronized void arcDeleted(Object nodeId, Object targetNodeId, Object arcId) {
stateLog.arcDeleted(nodeId, targetNodeId, arcId);
processChange(new ArcDeleteOperation(nodeId, targetNodeId, arcId));
}
// ****** helper methods ******
// =====================================================
private void processChange(GraphDiff diff) {
changeLog.addOperation(diff);
if (changeEventsEnabled) {
context.fireDataChannelChanged(context, diff);
}
}
/**
* Wraps GraphDiff in a GraphEvent and sends it via EventManager with specified
* subject.
*/
void send(GraphDiff diff, EventSubject subject, Object eventSource) {
EventManager manager = (context.getChannel() != null) ? context
.getChannel()
.getEventManager() : null;
if (manager != null) {
GraphEvent e = new GraphEvent(context, eventSource, diff);
manager.postEvent(e, subject);
}
}
void reset() {
changeLog.reset();
if (deadIds != null) {
// unregister dead ids...
for (final Object deadId : deadIds) {
nodes.remove(deadId);
}
deadIds = null;
}
}
Collection<Object> deadIds() {
if (deadIds == null) {
deadIds = new ArrayList<Object>();
}
return deadIds;
}
/**
* This change handler is used to perform rollback actions for Cayenne context
*/
class RollbackChangeHandler implements GraphChangeHandler {
public void arcCreated(Object nodeId, Object targetNodeId, Object arcId) {
context.mergeHandler.arcCreated(nodeId, targetNodeId, arcId);
CayenneContextGraphManager.this.arcCreated(nodeId, targetNodeId, arcId);
}
public void arcDeleted(Object nodeId, Object targetNodeId, Object arcId) {
context.mergeHandler.arcDeleted(nodeId, targetNodeId, arcId);
CayenneContextGraphManager.this.arcDeleted(nodeId, targetNodeId, arcId);
}
public void nodeCreated(Object nodeId) {
CayenneContextGraphManager.this.nodeCreated(nodeId);
}
public void nodeIdChanged(Object nodeId, Object newId) {
CayenneContextGraphManager.this.nodeIdChanged(nodeId, newId);
}
/**
* Need to write property directly to this context
*/
public void nodePropertyChanged(
Object nodeId,
String property,
Object oldValue,
Object newValue) {
context.mergeHandler
.nodePropertyChanged(nodeId, property, oldValue, newValue);
CayenneContextGraphManager.this.nodePropertyChanged(
nodeId,
property,
oldValue,
newValue);
}
public void nodeRemoved(Object nodeId) {
CayenneContextGraphManager.this.nodeRemoved(nodeId);
}
}
}