org.apache.cayenne.access.ObjectStore Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of cayenne-client-nodeps
Show all versions of cayenne-client-nodeps
Cayenne Object Persistence Framework
/*****************************************************************
* 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.cayenne.access;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import org.apache.cayenne.DataObject;
import org.apache.cayenne.DataRow;
import org.apache.cayenne.Fault;
import org.apache.cayenne.ObjectContext;
import org.apache.cayenne.ObjectId;
import org.apache.cayenne.PersistenceState;
import org.apache.cayenne.Persistent;
import org.apache.cayenne.access.ObjectDiff.ArcOperation;
import org.apache.cayenne.access.event.SnapshotEvent;
import org.apache.cayenne.access.event.SnapshotEventListener;
import org.apache.cayenne.graph.CompoundDiff;
import org.apache.cayenne.graph.GraphChangeHandler;
import org.apache.cayenne.graph.GraphDiff;
import org.apache.cayenne.graph.GraphManager;
import org.apache.cayenne.graph.NodeCreateOperation;
import org.apache.cayenne.graph.NodeDeleteOperation;
import org.apache.cayenne.graph.NodeDiff;
import org.apache.cayenne.map.ObjEntity;
import org.apache.cayenne.map.ObjRelationship;
import org.apache.cayenne.query.ObjectIdQuery;
import org.apache.cayenne.validation.ValidationException;
import org.apache.cayenne.validation.ValidationResult;
/**
* ObjectStore stores objects using their ObjectId as a key. It works as a dedicated
* object cache for a DataContext. Users rarely need to access ObjectStore directly, as
* DataContext serves as a facade, providing cover methods for most ObjectStore
* operations.
*
* @since 1.0
* @author Andrus Adamchik
*/
// Synchronization Note: There is often a need to do double synchronize on an ObjectStore
// and an underlying DataRowCache. To avoid deadlocks, Cayenne consistently follows the
// policy of locking an ObjectStore first, and then locking DataRowStore. This pattern
// must be followed in any new related developments.
public class ObjectStore implements Serializable, SnapshotEventListener, GraphManager {
protected transient Map newObjectsMap;
protected Map objectMap = new HashMap();
protected Map queryResultMap = new HashMap();
protected Map changes = new HashMap();
// a sequential id used to tag GraphDiffs so that they can later be sorted in the
// original creation order
int currentDiffId;
/**
* Stores a reference to the DataRowStore.
*
* Serialization note: It is up to the owner of this ObjectStore to initialize
* DataRowStore after deserialization of this object. ObjectStore will not know how to
* restore the DataRowStore by itself.
*
*/
protected transient DataRowStore dataRowCache;
// used to avoid incorrect on-demand DataRowStore initialization after deserialization
private boolean dataRowCacheSet;
/**
* The DataContext that owns this ObjectStore.
*/
protected DataContext context;
public ObjectStore() {
}
public ObjectStore(DataRowStore dataRowCache) {
setDataRowCache(dataRowCache);
}
/**
* @since 1.2
*/
void recordObjectDeleted(Persistent object) {
object.setPersistenceState(PersistenceState.DELETED);
registerDiff(object, new NodeDeleteOperation(object.getObjectId()));
}
/**
* @since 1.2
*/
void recordObjectCreated(Persistent object) {
registerDiff(object, new NodeCreateOperation(object.getObjectId()));
registerNode(object.getObjectId(), object);
}
/**
* Performs tracking of object relationship changes.
*
* @since 1.2
*/
// TODO: Andrus, 3/14/2006 - this method should be made non-public once we remove
// direct ObjectStore access from CayenneDataObject.
public void recordArcCreated(
Persistent object,
ObjectId targetId,
String relationshipName) {
registerDiff(object, new ArcOperation(
object.getObjectId(),
targetId,
relationshipName,
false));
}
/**
* Performs tracking of object relationship changes.
*
* @since 1.2
*/
// TODO: Andrus, 3/14/2006 - this method should be made non-public once we remove
// direct ObjectStore access from CayenneDataObject.
public void recordArcDeleted(
Persistent object,
ObjectId targetId,
String relationshipName) {
registerDiff(object, new ArcOperation(
object.getObjectId(),
targetId,
relationshipName,
true));
}
/**
* Registers object change.
*
* @since 1.2
*/
synchronized ObjectDiff registerDiff(Persistent object, NodeDiff diff) {
ObjectId id = object.getObjectId();
if (object.getPersistenceState() == PersistenceState.COMMITTED) {
object.setPersistenceState(PersistenceState.MODIFIED);
// TODO: andrus 3/23/2006 snapshot versions are obsolete, but there is no
// replacement yet, so we still need to handle them...
if (object instanceof DataObject) {
DataObject dataObject = (DataObject) object;
DataRow snapshot = getCachedSnapshot(id);
if (snapshot != null
&& snapshot.getVersion() != dataObject.getSnapshotVersion()) {
DataContextDelegate delegate = dataObject
.getDataContext()
.nonNullDelegate();
if (delegate.shouldMergeChanges(dataObject, snapshot)) {
ObjEntity entity = dataObject
.getDataContext()
.getEntityResolver()
.lookupObjEntity(object);
DataRowUtils.forceMergeWithSnapshot(entity, dataObject, snapshot);
dataObject.setSnapshotVersion(snapshot.getVersion());
delegate.finishedMergeChanges(dataObject);
}
}
}
}
if (diff != null) {
diff.setDiffId(++currentDiffId);
}
ObjectDiff objectDiff = (ObjectDiff) changes.get(id);
if (objectDiff == null) {
objectDiff = new ObjectDiff(this, object);
objectDiff.setDiffId(++currentDiffId);
changes.put(id, objectDiff);
}
if (diff != null) {
objectDiff.addDiff(diff);
}
return objectDiff;
}
/**
* Returns a number of objects currently registered with this ObjectStore.
*
* @since 1.2
*/
public int registeredObjectsCount() {
return objectMap.size();
}
/**
* Returns a number of query results cached by this object store. Note that each
* result is a list and can possibly contain a large number of entries.
*
* @since 1.2
*/
public int cachedQueriesCount() {
return queryResultMap.size();
}
/**
* Returns a DataRowStore associated with this ObjectStore.
*/
public DataRowStore getDataRowCache() {
// perform deferred initialization...
// Andrus, 11/7/2005 - potential problem with on-demand deferred initialization is
// that deserialized context won't receive any events... which maybe ok, since it
// didn't while it was stored in serialized form.
if (dataRowCache == null && context != null && dataRowCacheSet) {
synchronized (this) {
if (dataRowCache == null) {
DataDomain domain = context.getParentDataDomain();
if (domain != null) {
setDataRowCache(domain.getSharedSnapshotCache());
}
}
}
}
return dataRowCache;
}
/**
* Sets parent DataRowStore. Registers to receive SnapshotEvents if the cache is
* configured to allow ObjectStores to receive such events.
*/
// note that as of 1.2, ObjectStore does not access DataRowStore directly when
// retrieving snapshots. Instead it sends a query via the DataContext's channel so
// that every element in the channel chain could intercept snapshot requests
public void setDataRowCache(DataRowStore dataRowCache) {
if (dataRowCache == this.dataRowCache) {
return;
}
if (this.dataRowCache != null && dataRowCache.getEventManager() != null) {
dataRowCache.getEventManager().removeListener(
this,
this.dataRowCache.getSnapshotEventSubject());
}
this.dataRowCache = dataRowCache;
if (dataRowCache != null && dataRowCache.getEventManager() != null) {
// setting itself as non-blocking listener,
// since event sending thread will likely be locking sender's
// ObjectStore and snapshot cache itself.
dataRowCache.getEventManager().addNonBlockingListener(
this,
"snapshotsChanged",
SnapshotEvent.class,
dataRowCache.getSnapshotEventSubject(),
dataRowCache);
}
dataRowCacheSet = dataRowCache != null;
}
/**
* Invalidates a collection of DataObjects. Changes objects state to HOLLOW.
*
* @see #objectsUnregistered(Collection)
*/
public synchronized void objectsInvalidated(Collection objects) {
if (objects.isEmpty()) {
return;
}
Collection ids = new ArrayList(objects.size());
Iterator it = objects.iterator();
while (it.hasNext()) {
DataObject object = (DataObject) it.next();
// we don't care about NEW objects,
// but we still do care about HOLLOW, since snapshot might still be
// present
if (object.getPersistenceState() == PersistenceState.NEW) {
continue;
}
object.setPersistenceState(PersistenceState.HOLLOW);
// remove cached changes
changes.remove(object.getObjectId());
// remember the id
ids.add(object.getObjectId());
}
// TODO, andrus 3/28/2006 - DRC is null in nested contexts... implement
// propagation of invalidate operation through the stack
if (getDataRowCache() != null) {
// send an event for removed snapshots
getDataRowCache().processSnapshotChanges(
this,
Collections.EMPTY_MAP,
Collections.EMPTY_LIST,
ids,
Collections.EMPTY_LIST);
}
}
/**
* Evicts a collection of DataObjects from the ObjectStore, invalidates the underlying
* cache snapshots. Changes objects state to TRANSIENT. This method can be used for
* manual cleanup of Cayenne cache.
*
* @see #objectsInvalidated(Collection)
*/
// this method is exactly the same as "objectsInvalidated", only additionally it
// throws out registered objects
public synchronized void objectsUnregistered(Collection objects) {
if (objects.isEmpty()) {
return;
}
Collection ids = new ArrayList(objects.size());
Iterator it = objects.iterator();
while (it.hasNext()) {
DataObject object = (DataObject) it.next();
ObjectId id = object.getObjectId();
// remove object but not snapshot
objectMap.remove(id);
changes.remove(id);
ids.add(id);
object.setDataContext(null);
object.setObjectId(null);
object.setPersistenceState(PersistenceState.TRANSIENT);
}
// TODO, andrus 3/28/2006 - DRC is null in nested contexts... implement
// propagation of unregister operation through the stack ... or do the opposite
// and keep unregister local even for non-nested DC?
if (getDataRowCache() != null) {
// send an event for removed snapshots
getDataRowCache().processSnapshotChanges(
this,
Collections.EMPTY_MAP,
Collections.EMPTY_LIST,
ids,
Collections.EMPTY_LIST);
}
}
/**
* Reverts changes to all stored uncomitted objects.
*
* @since 1.1
*/
public synchronized void objectsRolledBack() {
Iterator it = getObjectIterator();
// collect candidates
while (it.hasNext()) {
DataObject object = (DataObject) it.next();
int objectState = object.getPersistenceState();
switch (objectState) {
case PersistenceState.NEW:
it.remove();
object.setDataContext(null);
object.setObjectId(null);
object.setPersistenceState(PersistenceState.TRANSIENT);
break;
case PersistenceState.DELETED:
// Do the same as for modified... deleted is only a persistence state,
// so
// rolling the object back will set the state to committed
case PersistenceState.MODIFIED:
// this will clean any modifications and defer refresh from snapshot
// till the next object accessor is called
object.setPersistenceState(PersistenceState.HOLLOW);
break;
default:
// Transient, committed and hollow need no handling
break;
}
}
// reset changes ... using new HashMap to allow event listeners to analyze the
// original changes map after the rollback
this.changes = new HashMap();
}
/**
* Performs tracking of object relationship changes.
*
* @since 1.1
* @deprecated since 1.2 use {@link #recordArcDeleted(Persistent, ObjectId, String)}.
*/
public void objectRelationshipUnset(
DataObject source,
DataObject target,
ObjRelationship relationship,
boolean processFlattened) {
ObjectId targetId = (target != null) ? target.getObjectId() : null;
recordArcDeleted(source, targetId, relationship.getName());
}
/**
* Performs tracking of object relationship changes.
*
* @since 1.1
* @deprecated since 1.2 use {@link #recordArcCreated(Persistent, ObjectId, String)}.
*/
public void objectRelationshipSet(
DataObject source,
DataObject target,
ObjRelationship relationship,
boolean processFlattened) {
ObjectId targetId = (target != null) ? target.getObjectId() : null;
recordArcCreated(source, targetId, relationship.getName());
}
/**
* Updates snapshots in the underlying DataRowStore. If refresh is
* true, all snapshots in snapshots will be loaded into DataRowStore,
* regardless of the existing cache state. If refresh is false, only
* missing snapshots are loaded. This method is normally called internally by the
* DataContext owning the ObjectStore to update the caches after a select query.
*
* @param objects a list of object whose snapshots need to be updated.
* @param snapshots a list of snapshots. Must be of the same length and use the same
* order as objects list.
* @param refresh controls whether existing cached snapshots should be replaced with
* the new ones.
* @since 1.1
*/
// TODO:, andrus 5/25/2006 - mark as deprecated after 1.2 - this method is no longer
// used.
public void snapshotsUpdatedForObjects(List objects, List snapshots, boolean refresh) {
DataRowStore cache = getDataRowCache();
if (cache != null) {
synchronized (this) {
cache.snapshotsUpdatedForObjects(objects, snapshots, refresh);
}
}
}
/**
* Processes internal objects after the parent DataContext was committed. Changes
* object persistence state and handles snapshot updates.
*
* @since 1.1
* @deprecated since 1.2 unused.
*/
public synchronized void objectsCommitted() {
postprocessAfterCommit(new CompoundDiff());
}
/**
* Builds and returns GraphDiff reflecting all uncommitted object changes.
*
* @since 1.2
*/
ObjectStoreGraphDiff getChanges() {
return new ObjectStoreGraphDiff(this);
}
/**
* Returns internal changes map.
*
* @since 1.2
*/
Map getChangesByObjectId() {
return changes;
}
/**
* @since 1.2
*/
void postprocessAfterPhantomCommit() {
Iterator it = changes.keySet().iterator();
while (it.hasNext()) {
ObjectId id = (ObjectId) it.next();
Persistent object = (Persistent) objectMap.get(id);
// assume that no new or deleted objects are present (as otherwise commit
// wouldn't have been phantom).
object.setPersistenceState(PersistenceState.COMMITTED);
}
// clear caches
this.changes.clear();
}
/**
* Internal unsynchronized method to process objects state after commit.
*
* @since 1.2
*/
void postprocessAfterCommit(GraphDiff parentChanges) {
Iterator entries = objectMap.entrySet().iterator();
// have to scan through all entries
while (entries.hasNext()) {
Map.Entry entry = (Map.Entry) entries.next();
DataObject object = (DataObject) entry.getValue();
switch (object.getPersistenceState()) {
case PersistenceState.DELETED:
entries.remove();
object.setObjectContext(null);
object.setPersistenceState(PersistenceState.TRANSIENT);
break;
case PersistenceState.NEW:
case PersistenceState.MODIFIED:
object.setPersistenceState(PersistenceState.COMMITTED);
break;
}
}
// re-register changed object ids
if (!parentChanges.isNoop()) {
parentChanges.apply(new GraphChangeHandler() {
public void arcCreated(Object nodeId, Object targetNodeId, Object arcId) {
}
public void arcDeleted(Object nodeId, Object targetNodeId, Object arcId) {
}
public void nodeCreated(Object nodeId) {
}
public void nodeIdChanged(Object nodeId, Object newId) {
processIdChange(nodeId, newId);
}
public void nodePropertyChanged(
Object nodeId,
String property,
Object oldValue,
Object newValue) {
}
public void nodeRemoved(Object nodeId) {
}
});
}
// create new instance of changes map so that event listeners who stored the
// original diff don't get affected
this.changes = new HashMap();
}
/**
* Adds a new object to the ObjectStore.
*
* @deprecated since 1.2 as a different change tracking algorithm is used.
*/
public synchronized void addObject(DataObject object) {
recordObjectCreated(object);
}
/**
* Starts tracking the registration of new objects from this ObjectStore. Used in
* conjunction with unregisterNewObjects() to control garbage collection when an
* instance of ObjectStore is used over a longer time for batch processing.
*
* @see org.apache.cayenne.access.ObjectStore#unregisterNewObjects()
*/
public synchronized void startTrackingNewObjects() {
newObjectsMap = new HashMap();
}
/**
* Unregisters the newly registered DataObjects from this objectStore. Used in
* conjunction with startTrackingNewObjects() to control garbage collection when an
* instance of ObjectStore is used over a longer time for batch processing.
*
* @see org.apache.cayenne.access.ObjectStore#startTrackingNewObjects()
*/
public synchronized void unregisterNewObjects() {
if (newObjectsMap != null) {
objectsUnregistered(newObjectsMap.values());
newObjectsMap = null;
}
}
/**
* Returns a DataObject registered for a given ObjectId, or null if no such object
* exists. This method does not do a database fetch.
*
* @deprecated since 1.2 a GraphManager {@link #getNode(Object)} method should be
* used.
*/
public DataObject getObject(ObjectId id) {
return (DataObject) getNode(id);
}
/**
* Returns a snapshot for ObjectId from the underlying snapshot cache. If cache
* contains no snapshot, a null is returned.
*
* @since 1.1
*/
public DataRow getCachedSnapshot(ObjectId oid) {
if (context != null && context.getChannel() != null) {
ObjectIdQuery query = new CachedSnapshotQuery(oid);
List results = context.getChannel().onQuery(context, query).firstList();
return results.isEmpty() ? null : (DataRow) results.get(0);
}
else {
return null;
}
}
/**
* Returns cached query results for a given query, or null if no results are cached.
* Note that ObjectStore will only lookup results in its local cache, and not the
* shared cache associated with the underlying DataRowStore.
*
* @since 1.1
*/
public synchronized List getCachedQueryResult(String name) {
// results should have been stored as rows or objects when
// they were originally cached... do no conversions here
return (List) queryResultMap.get(name);
}
/**
* Caches a list of query results.
*
* @since 1.1
*/
public synchronized void cacheQueryResult(String name, List results) {
queryResultMap.put(name, results);
}
/**
* Returns a snapshot for ObjectId from the underlying snapshot cache. If cache
* contains no snapshot, it will attempt fetching it using provided QueryEngine. If
* fetch attempt fails or inconsistent data is returned, underlying cache will throw a
* CayenneRuntimeException.
*
* @since 1.1
* @deprecated since 1.2. Use {@link #getSnapshot(ObjectId)} instead.
*/
public synchronized DataRow getSnapshot(ObjectId oid, QueryEngine engine) {
return getDataRowCache().getSnapshot(oid, engine);
}
/**
* Returns a snapshot for ObjectId from the underlying snapshot cache. If cache
* contains no snapshot, it will attempt fetching it using provided QueryEngine. If
* fetch attempt fails or inconsistent data is returned, underlying cache will throw a
* CayenneRuntimeException.
*
* @since 1.2
*/
public synchronized DataRow getSnapshot(ObjectId oid) {
if (context != null && context.getChannel() != null) {
ObjectIdQuery query = new ObjectIdQuery(oid, true, ObjectIdQuery.CACHE);
List results = context.getChannel().onQuery(context, query).firstList();
return results.isEmpty() ? null : (DataRow) results.get(0);
}
else {
return null;
}
}
/**
* Returns a list of objects that are registered with this DataContext, regardless of
* their persistence state. List is returned by copy and can be modified by the
* caller.
*
* @deprecated since 1.2 use GraphManager method {@link #registeredNodes()}.
*/
public synchronized List getObjects() {
return new ArrayList(objectMap.values());
}
/**
* Returns an iterator over the registered objects.
*/
public synchronized Iterator getObjectIterator() {
return objectMap.values().iterator();
}
/**
* Returns true if there are any modified, deleted or new objects
* registered with this ObjectStore, false otherwise. This method will
* treat "phantom" modifications are real ones. I.e. if you "change" an object
* property to an equivalent value, this method will still think such object is
* modified. Phantom modifications are only detected and discarded during commit.
*/
public synchronized boolean hasChanges() {
return !changes.isEmpty();
}
/**
* Return a subset of registered objects that are in a certian persistence state.
* Collection is returned by copy.
*/
public synchronized List objectsInState(int state) {
List filteredObjects = new ArrayList();
Iterator it = objectMap.values().iterator();
while (it.hasNext()) {
DataObject nextObj = (DataObject) it.next();
if (nextObj.getPersistenceState() == state)
filteredObjects.add(nextObj);
}
return filteredObjects;
}
/**
* SnapshotEventListener implementation that processes snapshot change event, updating
* DataObjects that have the changes.
*
* Implementation note: This method should not attempt to alter the underlying
* DataRowStore, since it is normally invoked *AFTER* the DataRowStore was modified as
* a result of some external interaction.
*
*
* @since 1.1
*/
public void snapshotsChanged(SnapshotEvent event) {
// filter events that we should not process
if (event.getPostedBy() != this && event.getSource() == this.getDataRowCache()) {
processSnapshotEvent(event);
}
}
/**
* @since 1.2
*/
synchronized void processSnapshotEvent(SnapshotEvent event) {
Map modifiedDiffs = event.getModifiedDiffs();
if (modifiedDiffs != null && !modifiedDiffs.isEmpty()) {
Iterator oids = modifiedDiffs.entrySet().iterator();
while (oids.hasNext()) {
Map.Entry entry = (Map.Entry) oids.next();
processUpdatedSnapshot(entry.getKey(), (DataRow) entry.getValue());
}
}
Collection deletedIDs = event.getDeletedIds();
if (deletedIDs != null && !deletedIDs.isEmpty()) {
Iterator it = deletedIDs.iterator();
while (it.hasNext()) {
processDeletedID(it.next());
}
}
processInvalidatedIDs(event.getInvalidatedIds());
processIndirectlyModifiedIDs(event.getIndirectlyModifiedIds());
// TODO: andrus, 3/28/2006 - 'SnapshotEventDecorator' serves as a bridge (or
// rather a noop wrapper) between old snapshot events and new GraphEvents. Once
// SnapshotEvents are replaced with GraphEvents (in 2.0) we won't need it
GraphDiff diff = new SnapshotEventDecorator(event);
ObjectContext originatingContext = (event.getPostedBy() instanceof ObjectContext)
? (ObjectContext) event.getPostedBy()
: null;
context.fireDataChannelChanged(originatingContext, diff);
}
/**
* Performs validation of all uncommitted objects in the ObjectStore. If validation
* fails, a ValidationException is thrown, listing all encountered failures. This is a
* utility method for the users to call. Cayenne itself uses a different mechanism to
* validate objects on commit.
*
* @since 1.1
* @throws ValidationException
* @deprecated since 1.2 - This method is no longer used in Cayenne internally.
*/
public synchronized void validateUncommittedObjects() throws ValidationException {
// we must iterate over a copy of object list,
// as calling validateFor* on DataObjects can have a side effect
// of modifying this ObjectStore, and thus resulting in
// ConcurrentModificationExceptions in the Iterator
Collection deleted = null;
Collection inserted = null;
Collection updated = null;
Iterator allIt = getObjectIterator();
while (allIt.hasNext()) {
DataObject dataObject = (DataObject) allIt.next();
switch (dataObject.getPersistenceState()) {
case PersistenceState.NEW:
if (inserted == null) {
inserted = new ArrayList();
}
inserted.add(dataObject);
break;
case PersistenceState.MODIFIED:
if (updated == null) {
updated = new ArrayList();
}
updated.add(dataObject);
break;
case PersistenceState.DELETED:
if (deleted == null) {
deleted = new ArrayList();
}
deleted.add(dataObject);
break;
}
}
ValidationResult validationResult = new ValidationResult();
if (deleted != null) {
Iterator it = deleted.iterator();
while (it.hasNext()) {
DataObject dataObject = (DataObject) it.next();
dataObject.validateForDelete(validationResult);
}
}
if (inserted != null) {
Iterator it = inserted.iterator();
while (it.hasNext()) {
DataObject dataObject = (DataObject) it.next();
dataObject.validateForInsert(validationResult);
}
}
if (updated != null) {
Iterator it = updated.iterator();
while (it.hasNext()) {
DataObject dataObject = (DataObject) it.next();
dataObject.validateForUpdate(validationResult);
}
}
if (validationResult.hasFailures()) {
throw new ValidationException(validationResult);
}
}
/**
* Initializes object with data from cache or from the database, if this object is not
* fully resolved.
*
* @since 1.1
*/
public void resolveHollow(DataObject object) {
if (object.getPersistenceState() != PersistenceState.HOLLOW) {
return;
}
// no way to resolve faults outside of DataContext.
DataContext context = object.getDataContext();
if (context == null) {
object.setPersistenceState(PersistenceState.TRANSIENT);
return;
}
synchronized (this) {
ObjectIdQuery query = new ObjectIdQuery(
object.getObjectId(),
false,
ObjectIdQuery.CACHE);
List results = context.getChannel().onQuery(context, query).firstList();
// handle deleted object
if (results.size() == 0) {
processDeletedID(object.getObjectId());
}
else if (object.getPersistenceState() == PersistenceState.HOLLOW) {
// if HOLLOW is returned (from parent DC?), rerun the query with forced
// fetch
query = new ObjectIdQuery(
object.getObjectId(),
false,
ObjectIdQuery.CACHE_REFRESH);
results = context.getChannel().onQuery(context, query).firstList();
if (results.size() == 0) {
processDeletedID(object.getObjectId());
}
}
}
}
void processIdChange(Object nodeId, Object newId) {
Persistent object = (Persistent) objectMap.remove(nodeId);
if (object != null) {
object.setObjectId((ObjectId) newId);
objectMap.put(newId, object);
Object change = changes.remove(nodeId);
if (change != null) {
changes.put(newId, change);
}
}
}
/**
* Requires external synchronization.
*
* @since 1.2
*/
void processDeletedID(Object nodeId) {
// access object map directly - the method should be called in a synchronized
// context...
DataObject object = (DataObject) objectMap.get(nodeId);
if (object != null) {
DataContextDelegate delegate;
switch (object.getPersistenceState()) {
case PersistenceState.COMMITTED:
case PersistenceState.HOLLOW:
case PersistenceState.DELETED:
// consult delegate
delegate = context.nonNullDelegate();
if (delegate.shouldProcessDelete(object)) {
objectMap.remove(nodeId);
changes.remove(nodeId);
// setting DataContext to null will also set
// state to transient
object.setObjectContext(null);
delegate.finishedProcessDelete(object);
}
break;
case PersistenceState.MODIFIED:
// consult delegate
delegate = context.nonNullDelegate();
if (delegate.shouldProcessDelete(object)) {
object.setPersistenceState(PersistenceState.NEW);
changes.remove(nodeId);
recordObjectCreated(object);
delegate.finishedProcessDelete(object);
}
break;
}
}
}
/**
* @since 1.1
*/
void processInvalidatedIDs(Collection invalidatedIDs) {
if (invalidatedIDs != null && !invalidatedIDs.isEmpty()) {
Iterator it = invalidatedIDs.iterator();
while (it.hasNext()) {
ObjectId oid = (ObjectId) it.next();
DataObject object = (DataObject) getNode(oid);
if (object == null) {
continue;
}
// TODO: refactor "switch" to avoid code duplication
switch (object.getPersistenceState()) {
case PersistenceState.COMMITTED:
object.setPersistenceState(PersistenceState.HOLLOW);
break;
case PersistenceState.MODIFIED:
DataContext context = object.getDataContext();
DataRow diff = getSnapshot(oid);
// consult delegate if it exists
DataContextDelegate delegate = context.nonNullDelegate();
if (delegate.shouldMergeChanges(object, diff)) {
ObjEntity entity = context
.getEntityResolver()
.lookupObjEntity(object);
DataRowUtils.forceMergeWithSnapshot(entity, object, diff);
delegate.finishedMergeChanges(object);
}
case PersistenceState.HOLLOW:
// do nothing
break;
case PersistenceState.DELETED:
// TODO: Do nothing? Or treat as merged?
break;
}
}
}
}
/**
* Requires external synchronization.
*
* @since 1.1
*/
void processIndirectlyModifiedIDs(Collection indirectlyModifiedIDs) {
Iterator indirectlyModifiedIt = indirectlyModifiedIDs.iterator();
while (indirectlyModifiedIt.hasNext()) {
Object oid = indirectlyModifiedIt.next();
// access object map directly - the method should be called in a synchronized
// context...
DataObject object = (DataObject) objectMap.get(oid);
if (object == null
|| object.getPersistenceState() != PersistenceState.COMMITTED) {
continue;
}
// for now "break" all "independent" object relationships...
// in the future we may want to be more precise and go after modified
// relationships only, or even process updated lists without invalidating...
DataContextDelegate delegate = object.getDataContext().nonNullDelegate();
if (delegate.shouldMergeChanges(object, null)) {
ObjEntity entity = context.getEntityResolver().lookupObjEntity(object);
Iterator relationshipIterator = entity.getRelationships().iterator();
while (relationshipIterator.hasNext()) {
ObjRelationship relationship = (ObjRelationship) relationshipIterator
.next();
if (relationship.isSourceIndependentFromTargetChange()) {
Object fault = relationship.isToMany()
? Fault.getToManyFault()
: Fault.getToOneFault();
object.writePropertyDirectly(relationship.getName(), fault);
}
}
delegate.finishedProcessDelete(object);
}
}
}
/**
* Requires external synchronization.
*
* @since 1.1
*/
void processUpdatedSnapshot(Object nodeId, DataRow diff) {
// access object map directly - the method should be called ina synchronized
// context...
DataObject object = (DataObject) objectMap.get(nodeId);
// no object, or HOLLOW object require no processing
if (object != null) {
int state = object.getPersistenceState();
if (state != PersistenceState.HOLLOW) {
// perform same steps as resolveHollow()
if (state == PersistenceState.COMMITTED) {
// consult delegate if it exists
DataContextDelegate delegate = context.nonNullDelegate();
if (delegate.shouldMergeChanges(object, diff)) {
ObjEntity entity = context.getEntityResolver().lookupObjEntity(
object);
// TODO: andrus, 5/26/2006 - call to 'getSnapshot' is expensive,
// however my attempts to merge the 'diff' instead of snapshot
// via 'refreshObjectWithSnapshot' resulted in even worse
// performance.
// This sounds counterintuitive (Not sure if this is some HotSpot
// related glitch)... still keeping the old algorithm here until
// we
// switch from snapshot events to GraphEvents and all this code
// becomes obsolete.
DataRow snapshot = getSnapshot(object.getObjectId());
DataRowUtils.refreshObjectWithSnapshot(
entity,
object,
snapshot,
true);
delegate.finishedMergeChanges(object);
}
}
// merge modified and deleted
else if (state == PersistenceState.DELETED
|| state == PersistenceState.MODIFIED) {
// consult delegate if it exists
DataContextDelegate delegate = context.nonNullDelegate();
if (delegate.shouldMergeChanges(object, diff)) {
ObjEntity entity = context.getEntityResolver().lookupObjEntity(
object);
DataRowUtils.forceMergeWithSnapshot(entity, object, diff);
delegate.finishedMergeChanges(object);
}
}
}
}
}
/**
* @since 1.2
*/
public DataContext getContext() {
return context;
}
/**
* @since 1.2
*/
public void setContext(DataContext context) {
this.context = context;
}
// *********** GraphManager Methods ********
// =========================================
/**
* Returns a registered DataObject or null of no object exists for the ObjectId.
*
* @since 1.2
*/
public synchronized Object getNode(Object nodeId) {
return objectMap.get(nodeId);
}
// non-synchronized version of getNode for private use
final Object getNodeNoSync(Object nodeId) {
return objectMap.get(nodeId);
}
/**
* Returns all registered DataObjects. List is returned by copy and can be modified by
* the caller.
*
* @since 1.2
*/
public synchronized Collection registeredNodes() {
return new ArrayList(objectMap.values());
}
/**
* @since 1.2
*/
public void registerNode(Object nodeId, Object nodeObject) {
objectMap.put(nodeId, nodeObject);
if (newObjectsMap != null) {
newObjectsMap.put(nodeId, nodeObject);
}
}
/**
* @since 1.2
*/
public Object unregisterNode(Object nodeId) {
Object object = getNode(nodeId);
if (object != null) {
objectsUnregistered(Collections.singleton(object));
}
return object;
}
/**
* Does nothing.
*
* @since 1.2
*/
public void graphCommitAborted() {
}
/**
* Does nothing.
*
* @since 1.2
*/
public void graphCommitStarted() {
}
/**
* Does nothing.
*
* @since 1.2
*/
public void graphCommitted() {
}
/**
* Does nothing.
*
* @since 1.2
*/
public void graphRolledback() {
}
/**
* Does nothing.
*
* @since 1.2
*/
public void nodeIdChanged(Object nodeId, Object newId) {
// noop
}
/**
* Does nothing.
*
* @since 1.2
*/
public void nodeCreated(Object nodeId) {
// noop
}
/**
* Does nothing.
*
* @since 1.2
*/
public void nodeRemoved(Object nodeId) {
// noop
}
/**
* Does nothing.
*
* @since 1.2
*/
public void nodePropertyChanged(
Object nodeId,
String property,
Object oldValue,
Object newValue) {
// noop
}
/**
* Does nothing.
*
* @since 1.2
*/
public void arcCreated(Object nodeId, Object targetNodeId, Object arcId) {
// noop
}
/**
* Does nothing.
*
* @since 1.2
*/
public void arcDeleted(Object nodeId, Object targetNodeId, Object arcId) {
// noop
}
// an ObjectIdQuery optimized for retrieval of multiple snapshots - it can be reset
// with the new id
final class CachedSnapshotQuery extends ObjectIdQuery {
CachedSnapshotQuery(ObjectId oid) {
super(oid, true, ObjectIdQuery.CACHE_NOREFRESH);
}
void resetId(ObjectId oid) {
this.objectId = oid;
this.replacementQuery = null;
}
}
class SnapshotEventDecorator implements GraphDiff {
SnapshotEvent event;
SnapshotEventDecorator(SnapshotEvent event) {
this.event = event;
}
SnapshotEvent getEvent() {
return event;
}
public void apply(GraphChangeHandler handler) {
throw new UnsupportedOperationException();
}
public boolean isNoop() {
throw new UnsupportedOperationException();
}
public void undo(GraphChangeHandler handler) {
throw new UnsupportedOperationException();
}
}
}
© 2015 - 2024 Weber Informatics LLC | Privacy Policy