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* 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
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* KIND, either express or implied. See the License for the
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package org.apache.cayenne.access;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import org.apache.cayenne.ObjectContext;
import org.apache.cayenne.PersistenceState;
import org.apache.cayenne.Persistent;
import org.apache.cayenne.map.DbEntity;
import org.apache.cayenne.query.ObjectIdQuery;
import org.apache.cayenne.query.Query;
import org.apache.cayenne.query.RefreshQuery;
import org.apache.cayenne.util.ListResponse;
import org.apache.cayenne.util.ObjectContextQueryAction;
/**
* A DataContext-specific version of
* {@link org.apache.cayenne.util.ObjectContextQueryAction}.
*
* @since 1.2
*/
class DataContextQueryAction extends ObjectContextQueryAction {
protected DataContext actingDataContext;
public DataContextQueryAction(DataContext actingContext, ObjectContext targetContext,
Query query) {
super(actingContext, targetContext, query);
actingDataContext = actingContext;
}
@Override
protected boolean interceptInternalQuery() {
return interceptObjectFromDataRowsQuery();
}
private boolean interceptObjectFromDataRowsQuery() {
if (query instanceof ObjectsFromDataRowsQuery) {
ObjectsFromDataRowsQuery objectsFromDataRowsQuery = (ObjectsFromDataRowsQuery) query;
response = new ListResponse(actingDataContext.objectsFromDataRows(
objectsFromDataRowsQuery.getDescriptor(),
objectsFromDataRowsQuery.getDataRows()));
return DONE;
}
return !DONE;
}
/**
* Overrides super implementation to property handle data row fetches.
*/
@Override
protected boolean interceptOIDQuery() {
if (query instanceof ObjectIdQuery) {
ObjectIdQuery oidQuery = (ObjectIdQuery) query;
if (!oidQuery.isFetchMandatory()) {
Object object = actingContext.getGraphManager().getNode(
oidQuery.getObjectId());
if (object != null) {
// TODO: andrus, 10/14/2006 - obtaining a row from an object is the
// only piece that makes this method different from the super
// implementation. This is used in NEW objects sorting on insert. It
// would be nice to implement an alternative algorithm that wouldn't
// require this hack.
if (oidQuery.isFetchingDataRows()) {
object = ((DataContext) actingContext)
.currentSnapshot((Persistent) object);
}
// do not return hollow objects
else if (((Persistent) object).getPersistenceState() == PersistenceState.HOLLOW) {
return !DONE;
}
this.response = new ListResponse(object);
return DONE;
}
}
}
return !DONE;
}
@Override
protected boolean interceptPaginatedQuery() {
if (metadata.getPageSize() > 0) {
DbEntity dbEntity = metadata.getDbEntity();
List<?> paginatedList = dbEntity != null
&& dbEntity.getPrimaryKeys().size() == 1
? new SimpleIdIncrementalFaultList<Object>(
(DataContext) actingContext,
query)
: new IncrementalFaultList<Object>((DataContext) actingContext, query);
response = new ListResponse(paginatedList);
return DONE;
}
return !DONE;
}
@Override
protected boolean interceptRefreshQuery() {
if (query instanceof RefreshQuery) {
RefreshQuery refreshQuery = (RefreshQuery) query;
DataContext context = (DataContext) actingContext;
// handle four separate cases, but do not combine them as it will be
// unclear how to handle cascading behavior
// 1. refresh all
if (refreshQuery.isRefreshAll()) {
synchronized (context.getObjectStore()) {
invalidateLocally(context.getObjectStore(), context
.getObjectStore()
.getObjectIterator());
context.getQueryCache().clear();
}
// cascade
return !DONE;
}
// 2. invalidate object collection
Collection objects = refreshQuery.getObjects();
if (objects != null && !objects.isEmpty()) {
synchronized (context.getObjectStore()) {
invalidateLocally(context.getObjectStore(), objects.iterator());
}
// cascade
return !DONE;
}
// 3. refresh query - have to do it eagerly to refresh the objects involved
Query cachedQuery = refreshQuery.getQuery();
if (cachedQuery != null) {
String cacheKey = cachedQuery
.getMetaData(context.getEntityResolver())
.getCacheKey();
context.getQueryCache().remove(cacheKey);
this.response = context.performGenericQuery(cachedQuery);
// do not cascade to avoid running query twice
return DONE;
}
// 4. refresh groups...
String[] groups = refreshQuery.getGroupKeys();
if (groups != null && groups.length > 0) {
for (String group : groups) {
context.getQueryCache().removeGroup(group);
}
// cascade group invalidation
return !DONE;
}
// shouldn't ever happen
return DONE;
}
return !DONE;
}
private void invalidateLocally(ObjectStore objectStore, Iterator it) {
Map<Object, ObjectDiff> diffMap = objectStore.getChangesByObjectId();
while (it.hasNext()) {
Persistent object = (Persistent) it.next();
int state = object.getPersistenceState();
// we don't care about NEW objects,
// but we still do care about HOLLOW, since snapshot might still
// be present
if (state == PersistenceState.NEW) {
continue;
}
if (state == PersistenceState.MODIFIED || state == PersistenceState.DELETED) {
// remove cached changes
diffMap.remove(object.getObjectId());
}
object.setPersistenceState(PersistenceState.HOLLOW);
}
}
}