/*
* 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.openjpa.meta;
import java.util.Comparator;
import org.apache.openjpa.enhance.PersistenceCapable;
import org.apache.openjpa.kernel.OpenJPAStateManager;
import org.apache.openjpa.conf.OpenJPAConfiguration;
import org.apache.openjpa.util.ImplHelper;
/**
* Order by a field in the related type in memory.
*
* @author Abe White
*/
class InMemoryRelatedFieldOrder
implements Order, Comparator {
private final FieldMetaData _rel;
private final boolean _asc;
private final OpenJPAConfiguration _conf;
public InMemoryRelatedFieldOrder(FieldMetaData rel, boolean asc,
OpenJPAConfiguration conf) {
_rel = rel;
_asc = asc;
_conf = conf;
}
public String getName() {
return _rel.getName();
}
public boolean isAscending() {
return _asc;
}
public Comparator getComparator() {
return this;
}
public int compare(Object o1, Object o2) {
if (o1 == o2)
return 0;
if (!(ImplHelper.isManageable(o1))
|| !(ImplHelper.isManageable(o2)))
return 0;
PersistenceCapable pc1 = ImplHelper.toPersistenceCapable(o1, _conf);
PersistenceCapable pc2 = ImplHelper.toPersistenceCapable(o2, _conf);
OpenJPAStateManager sm1 = (OpenJPAStateManager) pc1.pcGetStateManager();
OpenJPAStateManager sm2 = (OpenJPAStateManager) pc2.pcGetStateManager();
if (sm1 == null || sm2 == null)
return 0;
Object v1 = sm1.fetchField(_rel.getIndex(), false);
Object v2 = sm2.fetchField(_rel.getIndex(), false);
if (v1 == v2)
return 0;
if (v1 == null)
return (_asc) ? -1 : 1;
if (v2 == null)
return (_asc) ? 1 : -1;
int cmp = ((Comparable) v1).compareTo(v2);
return (_asc) ? cmp : -cmp;
}
}