/**********************************************************************
Copyright (c) 2009 Andy Jefferson and others. All rights reserved.
Licensed 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.
Contributors:
...
**********************************************************************/
package org.datanucleus.store.mapped.scostore;
import java.util.ArrayList;
import java.util.ListIterator;
import org.datanucleus.ObjectManager;
import org.datanucleus.StateManager;
import org.datanucleus.metadata.AbstractMemberMetaData;
import org.datanucleus.store.mapped.DatastoreContainerObject;
import org.datanucleus.store.mapped.exceptions.MappedDatastoreException;
import org.datanucleus.store.mapped.mapping.EmbeddedElementPCMapping;
import org.datanucleus.store.mapped.mapping.JavaTypeMapping;
import org.datanucleus.store.mapped.mapping.ReferenceMapping;
import org.datanucleus.store.mapped.mapping.SerialisedPCMapping;
import org.datanucleus.store.mapped.mapping.SerialisedReferenceMapping;
import org.datanucleus.store.query.ResultObjectFactory;
/**
* Abstract iterator for presenting the results for a list store.
*/
public abstract class ListStoreIterator implements ListIterator
{
private final StateManager sm;
private final ListIterator delegate;
private Object lastElement = null;
private int currentIndex = -1;
private final AbstractListStore abstractListStore;
/**
* Constructor
* @param sm the StateManager
* @param resultSet the ResultSet
* @param rof the Query.ResultObjectFactory
* @throws SQLException
*/
public ListStoreIterator(StateManager sm, Object resultSet, ResultObjectFactory rof, AbstractListStore als)
throws MappedDatastoreException
{
this.sm = sm;
this.abstractListStore = als;
ObjectManager om = sm.getObjectManager();
ArrayList results = new ArrayList();
if (resultSet != null)
{
DatastoreContainerObject containerTable = als.getContainerTable();
boolean elementsAreSerialised = als.isElementsAreSerialised();
boolean elementsAreEmbedded = als.isElementsAreEmbedded();
JavaTypeMapping elementMapping = als.getElementMapping();
while (next(resultSet))
{
Object nextElement;
if (elementsAreEmbedded || elementsAreSerialised)
{
int param[] = new int[elementMapping.getNumberOfDatastoreFields()];
for (int i = 0; i < param.length; ++i)
{
param[i] = i + 1;
}
if (elementMapping instanceof SerialisedPCMapping ||
elementMapping instanceof SerialisedReferenceMapping ||
elementMapping instanceof EmbeddedElementPCMapping)
{
// Element = Serialised
int ownerFieldNumber = -1;
if (containerTable != null)
{
ownerFieldNumber =
getOwnerMemberMetaData(abstractListStore.containerTable).getAbsoluteFieldNumber();
}
nextElement = elementMapping.getObject(om, resultSet, param, sm, ownerFieldNumber);
}
else
{
// Element = Non-PC
nextElement = elementMapping.getObject(om, resultSet, param);
}
}
else if (elementMapping instanceof ReferenceMapping)
{
// Element = Reference (Interface/Object)
int param[] = new int[elementMapping.getNumberOfDatastoreFields()];
for (int i = 0; i < param.length; ++i)
{
param[i] = i + 1;
}
nextElement = elementMapping.getObject(om, resultSet, param);
}
else
{
nextElement = rof.getObject(om, resultSet);
}
results.add(nextElement);
}
}
delegate = results.listIterator();
}
public void add(Object o)
{
currentIndex = delegate.nextIndex();
abstractListStore.add(sm, o, currentIndex, -1);
delegate.add(o);
lastElement = null;
}
public boolean hasNext()
{
return delegate.hasNext();
}
public boolean hasPrevious()
{
return delegate.hasPrevious();
}
public Object next()
{
currentIndex = delegate.nextIndex();
lastElement = delegate.next();
return lastElement;
}
public int nextIndex()
{
return delegate.nextIndex();
}
public Object previous()
{
currentIndex = delegate.previousIndex();
lastElement = delegate.previous();
return lastElement;
}
public int previousIndex()
{
return delegate.previousIndex();
}
public synchronized void remove()
{
if (lastElement == null)
{
throw new IllegalStateException("No entry to remove");
}
abstractListStore.remove(sm, currentIndex, -1);
delegate.remove();
lastElement = null;
currentIndex = -1;
}
public synchronized void set(Object o)
{
if (lastElement == null)
{
throw new IllegalStateException("No entry to replace");
}
abstractListStore.set(sm, currentIndex, o, true);
delegate.set(o);
lastElement = o;
}
/**
* Method to move to the next row in the results.
* @param resultSet The result set
* @return Whether there is a next row
* @throws MappedDatastoreException
*/
protected abstract boolean next(Object resultSet) throws MappedDatastoreException;
/**
* Method to return the owner member metadata for the supplied table
* @param containerTable The table for the list
* @return the metadata for the owner member
*/
protected abstract AbstractMemberMetaData getOwnerMemberMetaData(DatastoreContainerObject containerTable);
}