net.sf.jasperreports.engine.base.VirtualizableElementList Maven / Gradle / Ivy
/*
* JasperReports - Free Java Reporting Library.
* Copyright (C) 2001 - 2023 Cloud Software Group, Inc. All rights reserved.
* http://www.jaspersoft.com
*
* Unless you have purchased a commercial license agreement from Jaspersoft,
* the following license terms apply:
*
* This program is part of JasperReports.
*
* JasperReports is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* JasperReports is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with JasperReports. If not, see .
*/
package net.sf.jasperreports.engine.base;
import java.io.Serializable;
import java.util.AbstractList;
import java.util.List;
import java.util.function.Consumer;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import net.sf.jasperreports.engine.JRConstants;
import net.sf.jasperreports.engine.JRPrintElement;
import net.sf.jasperreports.engine.fill.JRVirtualizationContext;
/**
* List implementation that can virtualize blocks of elements.
*
* @author Lucian Chirita ([email protected])
*/
public class VirtualizableElementList extends AbstractList implements Serializable
{
private static final long serialVersionUID = JRConstants.SERIAL_VERSION_UID;
private static final Log log = LogFactory.getLog(VirtualizableElementList.class);
protected final JRVirtualizationContext virtualizationContext;
protected ElementStore store;
public VirtualizableElementList(JRVirtualizationContext virtualizationContext, JRVirtualPrintPage page)
{
this.virtualizationContext = virtualizationContext;
initStore(page);
}
public VirtualizableElementList(JRVirtualizationContext virtualizationContext, ElementStore store)
{
this.virtualizationContext = virtualizationContext;
this.store = store;
}
private void initStore(JRVirtualPrintPage page)
{
// start with a simple block to reduce memory consumption for small pages
this.store = new ElementsBlock(virtualizationContext, page);
if (log.isDebugEnabled())
{
log.debug("created block " + this.store + " for " + this);
}
}
public ElementStore getElementStore()
{
return store;
}
public synchronized void set(List elements)
{
clear();
addAll(elements);
}
private void cacheInContext(JRPrintElement element)
{
virtualizationContext.cacheTemplate(element);
}
@Override
public synchronized JRPrintElement get(int index)
{
return store.get(index);
}
@Override
public synchronized int size()
{
return store.size();
}
@Override
public synchronized JRPrintElement set(int index, JRPrintElement element)
{
cacheInContext(element);
return store.set(index, element);
}
private void createBlockList()
{
ElementsBlockList blockList = new ElementsBlockList((ElementsBlock) store);
blockList.addBlock();
store = blockList;
}
@Override
public synchronized boolean add(JRPrintElement element)
{
cacheInContext(element);
if (!store.add(element))
{
// we had a single block and it overflowed.
// create a block list.
createBlockList();
// add again, block list never overflows.
store.add(element);
}
return true;
}
@Override
public synchronized void add(int index, JRPrintElement element)
{
cacheInContext(element);
if (!store.add(index, element))
{
// we had a single block and it overflowed.
// create a block list.
createBlockList();
// add again, block list never overflows.
store.add(index, element);
}
}
@Override
public synchronized JRPrintElement remove(int index)
{
return store.remove(index);
}
@Override
public synchronized void clear()
{
// recreating the store
JRVirtualPrintPage page = store.getPage();
store.dispose();
initStore(page);
}
public synchronized void dispose()
{
store.dispose();
}
public JRVirtualizationContext getVirtualizationContext()
{
return virtualizationContext;
}
public void updatePage(JRVirtualPrintPage page)
{
store.updatePage(page);
}
public ElementStore transferStore(JRVirtualizationContext context, JRVirtualPrintPage page)
{
ElementStore existingStore = store;
initStore(store.getPage());
existingStore.updateContext(context, page);
return existingStore;
}
public void transferElements(Consumer consumer)
{
store.transferElements(consumer);
//recreate store
initStore(store.getPage());
}
//FIXME implement faster bulk methods such as addAll
}