/*
* JasperReports - Free Java Reporting Library.
* Copyright (C) 2005 - 2009 Works, Inc. All rights reserved.
* http://www.works.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 <http://www.gnu.org/licenses/>.
*/
/*
* Licensed to Jaspersoft Corporation under a Contributer Agreement
*/
package net.sf.jasperreports.engine.fill;
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import net.sf.jasperreports.engine.JRRuntimeException;
import net.sf.jasperreports.engine.JRVirtualizable;
import net.sf.jasperreports.engine.util.JRProperties;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
/**
* Virtualizes data to the filesystem. When this object is finalized, it removes
* the swap files it makes. The virtualized objects have references to this
* object, so finalization does not occur until this object and the objects
* using it are only weakly referenced.
*
* @author John Bindel
* @version $Id: JRFileVirtualizer.java 3034 2009-08-27 11:58:04Z teodord $
*/
public class JRFileVirtualizer extends JRAbstractLRUVirtualizer {
private static final Log log = LogFactory.getLog(JRFileVirtualizer.class);
/**
* Property used to decide whether {@link File#deleteOnExit() deleteOnExit} should be requested
* for temporary files created by the virtualizer.
* <p>
* Calling {@link File#deleteOnExit() File.deleteOnExit()} will accumulate JVM process memory
* (see this <a href="http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=4513817">bug</a>), and this
* should abviously be avoided in long-running applications.
* <p>
* Temporary files will be deleted by explicitly calling {@link #cleanup() cleanup()} or from the virtualizer
* <code>finalize()</code> method.
*/
public static final String PROPERTY_TEMP_FILES_SET_DELETE_ON_EXIT = JRProperties.PROPERTY_PREFIX + "virtualizer.files.delete.on.exit";
private final String directory;
/**
* Uses the process's working directory as the location to store files.
*
* @param maxSize
* the maximum size (in JRVirtualizable objects) of the paged in
* cache.
*/
public JRFileVirtualizer(int maxSize) {
this(maxSize, null);
}
/**
* @param maxSize
* the maximum size (in JRVirtualizable objects) of the paged in
* cache.
* @param directory
* the base directory in the filesystem where the paged out data
* is to be stored
*/
public JRFileVirtualizer(int maxSize, String directory) {
super(maxSize);
this.directory = directory;
}
private String makeFilename(JRVirtualizable o) {
String uid = o.getUID();
return "virt" + uid;
}
private String makeFilename(String virtualId) {
return "virt" + virtualId;
}
protected void pageOut(JRVirtualizable o) throws IOException {
// Store data to a file.
String filename = makeFilename(o);
File file = new File(directory, filename);
if (file.createNewFile()) {
if (JRProperties.getBooleanProperty(PROPERTY_TEMP_FILES_SET_DELETE_ON_EXIT)) {
file.deleteOnExit();
}
FileOutputStream fos = null;
try {
fos = new FileOutputStream(file);
BufferedOutputStream bufferedOut = new BufferedOutputStream(fos);
writeData(o, bufferedOut);
}
catch (FileNotFoundException e) {
log.error("Error virtualizing object", e);
throw new JRRuntimeException(e);
}
finally {
if (fos != null) {
fos.close();
}
}
} else {
if (!isReadOnly(o)) {
throw new IllegalStateException(
"Cannot virtualize data because the file \"" + filename
+ "\" already exists.");
}
}
}
protected void pageIn(JRVirtualizable o) throws IOException {
// Load data from a file.
String filename = makeFilename(o);
File file = new File(directory, filename);
FileInputStream fis = null;
try {
fis = new FileInputStream(file);
BufferedInputStream bufferedIn = new BufferedInputStream(fis);
readData(o, bufferedIn);
}
catch (FileNotFoundException e) {
log.error("Error devirtualizing object", e);
throw new JRRuntimeException(e);
}
finally {
if (fis != null) {
fis.close();
}
}
if (!isReadOnly(o)) {
// Wait until we know it worked before tossing the data.
file.delete();
}
}
protected void dispose(String virtualId) {
String filename = makeFilename(virtualId);
File file = new File(directory, filename);
file.delete();
}
/**
* Called when we are done with the virtualizer and wish to
* cleanup any resources it has.
*/
public synchronized void cleanup()
{
disposeAll();
reset();
}
}