/*
* This library is part of OpenCms -
* the Open Source Content Management System
*
* Copyright (c) Alkacon Software GmbH (http://www.alkacon.com)
*
* This library 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 2.1 of the License, or (at your option) any later version.
*
* This library 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.
*
* For further information about Alkacon Software, please see the
* company website: http://www.alkacon.com
*
* For further information about OpenCms, please see the
* project website: http://www.opencms.org
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
package org.opencms.cache;
import org.opencms.util.CmsFileUtil;
import org.opencms.util.CmsStringUtil;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
/**
* Implements a RFS file based disk cache, that handles parameter based versions of VFS files,
* providing a cache for the "online" and another for the "offline" project.<p>
*
* @since 6.2.0
*/
public class CmsVfsDiskCache {
/** The name of the cache base repository folder in the RFS. */
private String m_rfsRepository;
/**
* Creates a new disk cache.<p>
*
* @param basepath the base path for the cache in the RFS
* @param foldername the folder name for this cache, to be used a subfolder for the base folder
*/
public CmsVfsDiskCache(String basepath, String foldername) {
// normalize the given folder name
m_rfsRepository = CmsFileUtil.normalizePath(basepath + foldername + File.separatorChar);
}
/**
* Saves the given file content to a RFS file of the given name (full path).<p>
*
* If the required parent folders do not exists, they are also created.<p>
*
* @param rfsName the RFS name of the file to save the content in
* @param content the content of the file to save
*
* @return a reference to the File that was saved
*
* @throws IOException in case of disk access errors
*/
public static File saveFile(String rfsName, byte[] content) throws IOException {
File f = new File(rfsName);
File p = f.getParentFile();
if (!p.exists()) {
// create parent folders
p.mkdirs();
}
// write file contents
FileOutputStream fs = new FileOutputStream(f);
fs.write(content);
fs.close();
return f;
}
/**
* Returns the content of the requested file in the disk cache, or <code>null</code> if the
* file is not found in the cache, or is found but outdated.<p>
*
* @param rfsName the file RFS name to look up in the cache
* @param dateLastModified the date of last modification for the cache
*
* @return the content of the requested file in the VFS disk cache, or <code>null</code>
*/
public byte[] getCacheContent(String rfsName, long dateLastModified) {
dateLastModified = simplifyDateLastModified(dateLastModified);
try {
File f = new File(rfsName);
if (f.exists()) {
if (f.lastModified() != dateLastModified) {
// last modification time different, remove cached file in RFS
f.delete();
} else {
return CmsFileUtil.readFile(f);
}
}
} catch (IOException e) {
// unable to read content
}
return null;
}
/**
* Returns the RFS name to use for caching the given VFS resource with parameters in the disk cache.<p>
*
* @param online if true, the online disk cache is used, the offline disk cache otherwise
* @param rootPath the VFS resource root path to get the RFS cache name for
* @param parameters the parameters of the request to the VFS resource
*
* @return the RFS name to use for caching the given VFS resource with parameters
*/
public String getCacheName(boolean online, String rootPath, String parameters) {
String rfsName = CmsFileUtil.getRepositoryName(m_rfsRepository, rootPath, online);
if (CmsStringUtil.isNotEmpty(parameters)) {
String extension = CmsFileUtil.getExtension(rfsName);
// build the RFS name for the VFS name with parameters
rfsName = CmsFileUtil.getRfsPath(rfsName, extension, parameters);
}
return rfsName;
}
/**
* Returns the absolute path of the cache repository in the RFS.<p>
*
* @return the absolute path of the cache repository in the RFS
*/
public String getRepositoryPath() {
return m_rfsRepository;
}
/**
* Saves the given file content in the disk cache.<p>
*
* @param rfsName the RFS name of the file to save the content in
* @param content the content of the file to save
* @param dateLastModified the date of last modification to set for the save file
*
* @throws IOException in case of disk access errors
*/
public void saveCacheFile(String rfsName, byte[] content, long dateLastModified) throws IOException {
dateLastModified = simplifyDateLastModified(dateLastModified);
File f = saveFile(rfsName, content);
// set last modification date
f.setLastModified(dateLastModified);
}
/**
* Simplifies the "date last modified" from the OpenCms VFS based milliseconds
* to just seconds, to support file systems that don't use milliseconds.<p>
*
* @param dateLastModified the date to simplify
*
* @return the simplified date last modified
*/
private long simplifyDateLastModified(long dateLastModified) {
return dateLastModified / 1000L;
}
}