/*
* 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.search.documents;
import org.opencms.cache.CmsVfsDiskCache;
import org.opencms.file.CmsResource;
import org.opencms.main.CmsLog;
import org.opencms.search.extractors.CmsExtractionResult;
import org.opencms.search.extractors.I_CmsExtractionResult;
import org.opencms.util.CmsFileUtil;
import java.io.File;
import java.io.IOException;
import java.util.Locale;
import org.apache.commons.logging.Log;
/**
* Implements a disk cache that stores text extraction results in the RFS.<p>
*
* This cache operates on resource file names, plus a hash code calculated from
* {@link org.opencms.file.CmsResource#getDateLastModified()}
* and {@link org.opencms.file.CmsResource#getLength()}. Optional a locale can be appended to this name.<p>
*
* Since text extraction is done only on the content of a resource, all siblings must have the same content.
* The difference can be only by the locale setting in case of an XML content or XML page. However,
* the most problematic contents to extract for the search are in fact the MS Office and PDF formats.
* For these documents, all siblings must produce the exact same text extraction result.<p>
*
* This cache is usable for resources from the online AND the offline project at the same time,
* because any change to a resource will result in a changed hash code. This means a resource changed in the offline
* project will have a new hash code compared to the online project. If the resource is identical in the online and
* the offline project, the generated hash codes will be the same.<p>
*
* @since 6.2.0
*/
public class CmsExtractionResultCache {
/** The log object for this class. */
private static final Log LOG = CmsLog.getLog(CmsExtractionResultCache.class);
/** 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 CmsExtractionResultCache(String basepath, String foldername) {
// normalize the given folder name
m_rfsRepository = CmsFileUtil.normalizePath(basepath + foldername + File.separatorChar);
}
/**
* Removes all expired extraction result cache entries from the RFS cache.<p>
*
* @param maxAge the maximum age of the extraction result cache files in hours (or fractions of hours)
*
* @return the total number of deleted resources
*/
public synchronized int cleanCache(float maxAge) {
// calculate oldest possible date for the cache files
long expireDate = System.currentTimeMillis() - (long)(maxAge * 60.0f * 60.0f * 1000.0f);
File basedir = new File(m_rfsRepository);
// perform the cache cleanup
int count = 0;
if (basedir.canRead() && basedir.isDirectory()) {
File[] files = basedir.listFiles();
if (files != null) {
for (int i = 0; i < files.length; i++) {
File f = files[i];
if (f.canWrite()) {
if (f.lastModified() < expireDate) {
try {
f.delete();
count++;
} catch (Exception e) {
if (LOG.isWarnEnabled()) {
LOG.warn(Messages.get().getBundle().key(
Messages.LOG_EXCERPT_CACHE_DELETE_ERROR_1,
f.getAbsolutePath()), e);
}
}
}
}
}
}
}
return count;
}
/**
* Returns the RFS name used for caching an the text extraction result
* based on the given VFS resource and locale.<p>
*
* @param resource the VFS resource to generate the cache name for
* @param locale the locale to generate the cache name for (may be <code>null</code>)
*
* @return the RFS name to use for caching the given VFS resource with parameters
*/
public String getCacheName(CmsResource resource, Locale locale) {
// create a StringBuffer for the result
StringBuffer buf = new StringBuffer(m_rfsRepository.length() + 36);
buf.append(m_rfsRepository);
buf.append('/');
buf.append(resource.getResourceId().toString());
// check if parameters are provided, if so add them as well
if (locale != null) {
buf.append('_');
buf.append(locale.toString());
}
// append the date of last content modification to the result buffer
// please note that we need only worry about last change in content, since properties are ignored here
buf.append('_');
buf.append(resource.getDateContent());
// finally append the extension
buf.append(".ext");
return buf.toString();
}
/**
* Returns the extraction result in the requested file in the disk cache, or <code>null</code> if the
* file is not found in the cache, or is found but out-dated.<p>
*
* @param rfsName the file RFS name to look up in the cache
*
* @return the extraction result stored in the requested file in the RFS disk cache, or <code>null</code>
*/
public CmsExtractionResult getCacheObject(String rfsName) {
try {
File f = new File(rfsName);
if (f.exists()) {
long age = f.lastModified();
if ((System.currentTimeMillis() - age) > 3600000) {
// file has not been touched for 1 hour, touch the file with the current date
f.setLastModified(System.currentTimeMillis());
}
byte[] byteContent = CmsFileUtil.readFile(f);
return CmsExtractionResult.fromBytes(byteContent);
}
} catch (IOException e) {
// unable to read content
}
// this code can be reached only in case of an error
return null;
}
/**
* 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;
}
/**
* Serializes the given extraction result and saves it in the disk cache.<p>
*
* @param rfsName the RFS name of the file to save the extraction result in
* @param content the extraction result to serialize and save
*
* @throws IOException in case of disk access errors
*/
public void saveCacheObject(String rfsName, I_CmsExtractionResult content) throws IOException {
byte[] byteContent = content.getBytes();
if (byteContent != null) {
CmsVfsDiskCache.saveFile(rfsName, byteContent);
}
}
}