content: /*
   * This library is part of OpenCms -
   * the Open Source Content Management System
   *
   * Copyright (c) Alkacon Software GmbH & Co. KG (https://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: https://www.alkacon.com
   *
   * For further information about OpenCms, please see the
   * project website: https://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>)
       * @param docTypeName the name of the search document type
       *
       * @return the RFS name to use for caching the given VFS resource with parameters
       */
      public String getCacheName(CmsResource resource, Locale locale, String docTypeName) {
  
          // 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());
  
          if (docTypeName != null) {
              buf.append('_');
              buf.append(docTypeName);
          }
  
          // 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);
          }
      }
  }