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.loader;
  
  import org.opencms.ade.galleries.CmsPreviewService;
  import org.opencms.cache.CmsVfsNameBasedDiskCache;
  import org.opencms.configuration.CmsParameterConfiguration;
  import org.opencms.file.CmsFile;
  import org.opencms.file.CmsObject;
  import org.opencms.file.CmsResource;
  import org.opencms.main.CmsEvent;
  import org.opencms.main.CmsException;
  import org.opencms.main.CmsLog;
  import org.opencms.main.I_CmsEventListener;
  import org.opencms.main.OpenCms;
  import org.opencms.scheduler.jobs.CmsImageCacheCleanupJob;
  import org.opencms.util.CmsStringUtil;
  
  import java.io.IOException;
  import java.util.Map;
  
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpServletResponse;
  
  import org.apache.commons.logging.Log;
  
  /**
   * Loader for images from the OpenCms VSF with integrated image scaling and processing capabilities.<p>
   *
   * To scale or process an image, the parameter <code>{@link org.opencms.loader.CmsImageScaler#PARAM_SCALE}</code>
   * has to be appended to the image URI. The value for the parameter needs to be composed from the <code>SCALE_PARAM</code>
   * options provided by the constants in the <code>{@link org.opencms.file.types.CmsResourceTypeImage}</code> class.<p>
   *
   * For example, to scale an image to exact 800x600 pixel with center fitting and a background color of grey,
   * the following parameter String can be used: <code>w:800,h:600,t:0,c:c0c0c0</code>.<p>
   *
   * @since 6.2.0
   */
  public class CmsImageLoader extends CmsDumpLoader implements I_CmsEventListener {
  
      /** Controls max number of threads that are allowed to scale images concurrently. */
      public static final String CONFIGURATION_CONCURRENCY = "image.scaling.concurrency";
  
      /** The configuration parameter for the OpenCms XML configuration to set the image down scale operation. */
      public static final String CONFIGURATION_DOWNSCALE = "image.scaling.downscale";
  
      /** The configuration parameter for the OpenCms XML configuration to set the image cache repository. */
      public static final String CONFIGURATION_IMAGE_FOLDER = "image.folder";
  
      /** The configuration parameter for the OpenCms XML configuration to set the maximum image blur size. */
      public static final String CONFIGURATION_MAX_BLUR_SIZE = "image.scaling.maxblursize";
  
      /** The configuration parameter for the OpenCms XML configuration to set the maximum image scale size. */
      public static final String CONFIGURATION_MAX_SCALE_SIZE = "image.scaling.maxsize";
  
      /** The configuration parameter for the OpenCms XML configuration to enable the image scaling. */
      public static final String CONFIGURATION_SCALING_ENABLED = "image.scaling.enabled";
  
      /** Default name for the image cache repository. */
      public static final String IMAGE_REPOSITORY_DEFAULT = "/WEB-INF/imagecache/";
  
      /** Clear event parameter. */
      public static final String PARAM_CLEAR_IMAGES_CACHE = "_IMAGES_CACHE_";
  
      /** The id of this loader. */
      public static final int RESOURCE_LOADER_ID_IMAGE_LOADER = 2;
  
      /** The log object for this class. */
      protected static final Log LOG = CmsLog.getLog(CmsImageLoader.class);
  
      /** The (optional) image down scale parameters for image write operations. */
      protected static String m_downScaleParams;
  
      /** Indicates if image scaling is active. */
      protected static boolean m_enabled;
  
      /** The maximum image size (width * height) to apply image blurring when down scaling (setting this to high may cause "out of memory" errors). */
      protected static int m_maxBlurSize = CmsImageScaler.SCALE_DEFAULT_MAX_BLUR_SIZE;
  
      /** The disk cache to use for saving scaled image versions. */
      protected static CmsVfsNameBasedDiskCache m_vfsDiskCache;
  
      /** The name of the configured image cache repository. */
      protected String m_imageRepositoryFolder;
  
      /** The maximum image size (width or height) to allow when up scaling an image using request parameters. */
      protected int m_maxScaleSize = CmsImageScaler.SCALE_DEFAULT_MAX_SIZE;
  
      /**
       * Creates a new image loader.<p>
       */
      public CmsImageLoader() {
  
          super();
      }
  
      /**
       * Returns the image down scale parameters,
       * which is set with the {@link #CONFIGURATION_DOWNSCALE} configuration option.<p>
       *
       * If no down scale parameters have been set in the configuration, this will return <code>null</code>.
       *
       * @return the image down scale parameters
       */
      public static String getDownScaleParams() {
  
          return m_downScaleParams;
      }
  
      /**
       * Returns the path of the image cache repository folder in the RFS,
       * which is set with the {@link #CONFIGURATION_IMAGE_FOLDER} configuration option.<p>
       *
       * @return the path of the image cache repository folder in the RFS
       */
      public static String getImageRepositoryPath() {
  
          return m_vfsDiskCache.getRepositoryPath();
      }
  
      /**
       * The maximum blur size for image re-scale operations,
       * which is set with the {@link #CONFIGURATION_MAX_BLUR_SIZE} configuration option.<p>
       *
       * The default is 2500 * 2500 pixel.<p>
       *
       * @return the maximum blur size for image re-scale operations
       */
      public static int getMaxBlurSize() {
  
          return m_maxBlurSize;
      }
  
      /**
       * Returns <code>true</code> if the image scaling and processing capabilities for the
       * OpenCms VFS images have been enabled, <code>false</code> if not.<p>
       *
       * Image scaling is enabled by setting the loader parameter <code>image.scaling.enabled</code>
       * to the value <code>true</code> in the configuration file <code>opencms-vfs.xml</code>.<p>
       *
       * Enabling image processing in OpenCms may require several additional configuration steps
       * on the server running OpenCms, especially in UNIX systems. Here it is often required to have an X window server
       * configured and accessible so that the required Java ImageIO operations work.
       * Therefore the image scaling capabilities in OpenCms are disabled by default.<p>
       *
       * @return <code>true</code> if the image scaling and processing capabilities for the
       *      OpenCms VFS images have been enabled
       */
      public static boolean isEnabled() {
  
          return m_enabled;
      }
  
      /**
       * @see org.opencms.configuration.I_CmsConfigurationParameterHandler#addConfigurationParameter(java.lang.String, java.lang.String)
       */
      @Override
      public void addConfigurationParameter(String paramName, String paramValue) {
  
          if (CmsStringUtil.isNotEmpty(paramName) && CmsStringUtil.isNotEmpty(paramValue)) {
              if (CONFIGURATION_SCALING_ENABLED.equals(paramName)) {
                  m_enabled = Boolean.valueOf(paramValue).booleanValue();
              }
              if (CONFIGURATION_IMAGE_FOLDER.equals(paramName)) {
                  m_imageRepositoryFolder = paramValue.trim();
              }
              if (CONFIGURATION_MAX_SCALE_SIZE.equals(paramName)) {
                  m_maxScaleSize = CmsStringUtil.getIntValue(
                      paramValue,
                      CmsImageScaler.SCALE_DEFAULT_MAX_SIZE,
                      paramName);
              }
              if (CONFIGURATION_MAX_BLUR_SIZE.equals(paramName)) {
                  m_maxBlurSize = CmsStringUtil.getIntValue(
                      paramValue,
                      CmsImageScaler.SCALE_DEFAULT_MAX_BLUR_SIZE,
                      paramName);
              }
              if (CONFIGURATION_DOWNSCALE.equals(paramName)) {
                  m_downScaleParams = paramValue.trim();
              }
  
              if (CONFIGURATION_CONCURRENCY.equals(paramName)) {
                  int concurrency = CmsStringUtil.getIntValue(paramValue, CmsImageScaler.DEFAULT_CONCURRENCY, paramName);
                  if (concurrency > 0) {
                      CmsImageScaler.setConcurrency(concurrency);
                  }
              }
          }
          super.addConfigurationParameter(paramName, paramValue);
      }
  
      /**
       * @see org.opencms.main.I_CmsEventListener#cmsEvent(org.opencms.main.CmsEvent)
       */
      public void cmsEvent(CmsEvent event) {
  
          if (event == null) {
              return;
          }
          // only react on the clear caches event
          int type = event.getType();
          if (type != I_CmsEventListener.EVENT_CLEAR_CACHES) {
              return;
          }
          // only react if the clear images cache parameter is set
          Map<String, ?> data = event.getData();
          if (data == null) {
              return;
          }
          Object param = data.get(PARAM_CLEAR_IMAGES_CACHE);
          if (param == null) {
              return;
          }
          float age = -1;
          if (param instanceof String) {
              age = Float.valueOf((String)param).floatValue();
          } else if (param instanceof Number) {
              age = ((Number)param).floatValue();
          }
          CmsImageCacheCleanupJob.cleanImageCache(age);
      }
  
      /**
       * @see org.opencms.loader.I_CmsResourceLoader#destroy()
       */
      @Override
      public void destroy() {
  
          m_enabled = false;
          m_imageRepositoryFolder = null;
          m_vfsDiskCache = null;
      }
  
      /**
       * @see org.opencms.configuration.I_CmsConfigurationParameterHandler#getConfiguration()
       */
      @Override
      public CmsParameterConfiguration getConfiguration() {
  
          CmsParameterConfiguration result = new CmsParameterConfiguration();
          CmsParameterConfiguration config = super.getConfiguration();
          if (config != null) {
              result.putAll(config);
          }
          result.put(CONFIGURATION_SCALING_ENABLED, String.valueOf(m_enabled));
          result.put(CONFIGURATION_IMAGE_FOLDER, m_imageRepositoryFolder);
          return result;
      }
  
      /**
       * @see org.opencms.loader.I_CmsResourceLoader#getLoaderId()
       */
      @Override
      public int getLoaderId() {
  
          return RESOURCE_LOADER_ID_IMAGE_LOADER;
      }
  
      /**
       * @see org.opencms.configuration.I_CmsConfigurationParameterHandler#initConfiguration()
       */
      @Override
      public void initConfiguration() {
  
          if (CmsStringUtil.isEmpty(m_imageRepositoryFolder)) {
              m_imageRepositoryFolder = IMAGE_REPOSITORY_DEFAULT;
          }
          // initialize the image cache
          if (m_vfsDiskCache == null) {
              m_vfsDiskCache = new CmsVfsNameBasedDiskCache(
                  OpenCms.getSystemInfo().getWebApplicationRfsPath(),
                  m_imageRepositoryFolder);
          }
          OpenCms.addCmsEventListener(this);
          // output setup information
          if (CmsLog.INIT.isInfoEnabled()) {
              CmsLog.INIT.info(
                  Messages.get().getBundle().key(
                      Messages.INIT_IMAGE_REPOSITORY_PATH_1,
                      m_vfsDiskCache.getRepositoryPath()));
              CmsLog.INIT.info(
                  Messages.get().getBundle().key(Messages.INIT_IMAGE_SCALING_ENABLED_1, Boolean.valueOf(m_enabled)));
          }
      }
  
      /**
       * @see org.opencms.loader.I_CmsResourceLoader#load(org.opencms.file.CmsObject, org.opencms.file.CmsResource, javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse)
       */
      @Override
      public void load(CmsObject cms, CmsResource resource, HttpServletRequest req, HttpServletResponse res)
      throws IOException, CmsException {
  
          if (m_enabled) {
              if (canSendLastModifiedHeader(resource, req, res)) {
                  // no image processing required at all
                  return;
              }
              // get the scale information from the request
              CmsImageScaler scaler = new CmsImageScaler(req, m_maxScaleSize, m_maxBlurSize);
              // load the file from the cache
              CmsFile file = getScaledImage(cms, resource, scaler);
              // now perform standard load operation inherited from dump loader
              super.load(cms, file, req, res);
          } else {
              // scaling is disabled
              super.load(cms, resource, req, res);
          }
      }
  
      /**
       * Returns a scaled version of the given OpenCms VFS image resource.<p>
       *
       * All results are cached in disk.
       * If the scaled version does not exist in the cache, it is created.
       * Unscaled versions of the images are also stored in the cache.<p>
       *
       * @param cms the current users OpenCms context
       * @param resource the base VFS resource for the image
       * @param scaler the configured image scaler
       *
       * @return a scaled version of the given OpenCms VFS image resource
       *
       * @throws IOException in case of errors accessing the disk based cache
       * @throws CmsException in case of errors accessing the OpenCms VFS
       */
      protected CmsFile getScaledImage(CmsObject cms, CmsResource resource, CmsImageScaler scaler)
      throws IOException, CmsException {
  
          String cacheParam = scaler.isValid() ? scaler.toString() : null;
          String cacheName = m_vfsDiskCache.getCacheName(resource, cacheParam);
          byte[] content = m_vfsDiskCache.getCacheContent(cacheName);
  
          CmsFile file;
          if (content != null) {
              if (resource instanceof CmsFile) {
                  // the original file content must be modified (required e.g. for static export)
                  file = (CmsFile)resource;
              } else {
                  // this is no file, but we don't want to use "upgrade" since we don't need to read the content from the VFS
                  file = new CmsFile(resource);
              }
              // save the content in the file
              file.setContents(content);
          } else {
              // we must read the content from the VFS (if this has not been done yet)
              file = cms.readFile(resource);
              // upgrade the file (load the content)
              if (scaler.isValid()) {
                  if (scaler.getType() == 8) {
                      // only need the focal point for mode 8
                      scaler.setFocalPoint(CmsPreviewService.readFocalPoint(cms, resource));
                  }
                  // valid scaling parameters found, scale the content
                  content = scaler.scaleImage(file);
                  // exchange the content of the file with the scaled version
                  file.setContents(content);
              }
              // save the file content in the cache
              m_vfsDiskCache.saveCacheFile(cacheName, file.getContents());
          }
          return file;
      }
  }