001/*
002 * This library is part of OpenCms -
003 * the Open Source Content Management System
004 *
005 * Copyright (c) Alkacon Software GmbH & Co. KG (http://www.alkacon.com)
006 *
007 * This library is free software; you can redistribute it and/or
008 * modify it under the terms of the GNU Lesser General Public
009 * License as published by the Free Software Foundation; either
010 * version 2.1 of the License, or (at your option) any later version.
011 *
012 * This library is distributed in the hope that it will be useful,
013 * but WITHOUT ANY WARRANTY; without even the implied warranty of
014 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
015 * Lesser General Public License for more details.
016 *
017 * For further information about Alkacon Software, please see the
018 * company website: http://www.alkacon.com
019 *
020 * For further information about OpenCms, please see the
021 * project website: http://www.opencms.org
022 *
023 * You should have received a copy of the GNU Lesser General Public
024 * License along with this library; if not, write to the Free Software
025 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
026 */
027
028package org.opencms.loader;
029
030import org.opencms.ade.galleries.CmsPreviewService;
031import org.opencms.cache.CmsVfsNameBasedDiskCache;
032import org.opencms.configuration.CmsParameterConfiguration;
033import org.opencms.file.CmsFile;
034import org.opencms.file.CmsObject;
035import org.opencms.file.CmsResource;
036import org.opencms.main.CmsEvent;
037import org.opencms.main.CmsException;
038import org.opencms.main.CmsLog;
039import org.opencms.main.I_CmsEventListener;
040import org.opencms.main.OpenCms;
041import org.opencms.scheduler.jobs.CmsImageCacheCleanupJob;
042import org.opencms.util.CmsStringUtil;
043
044import java.io.IOException;
045import java.util.Map;
046
047import javax.servlet.http.HttpServletRequest;
048import javax.servlet.http.HttpServletResponse;
049
050import org.apache.commons.logging.Log;
051
052/**
053 * Loader for images from the OpenCms VSF with integrated image scaling and processing capabilities.<p>
054 *
055 * To scale or process an image, the parameter <code>{@link org.opencms.loader.CmsImageScaler#PARAM_SCALE}</code>
056 * has to be appended to the image URI. The value for the parameter needs to be composed from the <code>SCALE_PARAM</code>
057 * options provided by the constants in the <code>{@link org.opencms.file.types.CmsResourceTypeImage}</code> class.<p>
058 *
059 * For example, to scale an image to exact 800x600 pixel with center fitting and a background color of grey,
060 * the following parameter String can be used: <code>w:800,h:600,t:0,c:c0c0c0</code>.<p>
061 *
062 * @since 6.2.0
063 */
064public class CmsImageLoader extends CmsDumpLoader implements I_CmsEventListener {
065
066    /** The configuration parameter for the OpenCms XML configuration to set the image down scale operation. */
067    public static final String CONFIGURATION_DOWNSCALE = "image.scaling.downscale";
068
069    /** The configuration parameter for the OpenCms XML configuration to set the image cache repository. */
070    public static final String CONFIGURATION_IMAGE_FOLDER = "image.folder";
071
072    /** The configuration parameter for the OpenCms XML configuration to set the maximum image blur size. */
073    public static final String CONFIGURATION_MAX_BLUR_SIZE = "image.scaling.maxblursize";
074
075    /** The configuration parameter for the OpenCms XML configuration to set the maximum image scale size. */
076    public static final String CONFIGURATION_MAX_SCALE_SIZE = "image.scaling.maxsize";
077
078    /** The configuration parameter for the OpenCms XML configuration to enable the image scaling. */
079    public static final String CONFIGURATION_SCALING_ENABLED = "image.scaling.enabled";
080
081    /** Default name for the image cache repository. */
082    public static final String IMAGE_REPOSITORY_DEFAULT = "/WEB-INF/imagecache/";
083
084    /** Clear event parameter. */
085    public static final String PARAM_CLEAR_IMAGES_CACHE = "_IMAGES_CACHE_";
086
087    /** The id of this loader. */
088    public static final int RESOURCE_LOADER_ID_IMAGE_LOADER = 2;
089
090    /** The log object for this class. */
091    protected static final Log LOG = CmsLog.getLog(CmsImageLoader.class);
092
093    /** The (optional) image down scale parameters for image write operations. */
094    protected static String m_downScaleParams;
095
096    /** Indicates if image scaling is active. */
097    protected static boolean m_enabled;
098
099    /** The maximum image size (width * height) to apply image blurring when down scaling (setting this to high may cause "out of memory" errors). */
100    protected static int m_maxBlurSize = CmsImageScaler.SCALE_DEFAULT_MAX_BLUR_SIZE;
101
102    /** The disk cache to use for saving scaled image versions. */
103    protected static CmsVfsNameBasedDiskCache m_vfsDiskCache;
104
105    /** The name of the configured image cache repository. */
106    protected String m_imageRepositoryFolder;
107
108    /** The maximum image size (width or height) to allow when up scaling an image using request parameters. */
109    protected int m_maxScaleSize = CmsImageScaler.SCALE_DEFAULT_MAX_SIZE;
110
111    /**
112     * Creates a new image loader.<p>
113     */
114    public CmsImageLoader() {
115
116        super();
117    }
118
119    /**
120     * Returns the image down scale parameters,
121     * which is set with the {@link #CONFIGURATION_DOWNSCALE} configuration option.<p>
122     *
123     * If no down scale parameters have been set in the configuration, this will return <code>null</code>.
124     *
125     * @return the image down scale parameters
126     */
127    public static String getDownScaleParams() {
128
129        return m_downScaleParams;
130    }
131
132    /**
133     * Returns the path of the image cache repository folder in the RFS,
134     * which is set with the {@link #CONFIGURATION_IMAGE_FOLDER} configuration option.<p>
135     *
136     * @return the path of the image cache repository folder in the RFS
137     */
138    public static String getImageRepositoryPath() {
139
140        return m_vfsDiskCache.getRepositoryPath();
141    }
142
143    /**
144     * The maximum blur size for image re-scale operations,
145     * which is set with the {@link #CONFIGURATION_MAX_BLUR_SIZE} configuration option.<p>
146     *
147     * The default is 2500 * 2500 pixel.<p>
148     *
149     * @return the maximum blur size for image re-scale operations
150     */
151    public static int getMaxBlurSize() {
152
153        return m_maxBlurSize;
154    }
155
156    /**
157     * Returns <code>true</code> if the image scaling and processing capabilities for the
158     * OpenCms VFS images have been enabled, <code>false</code> if not.<p>
159     *
160     * Image scaling is enabled by setting the loader parameter <code>image.scaling.enabled</code>
161     * to the value <code>true</code> in the configuration file <code>opencms-vfs.xml</code>.<p>
162     *
163     * Enabling image processing in OpenCms may require several additional configuration steps
164     * on the server running OpenCms, especially in UNIX systems. Here it is often required to have an X window server
165     * configured and accessible so that the required Java ImageIO operations work.
166     * Therefore the image scaling capabilities in OpenCms are disabled by default.<p>
167     *
168     * @return <code>true</code> if the image scaling and processing capabilities for the
169     *      OpenCms VFS images have been enabled
170     */
171    public static boolean isEnabled() {
172
173        return m_enabled;
174    }
175
176    /**
177     * @see org.opencms.configuration.I_CmsConfigurationParameterHandler#addConfigurationParameter(java.lang.String, java.lang.String)
178     */
179    @Override
180    public void addConfigurationParameter(String paramName, String paramValue) {
181
182        if (CmsStringUtil.isNotEmpty(paramName) && CmsStringUtil.isNotEmpty(paramValue)) {
183            if (CONFIGURATION_SCALING_ENABLED.equals(paramName)) {
184                m_enabled = Boolean.valueOf(paramValue).booleanValue();
185            }
186            if (CONFIGURATION_IMAGE_FOLDER.equals(paramName)) {
187                m_imageRepositoryFolder = paramValue.trim();
188            }
189            if (CONFIGURATION_MAX_SCALE_SIZE.equals(paramName)) {
190                m_maxScaleSize = CmsStringUtil.getIntValue(
191                    paramValue,
192                    CmsImageScaler.SCALE_DEFAULT_MAX_SIZE,
193                    paramName);
194            }
195            if (CONFIGURATION_MAX_BLUR_SIZE.equals(paramName)) {
196                m_maxBlurSize = CmsStringUtil.getIntValue(
197                    paramValue,
198                    CmsImageScaler.SCALE_DEFAULT_MAX_BLUR_SIZE,
199                    paramName);
200            }
201            if (CONFIGURATION_DOWNSCALE.equals(paramName)) {
202                m_downScaleParams = paramValue.trim();
203            }
204        }
205        super.addConfigurationParameter(paramName, paramValue);
206    }
207
208    /**
209     * @see org.opencms.main.I_CmsEventListener#cmsEvent(org.opencms.main.CmsEvent)
210     */
211    public void cmsEvent(CmsEvent event) {
212
213        if (event == null) {
214            return;
215        }
216        // only react on the clear caches event
217        int type = event.getType();
218        if (type != I_CmsEventListener.EVENT_CLEAR_CACHES) {
219            return;
220        }
221        // only react if the clear images cache parameter is set
222        Map<String, ?> data = event.getData();
223        if (data == null) {
224            return;
225        }
226        Object param = data.get(PARAM_CLEAR_IMAGES_CACHE);
227        if (param == null) {
228            return;
229        }
230        float age = -1;
231        if (param instanceof String) {
232            age = Float.valueOf((String)param).floatValue();
233        } else if (param instanceof Number) {
234            age = ((Number)param).floatValue();
235        }
236        CmsImageCacheCleanupJob.cleanImageCache(age);
237    }
238
239    /**
240     * @see org.opencms.loader.I_CmsResourceLoader#destroy()
241     */
242    @Override
243    public void destroy() {
244
245        m_enabled = false;
246        m_imageRepositoryFolder = null;
247        m_vfsDiskCache = null;
248    }
249
250    /**
251     * @see org.opencms.configuration.I_CmsConfigurationParameterHandler#getConfiguration()
252     */
253    @Override
254    public CmsParameterConfiguration getConfiguration() {
255
256        CmsParameterConfiguration result = new CmsParameterConfiguration();
257        CmsParameterConfiguration config = super.getConfiguration();
258        if (config != null) {
259            result.putAll(config);
260        }
261        result.put(CONFIGURATION_SCALING_ENABLED, String.valueOf(m_enabled));
262        result.put(CONFIGURATION_IMAGE_FOLDER, m_imageRepositoryFolder);
263        return result;
264    }
265
266    /**
267     * @see org.opencms.loader.I_CmsResourceLoader#getLoaderId()
268     */
269    @Override
270    public int getLoaderId() {
271
272        return RESOURCE_LOADER_ID_IMAGE_LOADER;
273    }
274
275    /**
276     * @see org.opencms.configuration.I_CmsConfigurationParameterHandler#initConfiguration()
277     */
278    @Override
279    public void initConfiguration() {
280
281        if (CmsStringUtil.isEmpty(m_imageRepositoryFolder)) {
282            m_imageRepositoryFolder = IMAGE_REPOSITORY_DEFAULT;
283        }
284        // initialize the image cache
285        if (m_vfsDiskCache == null) {
286            m_vfsDiskCache = new CmsVfsNameBasedDiskCache(
287                OpenCms.getSystemInfo().getWebApplicationRfsPath(),
288                m_imageRepositoryFolder);
289        }
290        OpenCms.addCmsEventListener(this);
291        // output setup information
292        if (CmsLog.INIT.isInfoEnabled()) {
293            CmsLog.INIT.info(
294                Messages.get().getBundle().key(
295                    Messages.INIT_IMAGE_REPOSITORY_PATH_1,
296                    m_vfsDiskCache.getRepositoryPath()));
297            CmsLog.INIT.info(
298                Messages.get().getBundle().key(Messages.INIT_IMAGE_SCALING_ENABLED_1, Boolean.valueOf(m_enabled)));
299        }
300    }
301
302    /**
303     * @see org.opencms.loader.I_CmsResourceLoader#load(org.opencms.file.CmsObject, org.opencms.file.CmsResource, javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse)
304     */
305    @Override
306    public void load(CmsObject cms, CmsResource resource, HttpServletRequest req, HttpServletResponse res)
307    throws IOException, CmsException {
308
309        if (m_enabled) {
310            if (canSendLastModifiedHeader(resource, req, res)) {
311                // no image processing required at all
312                return;
313            }
314            // get the scale information from the request
315            CmsImageScaler scaler = new CmsImageScaler(req, m_maxScaleSize, m_maxBlurSize);
316            // load the file from the cache
317            CmsFile file = getScaledImage(cms, resource, scaler);
318            // now perform standard load operation inherited from dump loader
319            super.load(cms, file, req, res);
320        } else {
321            // scaling is disabled
322            super.load(cms, resource, req, res);
323        }
324    }
325
326    /**
327     * Returns a scaled version of the given OpenCms VFS image resource.<p>
328     *
329     * All results are cached in disk.
330     * If the scaled version does not exist in the cache, it is created.
331     * Unscaled versions of the images are also stored in the cache.<p>
332     *
333     * @param cms the current users OpenCms context
334     * @param resource the base VFS resource for the image
335     * @param scaler the configured image scaler
336     *
337     * @return a scaled version of the given OpenCms VFS image resource
338     *
339     * @throws IOException in case of errors accessing the disk based cache
340     * @throws CmsException in case of errors accessing the OpenCms VFS
341     */
342    protected CmsFile getScaledImage(CmsObject cms, CmsResource resource, CmsImageScaler scaler)
343    throws IOException, CmsException {
344
345        String cacheParam = scaler.isValid() ? scaler.toString() : null;
346        String cacheName = m_vfsDiskCache.getCacheName(resource, cacheParam);
347        byte[] content = m_vfsDiskCache.getCacheContent(cacheName);
348
349        CmsFile file;
350        if (content != null) {
351            if (resource instanceof CmsFile) {
352                // the original file content must be modified (required e.g. for static export)
353                file = (CmsFile)resource;
354            } else {
355                // this is no file, but we don't want to use "upgrade" since we don't need to read the content from the VFS
356                file = new CmsFile(resource);
357            }
358            // save the content in the file
359            file.setContents(content);
360        } else {
361            // we must read the content from the VFS (if this has not been done yet)
362            file = cms.readFile(resource);
363            // upgrade the file (load the content)
364            if (scaler.isValid()) {
365                if (scaler.getType() == 8) {
366                    // only need the focal point for mode 8
367                    scaler.setFocalPoint(CmsPreviewService.readFocalPoint(cms, resource));
368                }
369                // valid scaling parameters found, scale the content
370                content = scaler.scaleImage(file);
371                // exchange the content of the file with the scaled version
372                file.setContents(content);
373            }
374            // save the file content in the cache
375            m_vfsDiskCache.saveCacheFile(cacheName, file.getContents());
376        }
377        return file;
378    }
379}