/*
* [The "BSD licence"]
* Copyright (c) 2013-2014 Dandelion
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of Dandelion nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package com.github.dandelion.extras.cache.ehcache;
import java.io.IOException;
import java.io.InputStream;
import java.util.Set;
import net.sf.ehcache.Cache;
import net.sf.ehcache.CacheManager;
import net.sf.ehcache.Element;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.github.dandelion.core.Context;
import com.github.dandelion.core.asset.Asset;
import com.github.dandelion.core.asset.cache.spi.AbstractAssetCache;
import com.github.dandelion.core.asset.cache.spi.AssetCache;
import com.github.dandelion.core.utils.ResourceScanner;
import com.github.dandelion.core.utils.StringUtils;
import com.github.dandelion.core.web.DandelionServlet;
/**
* <p>
* EhCache implementation of the {@link AssetCache}.
*
* <p>
* The initialization of this cache has two prerequisites: obtain a
* {@link CacheManager} instance and a {@code ehcache.xml} configuration file.
*
* <p>
* The {@link CacheManager} instance is obtained using the following strategy:
* <ul>
* <li>First tries to get an existing {@link CacheManager} using the
* {@code cache.manager.name} configuration property.</li>
* <li>If no {@link CacheManager} is configured, a default one is created.</li>
* </ul>
*
* <p>
* Once the {@link CacheManager} obtained, then the configuration file is loaded
* using the following strategy:
* <ul>
* <li>First checks if the {@code cache.configuration.location} configuration
* property exists and uses this path to load the file.</li>
* <li>If the above configuration property is not used, scans the classpath
* (starting from the root) for the {@code ehcache.xml} configuration file.</li>
* </li>
* </ul>
*
* <p>
* Note that Dandelion uses a cache called {@code dandelionCache}. If it doesn't
* exist in your {@code ehcache.xml} configuration file, Dandelion will
* automatically add and use it.
*
* <p>
* Note finally that the same cache is used for two purposes:
* <ul>
* <li>Store the content of {@link Asset}s that are served by the
* {@link DandelionServlet}</li>
* <li>Store the set of {@link Asset}s to be displayed on a page, for a given
* request, thus avoiding location resolution and processing</li>
* </ul>
*
* @author Thibault Duchateau
* @since 0.10.0
*/
public class EhCacheAssetCache extends AbstractAssetCache {
private static final Logger LOG = LoggerFactory.getLogger(EhCacheAssetCache.class);
private Cache cache;
/**
* {@inheritDoc}
*/
@Override
public String getCacheName() {
return "ehcache";
}
@Override
public void initCache(Context context) {
super.initCache(context);
CacheManager cacheManager = null;
String cacheManagerName = context.getConfiguration().getCacheManagerName();
// First try to get an existing CacheManager
if (StringUtils.isNotBlank(cacheManagerName)) {
cacheManager = CacheManager.getCacheManager(cacheManagerName);
LOG.warn("No cache manager found with the name '{}'. Dandelion will create one.", cacheManagerName);
}
if(cacheManager == null){
InputStream stream = null;
String cacheConfigurationPath = context.getConfiguration().getCacheConfigurationLocation();
if (StringUtils.isBlank(cacheConfigurationPath)) {
LOG.warn("The 'cache.configuration.location' configuration is not set. Dandelion will scan for any ehcache.xml file inside the classpath.");
try {
cacheConfigurationPath = ResourceScanner.findResourcePath("", "ehcache.xml");
LOG.debug("ehcache.xml file found: {}", cacheConfigurationPath);
}
catch (IOException e) {
LOG.warn("No ehcache.xml configuration file has been found. Dandelion will let EhCache use the default configuration.");
}
}
stream = Thread.currentThread().getContextClassLoader().getResourceAsStream(cacheConfigurationPath);
cacheManager = stream == null ? CacheManager.create() : CacheManager.create(stream);
}
if(!cacheManager.cacheExists(DANDELION_CACHE_NAME)){
cacheManager.addCache(DANDELION_CACHE_NAME);
LOG.debug("Added cache called '{}' to the cache manager", DANDELION_CACHE_NAME);
}
cache = cacheManager.getCache(DANDELION_CACHE_NAME);
}
/**
* {@inheritDoc}
*/
@Override
public String getAssetContent(String cacheKey) {
Element element = cache.get(cacheKey);
return element == null ? null : (String) element.getObjectValue();
}
/**
* {@inheritDoc}
*/
@Override
public void storeAssetContent(String cacheKey, String cacheContent) {
cache.put(new Element(cacheKey, cacheContent));
}
/**
* {@inheritDoc}
*/
@Override
public void remove(String cacheKey) {
cache.remove(cacheKey);
}
/**
* {@inheritDoc}
*/
@Override
@SuppressWarnings("unchecked")
public Set<Asset> getRequestAssets(String cacheKey) {
Element element = cache.get(cacheKey);
return element == null ? null : (Set<Asset>) element.getObjectValue();
}
/**
* {@inheritDoc}
*/
@Override
public void storeRequestAssets(String cacheKey, Set<Asset> assets) {
cache.put(new Element(cacheKey, assets));
}
/**
* {@inheritDoc}
*/
@Override
public void clearAll() {
cache.removeAll();
}
}