sascha@541: package de.intevation.gnv.geobackend.base.query;
sascha@541: 
sascha@886: import de.intevation.gnv.geobackend.base.Result;
sascha@886: 
sascha@541: import java.util.Collection;
sascha@541: 
sascha@541: import net.sf.ehcache.Cache;
sascha@886: import net.sf.ehcache.CacheManager;
sascha@541: import net.sf.ehcache.Element;
sascha@541: 
sascha@542: import org.apache.log4j.Logger;
sascha@541: 
sascha@541: /**
sascha@541:  * @author Sascha L. Teichmann <sascha.teichmann@intevation.de>
sascha@541:  */
sascha@541: public class CachingQueryExecutorFactory
sascha@541: extends      QueryExecutorFactory
sascha@541: {
sascha@541:     public static final String QUERY_EXECUTOR_FACTORY = "caching.query.executor.config";
sascha@541:     public static final String CACHE_NAME             = "sql.cache";
sascha@541: 
sascha@542:     private static Logger log = Logger.getLogger(CachingQueryExecutorFactory.class);
sascha@542: 
sascha@541:     protected CacheManager manager;
sascha@541: 
sascha@541:     public CachingQueryExecutorFactory() {
sascha@542:         log.info("using SQL cache");
sascha@541:         String configFile = System.getProperty(QUERY_EXECUTOR_FACTORY);
sascha@541:         manager = configFile != null
sascha@541:             ? new CacheManager(configFile)
sascha@541:             : new CacheManager();
sascha@541:         manager.addCache(CACHE_NAME);
sascha@541:     }
sascha@541: 
sascha@541:     public QueryExecutor getQueryExecutor() {
sascha@541:         return new DefaultQueryExceutor() {
sascha@541: 
sascha@541:             public Collection<Result> cachedResults(String query) {
sascha@541:                 Cache   cache   = manager.getCache(CACHE_NAME);
sascha@541:                 Element element = cache.get(query);
sascha@542:                 if (log.isDebugEnabled()) {
sascha@542:                     log.debug("found results in SQL cache: " + (element != null));
sascha@542:                 }
sascha@541:                 return element != null
sascha@541:                     ? (Collection<Result>)element.getObjectValue()
sascha@541:                     : null;
sascha@541:             }
sascha@541: 
sascha@542:             public void cacheResults(String query, Collection<Result> results) {
sascha@542:                 log.debug("store results in SQL cache");
sascha@541:                 Cache cache = manager.getCache(CACHE_NAME);
sascha@541:                 cache.put(new Element(query, results));
sascha@541:             }
sascha@541:         };
sascha@541:     }
sascha@542: 
sascha@542:     public void shutdown() {
sascha@542:         log.info("shutting down SQL cache");
sascha@542:         manager.getCache(CACHE_NAME).flush();
sascha@542:         manager.shutdown();
sascha@542:     }
sascha@541: }
sascha@541: // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8: