001 /*
002 *
003 * $Revision: 14975 $ $Date: 2009-03-20 12:19:57 +0100 (Fri, 20 Mar 2009) $
004 *
005 * This file is part of *** M y C o R e ***
006 * See http://www.mycore.de/ for details.
007 *
008 * This program is free software; you can use it, redistribute it
009 * and / or modify it under the terms of the GNU General Public License
010 * (GPL) as published by the Free Software Foundation; either version 2
011 * of the License or (at your option) any later version.
012 *
013 * This program is distributed in the hope that it will be useful, but
014 * WITHOUT ANY WARRANTY; without even the implied warranty of
015 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
016 * GNU General Public License for more details.
017 *
018 * You should have received a copy of the GNU General Public License
019 * along with this program, in a file called gpl.txt or license.txt.
020 * If not, write to the Free Software Foundation Inc.,
021 * 59 Temple Place - Suite 330, Boston, MA 02111-1307 USA
022 */
023
024 package org.mycore.services.fieldquery;
025
026 import org.jdom.Document;
027 import org.mycore.common.MCRCache;
028 import org.mycore.common.MCRConfiguration;
029 import org.mycore.common.MCRSessionMgr;
030 import org.mycore.parsers.bool.MCRCondition;
031
032 /**
033 * Manages a cache that contains the data of the most recently used queries.
034 * There are {MCR.SearchServlet.CacheSize} most recently used queries
035 * in a global cache. Additionally, the last query of search session is always
036 * stored within the MCRSession.
037 *
038 * @author Frank Lützenkirchen
039 */
040 public class MCRCachedQueryData
041 {
042 /** A cache that contains the data of the most recently used queries */
043 protected static MCRCache cache;
044
045 static
046 {
047 int cacheSize = MCRConfiguration.instance().getInt( "MCR.SearchServlet.CacheSize", 50 );
048 cache = new MCRCache( cacheSize, "SearchServlet query data cache" );
049 }
050
051 private final static String LAST_QUERY_IN_SESSION = "LastQuery";
052
053 public static MCRCachedQueryData getData(String id) {
054 // The n most recently used queries are in a global cache
055 MCRCachedQueryData data = (MCRCachedQueryData) (cache.get(id));
056 if (data == null) {
057 // Additionally, the last query of a single session is always there
058 data = (MCRCachedQueryData) (MCRSessionMgr.getCurrentSession().get(LAST_QUERY_IN_SESSION));
059 // May be the last query in session is the one we are looking for
060 if ((data != null) && (data.getResults().getID().equals(id)))
061 return data;
062 }
063 return data; // May be null, if no cached query data found
064 }
065
066 /** The query as XML, for later reloading into search mask editor form */
067 private Document query;
068 /** The result list */
069 private MCRResults results;
070 /** The normalized query condition */
071 private MCRCondition condition;
072 /** The page last displayed */
073 private int page;
074 /** The number of hits per page */
075 private int numPerPage;
076
077 public static void cache(MCRResults results, Document query, MCRCondition condition) {
078 MCRCachedQueryData data = new MCRCachedQueryData(results, query, condition);
079 cache.put( results.getID(), data );
080 MCRSessionMgr.getCurrentSession().put( LAST_QUERY_IN_SESSION, data );
081 }
082
083 private MCRCachedQueryData( MCRResults results, Document query, MCRCondition condition )
084 {
085 this.results = results;
086 this.query = query;
087 this.condition = condition;
088 }
089
090 public int getNumPerPage()
091 {
092 return numPerPage;
093 }
094
095 public void setNumPerPage( int numPerPage )
096 {
097 this.numPerPage = numPerPage;
098 }
099
100 public int getPage()
101 {
102 return page;
103 }
104
105 public void setPage( int page )
106 {
107 this.page = page;
108 }
109
110 public MCRCondition getCondition()
111 {
112 return condition;
113 }
114
115 public Document getQuery()
116 {
117 return query;
118 }
119
120 public MCRResults getResults()
121 {
122 return results;
123 }
124 }