ingo@1127: /*
ingo@1127:  * Copyright (c) 2010 by Intevation GmbH
ingo@1127:  *
ingo@1127:  * This program is free software under the LGPL (>=v2.1)
ingo@1127:  * Read the file LGPL.txt coming with the software for details
ingo@1127:  * or visit http://www.gnu.org/licenses/ if it does not exist.
ingo@1127:  */
ingo@1127: 
tim@895: /**
tim@895:  *
tim@895:  */
tim@895: package de.intevation.gnv.geobackend.base.query.cache;
tim@895: 
tim@895: import java.sql.Date;
tim@895: import java.util.Collection;
tim@895: import java.util.Iterator;
tim@895: 
tim@895: import org.apache.log4j.Logger;
tim@895: 
tim@895: import de.intevation.gnv.geobackend.base.Result;
tim@895: import de.intevation.gnv.geobackend.base.query.DefaultQueryExceutor;
tim@895: import de.intevation.gnv.geobackend.base.query.QueryExecutor;
tim@895: import de.intevation.gnv.geobackend.base.query.QueryExecutorFactory;
tim@895: import de.intevation.gnv.geobackend.base.query.exception.QueryException;
tim@895: import de.intevation.gnv.geobackend.util.DateUtils;
tim@895: 
tim@895: /**
tim@895:  * Thread that looks every n - Minutes if an Cache has to be cleanedup.
tim@895:  * You can configure the Timeout in Seconds using the Systemproperty
tim@895:  * @author <a href="mailto:tim.englich@intevation.de">Tim Englich</a>
tim@895:  *
tim@895:  */
tim@895: public class CacheCleaner extends Thread {
tim@895: 
tim@895:     /**
tim@895:      * the logger, used to log exceptions and additonaly information
tim@895:      */
tim@895:     private static Logger log = Logger.getLogger(CacheCleaner.class);
tim@895: 
tim@895:     /**
tim@895:      * The Systemproperty-identifier for the Configuration of the TimeInterval
tim@895:      */
tim@895:     public static final String CACHE_CLEANER_INTERVAL = "caching.cleaner.interval";
ingo@897: 
tim@895:     /**
tim@895:      * The Time To wait between two Cleanups.
tim@895:      */
tim@895:     private long timeout = 1000 * 60; // 1 Minute
ingo@897: 
tim@895:     /**
tim@895:      * The Border which has to be used to Query the updated Tables.
tim@895:      */
tim@895:     private long lowerBorderTime = 0;
tim@895: 
tim@895:     /**
tim@895:      * The Id to Lookup the SQL-Statement for fetchung the Names of the
tim@895:      * updated Tables.
tim@895:      */
tim@895:     private String queryID = "updated_tables";
tim@895: 
tim@895:     /**
tim@895:      * Constructor
tim@895:      */
tim@895:     public CacheCleaner() {
tim@895:         this.setUp();
tim@895:     }
tim@895: 
tim@895:     /**
tim@895:      * Constructor
tim@895:      * @param arg0
tim@895:      */
tim@895:     public CacheCleaner(Runnable arg0) {
tim@895:         super(arg0);
tim@895:         this.setUp();
tim@895:     }
tim@895: 
tim@895:     /**
tim@895:      * Constructor
tim@895:      * @param arg0
tim@895:      */
tim@895:     public CacheCleaner(String arg0) {
tim@895:         super(arg0);
tim@895:         this.setUp();
tim@895:     }
tim@895: 
tim@895:     /**
tim@895:      * Constructor
tim@895:      * @param arg0
tim@895:      * @param arg1
tim@895:      */
tim@895:     public CacheCleaner(ThreadGroup arg0, Runnable arg1) {
tim@895:         super(arg0, arg1);
tim@895:         this.setUp();
tim@895:     }
tim@895: 
tim@895:     /**
tim@895:      * Constructor
tim@895:      * @param arg0
tim@895:      * @param arg1
tim@895:      */
tim@895:     public CacheCleaner(ThreadGroup arg0, String arg1) {
tim@895:         super(arg0, arg1);
tim@895:         this.setUp();
tim@895:     }
tim@895: 
tim@895:     /**
tim@895:      * Constructor
tim@895:      * @param arg0
tim@895:      * @param arg1
tim@895:      */
tim@895:     public CacheCleaner(Runnable arg0, String arg1) {
tim@895:         super(arg0, arg1);
tim@895:         this.setUp();
tim@895:     }
tim@895: 
tim@895:     /**
tim@895:      * Constructor
tim@895:      * @param arg0
tim@895:      * @param arg1
tim@895:      * @param arg2
tim@895:      */
tim@895:     public CacheCleaner(ThreadGroup arg0, Runnable arg1, String arg2) {
tim@895:         super(arg0, arg1, arg2);
tim@895:         this.setUp();
tim@895:     }
tim@895: 
tim@895:     /**
tim@895:      * Constructor
tim@895:      * @param arg0
tim@895:      * @param arg1
tim@895:      * @param arg2
tim@895:      * @param arg3
tim@895:      */
tim@895:     public CacheCleaner(ThreadGroup arg0, Runnable arg1, String arg2, long arg3) {
tim@895:         super(arg0, arg1, arg2, arg3);
tim@895:         this.setUp();
tim@895:     }
ingo@897: 
tim@895:     /**
tim@895:      * Sets up the members of the CacheCleaner.
tim@895:      */
tim@895:     protected void setUp(){
tim@895:         String intervalValue = System.getProperty(CACHE_CLEANER_INTERVAL);
tim@895:         if (intervalValue != null){
tim@895:             log.info("Set Interval to "+intervalValue+" Seconds");
tim@895:             try {
tim@895:                 this.timeout = Long.parseLong(intervalValue) * 1000;
tim@895:             } catch (NumberFormatException e) {
tim@895:                 log.error(e,e);
tim@895:             }
tim@895:         }
tim@895:     }
tim@895: 
tim@895:     /**
tim@895:      * This Method can be used do run the Main-Mechanism of the Thread e.g
tim@895:      * from a Unittest.
tim@895:      * @return
tim@895:      */
tim@895:     public boolean test(){
tim@895:         log.debug("CacheCleaner.test");
tim@895:         this.cleanup();
tim@895:         return true;
tim@895:     }
tim@895: 
tim@895:     @Override
tim@895:     public void run() {
tim@895:         log.debug("CacheCleaner.run");
tim@895:         long requiredTime = 0;
tim@895:         this.lowerBorderTime = System.currentTimeMillis();
tim@895:         while (true){
tim@895:             long startTime = 0;
tim@895:             try {
tim@895:                 long nextTimeout = timeout-requiredTime;
tim@895:                 if (nextTimeout > 0){
tim@895:                     Thread.sleep(nextTimeout);
tim@895:                 }
tim@895:                 startTime = System.currentTimeMillis();
tim@895:                 log.debug("Sleep "+nextTimeout+"ms cleanup Cache now");
tim@895:                 this.cleanup();
tim@895:             } catch (InterruptedException e) {
tim@895:                 log.error(e,e);
tim@895:             } catch (Exception e){
tim@895:                 log.error(e,e);
tim@895:             }  catch (Throwable t){
tim@895:                 log.error(t,t);
tim@895:             }finally{
tim@895:                 requiredTime = System.currentTimeMillis() - startTime;
tim@895:                 log.debug("CleanUp required "+requiredTime);
tim@895:             }
tim@895:         }
tim@895:     }
tim@895: 
tim@895:     /**
tim@895:      * Method that do the Cleanup-Work
tim@895:      */
tim@895:     protected void cleanup(){
tim@895:         log.debug("CacheCleaner.cleanup");
tim@895:         try {
tim@895:             // We have to go this Way to avoid using the Cache for this Query.
tim@895:             String[] tableNames = this.getUpdatedTableNames();
tim@895:             if (tableNames != null){
tim@895:                 QueryExecutorFactory.getInstance()
tim@895:                                     .getQueryExecutor().clearCache(tableNames);
tim@895:             }
tim@895:         } catch (QueryException e) {
tim@895:             log.error(e,e);
tim@895:         }
ingo@897: 
tim@895:     }
tim@895: 
tim@895:     /**
tim@895:      * Returns the Names of the Tables which have been updated.
tim@895:      * @return the Names of the Tables which have been updated.
tim@895:      * @throws QueryException
tim@895:      */
tim@895:     protected String[] getUpdatedTableNames()throws QueryException {
tim@895:         String[] tableNames = null;
tim@895:         QueryExecutor queryExecutor = new DefaultQueryExceutor();
tim@895:         Date date = new Date(this.lowerBorderTime);
tim@895:         this.lowerBorderTime = System.currentTimeMillis();
tim@895:         log.debug("New Lookup at "+DateUtils.getPatternedDateAmer(new Date(lowerBorderTime)));
tim@895:         String queryDate = DateUtils.getPatternedDateAmer(date);
tim@895:         Collection<Result> result = queryExecutor.
ingo@897:                                       executeQuery(queryID,
tim@895:                                                    new String[]{queryDate});
tim@895:         if (result != null && !result.isEmpty()){
tim@895:             tableNames = new String[result.size()];
tim@895:             Iterator<Result> it = result.iterator();
tim@895:             int i = 0;
tim@895:             while (it.hasNext()){
tim@895:                 tableNames[i++] = it.next().getString(0).toUpperCase();
tim@895:                 log.debug("Table that was updated: "+tableNames[i-1]);
tim@895:             }
tim@895:         }
tim@895:         return tableNames;
tim@895:     }
tim@895: }