Mercurial > dive4elements > river
view artifacts/src/main/java/org/dive4elements/river/artifacts/model/GaugeFinderFactory.java @ 7471:fff862f4ef76
Experimental caching of datacage recommendations. The respective hook is called a lot and running the datacage over and over again when loading data can be expensive. So the generated recommendations are cached for some time.
Hopefully this improves the overall speed of loading data from the datacage.
author | Sascha L. Teichmann <teichmann@intevation.de> |
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date | Wed, 30 Oct 2013 15:26:21 +0100 |
parents | af13ceeba52a |
children | 0a5239a1e46e |
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/* Copyright (C) 2011, 2012, 2013 by Bundesanstalt für Gewässerkunde * Software engineering by Intevation GmbH * * This file is Free Software under the GNU AGPL (>=v3) * and comes with ABSOLUTELY NO WARRANTY! Check out the * documentation coming with Dive4Elements River for details. */ package org.dive4elements.river.artifacts.model; import org.dive4elements.river.artifacts.cache.CacheFactory; import org.dive4elements.river.backend.SessionHolder; import org.dive4elements.river.model.River; import java.util.ArrayList; import java.util.List; import net.sf.ehcache.Cache; import net.sf.ehcache.Element; import org.apache.log4j.Logger; import org.hibernate.SQLQuery; import org.hibernate.Session; import org.hibernate.type.StandardBasicTypes; /** Get GaugeFinders. */ public class GaugeFinderFactory { private static Logger log = Logger.getLogger(GaugeFinderFactory.class); public static final String CACHE_NAME = "gauge-finders"; public static final String SQL_GAUGES = "SELECT" + " g.id AS gauge_id," + " g.name AS name," + " r.a AS a," + " r.b AS b " + "FROM gauges g" + " JOIN ranges r ON g.range_id = r.id " + "WHERE" + " g.river_id = :river_id " + "ORDER BY r.a"; private static GaugeFinderFactory INSTANCE; protected GaugeFinderFactory() { } public static synchronized GaugeFinderFactory getInstance() { if (INSTANCE == null) { INSTANCE = new GaugeFinderFactory(); } return INSTANCE; } public GaugeFinder getGaugeFinder(String riverName) { River river = RiverFactory.getRiver(riverName); return river != null ? getGaugeFinder(river.getId(), river.getKmUp()) : null; } public synchronized GaugeFinder getGaugeFinder( int riverId, boolean isKmUp ) { Cache cache = CacheFactory.getCache(CACHE_NAME); if (cache == null) { return getUncached(riverId, isKmUp); } String cacheKey = riverId + "-" + isKmUp; Element element = cache.get(cacheKey); if (element != null) { return (GaugeFinder)element.getValue(); } GaugeFinder finder = getUncached(riverId, isKmUp); if (finder != null) { cache.put(new Element(cacheKey, finder)); } return finder; } protected GaugeFinder loadGauges( Session session, int riverId, boolean isKmUp ) { SQLQuery query = session.createSQLQuery(SQL_GAUGES) .addScalar("gauge_id", StandardBasicTypes.INTEGER) .addScalar("name", StandardBasicTypes.STRING) .addScalar("a", StandardBasicTypes.DOUBLE) .addScalar("b", StandardBasicTypes.DOUBLE); query.setInteger("river_id", riverId); List<Object []> list = query.list(); if (list.isEmpty()) { log.warn("River " + riverId + " has no gauges."); return null; } List<GaugeRange> gauges = new ArrayList<GaugeRange>(); for (Object [] row: list) { int gaugeId = (Integer)row[0]; String name = (String) row[1]; double start = (Double) row[2]; double end = (Double) row[3]; GaugeRange gauge = new GaugeRange(start, end, name, gaugeId); gauges.add(gauge); } return new GaugeFinder(gauges, isKmUp); } protected GaugeFinder getUncached(int riverId, boolean isKmUp) { Session session = SessionHolder.HOLDER.get(); GaugeFinder finder = loadGauges(session, riverId, isKmUp); if (finder == null || !finder.loadDischargeSectors(session, riverId)) { return null; } return finder; } } // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :