Mercurial > dive4elements > river
view artifacts/src/main/java/org/dive4elements/river/artifacts/model/SQOverview.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 | 2e11fc7f5d35 |
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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 java.io.Serializable; import java.text.SimpleDateFormat; import java.util.ArrayList; import java.util.Date; import java.util.List; import org.apache.log4j.Logger; import org.hibernate.SQLQuery; import org.hibernate.Session; import org.hibernate.type.StandardBasicTypes; import org.w3c.dom.Document; import org.w3c.dom.Element; import org.dive4elements.river.utils.KMIndex; public class SQOverview implements Serializable { private static Logger log = Logger.getLogger(SQOverview.class); /** * Serial version UId. */ private static final long serialVersionUID = -8934372438968398508L; public interface Filter { boolean accept(KMIndex<List<Date>> entry); } // interface Filter public static final Filter ACCEPT = new Filter() { @Override public boolean accept(KMIndex<List<Date>> entry) { return true; } }; public static class KmFilter implements Filter { protected double km; public KmFilter (double km) { this.km = km; } @Override public boolean accept(KMIndex<List<Date>> list) { for (KMIndex.Entry<List<Date>> e: list){ if (e.getKm() == km) { return true; } } return false; } }; public static class DateFilter implements Filter { protected Date date; public DateFilter (Date date) { this.date = date; } @Override public boolean accept(KMIndex<List<Date>> list) { for (KMIndex.Entry<List<Date>> e: list){ if (e.getValue().equals(this.date)) { return true; } } return false; } }; public static final double EPSILON = 1e-4; public static final String DATE_FORMAT = "dd.MM.yyyy"; public static final String SQL_SQ = "SELECT" + " s.km AS km," + " m.datum AS datum " + "FROM messung m " + " JOIN station s" + " ON m.stationid = s.stationid " + " JOIN gewaesser g " + " ON s.gewaesserid = g.gewaesserid " + "WHERE" + " m.q_bpegel IS NOT NULL AND" + " g.name = :name " + "ORDER by" + " s.km, m.datum"; protected String riverName; protected KMIndex<List<Date>> entries; public SQOverview() { entries = new KMIndex<List<Date>>(); } public SQOverview(String riverName) { this(); this.riverName = riverName; } private static final boolean epsilonEquals(double a, double b) { return Math.abs(a - b) < EPSILON; } protected void loadData(Session session) { SQLQuery query = session.createSQLQuery(SQL_SQ) .addScalar("km", StandardBasicTypes.DOUBLE) .addScalar("datum", StandardBasicTypes.DATE); query.setString("name", riverName); List<Object []> list = query.list(); if (list.isEmpty()) { log.warn("No river '" + riverName + "' found."); } Double prevKm = -Double.MAX_VALUE; List<Date> dates = new ArrayList<Date>(); for (Object [] row: list) { Double km = (Double)row[0]; if (!epsilonEquals(km, prevKm) && !dates.isEmpty()) { entries.add(prevKm, dates); dates = new ArrayList<Date>(); } dates.add((Date)row[1]); prevKm = km; } if (!dates.isEmpty()) { entries.add(prevKm, dates); } } public boolean load(Session session) { loadData(session); return true; } public void generateOverview(Document document) { generateOverview(document, ACCEPT); } public KMIndex<List<Date>> filter(Filter f) { // TODO: Apply filter return entries; } public void generateOverview( Document document, Filter filter ) { KMIndex<List<Date>> filtered = filter(ACCEPT); Element sqElement = document.createElement("sq"); Element riverElement = document.createElement("river"); riverElement.setAttribute("name", riverName); sqElement.appendChild(riverElement); SimpleDateFormat df = new SimpleDateFormat(DATE_FORMAT); Element kmE = document.createElement("km"); for (KMIndex.Entry<List<Date>> e: filtered) { List<Date> dates = e.getValue(); if (!dates.isEmpty()) { Element dEs = document.createElement("dates"); for (Date d: dates) { Element dE = document.createElement("date"); dE.setAttribute("value", df.format(d)); dEs.appendChild(dE); } kmE.appendChild(dEs); } } sqElement.appendChild(kmE); document.appendChild(sqElement); } } // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :