view flys-client/src/main/java/de/intevation/flys/client/server/MapOutputServiceImpl.java @ 5779:ebec12def170

Datacage: Add a pool of builders to make it multi threadable. XML DOM is not thread safe. Therefore the old implementation only allowed one thread to use the builder at a time. As the complexity of the configuration has increased over time this has become a bottleneck of the whole application because it took quiet some time to build a result. Furthermore the builder code path is visited very frequent. So many concurrent requests were piled up resulting in long waits for the users. To mitigate this problem a round robin pool of builders is used now. Each of the pooled builders has an independent copy of the XML template and can be run in parallel. The number of builders is determined by the system property 'flys.datacage.pool.size'. It defaults to 4.
author Sascha L. Teichmann <teichmann@intevation.de>
date Sun, 21 Apr 2013 12:48:09 +0200
parents f7b3d5833f3b
children
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package de.intevation.flys.client.server;

import java.io.InputStream;
import java.io.IOException;

import java.util.Map;

import org.w3c.dom.Document;

import org.apache.log4j.Logger;

import com.google.gwt.user.server.rpc.RemoteServiceServlet;

import de.intevation.artifacts.common.utils.ClientProtocolUtils;
import de.intevation.artifacts.common.utils.XMLUtils;

import de.intevation.artifacts.httpclient.http.HttpClient;
import de.intevation.artifacts.httpclient.http.HttpClientImpl;
import de.intevation.artifacts.httpclient.exceptions.ConnectionException;

import de.intevation.flys.client.shared.exceptions.ServerException;
import de.intevation.flys.client.shared.model.Collection;
import de.intevation.flys.client.shared.model.MapConfig;
import de.intevation.flys.client.shared.model.OutputMode;
import de.intevation.flys.client.client.services.MapOutputService;


public class MapOutputServiceImpl
extends      RemoteServiceServlet
implements   MapOutputService
{

    private static final Logger logger =
        Logger.getLogger(MapOutputServiceImpl.class);


    public static final String ERROR_NO_MAP_CONFIG = "error_no_map_config";

    public static final String ERROR_NO_MAP_OUTPUT_TYPE = "error_no_map_output_type";

    public MapConfig doOut(Collection collection)
    throws ServerException
    {
        logger.info("MapOutputServiceImpl.doOut");

        String url  = getServletContext().getInitParameter("server-url");
        String uuid = collection.identifier();

        Map<String, OutputMode> modes = collection.getOutputModes();
        String requestMode = "";
        if (modes.containsKey("floodmap")) {
            requestMode = "floodmap";
        }
        else if (modes.containsKey("map")) {
            requestMode = "map";
        }
        else {
           throw new ServerException(ERROR_NO_MAP_OUTPUT_TYPE);
        }

        try {
            Document request = ClientProtocolUtils.newOutCollectionDocument(
                uuid, requestMode, requestMode);

            HttpClient client = new HttpClientImpl(url);
            InputStream    is = client.collectionOut(request, uuid, requestMode);

            Document response = XMLUtils.parseDocument(is);

            return MapHelper.parseConfig(response);
        }
        catch (ConnectionException e) {
            logger.error(e, e);
        }
        catch (IOException ioe) {
            logger.error(ioe, ioe);
        }

        throw new ServerException(ERROR_NO_MAP_CONFIG);
    }
}
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