view flys-artifacts/src/main/java/de/intevation/flys/artifacts/ExternalWMSArtifact.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 a2735a4bf75e
children
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package de.intevation.flys.artifacts;

import java.util.ArrayList;
import java.util.List;

import org.apache.log4j.Logger;

import org.w3c.dom.Document;

import de.intevation.artifacts.Artifact;
import de.intevation.artifacts.ArtifactFactory;
import de.intevation.artifacts.CallMeta;

import de.intevation.artifactdatabase.state.DefaultOutput;
import de.intevation.artifactdatabase.state.Facet;
import de.intevation.artifactdatabase.state.State;

import de.intevation.flys.artifacts.states.WMSBackgroundState;


public class ExternalWMSArtifact extends StaticFLYSArtifact {

    public static final String NAME = "external_wms";

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


    @Override
    public String getName() {
        return NAME;
    }


    @Override
    public void setup(
        String          identifier,
        ArtifactFactory factory,
        Object          context,
        CallMeta        callMeta,
        Document        data)
    {
        logger.info("ExternalWMSArtifact.setup");

        super.setup(identifier, factory, context, callMeta, data);

        String ids = getDatacageIDValue(data);

        if (ids != null && ids.length() > 0) {
            addStringData("ids", ids);
        }
        else {
            throw new IllegalArgumentException("No attribute 'ids' found!");
        }

        List<Facet> fs = new ArrayList<Facet>();

        WMSBackgroundState s = (WMSBackgroundState) getCurrentState(context);
        s.computeInit(this, hash(), context, callMeta, fs);

        if (!fs.isEmpty()) {
            addFacets(getCurrentStateId(), fs);
        }
    }


    @Override
    protected void initialize(
        Artifact artifact,
        Object   context,
        CallMeta callMeta)
    {
        // do nothing
    }


    @Override
    public State getCurrentState(Object cc) {
        State s = new ExternalWMSState(this);

        List<Facet> fs = getFacets(getCurrentStateId());

        DefaultOutput o = new DefaultOutput(
            "floodmap",
            "floodmap",
            "image/png",
            fs,
            "map");

        s.getOutputs().add(o);

        return s;
    }


    /**
     * Get a list containing the one and only State.
     * @param  context ignored.
     * @return list with one and only state.
     */
    @Override
    protected List<State> getStates(Object context) {
        ArrayList<State> states = new ArrayList<State>();
        states.add(getCurrentState(context));

        return states;
    }


    public static class ExternalWMSState extends WMSBackgroundState {

        protected ExternalWMSArtifact artifact;

        protected String ids;


        public ExternalWMSState(ExternalWMSArtifact artifact) {
            super();
            this.artifact = artifact;
        }

        protected String getIds() {
            if (ids == null || ids.length() == 0) {
                ids = artifact.getDataAsString("ids");
            }

            return ids;
        }

        @Override
        protected String getFacetType() {
            return FLOODMAP_EXTERNAL_WMS;
        }

        @Override
        protected String getSrid() {
            return "";
        }

        @Override
        protected String getUrl() {
            String   ids   = getIds();
            String[] parts = ids.split(";");

            return parts[0];
        }

        @Override
        protected String getLayer() {
            String   ids   = getIds();
            String[] parts = ids.split(";");

            return parts[1];
        }

        @Override
        protected String getTitle(CallMeta meta) {
            String   ids   = getIds();
            String[] parts = ids.split(";");

            return parts[2];
        }
    } // end of class ExternalWMSState
}
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