ScriptFacetCollector.java

/*
 * Copyright 2012 Igor Motov
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.elasticsearch.search.facet.script;

import static org.elasticsearch.common.collect.Maps.newHashMap;

import org.apache.lucene.index.AtomicReaderContext;
import org.apache.lucene.search.Scorer;
import org.elasticsearch.client.Client;
import org.elasticsearch.script.ExecutableScript;
import org.elasticsearch.script.ScriptService;
import org.elasticsearch.script.SearchScript;
import org.elasticsearch.search.facet.FacetExecutor;
import org.elasticsearch.search.facet.InternalFacet;
import org.elasticsearch.search.internal.SearchContext;

import java.io.IOException;
import java.util.Map;

/**
 *
 */
public class ScriptFacetCollector extends FacetExecutor {

    private final String scriptLang;

    private final SearchScript mapScript;

    private final ExecutableScript combineScript;

    private final String reduceScript;

    // initial parameters for same shard scripts {init, map, combine}
    // state can be passed in params between them too
    private final Map<String, Object> params;
    // initial parameters for {reduce}
    private final Map<String, Object> reduceParams;

    private ScriptService scriptService;

    private Client client;

    public ScriptFacetCollector(String scriptLang, String initScript, String mapScript, String combineScript,
                                String reduceScript, Map<String, Object> params, Map<String, Object> reduceParams,
                                SearchContext context, Client client) {
        this.scriptService = context.scriptService();
        this.client = client;
        this.scriptLang = scriptLang;
        if (params == null) {
            this.params = newHashMap();
        } else {
            this.params = params;
        }
        if (reduceParams == null) {
          this.reduceParams = newHashMap();
        } else {
          this.reduceParams = reduceParams;
        }
        this.params.put("_ctx", context);
        this.params.put("_client", client);
        if (initScript != null) {
            scriptService.executable(scriptLang, initScript, this.params).run();
        }
        this.mapScript = scriptService.search(context.lookup(), scriptLang, mapScript, this.params);
        if (combineScript != null) {
            this.combineScript = scriptService.executable(scriptLang, combineScript, this.params);
        } else {
            this.combineScript = null;
        }
        this.reduceScript = reduceScript;
    }

    @Override
    public InternalFacet buildFacet(String facetName) {
        Object facet;
        if (combineScript != null) {
            facet = combineScript.run();
        } else {
            facet = params.get("facet");
        }
        return new InternalScriptFacet(facetName, facet, scriptLang, reduceScript, reduceParams, scriptService, client);
    }

    @Override
    public Collector collector() {
        return new Collector();
    }

    class Collector extends FacetExecutor.Collector {

        @Override
        public void postCollection() {
        }

        @Override
        public void collect(int doc) throws IOException {
            mapScript.setNextDocId(doc);
            mapScript.run();
        }

        @Override
        public void setNextReader(AtomicReaderContext context) throws IOException {
            mapScript.setNextReader(context);
        }

        @Override
        public void setScorer(Scorer scorer) throws IOException {
            mapScript.setScorer(scorer);
        }
    }
}