org.apache.solr.spelling.suggest.fst.BlendedInfixLookupFactory.java Source code

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Here is the source code for org.apache.solr.spelling.suggest.fst.BlendedInfixLookupFactory.java

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package org.apache.solr.spelling.suggest.fst;

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.
 */

import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.Set;

import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.search.suggest.Lookup;
import org.apache.lucene.search.suggest.analyzing.AnalyzingInfixSuggester;
import org.apache.lucene.search.suggest.analyzing.BlendedInfixSuggester;
import org.apache.lucene.search.suggest.analyzing.BlendedInfixSuggester.BlenderType;
import org.apache.lucene.store.FSDirectory;
import org.apache.lucene.util.BytesRef;
import org.apache.solr.common.util.NamedList;
import org.apache.solr.core.SolrCore;
import org.apache.solr.schema.FieldType;

/**
 * Factory for {@link BlendedInfixLookupFactory}
 * @lucene.experimental
 */
public class BlendedInfixLookupFactory extends AnalyzingInfixLookupFactory {

    /**
     * Blender type used to calculate weight coefficient using the position
     * of the first matching word
     * </p>
     * Available blender types are: </br>
     *  linear: weight*(1 - 0.10*position) [default]</br>
     *  reciprocal: weight/(1+position) 
     */
    private static final String BLENDER_TYPE = "blenderType";

    /** 
     * Factor to multiply the number of searched elements
     * Default is 10
     */
    private static final String NUM_FACTOR = "numFactor";

    /** 
     * Default path where the index for the suggester is stored/loaded from
     * */
    private static final String DEFAULT_INDEX_PATH = "blendedInfixSuggesterIndexDir";

    /**
     * File name for the automaton.
     */
    private static final String FILENAME = "bifsta.bin";

    @Override
    public Lookup create(NamedList params, SolrCore core) {
        // mandatory parameter
        Object fieldTypeName = params.get(QUERY_ANALYZER);
        if (fieldTypeName == null) {
            throw new IllegalArgumentException(
                    "Error in configuration: " + QUERY_ANALYZER + " parameter is mandatory");
        }
        FieldType ft = core.getLatestSchema().getFieldTypeByName(fieldTypeName.toString());
        if (ft == null) {
            throw new IllegalArgumentException(
                    "Error in configuration: " + fieldTypeName.toString() + " is not defined in the schema");
        }
        Analyzer indexAnalyzer = ft.getIndexAnalyzer();
        Analyzer queryAnalyzer = ft.getQueryAnalyzer();

        // optional parameters

        String indexPath = params.get(INDEX_PATH) != null ? params.get(INDEX_PATH).toString() : DEFAULT_INDEX_PATH;
        if (new File(indexPath).isAbsolute() == false) {
            indexPath = core.getDataDir() + File.separator + indexPath;
        }

        int minPrefixChars = params.get(MIN_PREFIX_CHARS) != null
                ? Integer.parseInt(params.get(MIN_PREFIX_CHARS).toString())
                : AnalyzingInfixSuggester.DEFAULT_MIN_PREFIX_CHARS;

        BlenderType blenderType = getBlenderType(params.get(BLENDER_TYPE));

        int numFactor = params.get(NUM_FACTOR) != null ? Integer.parseInt(params.get(NUM_FACTOR).toString())
                : BlendedInfixSuggester.DEFAULT_NUM_FACTOR;

        try {
            return new BlendedInfixSuggester(core.getSolrConfig().luceneMatchVersion,
                    FSDirectory.open(new File(indexPath)), indexAnalyzer, queryAnalyzer, minPrefixChars,
                    blenderType, numFactor) {
                @Override
                public List<LookupResult> lookup(CharSequence key, Set<BytesRef> contexts, int num,
                        boolean allTermsRequired, boolean doHighlight) throws IOException {
                    List<LookupResult> res = super.lookup(key, contexts, num, allTermsRequired, doHighlight);
                    if (doHighlight) {
                        List<LookupResult> res2 = new ArrayList<>();
                        for (LookupResult hit : res) {
                            res2.add(new LookupResult(hit.highlightKey.toString(), hit.highlightKey, hit.value,
                                    hit.payload, hit.contexts));
                        }
                        res = res2;
                    }

                    return res;
                }
            };
        } catch (IOException e) {
            throw new RuntimeException();
        }
    }

    @Override
    public String storeFileName() {
        return FILENAME;
    }

    private BlenderType getBlenderType(Object blenderTypeParam) {
        BlenderType blenderType = BlenderType.POSITION_LINEAR;
        if (blenderTypeParam != null) {
            String blenderTypeStr = blenderTypeParam.toString();
            if (blenderTypeStr.equalsIgnoreCase("reciprocal")) {
                blenderType = BlenderType.POSITION_RECIPROCAL;
            }
        }
        return blenderType;
    }
}