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

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Here is the source code for org.apache.solr.spelling.suggest.fst.AnalyzingInfixLookupFactory.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 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.AnalyzingSuggester;
import org.apache.solr.common.util.NamedList;
import org.apache.solr.core.SolrCore;
import org.apache.solr.schema.FieldType;
import org.apache.solr.spelling.suggest.LookupFactory;

/**
 * Factory for {@link AnalyzingInfixSuggester}
 * @lucene.experimental
 */
public class AnalyzingInfixLookupFactory extends LookupFactory {
    /**
     * The analyzer used at "query-time" and "build-time" to analyze suggestions.
     */
    public static final String QUERY_ANALYZER = "suggestAnalyzerFieldType";

    /**
     * The path where the underlying index is stored
     * if no index is found, it will be generated by
     * the AnalyzingInfixSuggester
     */
    public static final String INDEX_PATH = "indexPath";

    /**
     * Minimum number of leading characters before PrefixQuery is used (default 4). 
     * Prefixes shorter than this are indexed as character ngrams 
     * (increasing index size but making lookups faster)
     */
    private static final String MIN_PREFIX_CHARS = "minPrefixChars";

    private static final String DEFAULT_INDEX_PATH = "analyzingInfixSuggesterIndexDir";

    /**
     * File name for the automaton.
     */
    private static final String FILENAME = "iwfsta.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());
        Analyzer indexAnalyzer = ft.getAnalyzer();
        Analyzer queryAnalyzer = ft.getQueryAnalyzer();

        // optional parameters

        String indexPath = params.get(INDEX_PATH) != null ? params.get(INDEX_PATH).toString() : DEFAULT_INDEX_PATH;

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

        try {
            return new AnalyzingInfixSuggester(core.getSolrConfig().luceneMatchVersion, new File(indexPath),
                    indexAnalyzer, queryAnalyzer, minPrefixChars);
        } catch (IOException e) {
            throw new RuntimeException();
        }
    }

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