/*
* 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.
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package org.apache.solr.search.mlt;
import org.apache.lucene.index.Term;
import org.apache.lucene.legacy.LegacyNumericUtils;
import org.apache.lucene.queries.mlt.MoreLikeThis;
import org.apache.lucene.search.BooleanClause;
import org.apache.lucene.search.BooleanQuery;
import org.apache.lucene.search.BoostQuery;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.ScoreDoc;
import org.apache.lucene.search.TermQuery;
import org.apache.lucene.search.TopDocs;
import org.apache.lucene.util.BytesRefBuilder;
import org.apache.solr.common.SolrException;
import org.apache.solr.common.StringUtils;
import org.apache.solr.common.params.SolrParams;
import org.apache.solr.request.SolrQueryRequest;
import org.apache.solr.schema.SchemaField;
import org.apache.solr.search.QParser;
import org.apache.solr.search.QueryParsing;
import org.apache.solr.search.SolrIndexSearcher;
import org.apache.solr.util.SolrPluginUtils;
import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Map;
import java.util.regex.Pattern;
public class SimpleMLTQParser extends QParser {
// Pattern is thread safe -- TODO? share this with general 'fl' param
private static final Pattern splitList = Pattern.compile(",| ");
public SimpleMLTQParser(String qstr, SolrParams localParams,
SolrParams params, SolrQueryRequest req) {
super(qstr, localParams, params, req);
}
public Query parse() {
String defaultField = req.getSchema().getUniqueKeyField().getName();
String uniqueValue = localParams.get(QueryParsing.V);
String[] qf = localParams.getParams("qf");
SolrIndexSearcher searcher = req.getSearcher();
Query docIdQuery = createIdQuery(defaultField, uniqueValue);
Map<String,Float> boostFields = new HashMap<>();
try {
TopDocs td = searcher.search(docIdQuery, 1);
if (td.totalHits != 1) throw new SolrException(
SolrException.ErrorCode.BAD_REQUEST, "Error completing MLT request. Could not fetch " +
"document with id [" + uniqueValue + "]");
ScoreDoc[] scoreDocs = td.scoreDocs;
MoreLikeThis mlt = new MoreLikeThis(req.getSearcher().getIndexReader());
mlt.setMinTermFreq(localParams.getInt("mintf", MoreLikeThis.DEFAULT_MIN_TERM_FREQ));
mlt.setMinDocFreq(localParams.getInt("mindf", MoreLikeThis.DEFAULT_MIN_DOC_FREQ));
mlt.setMinWordLen(localParams.getInt("minwl", MoreLikeThis.DEFAULT_MIN_WORD_LENGTH));
mlt.setMaxWordLen(localParams.getInt("maxwl", MoreLikeThis.DEFAULT_MAX_WORD_LENGTH));
mlt.setMaxQueryTerms(localParams.getInt("maxqt", MoreLikeThis.DEFAULT_MAX_QUERY_TERMS));
mlt.setMaxNumTokensParsed(localParams.getInt("maxntp", MoreLikeThis.DEFAULT_MAX_NUM_TOKENS_PARSED));
mlt.setMaxDocFreq(localParams.getInt("maxdf", MoreLikeThis.DEFAULT_MAX_DOC_FREQ));
Boolean boost = localParams.getBool("boost", false);
mlt.setBoost(boost);
String[] fieldNames;
if (qf != null) {
ArrayList<String> fields = new ArrayList<>();
for (String fieldName : qf) {
if (!StringUtils.isEmpty(fieldName)) {
String[] strings = splitList.split(fieldName);
for (String string : strings) {
if (!StringUtils.isEmpty(string)) {
fields.add(string);
}
}
}
}
// Parse field names and boosts from the fields
boostFields = SolrPluginUtils.parseFieldBoosts(fields.toArray(new String[0]));
fieldNames = boostFields.keySet().toArray(new String[0]);
} else {
Map<String, SchemaField> fieldDefinitions = req.getSearcher().getSchema().getFields();
ArrayList<String> fields = new ArrayList();
for (String fieldName : fieldDefinitions.keySet()) {
if (fieldDefinitions.get(fieldName).indexed() && fieldDefinitions.get(fieldName).stored())
if (fieldDefinitions.get(fieldName).getType().getNumberType() == null)
fields.add(fieldName);
}
fieldNames = fields.toArray(new String[0]);
}
if (fieldNames.length < 1) {
throw new SolrException( SolrException.ErrorCode.BAD_REQUEST,
"MoreLikeThis requires at least one similarity field: qf" );
}
mlt.setFieldNames(fieldNames);
mlt.setAnalyzer(req.getSchema().getIndexAnalyzer());
Query rawMLTQuery = mlt.like(scoreDocs[0].doc);
BooleanQuery boostedMLTQuery = (BooleanQuery) rawMLTQuery;
if (boost && boostFields.size() > 0) {
BooleanQuery.Builder newQ = new BooleanQuery.Builder();
newQ.setMinimumNumberShouldMatch(boostedMLTQuery.getMinimumNumberShouldMatch());
for (BooleanClause clause : boostedMLTQuery) {
Query q = clause.getQuery();
float originalBoost = 1f;
if (q instanceof BoostQuery) {
BoostQuery bq = (BoostQuery) q;
q = bq.getQuery();
originalBoost = bq.getBoost();
}
Float fieldBoost = boostFields.get(((TermQuery) q).getTerm().field());
q = ((fieldBoost != null) ? new BoostQuery(q, fieldBoost * originalBoost) : clause.getQuery());
newQ.add(q, clause.getOccur());
}
boostedMLTQuery = newQ.build();
}
// exclude current document from results
BooleanQuery.Builder realMLTQuery = new BooleanQuery.Builder();
realMLTQuery.add(boostedMLTQuery, BooleanClause.Occur.MUST);
realMLTQuery.add(docIdQuery, BooleanClause.Occur.MUST_NOT);
return realMLTQuery.build();
} catch (IOException e) {
throw new SolrException(SolrException.ErrorCode.BAD_REQUEST,
"Error completing MLT request" + e.getMessage());
}
}
private Query createIdQuery(String defaultField, String uniqueValue) {
return new TermQuery(req.getSchema().getField(defaultField).getType().getNumberType() != null
? createNumericTerm(defaultField, uniqueValue)
: new Term(defaultField, uniqueValue));
}
private Term createNumericTerm(String field, String uniqueValue) {
BytesRefBuilder bytesRefBuilder = new BytesRefBuilder();
bytesRefBuilder.grow(LegacyNumericUtils.BUF_SIZE_INT);
LegacyNumericUtils.intToPrefixCoded(Integer.parseInt(uniqueValue), 0, bytesRefBuilder);
return new Term(field, bytesRefBuilder);
}
}