/*
* Licensed to Elasticsearch under one or more contributor
* license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright
* ownership. Elasticsearch 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.
*/
package org.elasticsearch.index.query;
import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.analysis.TokenStream;
import org.apache.lucene.analysis.tokenattributes.CharTermAttribute;
import org.apache.lucene.index.Term;
import org.apache.lucene.queries.ExtendedCommonTermsQuery;
import org.apache.lucene.search.BooleanClause;
import org.apache.lucene.search.BooleanClause.Occur;
import org.apache.lucene.search.Query;
import org.apache.lucene.util.BytesRefBuilder;
import org.elasticsearch.common.inject.Inject;
import org.elasticsearch.common.xcontent.XContentParser;
import org.elasticsearch.index.mapper.MappedFieldType;
import java.io.IOException;
/**
*
*/
public class CommonTermsQueryParser implements QueryParser {
public static final String NAME = "common";
static final float DEFAULT_MAX_TERM_DOC_FREQ = 0.01f;
static final Occur DEFAULT_HIGH_FREQ_OCCUR = Occur.SHOULD;
static final Occur DEFAULT_LOW_FREQ_OCCUR = Occur.SHOULD;
static final boolean DEFAULT_DISABLE_COORD = true;
@Inject
public CommonTermsQueryParser() {
}
@Override
public String[] names() {
return new String[] { NAME };
}
@Override
public Query parse(QueryParseContext parseContext) throws IOException, QueryParsingException {
XContentParser parser = parseContext.parser();
XContentParser.Token token = parser.nextToken();
if (token != XContentParser.Token.FIELD_NAME) {
throw new QueryParsingException(parseContext, "[common] query malformed, no field");
}
String fieldName = parser.currentName();
Object value = null;
float boost = 1.0f;
String queryAnalyzer = null;
String lowFreqMinimumShouldMatch = null;
String highFreqMinimumShouldMatch = null;
boolean disableCoord = DEFAULT_DISABLE_COORD;
Occur highFreqOccur = DEFAULT_HIGH_FREQ_OCCUR;
Occur lowFreqOccur = DEFAULT_LOW_FREQ_OCCUR;
float maxTermFrequency = DEFAULT_MAX_TERM_DOC_FREQ;
String queryName = null;
token = parser.nextToken();
if (token == XContentParser.Token.START_OBJECT) {
String currentFieldName = null;
while ((token = parser.nextToken()) != XContentParser.Token.END_OBJECT) {
if (token == XContentParser.Token.FIELD_NAME) {
currentFieldName = parser.currentName();
} else if (token == XContentParser.Token.START_OBJECT) {
if ("minimum_should_match".equals(currentFieldName) || "minimumShouldMatch".equals(currentFieldName)) {
String innerFieldName = null;
while ((token = parser.nextToken()) != XContentParser.Token.END_OBJECT) {
if (token == XContentParser.Token.FIELD_NAME) {
innerFieldName = parser.currentName();
} else if (token.isValue()) {
if ("low_freq".equals(innerFieldName) || "lowFreq".equals(innerFieldName)) {
lowFreqMinimumShouldMatch = parser.text();
} else if ("high_freq".equals(innerFieldName) || "highFreq".equals(innerFieldName)) {
highFreqMinimumShouldMatch = parser.text();
} else {
throw new QueryParsingException(parseContext, "[common] query does not support [" + innerFieldName
+ "] for [" + currentFieldName + "]");
}
}
}
} else {
throw new QueryParsingException(parseContext, "[common] query does not support [" + currentFieldName + "]");
}
} else if (token.isValue()) {
if ("query".equals(currentFieldName)) {
value = parser.objectText();
} else if ("analyzer".equals(currentFieldName)) {
String analyzer = parser.text();
if (parseContext.analysisService().analyzer(analyzer) == null) {
throw new QueryParsingException(parseContext, "[common] analyzer [" + parser.text() + "] not found");
}
queryAnalyzer = analyzer;
} else if ("disable_coord".equals(currentFieldName) || "disableCoord".equals(currentFieldName)) {
disableCoord = parser.booleanValue();
} else if ("boost".equals(currentFieldName)) {
boost = parser.floatValue();
} else if ("high_freq_operator".equals(currentFieldName) || "highFreqOperator".equals(currentFieldName)) {
String op = parser.text();
if ("or".equalsIgnoreCase(op)) {
highFreqOccur = BooleanClause.Occur.SHOULD;
} else if ("and".equalsIgnoreCase(op)) {
highFreqOccur = BooleanClause.Occur.MUST;
} else {
throw new QueryParsingException(parseContext,
"[common] query requires operator to be either 'and' or 'or', not [" + op + "]");
}
} else if ("low_freq_operator".equals(currentFieldName) || "lowFreqOperator".equals(currentFieldName)) {
String op = parser.text();
if ("or".equalsIgnoreCase(op)) {
lowFreqOccur = BooleanClause.Occur.SHOULD;
} else if ("and".equalsIgnoreCase(op)) {
lowFreqOccur = BooleanClause.Occur.MUST;
} else {
throw new QueryParsingException(parseContext,
"[common] query requires operator to be either 'and' or 'or', not [" + op + "]");
}
} else if ("minimum_should_match".equals(currentFieldName) || "minimumShouldMatch".equals(currentFieldName)) {
lowFreqMinimumShouldMatch = parser.text();
} else if ("cutoff_frequency".equals(currentFieldName)) {
maxTermFrequency = parser.floatValue();
} else if ("_name".equals(currentFieldName)) {
queryName = parser.text();
} else {
throw new QueryParsingException(parseContext, "[common] query does not support [" + currentFieldName + "]");
}
}
}
parser.nextToken();
} else {
value = parser.objectText();
// move to the next token
token = parser.nextToken();
if (token != XContentParser.Token.END_OBJECT) {
throw new QueryParsingException(
parseContext,
"[common] query parsed in simplified form, with direct field name, but included more options than just the field name, possibly use its 'options' form, with 'query' element?");
}
}
if (value == null) {
throw new QueryParsingException(parseContext, "No text specified for text query");
}
String field;
MappedFieldType fieldType = parseContext.fieldMapper(fieldName);
if (fieldType != null) {
field = fieldType.names().indexName();
} else {
field = fieldName;
}
Analyzer analyzer = null;
if (queryAnalyzer == null) {
if (fieldType != null) {
analyzer = fieldType.searchAnalyzer();
}
if (analyzer == null && fieldType != null) {
analyzer = parseContext.getSearchAnalyzer(fieldType);
}
if (analyzer == null) {
analyzer = parseContext.mapperService().searchAnalyzer();
}
} else {
analyzer = parseContext.mapperService().analysisService().analyzer(queryAnalyzer);
if (analyzer == null) {
throw new IllegalArgumentException("No analyzer found for [" + queryAnalyzer + "]");
}
}
ExtendedCommonTermsQuery commonsQuery = new ExtendedCommonTermsQuery(highFreqOccur, lowFreqOccur, maxTermFrequency, disableCoord, fieldType);
commonsQuery.setBoost(boost);
Query query = parseQueryString(commonsQuery, value.toString(), field, parseContext, analyzer, lowFreqMinimumShouldMatch, highFreqMinimumShouldMatch);
if (queryName != null) {
parseContext.addNamedQuery(queryName, query);
}
return query;
}
private final Query parseQueryString(ExtendedCommonTermsQuery query, String queryString, String field, QueryParseContext parseContext,
Analyzer analyzer, String lowFreqMinimumShouldMatch, String highFreqMinimumShouldMatch) throws IOException {
// Logic similar to QueryParser#getFieldQuery
int count = 0;
try (TokenStream source = analyzer.tokenStream(field, queryString.toString())) {
source.reset();
CharTermAttribute termAtt = source.addAttribute(CharTermAttribute.class);
BytesRefBuilder builder = new BytesRefBuilder();
while (source.incrementToken()) {
// UTF-8
builder.copyChars(termAtt);
query.add(new Term(field, builder.toBytesRef()));
count++;
}
}
if (count == 0) {
return null;
}
query.setLowFreqMinimumNumberShouldMatch(lowFreqMinimumShouldMatch);
query.setHighFreqMinimumNumberShouldMatch(highFreqMinimumShouldMatch);
return query;
}
}