org.apache.solr.response.transform.ChildDocTransformerFactory Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of solr-core Show documentation
Show all versions of solr-core Show documentation
Apache Solr (module: core)
/*
* 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.
*/
package org.apache.solr.response.transform;
import java.io.IOException;
import org.apache.lucene.search.BooleanClause;
import org.apache.lucene.search.BooleanQuery;
import org.apache.lucene.search.DocValuesFieldExistsQuery;
import org.apache.lucene.search.MatchAllDocsQuery;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.join.BitSetProducer;
import org.apache.lucene.search.join.QueryBitSetProducer;
import org.apache.solr.client.solrj.util.ClientUtils;
import org.apache.solr.common.SolrException;
import org.apache.solr.common.SolrException.ErrorCode;
import org.apache.solr.common.params.SolrParams;
import org.apache.solr.request.SolrQueryRequest;
import org.apache.solr.schema.SchemaField;
import org.apache.solr.search.DocSet;
import org.apache.solr.search.QParser;
import org.apache.solr.search.SolrReturnFields;
import org.apache.solr.search.SyntaxError;
import static org.apache.solr.schema.IndexSchema.NEST_PATH_FIELD_NAME;
/**
* Attaches all descendants (child documents) to each parent document.
*
* The "parentFilter" parameter is mandatory if the schema is not of nest/hierarchy.
*
* Optionally you can provide a "childFilter" param to filter out which child documents should be returned and a
* "limit" param which provides an option to specify the number of child documents
* to be returned per parent document. By default it's set to 10.
*
* Examples -
* [child parentFilter="fieldName:fieldValue"]
* [child parentFilter="fieldName:fieldValue" childFilter="fieldName:fieldValue"]
* [child parentFilter="fieldName:fieldValue" childFilter="fieldName:fieldValue" limit=20]
*
* @since solr 4.9
*/
public class ChildDocTransformerFactory extends TransformerFactory {
static final char PATH_SEP_CHAR = '/';
static final char NUM_SEP_CHAR = '#';
private static final ThreadLocal recursionCheckThreadLocal = ThreadLocal.withInitial(() -> Boolean.FALSE);
private static final BooleanQuery rootFilter = new BooleanQuery.Builder()
.add(new BooleanClause(new MatchAllDocsQuery(), BooleanClause.Occur.MUST))
.add(new BooleanClause(new DocValuesFieldExistsQuery(NEST_PATH_FIELD_NAME), BooleanClause.Occur.MUST_NOT)).build();
@Override
public DocTransformer create(String field, SolrParams params, SolrQueryRequest req) {
if(recursionCheckThreadLocal.get()) {
// this is a recursive call by SolrReturnFields, see ChildDocTransformerFactory#createChildDocTransformer
return new DocTransformer.NoopFieldTransformer();
} else {
try {
// transformer is yet to be initialized in this thread, create it
recursionCheckThreadLocal.set(true);
return createChildDocTransformer(field, params, req);
} finally {
recursionCheckThreadLocal.set(false);
}
}
}
private DocTransformer createChildDocTransformer(String field, SolrParams params, SolrQueryRequest req) {
SchemaField uniqueKeyField = req.getSchema().getUniqueKeyField();
if (uniqueKeyField == null) {
throw new SolrException( ErrorCode.BAD_REQUEST,
" ChildDocTransformer requires the schema to have a uniqueKeyField." );
}
// Do we build a hierarchy or flat list of child docs (attached anonymously)?
boolean buildHierarchy = req.getSchema().hasExplicitField(NEST_PATH_FIELD_NAME);
String parentFilterStr = params.get( "parentFilter" );
BitSetProducer parentsFilter;
// TODO reuse org.apache.solr.search.join.BlockJoinParentQParser.getCachedFilter (uses a cache)
// TODO shouldn't we try to use the Solr filter cache, and then ideally implement
// BitSetProducer over that?
// DocSet parentDocSet = req.getSearcher().getDocSet(parentFilterQuery);
// then return BitSetProducer with custom BitSet impl accessing the docSet
if (parentFilterStr == null) {
if (!buildHierarchy) {
throw new SolrException(ErrorCode.BAD_REQUEST, "Parent filter should be sent as parentFilter=filterCondition");
}
parentsFilter = new QueryBitSetProducer(rootFilter);
} else {
if(buildHierarchy) {
throw new SolrException(ErrorCode.BAD_REQUEST, "Parent filter should not be sent when the schema is nested");
}
parentsFilter = new QueryBitSetProducer(parseQuery(parentFilterStr, req, "parentFilter"));
}
String childFilterStr = params.get( "childFilter" );
DocSet childDocSet;
if (childFilterStr == null) {
childDocSet = null;
} else {
if (buildHierarchy) {
childFilterStr = processPathHierarchyQueryString(childFilterStr);
}
Query childFilter = parseQuery(childFilterStr, req, "childFilter");
try {
childDocSet = req.getSearcher().getDocSet(childFilter);
} catch (IOException e) {
throw new SolrException(ErrorCode.SERVER_ERROR, e);
}
}
String childReturnFields = params.get("fl");
SolrReturnFields childSolrReturnFields;
if(childReturnFields != null) {
childSolrReturnFields = new SolrReturnFields(childReturnFields, req);
} else if(req.getSchema().getDefaultLuceneMatchVersion().major < 8) {
// ensure backwards for versions prior to SOLR 8
childSolrReturnFields = new SolrReturnFields();
} else {
childSolrReturnFields = new SolrReturnFields(req);
}
int limit = params.getInt( "limit", 10 );
return new ChildDocTransformer(field, parentsFilter, childDocSet, childSolrReturnFields, buildHierarchy, limit);
}
private static Query parseQuery(String qstr, SolrQueryRequest req, String param) {
try {
return QParser.getParser(qstr, req).getQuery();
} catch (SyntaxError syntaxError) {
throw new SolrException(ErrorCode.BAD_REQUEST, "Failed to parse '" + param + "' param.");
}
}
// NOTE: THIS FEATURE IS PRESENTLY EXPERIMENTAL; WAIT TO SEE IT IN THE REF GUIDE. FINAL SYNTAX IS TBD.
protected static String processPathHierarchyQueryString(String queryString) {
// if the filter includes a path string, build a lucene query string to match those specific child documents.
// e.g. /toppings/ingredients/name_s:cocoa -> +_nest_path_:/toppings/ingredients +(name_s:cocoa)
// ingredients/name_s:cocoa -> +_nest_path_:*/ingredients +(name_s:cocoa)
int indexOfFirstColon = queryString.indexOf(':');
if (indexOfFirstColon <= 0) {
return queryString;// give up
}
int indexOfLastPathSepChar = queryString.lastIndexOf(PATH_SEP_CHAR, indexOfFirstColon);
if (indexOfLastPathSepChar < 0) {
// regular filter, not hierarchy based.
return ClientUtils.escapeQueryChars(queryString.substring(0, indexOfFirstColon))
+ ":" + ClientUtils.escapeQueryChars(queryString.substring(indexOfFirstColon + 1));
}
final boolean isAbsolutePath = queryString.charAt(0) == PATH_SEP_CHAR;
String path = ClientUtils.escapeQueryChars(queryString.substring(0, indexOfLastPathSepChar));
String remaining = queryString.substring(indexOfLastPathSepChar + 1); // last part of path hierarchy
return
"+" + NEST_PATH_FIELD_NAME + (isAbsolutePath? ":": ":*\\/") + path
+ " +(" + remaining + ")";
}
}