org.elasticsearch.index.search.child.HasParentFilter Maven / Gradle / Ivy
/*
* Licensed to ElasticSearch and Shay Banon 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.search.child;
import gnu.trove.set.hash.THashSet;
import org.apache.lucene.index.AtomicReaderContext;
import org.apache.lucene.index.IndexReader;
import org.apache.lucene.search.DocIdSet;
import org.apache.lucene.search.Filter;
import org.apache.lucene.search.Query;
import org.apache.lucene.util.Bits;
import org.elasticsearch.ElasticSearchIllegalStateException;
import org.elasticsearch.common.CacheRecycler;
import org.elasticsearch.common.bytes.HashedBytesArray;
import org.elasticsearch.common.lucene.docset.DocIdSets;
import org.elasticsearch.common.lucene.docset.MatchDocIdSet;
import org.elasticsearch.common.lucene.search.NoopCollector;
import org.elasticsearch.index.cache.id.IdReaderTypeCache;
import org.elasticsearch.search.internal.SearchContext;
import java.io.IOException;
/**
* A filter that only return child documents that are linked to the parent documents that matched with the inner query.
*/
public class HasParentFilter extends Filter implements SearchContext.Rewrite {
final Query parentQuery;
final String parentType;
final SearchContext context;
final Filter childrenFilter;
THashSet parents;
public HasParentFilter(Query parentQuery, String parentType, SearchContext context, Filter childrenFilter) {
this.parentQuery = parentQuery;
this.parentType = parentType;
this.context = context;
this.childrenFilter = childrenFilter;
}
@Override
public boolean equals(Object obj) {
if (this == obj) {
return true;
}
if (obj == null || obj.getClass() != this.getClass()) {
return false;
}
HasParentFilter that = (HasParentFilter) obj;
if (!parentQuery.equals(that.parentQuery)) {
return false;
}
if (!parentType.equals(that.parentType)) {
return false;
}
return true;
}
public DocIdSet getDocIdSet(AtomicReaderContext readerContext, Bits acceptDocs) throws IOException {
if (parents == null) {
throw new ElasticSearchIllegalStateException("has_parent filter hasn't executed properly");
}
DocIdSet childrenDocIdSet = childrenFilter.getDocIdSet(readerContext, null);
if (DocIdSets.isEmpty(childrenDocIdSet)) {
return null;
}
Bits childrenBits = DocIdSets.toSafeBits(readerContext.reader(), childrenDocIdSet);
IdReaderTypeCache idReaderTypeCache = context.idCache().reader(readerContext.reader()).type(parentType);
if (idReaderTypeCache != null) {
return new ChildrenDocSet(readerContext.reader(), childrenBits, parents, idReaderTypeCache);
} else {
return null;
}
}
@Override
public void contextRewrite(SearchContext searchContext) throws Exception {
searchContext.idCache().refresh(searchContext.searcher().getTopReaderContext().leaves());
parents = CacheRecycler.popHashSet();
ParentUidsCollector collector = new ParentUidsCollector(parents, context, parentType);
searchContext.searcher().search(parentQuery, collector);
parents = collector.collectedUids;
}
@Override
public void contextClear() {
if (parents != null) {
CacheRecycler.pushHashSet(parents);
}
parents = null;
}
final static class ChildrenDocSet extends MatchDocIdSet {
final IndexReader reader;
final THashSet parents;
final IdReaderTypeCache idReaderTypeCache;
ChildrenDocSet(IndexReader reader, Bits acceptDocs, THashSet parents, IdReaderTypeCache idReaderTypeCache) {
super(reader.maxDoc(), acceptDocs);
this.reader = reader;
this.parents = parents;
this.idReaderTypeCache = idReaderTypeCache;
}
@Override
protected boolean matchDoc(int doc) {
return parents.contains(idReaderTypeCache.parentIdByDoc(doc));
}
}
final static class ParentUidsCollector extends NoopCollector {
final THashSet collectedUids;
final SearchContext context;
final String parentType;
IdReaderTypeCache typeCache;
ParentUidsCollector(THashSet collectedUids, SearchContext context, String parentType) {
this.collectedUids = collectedUids;
this.context = context;
this.parentType = parentType;
}
public void collect(int doc) throws IOException {
// It can happen that for particular segment no document exist for an specific type. This prevents NPE
if (typeCache != null) {
collectedUids.add(typeCache.idByDoc(doc));
}
}
@Override
public void setNextReader(AtomicReaderContext readerContext) throws IOException {
typeCache = context.idCache().reader(readerContext.reader()).type(parentType);
}
}
@Override
public int hashCode() {
int result = parentQuery.hashCode();
result = 31 * result + parentType.hashCode();
return result;
}
@Override
public String toString() {
StringBuilder sb = new StringBuilder();
sb.append("parent_filter[").append(parentType).append("](").append(parentQuery).append(')');
return sb.toString();
}
}