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* 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.search.child;
import org.apache.lucene.index.IndexReader;
import org.apache.lucene.index.LeafReaderContext;
import org.apache.lucene.index.SortedDocValues;
import org.apache.lucene.index.Term;
import org.apache.lucene.search.DocIdSet;
import org.apache.lucene.search.DocIdSetIterator;
import org.apache.lucene.search.Explanation;
import org.apache.lucene.search.Filter;
import org.apache.lucene.search.FilteredDocIdSetIterator;
import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.Scorer;
import org.apache.lucene.search.Weight;
import org.apache.lucene.search.join.BitDocIdSetFilter;
import org.apache.lucene.util.Bits;
import org.apache.lucene.util.LongBitSet;
import org.elasticsearch.common.lucene.docset.DocIdSets;
import org.elasticsearch.common.lucene.search.NoopCollector;
import org.elasticsearch.common.lucene.search.Queries;
import org.elasticsearch.index.fielddata.AtomicParentChildFieldData;
import org.elasticsearch.index.fielddata.IndexParentChildFieldData;
import org.elasticsearch.index.fielddata.plain.ParentChildIndexFieldData;
import java.io.IOException;
import java.util.List;
import java.util.Set;
/**
* A query that only return child documents that are linked to the parent documents that matched with the inner query.
*/
public class ParentConstantScoreQuery extends Query {
private final ParentChildIndexFieldData parentChildIndexFieldData;
private Query originalParentQuery;
private final String parentType;
private final BitDocIdSetFilter childrenFilter;
private Query rewrittenParentQuery;
private IndexReader rewriteIndexReader;
public ParentConstantScoreQuery(ParentChildIndexFieldData parentChildIndexFieldData, Query parentQuery, String parentType, BitDocIdSetFilter childrenFilter) {
this.parentChildIndexFieldData = parentChildIndexFieldData;
this.originalParentQuery = parentQuery;
this.parentType = parentType;
this.childrenFilter = childrenFilter;
}
@Override
// See TopChildrenQuery#rewrite
public Query rewrite(IndexReader reader) throws IOException {
if (rewrittenParentQuery == null) {
rewrittenParentQuery = originalParentQuery.rewrite(reader);
rewriteIndexReader = reader;
}
return this;
}
@Override
public void extractTerms(Set<Term> terms) {
rewrittenParentQuery.extractTerms(terms);
}
@Override
public Query clone() {
ParentConstantScoreQuery q = (ParentConstantScoreQuery) super.clone();
q.originalParentQuery = originalParentQuery.clone();
if (q.rewrittenParentQuery != null) {
q.rewrittenParentQuery = rewrittenParentQuery.clone();
}
return q;
}
@Override
public Weight createWeight(IndexSearcher searcher) throws IOException {
IndexParentChildFieldData globalIfd = parentChildIndexFieldData.loadGlobal(searcher.getIndexReader());
assert rewrittenParentQuery != null;
assert rewriteIndexReader == searcher.getIndexReader() : "not equal, rewriteIndexReader=" + rewriteIndexReader + " searcher.getIndexReader()=" + searcher.getIndexReader();
final long maxOrd;
List<LeafReaderContext> leaves = searcher.getIndexReader().leaves();
if (globalIfd == null || leaves.isEmpty()) {
return Queries.newMatchNoDocsQuery().createWeight(searcher);
} else {
AtomicParentChildFieldData afd = globalIfd.load(leaves.get(0));
SortedDocValues globalValues = afd.getOrdinalsValues(parentType);
maxOrd = globalValues.getValueCount();
}
if (maxOrd == 0) {
return Queries.newMatchNoDocsQuery().createWeight(searcher);
}
final Query parentQuery = rewrittenParentQuery;
ParentOrdsCollector collector = new ParentOrdsCollector(globalIfd, maxOrd, parentType);
IndexSearcher indexSearcher = new IndexSearcher(searcher.getIndexReader());
indexSearcher.setSimilarity(searcher.getSimilarity());
indexSearcher.search(parentQuery, collector);
if (collector.parentCount() == 0) {
return Queries.newMatchNoDocsQuery().createWeight(searcher);
}
return new ChildrenWeight(childrenFilter, collector, globalIfd);
}
@Override
public int hashCode() {
int result = originalParentQuery.hashCode();
result = 31 * result + parentType.hashCode();
result = 31 * result + Float.floatToIntBits(getBoost());
return result;
}
@Override
public boolean equals(Object obj) {
if (this == obj) {
return true;
}
if (obj == null || obj.getClass() != this.getClass()) {
return false;
}
ParentConstantScoreQuery that = (ParentConstantScoreQuery) obj;
if (!originalParentQuery.equals(that.originalParentQuery)) {
return false;
}
if (!parentType.equals(that.parentType)) {
return false;
}
if (this.getBoost() != that.getBoost()) {
return false;
}
return true;
}
@Override
public String toString(String field) {
return "parent_filter[" + parentType + "](" + originalParentQuery + ')';
}
private final class ChildrenWeight extends Weight {
private final IndexParentChildFieldData globalIfd;
private final Filter childrenFilter;
private final LongBitSet parentOrds;
private float queryNorm;
private float queryWeight;
private ChildrenWeight(Filter childrenFilter, ParentOrdsCollector collector, IndexParentChildFieldData globalIfd) {
this.globalIfd = globalIfd;
this.childrenFilter = childrenFilter;
this.parentOrds = collector.parentOrds;
}
@Override
public Explanation explain(LeafReaderContext context, int doc) throws IOException {
return new Explanation(getBoost(), "not implemented yet...");
}
@Override
public Query getQuery() {
return ParentConstantScoreQuery.this;
}
@Override
public float getValueForNormalization() throws IOException {
queryWeight = getBoost();
return queryWeight * queryWeight;
}
@Override
public void normalize(float norm, float topLevelBoost) {
this.queryNorm = norm * topLevelBoost;
queryWeight *= this.queryNorm;
}
@Override
public Scorer scorer(LeafReaderContext context, Bits acceptDocs) throws IOException {
DocIdSet childrenDocIdSet = childrenFilter.getDocIdSet(context, acceptDocs);
if (DocIdSets.isEmpty(childrenDocIdSet)) {
return null;
}
SortedDocValues globalValues = globalIfd.load(context).getOrdinalsValues(parentType);
if (globalValues != null) {
DocIdSetIterator innerIterator = childrenDocIdSet.iterator();
if (innerIterator != null) {
ChildrenDocIdIterator childrenDocIdIterator = new ChildrenDocIdIterator(
innerIterator, parentOrds, globalValues
);
return ConstantScorer.create(childrenDocIdIterator, this, queryWeight);
}
}
return null;
}
}
private final class ChildrenDocIdIterator extends FilteredDocIdSetIterator {
private final LongBitSet parentOrds;
private final SortedDocValues globalOrdinals;
ChildrenDocIdIterator(DocIdSetIterator innerIterator, LongBitSet parentOrds, SortedDocValues globalOrdinals) {
super(innerIterator);
this.parentOrds = parentOrds;
this.globalOrdinals = globalOrdinals;
}
@Override
protected boolean match(int docId) {
int globalOrd = globalOrdinals.getOrd(docId);
if (globalOrd >= 0) {
return parentOrds.get(globalOrd);
} else {
return false;
}
}
}
private final static class ParentOrdsCollector extends NoopCollector {
private final LongBitSet parentOrds;
private final IndexParentChildFieldData globalIfd;
private final String parentType;
private SortedDocValues globalOrdinals;
ParentOrdsCollector(IndexParentChildFieldData globalIfd, long maxOrd, String parentType) {
this.parentOrds = new LongBitSet(maxOrd);
this.globalIfd = globalIfd;
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 (globalOrdinals != null) {
long globalOrd = globalOrdinals.getOrd(doc);
if (globalOrd >= 0) {
parentOrds.set(globalOrd);
}
}
}
@Override
public void doSetNextReader(LeafReaderContext readerContext) throws IOException {
globalOrdinals = globalIfd.load(readerContext).getOrdinalsValues(parentType);
}
public long parentCount() {
return parentOrds.cardinality();
}
}
}