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Elasticsearch subproject :server
/*
* 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.action.search;
import org.apache.lucene.search.FieldComparator;
import org.apache.lucene.search.FieldDoc;
import org.apache.lucene.search.SortField;
import org.apache.lucene.search.TopFieldDocs;
import org.elasticsearch.search.DocValueFormat;
import org.elasticsearch.search.SearchSortValuesAndFormats;
/**
* Utility class to keep track of the bottom doc's sort values in a distributed search.
*/
class BottomSortValuesCollector {
private final int topNSize;
private final SortField[] sortFields;
private final FieldComparator[] comparators;
private final int[] reverseMuls;
private volatile long totalHits;
private volatile SearchSortValuesAndFormats bottomSortValues;
BottomSortValuesCollector(int topNSize, SortField[] sortFields) {
this.topNSize = topNSize;
this.comparators = new FieldComparator[sortFields.length];
this.reverseMuls = new int[sortFields.length];
this.sortFields = sortFields;
for (int i = 0; i < sortFields.length; i++) {
comparators[i] = sortFields[i].getComparator(1, i);
reverseMuls[i] = sortFields[i].getReverse() ? -1 : 1;
}
}
long getTotalHits() {
return totalHits;
}
/**
* @return The best bottom sort values consumed so far.
*/
SearchSortValuesAndFormats getBottomSortValues() {
return bottomSortValues;
}
synchronized void consumeTopDocs(TopFieldDocs topDocs, DocValueFormat[] sortValuesFormat) {
totalHits += topDocs.totalHits.value;
if (validateShardSortFields(topDocs.fields) == false) {
return;
}
FieldDoc shardBottomDoc = extractBottom(topDocs);
if (shardBottomDoc == null) {
return;
}
if (bottomSortValues == null
|| compareValues(shardBottomDoc.fields, bottomSortValues.getRawSortValues()) < 0) {
bottomSortValues = new SearchSortValuesAndFormats(shardBottomDoc.fields, sortValuesFormat);
}
}
/**
* @return false
if the provided {@link SortField} array differs
* from the initial {@link BottomSortValuesCollector#sortFields}.
*/
private boolean validateShardSortFields(SortField[] shardSortFields) {
for (int i = 0; i < shardSortFields.length; i++) {
if (shardSortFields[i].equals(sortFields[i]) == false) {
// ignore shards response that would make the sort incompatible
// (e.g.: mixing keyword/numeric or long/double).
// TODO: we should fail the entire request because the topdocs
// merge will likely fail later but this is not possible with
// the current async logic that only allows shard failures here.
return false;
}
}
return true;
}
private FieldDoc extractBottom(TopFieldDocs topDocs) {
return topNSize > 0 && topDocs.scoreDocs.length == topNSize ?
(FieldDoc) topDocs.scoreDocs[topNSize-1] : null;
}
private int compareValues(Object[] v1, Object[] v2) {
for (int i = 0; i < v1.length; i++) {
int cmp = reverseMuls[i] * comparators[i].compareValues(v1[i], v2[i]);
if (cmp != 0) {
return cmp;
}
}
return 0;
}
}