/*
* Licensed to Elastic Search and Shay Banon under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. Elastic Search 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.cache.filter.support;
import org.apache.lucene.index.IndexReader;
import org.apache.lucene.search.DocIdSet;
import org.apache.lucene.search.DocIdSetIterator;
import org.apache.lucene.util.OpenBitSet;
import org.elasticsearch.common.Nullable;
import org.elasticsearch.common.lab.LongsLAB;
import org.elasticsearch.common.lucene.docset.DocSet;
import org.elasticsearch.common.lucene.docset.DocSets;
import org.elasticsearch.common.lucene.docset.OpenBitDocSet;
import org.elasticsearch.common.lucene.docset.SlicedOpenBitSet;
import java.io.IOException;
public class FilterCacheValue<T> {
private final T value;
private final LongsLAB longsLAB;
public FilterCacheValue(T value, LongsLAB longsLAB) {
this.value = value;
this.longsLAB = longsLAB;
}
public T value() {
return value;
}
public LongsLAB longsLAB() {
return longsLAB;
}
public static DocSet cacheable(IndexReader reader, @Nullable LongsLAB longsLAB, DocIdSet set) throws IOException {
if (set == null) {
return DocSet.EMPTY_DOC_SET;
}
if (set == DocIdSet.EMPTY_DOCIDSET) {
return DocSet.EMPTY_DOC_SET;
}
DocIdSetIterator it = set.iterator();
if (it == null) {
return DocSet.EMPTY_DOC_SET;
}
int doc = it.nextDoc();
if (doc == DocIdSetIterator.NO_MORE_DOCS) {
return DocSet.EMPTY_DOC_SET;
}
// we have a LAB, check if can be used...
if (longsLAB == null) {
return DocSets.cacheable(reader, set);
}
int numOfWords = OpenBitSet.bits2words(reader.maxDoc());
LongsLAB.Allocation allocation = longsLAB.allocateLongs(numOfWords);
if (allocation == null) {
return DocSets.cacheable(reader, set);
}
// we have an allocation, use it to create SlicedOpenBitSet
if (set instanceof OpenBitSet) {
return new SlicedOpenBitSet(allocation.getData(), allocation.getOffset(), (OpenBitSet) set);
} else if (set instanceof OpenBitDocSet) {
return new SlicedOpenBitSet(allocation.getData(), allocation.getOffset(), ((OpenBitDocSet) set).set());
} else {
SlicedOpenBitSet slicedSet = new SlicedOpenBitSet(allocation.getData(), numOfWords, allocation.getOffset());
slicedSet.fastSet(doc); // we already have an open iterator, so use it, and don't forget to set the initial one
while ((doc = it.nextDoc()) != DocIdSetIterator.NO_MORE_DOCS) {
slicedSet.fastSet(doc);
}
return slicedSet;
}
}
}