org.elasticsearch.common.lucene.docset.NotDocIdSet Maven / Gradle / Ivy
/*
* 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.common.lucene.docset;
import org.apache.lucene.search.DocIdSet;
import org.apache.lucene.search.DocIdSetIterator;
import org.apache.lucene.util.Bits;
import java.io.IOException;
/**
* A {@link DocIdSet} that matches the "inverse" of the provided doc id set.
*/
public class NotDocIdSet extends DocIdSet {
private final DocIdSet set;
private final int maxDoc;
public NotDocIdSet(DocIdSet set, int maxDoc) {
this.maxDoc = maxDoc;
this.set = set;
}
@Override
public boolean isCacheable() {
return set.isCacheable();
}
@Override
public Bits bits() throws IOException {
Bits bits = set.bits();
if (bits == null) {
return null;
}
return new NotBits(bits);
}
@Override
public DocIdSetIterator iterator() throws IOException {
DocIdSetIterator it = set.iterator();
if (it == null) {
return new AllDocIdSet.Iterator(maxDoc);
}
// TODO: can we optimize for the FixedBitSet case?
// if we have bits, its much faster to just check on the flipped end potentially
// really depends on the nature of the Bits, specifically with FixedBitSet, where
// most of the docs are set?
Bits bits = set.bits();
if (bits != null) {
return new BitsBasedIterator(bits);
}
return new IteratorBasedIterator(maxDoc, it);
}
public static class NotBits implements Bits {
private final Bits bits;
public NotBits(Bits bits) {
this.bits = bits;
}
@Override
public boolean get(int index) {
return !bits.get(index);
}
@Override
public int length() {
return bits.length();
}
}
public static class BitsBasedIterator extends MatchDocIdSetIterator {
private final Bits bits;
public BitsBasedIterator(Bits bits) {
super(bits.length());
this.bits = bits;
}
@Override
protected boolean matchDoc(int doc) {
return !bits.get(doc);
}
@Override
public long cost() {
return bits.length();
}
}
public static class IteratorBasedIterator extends DocIdSetIterator {
private final int max;
private DocIdSetIterator it1;
private int lastReturn = -1;
private int innerDocid = -1;
private final long cost;
IteratorBasedIterator(int max, DocIdSetIterator it) throws IOException {
this.max = max;
this.it1 = it;
this.cost = it1.cost();
if ((innerDocid = it1.nextDoc()) == DocIdSetIterator.NO_MORE_DOCS) {
it1 = null;
}
}
@Override
public int docID() {
return lastReturn;
}
@Override
public int nextDoc() throws IOException {
return advance(0);
}
@Override
public int advance(int target) throws IOException {
if (lastReturn == DocIdSetIterator.NO_MORE_DOCS) {
return DocIdSetIterator.NO_MORE_DOCS;
}
if (target <= lastReturn) target = lastReturn + 1;
if (it1 != null && innerDocid < target) {
if ((innerDocid = it1.advance(target)) == DocIdSetIterator.NO_MORE_DOCS) {
it1 = null;
}
}
while (it1 != null && innerDocid == target) {
target++;
if (target >= max) {
return (lastReturn = DocIdSetIterator.NO_MORE_DOCS);
}
if ((innerDocid = it1.advance(target)) == DocIdSetIterator.NO_MORE_DOCS) {
it1 = null;
}
}
// ADDED THIS, bug in original code
if (target >= max) {
return (lastReturn = DocIdSetIterator.NO_MORE_DOCS);
}
return (lastReturn = target);
}
@Override
public long cost() {
return cost;
}
}
}