/**
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF 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.apache.solr.search;
import org.apache.solr.util.OpenBitSet;
import org.apache.solr.util.BitSetIterator;
/**
* <code>BitDocSet</code> represents an unordered set of Lucene Document Ids
* using a BitSet. A set bit represents inclusion in the set for that document.
*
* @version $Id: BitDocSet.java 555343 2007-07-11 17:46:25Z hossman $
* @since solr 0.9
*/
public class BitDocSet extends DocSetBase {
final OpenBitSet bits;
int size; // number of docs in the set (cached for perf)
public BitDocSet() {
bits = new OpenBitSet();
}
/** Construct a BitDocSet.
* The capacity of the OpenBitSet should be at least maxDoc() */
public BitDocSet(OpenBitSet bits) {
this.bits = bits;
size=-1;
}
/** Construct a BitDocSet, and provides the number of set bits.
* The capacity of the OpenBitSet should be at least maxDoc()
*/
public BitDocSet(OpenBitSet bits, int size) {
this.bits = bits;
this.size = size;
}
/*** DocIterator using nextSetBit()
public DocIterator iterator() {
return new DocIterator() {
int pos=bits.nextSetBit(0);
public boolean hasNext() {
return pos>=0;
}
public Integer next() {
return nextDoc();
}
public void remove() {
bits.clear(pos);
}
public int nextDoc() {
int old=pos;
pos=bits.nextSetBit(old+1);
return old;
}
public float score() {
return 0.0f;
}
};
}
***/
public DocIterator iterator() {
return new DocIterator() {
private final BitSetIterator iter = new BitSetIterator(bits);
private int pos = iter.next();
public boolean hasNext() {
return pos>=0;
}
public Integer next() {
return nextDoc();
}
public void remove() {
bits.clear(pos);
}
public int nextDoc() {
int old=pos;
pos=iter.next();
return old;
}
public float score() {
return 0.0f;
}
};
}
/**
*
* @return the <b>internal</b> OpenBitSet that should <b>not</b> be modified.
*/
public OpenBitSet getBits() {
return bits;
}
public void add(int doc) {
bits.set(doc);
size=-1; // invalidate size
}
public void addUnique(int doc) {
bits.set(doc);
size=-1; // invalidate size
}
public int size() {
if (size!=-1) return size;
return size=(int)bits.cardinality();
}
/**
* The number of set bits - size - is cached. If the bitset is changed externally,
* this method should be used to invalidate the previously cached size.
*/
public void invalidateSize() {
size=-1;
}
public boolean exists(int doc) {
return bits.get(doc);
}
@Override
public int intersectionSize(DocSet other) {
if (other instanceof BitDocSet) {
return (int)OpenBitSet.intersectionCount(this.bits, ((BitDocSet)other).bits);
} else {
// they had better not call us back!
return other.intersectionSize(this);
}
}
@Override
public int unionSize(DocSet other) {
if (other instanceof BitDocSet) {
// if we don't know our current size, this is faster than
// size + other.size - intersection_size
return (int)OpenBitSet.unionCount(this.bits, ((BitDocSet)other).bits);
} else {
// they had better not call us back!
return other.unionSize(this);
}
}
@Override
public int andNotSize(DocSet other) {
if (other instanceof BitDocSet) {
// if we don't know our current size, this is faster than
// size - intersection_size
return (int)OpenBitSet.andNotCount(this.bits, ((BitDocSet)other).bits);
} else {
return super.andNotSize(other);
}
}
@Override
public DocSet andNot(DocSet other) {
OpenBitSet newbits = (OpenBitSet)(bits.clone());
if (other instanceof OpenBitSet) {
newbits.andNot(((BitDocSet)other).bits);
} else {
DocIterator iter = other.iterator();
while (iter.hasNext()) newbits.clear(iter.nextDoc());
}
return new BitDocSet(newbits);
}
@Override
public DocSet union(DocSet other) {
OpenBitSet newbits = (OpenBitSet)(bits.clone());
if (other instanceof BitDocSet) {
newbits.union(((BitDocSet)other).bits);
} else {
DocIterator iter = other.iterator();
while (iter.hasNext()) newbits.set(iter.nextDoc());
}
return new BitDocSet(newbits);
}
public long memSize() {
return (bits.getBits().length << 3) + 16;
}
}