/*
* 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 java.util.Collection;
import java.util.Collections;
import java.util.Objects;
import org.apache.lucene.index.LeafReader;
import org.apache.lucene.index.LeafReaderContext;
import org.apache.lucene.search.DocIdSet;
import org.apache.lucene.search.DocIdSetIterator;
import org.apache.lucene.util.Accountable;
import org.apache.lucene.util.BitDocIdSet;
import org.apache.lucene.util.BitSetIterator;
import org.apache.lucene.util.Bits;
import org.apache.lucene.util.FixedBitSet;
import org.apache.lucene.util.RamUsageEstimator;
/**
* <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.
*
* @since solr 0.9
*/
public class BitDocSet extends DocSetBase {
private static final long BASE_RAM_BYTES_USED = RamUsageEstimator.shallowSizeOfInstance(BitDocSet.class)
+ RamUsageEstimator.shallowSizeOfInstance(FixedBitSet.class)
+ RamUsageEstimator.NUM_BYTES_ARRAY_HEADER; // for the array object inside the FixedBitSet. long[] array won't change alignment, so no need to calculate it.
final FixedBitSet bits;
int size; // number of docs in the set (cached for perf)
public BitDocSet() {
bits = new FixedBitSet(64);
}
/**
* Construct a BitDocSet. The capacity of the {@link FixedBitSet} should be at
* least maxDoc()
*/
public BitDocSet(FixedBitSet bits) {
this.bits = bits;
size=-1;
}
/**
* Construct a BitDocSet, and provides the number of set bits. The capacity of
* the {@link FixedBitSet} should be at least maxDoc()
*/
public BitDocSet(FixedBitSet 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;
}
};
}
***/
@Override
public DocIterator iterator() {
return new DocIterator() {
private final BitSetIterator iter = new BitSetIterator(bits, 0L); // cost is not useful here
private int pos = iter.nextDoc();
@Override
public boolean hasNext() {
return pos != DocIdSetIterator.NO_MORE_DOCS;
}
@Override
public Integer next() {
return nextDoc();
}
@Override
public void remove() {
bits.clear(pos);
}
@Override
public int nextDoc() {
int old=pos;
pos=iter.nextDoc();
return old;
}
@Override
public float score() {
return 0.0f;
}
};
}
/**
* @return the <b>internal</b> {@link FixedBitSet} that should <b>not</b> be modified.
*/
@Override
public FixedBitSet getBits() {
return bits;
}
@Override
public void add(int doc) {
bits.set(doc);
size=-1; // invalidate size
}
@Override
public void addUnique(int doc) {
bits.set(doc);
size=-1; // invalidate size
}
@Override
public int size() {
if (size!=-1) return size;
return size = 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;
}
/**
* Returns true of the doc exists in the set. Should only be called when doc <
* {@link FixedBitSet#length()}.
*/
@Override
public boolean exists(int doc) {
return bits.get(doc);
}
@Override
public int intersectionSize(DocSet other) {
if (other instanceof BitDocSet) {
return (int) FixedBitSet.intersectionCount(this.bits, ((BitDocSet) other).bits);
} else {
// they had better not call us back!
return other.intersectionSize(this);
}
}
@Override
public boolean intersects(DocSet other) {
if (other instanceof BitDocSet) {
return bits.intersects(((BitDocSet)other).bits);
} else {
// they had better not call us back!
return other.intersects(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) FixedBitSet.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) FixedBitSet.andNotCount(this.bits, ((BitDocSet)other).bits);
} else {
return super.andNotSize(other);
}
}
@Override
public void addAllTo(DocSet target) {
if (target instanceof BitDocSet) {
((BitDocSet) target).bits.or(bits);
} else {
super.addAllTo(target);
}
}
@Override
public DocSet andNot(DocSet other) {
FixedBitSet newbits = bits.clone();
if (other instanceof BitDocSet) {
newbits.andNot(((BitDocSet) other).bits);
} else {
DocIterator iter = other.iterator();
while (iter.hasNext()) {
int doc = iter.nextDoc();
if (doc < newbits.length()) {
newbits.clear(doc);
}
}
}
return new BitDocSet(newbits);
}
@Override
public DocSet union(DocSet other) {
FixedBitSet newbits = bits.clone();
if (other instanceof BitDocSet) {
BitDocSet otherDocSet = (BitDocSet) other;
newbits = FixedBitSet.ensureCapacity(newbits, otherDocSet.bits.length());
newbits.or(otherDocSet.bits);
} else {
DocIterator iter = other.iterator();
while (iter.hasNext()) {
int doc = iter.nextDoc();
newbits = FixedBitSet.ensureCapacity(newbits, doc);
newbits.set(doc);
}
}
return new BitDocSet(newbits);
}
@Override
public BitDocSet clone() {
return new BitDocSet(bits.clone(), size);
}
@Override
public Filter getTopFilter() {
// TODO: if cardinality isn't cached, do a quick measure of sparseness
// and return null from bits() if too sparse.
return new Filter() {
final FixedBitSet bs = bits;
@Override
public DocIdSet getDocIdSet(final LeafReaderContext context, final Bits acceptDocs) {
LeafReader reader = context.reader();
// all Solr DocSets that are used as filters only include live docs
final Bits acceptDocs2 = acceptDocs == null ? null : (reader.getLiveDocs() == acceptDocs ? null : acceptDocs);
if (context.isTopLevel) {
return BitsFilteredDocIdSet.wrap(new BitDocIdSet(bs), acceptDocs);
}
final int base = context.docBase;
final int max = base + reader.maxDoc(); // one past the max doc in this segment.
return BitsFilteredDocIdSet.wrap(new DocIdSet() {
@Override
public DocIdSetIterator iterator() {
return new DocIdSetIterator() {
int pos = base - 1;
int adjustedDoc = -1;
@Override
public int docID() {
return adjustedDoc;
}
@Override
public int nextDoc() {
int next = pos+1;
if (next >= max) {
return adjustedDoc = NO_MORE_DOCS;
} else {
pos = bs.nextSetBit(next);
return adjustedDoc = pos < max ? pos - base : NO_MORE_DOCS;
}
}
@Override
public int advance(int target) {
if (target == NO_MORE_DOCS) return adjustedDoc = NO_MORE_DOCS;
int adjusted = target + base;
if (adjusted >= max) {
return adjustedDoc = NO_MORE_DOCS;
} else {
pos = bs.nextSetBit(adjusted);
return adjustedDoc = pos < max ? pos - base : NO_MORE_DOCS;
}
}
@Override
public long cost() {
// we don't want to actually compute cardinality, but
// if it's already been computed, we use it (pro-rated for the segment)
int maxDoc = max-base;
if (size != -1) {
return (long)(size * ((FixedBitSet.bits2words(maxDoc)<<6) / (float)bs.length()));
} else {
return maxDoc;
}
}
};
}
@Override
public long ramBytesUsed() {
return bs.ramBytesUsed();
}
@Override
public Bits bits() {
return new Bits() {
@Override
public boolean get(int index) {
return bs.get(index + base);
}
@Override
public int length() {
return max-base;
}
};
}
}, acceptDocs2);
}
@Override
public String toString(String field) {
return "BitSetDocTopFilter";
}
@Override
public boolean equals(Object other) {
return sameClassAs(other) &&
Objects.equals(bs, getClass().cast(other).bs);
}
@Override
public int hashCode() {
return classHash() * 31 + bs.hashCode();
}
};
}
@Override
public long ramBytesUsed() {
return BASE_RAM_BYTES_USED + ((long)bits.getBits().length << 3);
}
@Override
public Collection<Accountable> getChildResources() {
return Collections.emptyList();
}
}