Author: sannegrinovero Date: 2008-11-12 13:49:48 -0500 (Wed, 12 Nov 2008) New Revision: 15556 Modified: search/trunk/src/java/org/hibernate/search/filter/AndDocIdSet.java search/trunk/src/java/org/hibernate/search/filter/EmptyDocIdBitSet.java Log: HSEARCH-289 some more cleanup and minor optimizations Modified: search/trunk/src/java/org/hibernate/search/filter/AndDocIdSet.java =================================================================== --- search/trunk/src/java/org/hibernate/search/filter/AndDocIdSet.java 2008-11-12 18:27:38 UTC (rev 15555) +++ search/trunk/src/java/org/hibernate/search/filter/AndDocIdSet.java 2008-11-12 18:49:48 UTC (rev 15556) @@ -1,6 +1,7 @@ package org.hibernate.search.filter; import java.io.IOException; +import java.util.ArrayList; import java.util.List; import static java.lang.Math.max; @@ -17,7 +18,7 @@ */ public class AndDocIdSet extends DocIdSet { - private OpenBitSet docIdBitSet; + private DocIdSet docIdBitSet; private final List<DocIdSet> andedDocIdSets; private final int maxDocNumber; @@ -25,34 +26,26 @@ public AndDocIdSet(List<DocIdSet> andedDocIdSets, int maxDocs) { if ( andedDocIdSets == null || andedDocIdSets.size() < 2 ) throw new IllegalArgumentException( "To \"and\" some DocIdSet(s) they should be at least 2" ); - this.andedDocIdSets = andedDocIdSets; + this.andedDocIdSets = new ArrayList<DocIdSet>( andedDocIdSets ); // make a defensive mutable copy this.maxDocNumber = maxDocs; } - private synchronized OpenBitSet buildBitset() throws IOException { - if ( docIdBitSet != null ) return docIdBitSet; // double check for concurrent initialization + private synchronized DocIdSet buildBitset() throws IOException { + if ( docIdBitSet != null ) return docIdBitSet; // check for concurrent initialization //TODO if all andedDocIdSets are actually DocIdBitSet, use their internal BitSet instead of next algo. //TODO if some andedDocIdSets are DocIdBitSet, merge them first. int size = andedDocIdSets.size(); DocIdSetIterator[] iterators = new DocIdSetIterator[size]; - boolean valuesExist = true; for (int i=0; i<size; i++) { // build all iterators iterators[i] = andedDocIdSets.get(i).iterator(); } - OpenBitSet bitSet; - if ( valuesExist ) { // skip further processing if some idSet is empty - bitSet = new OpenBitSet( maxDocNumber ); - markBitSetOnAgree( iterators, bitSet ); - } - else { - bitSet = new OpenBitSet(); //TODO a less expensive "empty" - } - docIdBitSet = bitSet; - return bitSet; + andedDocIdSets.clear(); // contained DocIdSets are not needed any more, release them. + docIdBitSet = makeDocIdSetOnAgreedBits( iterators ); // before returning hold a copy as cache + return docIdBitSet; } - private final void markBitSetOnAgree(final DocIdSetIterator[] iterators, final OpenBitSet result) throws IOException { + private final DocIdSet makeDocIdSetOnAgreedBits(final DocIdSetIterator[] iterators) throws IOException { final int iteratorSize = iterators.length; int targetPosition = Integer.MIN_VALUE; int votes = 0; @@ -62,9 +55,12 @@ // for the others and he is considered "first" in the voting round (every iterator votes for himself ;-) int i = 0; //iterator initialize, just one "next" for each DocIdSetIterator - for ( ;i<iteratorSize; i++ ) { + for ( ; i<iteratorSize; i++ ) { final DocIdSetIterator iterator = iterators[i]; - if ( ! iterator.next() ) return; //current iterator has no values, so skip all + if ( ! iterator.next() ) { + //current iterator has no values, so skip all + return EmptyDocIdBitSet.instance; + } final int position = iterator.doc(); if ( targetPosition==position ) { votes++; //stopped as same position of others @@ -75,6 +71,7 @@ votes=1; } } + final OpenBitSet result = new OpenBitSet( maxDocNumber ); // end iterator initialize if (votes==iteratorSize) { result.fastSet( targetPosition ); @@ -87,7 +84,7 @@ final DocIdSetIterator iterator = iterators[i]; final boolean validPosition = iterator.skipTo( targetPosition ); if ( ! validPosition ) - return; //exit condition + return result; //exit condition final int position = iterator.doc(); if ( position == targetPosition ) { if ( ++votes == iteratorSize ) { Modified: search/trunk/src/java/org/hibernate/search/filter/EmptyDocIdBitSet.java =================================================================== --- search/trunk/src/java/org/hibernate/search/filter/EmptyDocIdBitSet.java 2008-11-12 18:27:38 UTC (rev 15555) +++ search/trunk/src/java/org/hibernate/search/filter/EmptyDocIdBitSet.java 2008-11-12 18:49:48 UTC (rev 15556) @@ -1,12 +1,20 @@ package org.hibernate.search.filter; import java.io.IOException; +import java.io.Serializable; import org.apache.lucene.search.DocIdSet; import org.apache.lucene.search.DocIdSetIterator; -public class EmptyDocIdBitSet extends DocIdSet { +/** + * A DocIdSet which is always empty. + * Stateless and ThreadSafe. + * @author Sanne Grinovero + */ +public final class EmptyDocIdBitSet extends DocIdSet implements Serializable { + private static final long serialVersionUID = 6429929383767238322L; + public static final DocIdSet instance = new EmptyDocIdBitSet(); private final DocIdSetIterator iterator = new EmptyDocIdSetIterator(); @@ -16,7 +24,7 @@ } @Override - public DocIdSetIterator iterator() { + public final DocIdSetIterator iterator() { return iterator; } @@ -24,20 +32,20 @@ * implements a DocIdSetIterator for an empty DocIdSet * As it is empty it also is stateless and so it can be reused. */ - private static class EmptyDocIdSetIterator extends DocIdSetIterator { + private static final class EmptyDocIdSetIterator extends DocIdSetIterator { @Override - public int doc() { - throw new IllegalStateException("Should never be called"); + public final int doc() { + throw new IllegalStateException( "Should never be called" ); } @Override - public boolean next() throws IOException { + public final boolean next() throws IOException { return false; } @Override - public boolean skipTo(int target) throws IOException { + public final boolean skipTo(int target) throws IOException { return false; }