package org.apache.blur.lucene.search;
/**
* 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.
*/
import java.io.IOException;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import org.apache.blur.log.Log;
import org.apache.blur.log.LogFactory;
import org.apache.lucene.index.AtomicReader;
import org.apache.lucene.index.DocsEnum;
import org.apache.lucene.index.IndexReader;
import org.apache.lucene.index.IndexReader.ReaderClosedListener;
import org.apache.lucene.index.Term;
import org.apache.lucene.search.DocIdSetIterator;
import org.apache.lucene.util.OpenBitSet;
public class PrimeDocCache {
private static final Log LOG = LogFactory.getLog(PrimeDocCache.class);
public static final OpenBitSet EMPTY_BIT_SET = new OpenBitSet();
private static Map<Term, Map<Object, OpenBitSet>> termPrimeDocMap = new ConcurrentHashMap<Term, Map<Object, OpenBitSet>>();
/**
* The way this method is called via warm up methods the likelihood of
* creating multiple bitsets during a race condition is very low, that's why
* this method is not synced.
*/
public static OpenBitSet getPrimeDocBitSet(Term primeDocTerm, AtomicReader reader) throws IOException {
Object key = reader.getCoreCacheKey();
final Map<Object, OpenBitSet> primeDocMap = getPrimeDocMap(primeDocTerm);
OpenBitSet bitSet = primeDocMap.get(key);
if (bitSet == null) {
synchronized (reader) {
reader.addReaderClosedListener(new ReaderClosedListener() {
@Override
public void onClose(IndexReader reader) {
Object key = reader.getCoreCacheKey();
LOG.debug("Current size [" + primeDocMap.size() + "] Prime Doc BitSet removing for segment [" + reader
+ "]");
primeDocMap.remove(key);
}
});
LOG.debug("Prime Doc BitSet missing for segment [" + reader + "] current size [" + primeDocMap.size() + "]");
final OpenBitSet bs = new OpenBitSet(reader.maxDoc());
DocsEnum termDocsEnum = reader.termDocsEnum(primeDocTerm);
if (termDocsEnum == null) {
return bs;
}
int docFreq = reader.docFreq(primeDocTerm);
int doc;
int count = 0;
while ((doc = termDocsEnum.nextDoc()) != DocIdSetIterator.NO_MORE_DOCS) {
bs.fastSet(doc);
count++;
}
if (count == docFreq) {
primeDocMap.put(key, bs);
} else {
LOG.info("PrimeDoc for reader [{0}] not stored, because count [{1}] and freq [{2}] do not match.", reader,
count, docFreq);
}
return bs;
}
}
return bitSet;
}
private static Map<Object, OpenBitSet> getPrimeDocMap(Term primeDocTerm) {
Map<Object, OpenBitSet> map = termPrimeDocMap.get(primeDocTerm);
if (map == null) {
termPrimeDocMap.put(primeDocTerm, new ConcurrentHashMap<Object, OpenBitSet>());
return termPrimeDocMap.get(primeDocTerm);
}
return map;
}
}