/*
* 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.exoplatform.services.jcr.impl.core.query.lucene;
import org.apache.lucene.index.IndexReader;
import org.apache.lucene.index.Term;
import org.apache.lucene.index.TermDocs;
import org.apache.lucene.index.TermEnum;
import org.apache.lucene.search.Collector;
import org.apache.lucene.search.Scorer;
import org.apache.lucene.search.Similarity;
import java.io.IOException;
import java.util.BitSet;
import java.util.HashMap;
import java.util.Map;
/**
* The MatchAllScorer implements a Scorer that scores / collects all
* documents in the index that match a field.
*/
class MatchAllScorer extends Scorer
{
/**
* next doc number
*/
private int nextDoc = -1;
/**
* IndexReader giving access to index
*/
private IndexReader reader;
/**
* The field to match
*/
private String field;
/**
* BitSet filtering documents without content is specified field
*/
private BitSet docFilter;
/**
* Creates a new MatchAllScorer.
*
* @param reader the IndexReader
* @param field the field name to match.
* @throws IOException if an error occurs while collecting hits.
* e.g. while reading from the search index.
*/
MatchAllScorer(IndexReader reader, String field) throws IOException
{
super(Similarity.getDefault());
this.reader = reader;
this.field = field;
calculateDocFilter();
}
/**
* {@inheritDoc}
*/
@Override
public void score(Collector collector) throws IOException
{
collector.setScorer(this);
while (nextDoc() != NO_MORE_DOCS)
{
collector.collect(docID());
}
}
/**
* {@inheritDoc}
*/
@Override
public int nextDoc() throws IOException
{
if (nextDoc == NO_MORE_DOCS)
{
return nextDoc;
}
nextDoc = docFilter.nextSetBit(nextDoc + 1);
if (nextDoc < 0)
{
nextDoc = NO_MORE_DOCS;
}
return nextDoc;
}
/**
* {@inheritDoc}
*/
@Override
public int docID()
{
return nextDoc;
}
/**
* {@inheritDoc}
*/
@Override
public float score() throws IOException
{
return 1.0f;
}
/**
* {@inheritDoc}
*/
@Override
public int advance(int target) throws IOException
{
if (nextDoc == NO_MORE_DOCS)
{
return nextDoc;
}
nextDoc = target - 1;
return nextDoc();
}
/**
* Calculates a BitSet filter that includes all the nodes
* that have content in properties according to the field name
* passed in the constructor of this MatchAllScorer.
*
* @throws IOException if an error occurs while reading from
* the search index.
*/
private void calculateDocFilter() throws IOException
{
PerQueryCache cache = PerQueryCache.getInstance();
@SuppressWarnings("unchecked")
Map<String, BitSet> readerCache =
(Map<String, BitSet>)cache.get(MatchAllScorer.class, reader);
if (readerCache == null)
{
readerCache = new HashMap<String, BitSet>();
cache.put(MatchAllScorer.class, reader, readerCache);
}
// get BitSet for field
docFilter = (BitSet)readerCache.get(field);
if (docFilter != null)
{
// use cached BitSet;
return;
}
// otherwise calculate new
docFilter = new BitSet(reader.maxDoc());
// we match all terms
String namedValue = FieldNames.createNamedValue(field, "");
TermEnum terms = reader.terms(new Term(FieldNames.PROPERTIES, namedValue));
try
{
TermDocs docs = reader.termDocs();
try
{
while (terms.term() != null && terms.term().field() == FieldNames.PROPERTIES
&& terms.term().text().startsWith(namedValue))
{
docs.seek(terms);
while (docs.next())
{
docFilter.set(docs.doc());
}
terms.next();
}
}
finally
{
docs.close();
}
}
finally
{
terms.close();
}
// put BitSet into cache
readerCache.put(field, docFilter);
}
}