/*
* 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.CorruptIndexException;
import org.apache.lucene.index.FilterIndexReader;
import org.apache.lucene.index.IndexReader;
import java.io.IOException;
import java.util.Set;
import java.util.concurrent.CopyOnWriteArraySet;
import java.util.concurrent.atomic.AtomicLong;
/**
* Wraps an <code>IndexReader</code> and allows to commit changes without
* closing the reader.
*/
class CommittableIndexReader extends FilterIndexReader {
/**
* A modification count on this index reader. Initialized with
* {@link IndexReader#getVersion()} and incremented with every call to
* {@link #doDelete(int)}.
*/
private final AtomicLong modCount;
/**
* If reader is created with flag transientDeletions, then reader
* deleted documents are stored in the memory buffer and not applied to underlying
* index reader.
*/
private final boolean transientDeletions;
private final Set<Integer> deletedDocs;
/**
* Creates a new <code>CommittableIndexReader</code> based on <code>in</code>.
*
* @param in the <code>IndexReader</code> to wrap.
* @param transientDeletions If reader is created with flag transientDeletions, then reader
* deleted documents are stored in the memory buffer and not applied to underlying
* index reader.
*/
CommittableIndexReader(IndexReader in, boolean transientDeletions) {
super(in);
modCount = new AtomicLong(in.getVersion());
this.transientDeletions = transientDeletions;
// no need to initialize Set if transientDeletions = false
this.deletedDocs = transientDeletions? new CopyOnWriteArraySet<Integer>() : null;
}
//------------------------< FilterIndexReader >-----------------------------
/**
* {@inheritDoc}
* <br>
* Increments the modification count.
*/
protected void doDelete(int n) throws CorruptIndexException, IOException {
if (transientDeletions) {
deletedDocs.add(n);
modCount.incrementAndGet(); // doDelete won't be executed, so incrementing modCount
} else {
super.doDelete(n);
modCount.incrementAndGet();
}
}
@Override
public boolean isDeleted(int n) {
if (transientDeletions) {
return deletedDocs.contains(n);
} else {
return super.isDeleted(n);
}
}
//------------------------< additional methods >----------------------------
/**
* @return the modification count of this index reader.
*/
long getModificationCount() {
return modCount.get();
}
}