/**
* 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.blur.index;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;
import org.apache.lucene.index.DirectoryReader;
import org.apache.lucene.index.IndexCommit;
import org.apache.lucene.index.IndexDeletionPolicy;
import org.apache.lucene.index.IndexReader;
import org.apache.lucene.index.IndexReader.ReaderClosedListener;
public class IndexDeletionPolicyReader extends IndexDeletionPolicy {
private final IndexDeletionPolicy _base;
private final Set<Long> _gens = Collections.newSetFromMap(new ConcurrentHashMap<Long, Boolean>());
public IndexDeletionPolicyReader(IndexDeletionPolicy base) {
_base = base;
}
@Override
public void onInit(List<? extends IndexCommit> commits) throws IOException {
_base.onInit(commits);
}
@Override
public void onCommit(List<? extends IndexCommit> commits) throws IOException {
commits = removeCommitsStillInUse(commits);
_base.onCommit(commits);
}
private List<? extends IndexCommit> removeCommitsStillInUse(List<? extends IndexCommit> commits) {
List<IndexCommit> validForRemoval = new ArrayList<IndexCommit>();
for (IndexCommit commit : commits) {
if (!isStillInUse(commit)) {
validForRemoval.add(commit);
}
}
return validForRemoval;
}
public DirectoryReader register(DirectoryReader reader) throws IOException {
final long generation = reader.getIndexCommit().getGeneration();
register(generation);
reader.addReaderClosedListener(new ReaderClosedListener() {
@Override
public void onClose(IndexReader reader) {
unregister(generation);
}
});
return reader;
}
private boolean isStillInUse(IndexCommit commit) {
long generation = commit.getGeneration();
return _gens.contains(generation);
}
public void register(long gen) {
_gens.add(gen);
}
public void unregister(long gen) {
_gens.remove(gen);
}
}