org.opensearch.index.engine.OpenSearchReaderManager Maven / Gradle / Ivy
/*
* SPDX-License-Identifier: Apache-2.0
*
* The OpenSearch Contributors require contributions made to
* this file be licensed under the Apache-2.0 license or a
* compatible open source license.
*/
/*
* Licensed to Elasticsearch under one or more contributor
* license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright
* ownership. Elasticsearch 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.
*/
/*
* Modifications Copyright OpenSearch Contributors. See
* GitHub history for details.
*/
package org.opensearch.index.engine;
import java.io.IOException;
import java.util.function.BiConsumer;
import org.apache.lucene.index.DirectoryReader;
import org.apache.lucene.search.ReferenceManager;
import org.apache.lucene.search.SearcherManager;
import org.opensearch.common.SuppressForbidden;
import org.opensearch.common.lucene.index.OpenSearchDirectoryReader;
/**
* Utility class to safely share {@link OpenSearchDirectoryReader} instances across
* multiple threads, while periodically reopening. This class ensures each
* reader is closed only once all threads have finished using it.
*
* @see SearcherManager
*
*/
@SuppressForbidden(reason = "reference counting is required here")
class OpenSearchReaderManager extends ReferenceManager {
private final BiConsumer refreshListener;
/**
* Creates and returns a new OpenSearchReaderManager from the given
* already-opened {@link OpenSearchDirectoryReader}, stealing
* the incoming reference.
*
* @param reader the directoryReader to use for future reopens
* @param refreshListener A consumer that is called every time a new reader is opened
*/
OpenSearchReaderManager(
OpenSearchDirectoryReader reader,
BiConsumer refreshListener
) {
this.current = reader;
this.refreshListener = refreshListener;
refreshListener.accept(current, null);
}
@Override
protected void decRef(OpenSearchDirectoryReader reference) throws IOException {
reference.decRef();
}
@Override
protected OpenSearchDirectoryReader refreshIfNeeded(OpenSearchDirectoryReader referenceToRefresh) throws IOException {
final OpenSearchDirectoryReader reader = (OpenSearchDirectoryReader) DirectoryReader.openIfChanged(referenceToRefresh);
if (reader != null) {
refreshListener.accept(reader, referenceToRefresh);
}
return reader;
}
@Override
protected boolean tryIncRef(OpenSearchDirectoryReader reference) {
return reference.tryIncRef();
}
@Override
protected int getRefCount(OpenSearchDirectoryReader reference) {
return reference.getRefCount();
}
}