| /* |
| * 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.lucene.index; |
| |
| |
| import java.io.IOException; |
| |
| import org.apache.lucene.search.IndexSearcher; |
| import org.apache.lucene.search.ReferenceManager; |
| import org.apache.lucene.search.SearcherManager; |
| import org.apache.lucene.store.Directory; |
| |
| /** |
| * Utility class to safely share {@link DirectoryReader} instances across |
| * multiple threads, while periodically reopening. This class ensures each |
| * reader is closed only once all threads have finished using it. |
| * |
| * @see SearcherManager |
| * |
| * @lucene.experimental |
| */ |
| public final class ReaderManager extends ReferenceManager<DirectoryReader> { |
| |
| /** |
| * Creates and returns a new ReaderManager from the given |
| * {@link IndexWriter}. |
| * |
| * @param writer |
| * the IndexWriter to open the IndexReader from. |
| * |
| * @throws IOException If there is a low-level I/O error |
| */ |
| public ReaderManager(IndexWriter writer) throws IOException { |
| this(writer, true, false); |
| } |
| |
| /** |
| * Expert: creates and returns a new ReaderManager from the given |
| * {@link IndexWriter}, controlling whether past deletions should be applied. |
| * |
| * @param writer |
| * the IndexWriter to open the IndexReader from. |
| * @param applyAllDeletes |
| * If <code>true</code>, all buffered deletes will be applied (made |
| * visible) in the {@link IndexSearcher} / {@link DirectoryReader}. |
| * If <code>false</code>, the deletes may or may not be applied, but |
| * remain buffered (in IndexWriter) so that they will be applied in |
| * the future. Applying deletes can be costly, so if your app can |
| * tolerate deleted documents being returned you might gain some |
| * performance by passing <code>false</code>. See |
| * {@link DirectoryReader#openIfChanged(DirectoryReader, IndexWriter, boolean)}. |
| * @param writeAllDeletes |
| * If <code>true</code>, new deletes will be forcefully written to index files. |
| * |
| * @throws IOException If there is a low-level I/O error |
| */ |
| public ReaderManager(IndexWriter writer, boolean applyAllDeletes, boolean writeAllDeletes) throws IOException { |
| current = DirectoryReader.open(writer, applyAllDeletes, writeAllDeletes); |
| } |
| |
| /** |
| * Creates and returns a new ReaderManager from the given {@link Directory}. |
| * @param dir the directory to open the DirectoryReader on. |
| * |
| * @throws IOException If there is a low-level I/O error |
| */ |
| public ReaderManager(Directory dir) throws IOException { |
| current = DirectoryReader.open(dir); |
| } |
| |
| /** |
| * Creates and returns a new ReaderManager from the given |
| * already-opened {@link DirectoryReader}, stealing |
| * the incoming reference. |
| * |
| * @param reader the directoryReader to use for future reopens |
| * |
| * @throws IOException If there is a low-level I/O error |
| */ |
| public ReaderManager(DirectoryReader reader) throws IOException { |
| current = reader; |
| } |
| |
| @Override |
| protected void decRef(DirectoryReader reference) throws IOException { |
| reference.decRef(); |
| } |
| |
| @Override |
| protected DirectoryReader refreshIfNeeded(DirectoryReader referenceToRefresh) throws IOException { |
| return DirectoryReader.openIfChanged(referenceToRefresh); |
| } |
| |
| @Override |
| protected boolean tryIncRef(DirectoryReader reference) { |
| return reference.tryIncRef(); |
| } |
| |
| @Override |
| protected int getRefCount(DirectoryReader reference) { |
| return reference.getRefCount(); |
| } |
| |
| } |