| /* |
| * 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.jackrabbit.oak.plugins.index.search.spi.query; |
| |
| import java.io.IOException; |
| import java.util.concurrent.Semaphore; |
| import java.util.concurrent.atomic.AtomicInteger; |
| import java.util.concurrent.locks.ReadWriteLock; |
| import java.util.concurrent.locks.ReentrantReadWriteLock; |
| |
| import org.apache.jackrabbit.oak.commons.PerfLogger; |
| import org.apache.jackrabbit.oak.plugins.index.search.IndexDefinition; |
| import org.apache.jackrabbit.oak.plugins.index.search.IndexNode; |
| import org.apache.jackrabbit.oak.plugins.index.search.update.ReaderRefreshPolicy; |
| import org.apache.jackrabbit.oak.spi.state.NodeState; |
| import org.jetbrains.annotations.Nullable; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| import static com.google.common.base.Preconditions.checkState; |
| import static org.apache.jackrabbit.oak.plugins.index.IndexConstants.ASYNC_PROPERTY_NAME; |
| import static org.apache.jackrabbit.oak.plugins.index.IndexUtils.getAsyncLaneName; |
| |
| /** |
| * Keeps track of the open read sessions for an index. |
| */ |
| public abstract class IndexNodeManager { |
| /** |
| * Name of the hidden node under which information about the checkpoints |
| * seen and indexed by each async indexer is kept. |
| */ |
| public static final String ASYNC = ":async"; |
| |
| private static final AtomicInteger SEARCHER_ID_COUNTER = new AtomicInteger(); |
| |
| private static final PerfLogger PERF_LOGGER = |
| new PerfLogger(LoggerFactory.getLogger(IndexNodeManager.class.getName() + ".perf")); |
| |
| protected abstract IndexNodeManager open(String indexPath, NodeState root, NodeState defnNodeState); |
| |
| protected abstract void releaseResources(); |
| |
| protected abstract IndexNode getIndexNode(); |
| |
| protected abstract ReaderRefreshPolicy getReaderRefreshPolicy(); |
| |
| protected abstract void refreshReaders(); |
| |
| protected abstract String getName(); |
| |
| protected abstract IndexDefinition getDefinition(); |
| |
| static boolean hasAsyncIndexerRun(NodeState root, String indexPath, NodeState defnNodeState) { |
| boolean hasAsyncNode = root.hasChildNode(ASYNC); |
| |
| String asyncLaneName = getAsyncLaneName(defnNodeState, indexPath, defnNodeState.getProperty(ASYNC_PROPERTY_NAME)); |
| |
| if (asyncLaneName != null) { |
| return hasAsyncNode && root.getChildNode(ASYNC).hasProperty(asyncLaneName); |
| } else { |
| // useful only for tests - basically non-async index defs which don't rely on /:async |
| // hence either readers are there (and this method doesn't come into play during open) |
| // OR there is no cycle (where we return false correctly) |
| return false; |
| } |
| } |
| |
| private static final Logger log = LoggerFactory.getLogger(IndexNodeManager.class); |
| |
| private final ReadWriteLock lock = new ReentrantReadWriteLock(); |
| |
| private final Semaphore refreshLock = new Semaphore(1); |
| |
| private final Runnable refreshCallback = new Runnable() { |
| @Override |
| public void run() { |
| if (refreshLock.tryAcquire()) { |
| try { |
| refreshReaders(); |
| }finally { |
| refreshLock.release(); |
| } |
| } |
| } |
| }; |
| |
| private boolean closed = false; |
| |
| |
| @Nullable |
| IndexNode acquire() { |
| lock.readLock().lock(); |
| if (closed) { |
| lock.readLock().unlock(); |
| return null; |
| } else { |
| boolean success = false; |
| try { |
| getReaderRefreshPolicy().refreshOnReadIfRequired(refreshCallback); |
| IndexNode indexNode = getIndexNode(); |
| success = true; |
| return indexNode; |
| } finally { |
| if (!success) { |
| lock.readLock().unlock(); |
| } |
| } |
| } |
| } |
| |
| private void release() { |
| lock.readLock().unlock(); |
| } |
| |
| void close() throws IOException { |
| lock.writeLock().lock(); |
| try { |
| checkState(!closed); |
| closed = true; |
| } finally { |
| lock.writeLock().unlock(); |
| } |
| |
| releaseResources(); |
| } |
| |
| } |