| /** |
| * |
| * 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.hadoop.hbase.mob; |
| |
| import java.io.IOException; |
| import java.util.concurrent.atomic.AtomicLong; |
| |
| import org.apache.hadoop.conf.Configuration; |
| import org.apache.hadoop.fs.FileSystem; |
| import org.apache.hadoop.fs.Path; |
| import org.apache.hadoop.hbase.classification.InterfaceAudience; |
| import org.apache.hadoop.hbase.io.hfile.CacheConfig; |
| import org.apache.hadoop.hbase.regionserver.BloomType; |
| import org.apache.hadoop.hbase.regionserver.StoreFile; |
| |
| /** |
| * Cached mob file. |
| */ |
| @InterfaceAudience.Private |
| public class CachedMobFile extends MobFile implements Comparable<CachedMobFile> { |
| |
| private long accessCount; |
| private AtomicLong referenceCount = new AtomicLong(0); |
| |
| public CachedMobFile(StoreFile sf) { |
| super(sf); |
| } |
| |
| public static CachedMobFile create(FileSystem fs, Path path, Configuration conf, |
| CacheConfig cacheConf) throws IOException { |
| StoreFile sf = new StoreFile(fs, path, conf, cacheConf, BloomType.NONE); |
| return new CachedMobFile(sf); |
| } |
| |
| public void access(long accessCount) { |
| this.accessCount = accessCount; |
| } |
| |
| public int compareTo(CachedMobFile that) { |
| if (this.accessCount == that.accessCount) return 0; |
| return this.accessCount < that.accessCount ? 1 : -1; |
| } |
| |
| @Override |
| public boolean equals(Object obj) { |
| if (this == obj) { |
| return true; |
| } |
| if (obj == null) { |
| return false; |
| } |
| if (!(obj instanceof CachedMobFile)) { |
| return false; |
| } |
| return compareTo((CachedMobFile) obj) == 0; |
| } |
| |
| @Override |
| public int hashCode() { |
| return (int)(accessCount ^ (accessCount >>> 32)); |
| } |
| |
| /** |
| * Opens the mob file if it's not opened yet and increases the reference. |
| * It's not thread-safe. Use MobFileCache.openFile() instead. |
| * The reader of the mob file is just opened when it's not opened no matter how many times |
| * this open() method is invoked. |
| * The reference is a counter that how many times this reader is referenced. When the |
| * reference is 0, this reader is closed. |
| */ |
| @Override |
| public void open() throws IOException { |
| super.open(); |
| referenceCount.incrementAndGet(); |
| } |
| |
| /** |
| * Decreases the reference of the underlying reader for the mob file. |
| * It's not thread-safe. Use MobFileCache.closeFile() instead. |
| * This underlying reader isn't closed until the reference is 0. |
| */ |
| @Override |
| public void close() throws IOException { |
| long refs = referenceCount.decrementAndGet(); |
| if (refs == 0) { |
| super.close(); |
| } |
| } |
| |
| /** |
| * Gets the reference of the current mob file. |
| * Internal usage, currently it's for testing. |
| * @return The reference of the current mob file. |
| */ |
| public long getReferenceCount() { |
| return this.referenceCount.longValue(); |
| } |
| } |