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1   /**
2    *
3    * Licensed to the Apache Software Foundation (ASF) under one
4    * or more contributor license agreements.  See the NOTICE file
5    * distributed with this work for additional information
6    * regarding copyright ownership.  The ASF licenses this file
7    * to you under the Apache License, Version 2.0 (the
8    * "License"); you may not use this file except in compliance
9    * with the License.  You may obtain a copy of the License at
10   *
11   *     http://www.apache.org/licenses/LICENSE-2.0
12   *
13   * Unless required by applicable law or agreed to in writing, software
14   * distributed under the License is distributed on an "AS IS" BASIS,
15   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
16   * See the License for the specific language governing permissions and
17   * limitations under the License.
18   */
19  
20  package org.apache.hadoop.hbase.regionserver.compactions;
21  
22  import java.io.IOException;
23  import java.util.Collection;
24  
25  import org.apache.hadoop.hbase.classification.InterfaceAudience;
26  import org.apache.hadoop.conf.Configuration;
27  import org.apache.hadoop.hbase.regionserver.StoreConfigInformation;
28  import org.apache.hadoop.hbase.regionserver.StoreFile;
29  
30  /**
31   * A compaction policy determines how to select files for compaction,
32   * how to compact them, and how to generate the compacted files.
33   */
34  @InterfaceAudience.Private
35  public abstract class CompactionPolicy {
36    protected CompactionConfiguration comConf;
37    protected StoreConfigInformation storeConfigInfo;
38  
39    public CompactionPolicy(Configuration conf, StoreConfigInformation storeConfigInfo) {
40      this.storeConfigInfo = storeConfigInfo;
41      this.comConf = new CompactionConfiguration(conf, this.storeConfigInfo);
42    }
43  
44    /**
45     * @param filesToCompact Files to compact. Can be null.
46     * @return True if we should run a major compaction.
47     */
48    public abstract boolean isMajorCompaction(
49      final Collection<StoreFile> filesToCompact) throws IOException;
50  
51    /**
52     * @param compactionSize Total size of some compaction
53     * @return whether this should be a large or small compaction
54     */
55    public abstract boolean throttleCompaction(long compactionSize);
56  
57    /**
58     * Inform the policy that some configuration has been change,
59     * so cached value should be updated it any.
60     */
61    public void setConf(Configuration conf) {
62      this.comConf = new CompactionConfiguration(conf, this.storeConfigInfo);
63    }
64  
65    /**
66     * @return The current compaction configuration settings.
67     */
68    public CompactionConfiguration getConf() {
69      return this.comConf;
70    }
71  }