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1   /**
2    * Licensed to the Apache Software Foundation (ASF) under one
3    * or more contributor license agreements.  See the NOTICE file
4    * distributed with this work for additional information
5    * regarding copyright ownership.  The ASF licenses this file
6    * to you under the Apache License, Version 2.0 (the
7    * "License"); you may not use this file except in compliance
8    * with the License.  You may obtain a copy of the License at
9    *
10   *     http://www.apache.org/licenses/LICENSE-2.0
11   *
12   * Unless required by applicable law or agreed to in writing, software
13   * distributed under the License is distributed on an "AS IS" BASIS,
14   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15   * See the License for the specific language governing permissions and
16   * limitations under the License.
17   */
18  
19  package org.apache.hadoop.hbase.replication;
20  
21  import java.util.ArrayList;
22  import java.util.List;
23  
24  import org.apache.hadoop.hbase.classification.InterfaceAudience;
25  import org.apache.hadoop.hbase.HBaseInterfaceAudience;
26  import org.apache.hadoop.hbase.regionserver.wal.HLog.Entry;
27  
28  /**
29   * A {@link WALEntryFilter} which contains multiple filters and applies them
30   * in chain order
31   */
32  @InterfaceAudience.LimitedPrivate(HBaseInterfaceAudience.REPLICATION)
33  public class ChainWALEntryFilter implements WALEntryFilter {
34  
35    private final WALEntryFilter[] filters;
36  
37    public ChainWALEntryFilter(WALEntryFilter...filters) {
38      this.filters = filters;
39    }
40  
41    public ChainWALEntryFilter(List<WALEntryFilter> filters) {
42      ArrayList<WALEntryFilter> rawFilters = new ArrayList<WALEntryFilter>(filters.size());
43      // flatten the chains
44      for (WALEntryFilter filter : filters) {
45        if (filter instanceof ChainWALEntryFilter) {
46          for (WALEntryFilter f : ((ChainWALEntryFilter) filter).filters) {
47            rawFilters.add(f);
48          }
49        } else {
50          rawFilters.add(filter);
51        }
52      }
53  
54      this.filters = rawFilters.toArray(new WALEntryFilter[rawFilters.size()]);
55    }
56  
57    @Override
58    public Entry filter(Entry entry) {
59      for (WALEntryFilter filter : filters) {
60        if (entry == null) {
61          return null;
62        }
63        entry = filter.filter(entry);
64      }
65      return entry;
66    }
67  
68  }