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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.util;
21  
22  import org.apache.hadoop.classification.InterfaceAudience;
23  import org.apache.hadoop.io.Writable;
24  
25  /**
26   * Specifies methods needed to add elements to a Bloom filter and serialize the
27   * resulting Bloom filter as a sequence of bytes.
28   */
29  @InterfaceAudience.Private
30  public interface BloomFilterWriter extends BloomFilterBase {
31  
32    /** Allocate memory for the bloom filter data. */
33    void allocBloom();
34  
35    /** Compact the Bloom filter before writing metadata & data to disk. */
36    void compactBloom();
37  
38    /**
39     * Get a writable interface into bloom filter meta data.
40     *
41     * @return a writable instance that can be later written to a stream
42     */
43    Writable getMetaWriter();
44  
45    /**
46     * Get a writable interface into bloom filter data (the actual Bloom bits).
47     * Not used for compound Bloom filters.
48     *
49     * @return a writable instance that can be later written to a stream
50     */
51    Writable getDataWriter();
52  
53    /**
54     * Add the specified binary to the bloom filter.
55     *
56     * @param buf data to be added to the bloom
57     * @param offset offset into the data to be added
58     * @param len length of the data to be added
59     */
60    void add(byte[] buf, int offset, int len);
61  
62  }