1/*
2 * Copyright (c) 2019 Inria
3 * Copyright (c) 1999-2008 Mark D. Hill and David A. Wood
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions are
8 * met: redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer;
10 * redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution;
13 * neither the name of the copyright holders nor the names of its
14 * contributors may be used to endorse or promote products derived from
15 * this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
18 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
19 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
20 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
21 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
22 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
23 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
27 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 *
29 * Authors: Daniel Carvalho
30 */
31
32#ifndef __BASE_FILTERS_BLOCK_BLOOM_FILTER_HH__
33#define __BASE_FILTERS_BLOCK_BLOOM_FILTER_HH__
34
35#include <vector>
36
37#include "base/filters/base.hh"
38
39struct BloomFilterBlockParams;
40
41namespace BloomFilter {
42
43/**
44 * Simple deletable (with false negatives) bloom filter that extracts
45 * bitfields of an address to use as indexes of the filter vector.
46 */
47class Block : public Base
48{
49  public:
50    Block(const BloomFilterBlockParams* p);
51    ~Block();
52
53    void set(Addr addr) override;
54    void unset(Addr addr) override;
55    int getCount(Addr addr) const override;
56
57  private:
58    /**
59     * XOR hash between bitfields of an address, provided by the mask vector.
60     *
61     * @param addr The address to be hashed.
62     * @return The value of the XOR of the masked bitfields of the address.
63     */
64    int hash(Addr addr) const;
65
66    /** Position of the LSB of each mask. */
67    std::vector<unsigned> masksLSBs;
68
69    /** Number of bits in each mask. */
70    std::vector<unsigned> masksSizes;
71};
72
73} // namespace BloomFilter
74
75#endif // __BASE_FILTERS_BLOCK_BLOOM_FILTER_HH__
76