1 | /* |
2 | * Copyright (C) 2011 Apple Inc. All rights reserved. |
3 | * |
4 | * Redistribution and use in source and binary forms, with or without |
5 | * modification, are permitted provided that the following conditions |
6 | * are met: |
7 | * 1. Redistributions of source code must retain the above copyright |
8 | * notice, this list of conditions and the following disclaimer. |
9 | * 2. Redistributions in binary form must reproduce the above copyright |
10 | * notice, this list of conditions and the following disclaimer in the |
11 | * documentation and/or other materials provided with the distribution. |
12 | * |
13 | * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' |
14 | * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, |
15 | * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
16 | * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS |
17 | * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
18 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
19 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
20 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
21 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
22 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF |
23 | * THE POSSIBILITY OF SUCH DAMAGE. |
24 | */ |
25 | |
26 | #pragma once |
27 | |
28 | namespace JSC { |
29 | |
30 | typedef uintptr_t Bits; |
31 | |
32 | class TinyBloomFilter { |
33 | public: |
34 | TinyBloomFilter(); |
35 | |
36 | void add(Bits); |
37 | void add(TinyBloomFilter&); |
38 | bool ruleOut(Bits) const; // True for 0. |
39 | void reset(); |
40 | |
41 | private: |
42 | Bits m_bits; |
43 | }; |
44 | |
45 | inline TinyBloomFilter::TinyBloomFilter() |
46 | : m_bits(0) |
47 | { |
48 | } |
49 | |
50 | inline void TinyBloomFilter::add(Bits bits) |
51 | { |
52 | m_bits |= bits; |
53 | } |
54 | |
55 | inline void TinyBloomFilter::add(TinyBloomFilter& other) |
56 | { |
57 | m_bits |= other.m_bits; |
58 | } |
59 | |
60 | inline bool TinyBloomFilter::ruleOut(Bits bits) const |
61 | { |
62 | if (!bits) |
63 | return true; |
64 | |
65 | if ((bits & m_bits) != bits) |
66 | return true; |
67 | |
68 | return false; |
69 | } |
70 | |
71 | inline void TinyBloomFilter::reset() |
72 | { |
73 | m_bits = 0; |
74 | } |
75 | |
76 | } // namespace JSC |
77 | |