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#include "base/filters/bulk_bloom_filter.hh" 33
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34#include <vector>
35
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34#include <limits> 35 36#include "base/bitfield.hh"
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37#include "base/logging.hh" |
38#include "params/BloomFilterBulk.hh" 39 40namespace BloomFilter { 41 42Bulk::Bulk(const BloomFilterBulkParams* p)
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44 : Base(p), sectorBits(sizeBits - 1)
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43 : MultiBitSel(p), sectorBits(floorLog2(parFilterSize)) |
44{
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45 fatal_if((numHashes * sectorBits) > 46 (std::numeric_limits<Addr>::digits - offsetBits), 47 "Sectors need more bits than available"); |
48} 49 50Bulk::~Bulk() 51{ 52} 53
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52void
53Bulk::set(Addr addr)
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54int 55Bulk::hash(Addr addr, int hash_number) const |
56{
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55 // c0 contains the cache index bits
56 int c0 = bits(addr, offsetBits + sectorBits - 1, offsetBits);
57 // c1 contains the lower sectorBits permuted bits
58 //Address permuted_bits = permute(addr);
59 int c1 = bits(addr, (offsetBits + 2 * sectorBits) - 1,
60 offsetBits + sectorBits);
61 //assert(c0 < (filter_size/2));
62 //assert(c0 + (filter_size/2) < filter_size);
63 //assert(c1 < (filter_size/2));
64 // set v0 bit
65 filter[c0 + (filter.size()/2)] = 1;
66 // set v1 bit
67 filter[c1] = 1;
68}
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57 addr = permute(addr); |
58
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70bool
71Bulk::isSet(Addr addr) const
72{
73 // c0 contains the cache index bits
74 const int filter_size = filter.size();
75 int c0 = bits(addr, offsetBits + sectorBits - 1, offsetBits);
76 // c1 contains the lower 10 permuted bits
77 //Address permuted_bits = permute(addr);
78 int c1 = bits(addr, (offsetBits + 2 * sectorBits) - 1,
79 offsetBits + sectorBits);
80 //assert(c0 < (filter_size/2));
81 //assert(c0 + (filter_size/2) < filter_size);
82 //assert(c1 < (filter_size/2));
83 // set v0 bit
84 std::vector<int> temp_filter(filter.size(), 0);
85 temp_filter[c0 + (filter_size/2)] = 1;
86 // set v1 bit
87 temp_filter[c1] = 1;
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59 // Get the sector-based c index 60 int c = bits(addr, (offsetBits + (hash_number + 1) * sectorBits) - 1, 61 offsetBits + hash_number * sectorBits); 62 assert(c < filter.size()/numHashes); |
63
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89 // perform filter intersection. If any c part is 0, no possibility
90 // of address being in signature. get first c intersection part
91 bool zero = false;
92 for (int i = 0; i < filter_size/2; ++i){
93 // get intersection of signatures
94 temp_filter[i] = temp_filter[i] && filter[i];
95 zero = zero || temp_filter[i];
96 }
97 zero = !zero;
98 if (zero) {
99 // one section is zero, no possiblility of address in signature
100 // reset bits we just set
101 temp_filter[c0 + (filter_size / 2)] = 0;
102 temp_filter[c1] = 0;
103 return false;
104 }
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64 // Transform the sector-based c index into a filder index (v) 65 c += (numHashes - 1 - hash_number) * (filter.size()/numHashes); 66 assert(c < filter.size()); |
67
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106 // check second section
107 zero = false;
108 for (int i = filter_size / 2; i < filter_size; ++i) {
109 // get intersection of signatures
110 temp_filter[i] = temp_filter[i] && filter[i];
111 zero = zero || temp_filter[i];
112 }
113 zero = !zero;
114 if (zero) {
115 // one section is zero, no possiblility of address in signature
116 temp_filter[c0 + (filter_size / 2)] = 0;
117 temp_filter[c1] = 0;
118 return false;
119 }
120 // one section has at least one bit set
121 temp_filter[c0 + (filter_size / 2)] = 0;
122 temp_filter[c1] = 0;
123 return true;
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68 return c; |
69} 70
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126int
127Bulk::getCount(Addr addr) const
128{
129 // TODO as in the multi-hashed filters
130 return 0;
131}
132
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71Addr
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134Bulk::hash(Addr addr) const
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72Bulk::permute(Addr addr) const |
73{ 74 // permutes the original address bits according to Table 5 75 Addr part1 = bits(addr, offsetBits + 6, offsetBits), 76 part2 = bits(addr, offsetBits + 9), 77 part3 = bits(addr, offsetBits + 11), 78 part4 = bits(addr, offsetBits + 17), 79 part5 = bits(addr, offsetBits + 8, offsetBits + 7), 80 part6 = bits(addr, offsetBits + 10), 81 part7 = bits(addr, offsetBits + 12), 82 part8 = bits(addr, offsetBits + 13), 83 part9 = bits(addr, offsetBits + 16, offsetBits + 15), 84 part10 = bits(addr, offsetBits + 20, offsetBits + 18), 85 part11 = bits(addr, offsetBits + 14); 86 87 Addr result = 88 (part1 << 14) | (part2 << 13) | (part3 << 12) | (part4 << 11) | 89 (part5 << 9) | (part6 << 8) | (part7 << 7) | (part8 << 6) | 90 (part9 << 4) | (part10 << 1) | (part11); 91 92 // Select the remaining high-order bits 93 Addr remaining_bits = bits(addr, std::numeric_limits<Addr>::digits - 1, 94 offsetBits + 21) << 21; 95 result = result | remaining_bits; 96 97 return result; 98} 99 100} // namespace BloomFilter 101 102BloomFilter::Bulk* 103BloomFilterBulkParams::create() 104{ 105 return new BloomFilter::Bulk(this); 106} 107
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