base.hh revision 14262:991410960fdb
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_BASE_HH__ 33#define __BASE_FILTERS_BASE_HH__ 34 35#include <vector> 36 37#include "base/intmath.hh" 38#include "base/types.hh" 39#include "params/BloomFilterBase.hh" 40#include "sim/sim_object.hh" 41 42namespace BloomFilter { 43 44class Base : public SimObject 45{ 46 protected: 47 /** Number of LSB bits to ignore from the the addresses. */ 48 const unsigned offsetBits; 49 50 /** The filter itself. */ 51 std::vector<int> filter; 52 53 /** Number of bits needed to represent the size of the filter. */ 54 const int sizeBits; 55 56 /** Threshold at which a filter entry starts being considered as set. */ 57 const int setThreshold; 58 59 public: 60 /** 61 * Create and clear the filter. 62 */ 63 Base(const BloomFilterBaseParams* p) 64 : SimObject(p), offsetBits(p->offset_bits), filter(p->size), 65 sizeBits(floorLog2(p->size)), setThreshold(p->threshold) 66 { 67 clear(); 68 } 69 virtual ~Base() {}; 70 71 /** 72 * Clear the filter by resetting all values. 73 */ 74 virtual void clear() 75 { 76 for (auto& entry : filter) { 77 entry = 0; 78 } 79 } 80 81 /** 82 * Merges the contents of both filters into this' (Bloom Filter union). 83 * Both must have the same number of entries. 84 * 85 * @param other The other bloom filter to merge with. 86 */ 87 virtual void 88 merge(const Base* other) 89 { 90 assert(filter.size() == other->filter.size()); 91 for (int i = 0; i < filter.size(); ++i){ 92 filter[i] |= other->filter[i]; 93 } 94 } 95 96 /** 97 * Perform the filter specific function to set the corresponding 98 * entries (can be multiple) of an address. 99 * 100 * @param addr The address being parsed. 101 */ 102 virtual void set(Addr addr) = 0; 103 104 /** 105 * Perform the filter specific function to clear the corresponding 106 * entries (can be multiple) of an address. By default a bloom 107 * filter does not support element deletion. 108 * 109 * @param addr The address being parsed. 110 */ 111 virtual void unset(Addr addr) {}; 112 113 /** 114 * Check if the corresponding filter entries of an address should be 115 * considered as set. 116 * 117 * @param addr The address being parsed. 118 * @return Whether the respective filter entry is set. 119 */ 120 virtual bool 121 isSet(Addr addr) const 122 { 123 return getCount(addr) >= setThreshold; 124 } 125 126 /** 127 * Get the value stored in the corresponding filter entry of an address. 128 * 129 * @param addr The address being parsed. 130 * @param Get the value stored in the respective filter entry. 131 */ 132 virtual int getCount(Addr addr) const { return 0; } 133 134 /** 135 * Get the total value stored in the filter entries. 136 * 137 * @return The sum of all filter entries. 138 */ 139 virtual int getTotalCount() const 140 { 141 int count = 0; 142 for (const auto& entry : filter) { 143 count += entry; 144 } 145 return count; 146 } 147}; 148 149} // namespace BloomFilter 150 151#endif // __BASE_FILTERS_BASE_HH__ 152