src/mem/ruby/filters/MultiGrainBloomFilter.cc

   1 /*
   2  * Copyright (c) 1999-2008 Mark D. Hill and David A. Wood
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions are
   7  * met: redistributions of source code must retain the above copyright
   8  * notice, this list of conditions and the following disclaimer;
   9  * 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  * neither the name of the copyright holders nor the names of its
  13  * contributors may be used to endorse or promote products derived from
  14  * this software without specific prior written permission.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  17  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  18  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  19  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  20  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  21  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  22  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  26  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27  */
  28
  29 #include "base/intmath.hh"
  30 #include "base/str.hh"
  31 #include "mem/ruby/filters/MultiGrainBloomFilter.hh"
  32
  33 using namespace std;
  34
  35 MultiGrainBloomFilter::MultiGrainBloomFilter(string str)
  36 {
  37     string head, tail;
  38 #ifndef NDEBUG
  39     bool success =
  40 #endif
  41         split_first(str, head, tail, '_');
  42     assert(success);
  43
  44     // head contains size of 1st bloom filter, tail contains size of
  45     // 2nd bloom filter
  46
  47     m_filter_size = atoi(head.c_str());
  48     m_filter_size_bits = floorLog2(m_filter_size);
  49
  50     m_page_filter_size = atoi(tail.c_str());
  51     m_page_filter_size_bits = floorLog2(m_page_filter_size);
  52
  53     m_filter.resize(m_filter_size);
  54     m_page_filter.resize(m_page_filter_size);
  55     clear();
  56 }
  57
  58 MultiGrainBloomFilter::~MultiGrainBloomFilter()
  59 {
  60 }
  61
  62 void
  63 MultiGrainBloomFilter::clear()
  64 {
  65     for (int i = 0; i < m_filter_size; i++) {
  66         m_filter[i] = 0;
  67     }
  68     for(int i=0; i < m_page_filter_size; ++i){
  69         m_page_filter[i] = 0;
  70     }
  71 }
  72
  73 void
  74 MultiGrainBloomFilter::increment(const Address& addr)
  75 {
  76     // Not used
  77 }
  78
  79
  80 void
  81 MultiGrainBloomFilter::decrement(const Address& addr)
  82 {
  83     // Not used
  84 }
  85
  86 void
  87 MultiGrainBloomFilter::merge(AbstractBloomFilter *other_filter)
  88 {
  89     // TODO
  90 }
  91
  92 void
  93 MultiGrainBloomFilter::set(const Address& addr)
  94 {
  95     int i = get_block_index(addr);
  96     assert(i < m_filter_size);
  97     assert(get_page_index(addr) < m_page_filter_size);
  98     m_filter[i] = 1;
  99     m_page_filter[i] = 1;
 100
 101 }
 102
 103 void
 104 MultiGrainBloomFilter::unset(const Address& addr)
 105 {
 106     // not used
 107 }
 108
 109 bool
 110 MultiGrainBloomFilter::isSet(const Address& addr)
 111 {
 112     int i = get_block_index(addr);
 113     assert(i < m_filter_size);
 114     assert(get_page_index(addr) < m_page_filter_size);
 115     // we have to have both indices set
 116     return (m_filter[i] && m_page_filter[i]);
 117 }
 118
 119 int
 120 MultiGrainBloomFilter::getCount(const Address& addr)
 121 {
 122     // not used
 123     return 0;
 124 }
 125
 126 int
 127 MultiGrainBloomFilter::getTotalCount()
 128 {
 129     int count = 0;
 130
 131     for (int i = 0; i < m_filter_size; i++) {
 132         count += m_filter[i];
 133     }
 134
 135     for(int i=0; i < m_page_filter_size; ++i) {
 136         count += m_page_filter[i] = 0;
 137     }
 138
 139     return count;
 140 }
 141
 142 int
 143 MultiGrainBloomFilter::getIndex(const Address& addr)
 144 {
 145     return 0;
 146     // TODO
 147 }
 148
 149 int
 150 MultiGrainBloomFilter::readBit(const int index)
 151 {
 152     return 0;
 153     // TODO
 154 }
 155
 156 void
 157 MultiGrainBloomFilter::writeBit(const int index, const int value)
 158 {
 159     // TODO
 160 }
 161
 162 void
 163 MultiGrainBloomFilter::print(ostream& out) const
 164 {
 165 }
 166
 167 int
 168 MultiGrainBloomFilter::get_block_index(const Address& addr)
 169 {
 170     // grap a chunk of bits after byte offset
 171     return addr.bitSelect(RubySystem::getBlockSizeBits(),
 172                           RubySystem::getBlockSizeBits() +
 173                           m_filter_size_bits - 1);
 174 }
 175
 176 int
 177 MultiGrainBloomFilter::get_page_index(const Address & addr)
 178 {
 179     int bits = RubySystem::getBlockSizeBits() + m_filter_size_bits - 1;
 180
 181     // grap a chunk of bits after first chunk
 182     return addr.bitSelect(bits, bits + m_page_filter_size_bits - 1);
 183 }
 184
 185
 186
 187