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Diffstat (limited to 'src/base/filters/base.hh')
| -rw-r--r-- | src/base/filters/base.hh | 151 |
1 files changed, 151 insertions, 0 deletions
diff --git a/src/base/filters/base.hh b/src/base/filters/base.hh new file mode 100644 index 000000000..1ce853979 --- /dev/null +++ b/src/base/filters/base.hh @@ -0,0 +1,151 @@ +/* + * Copyright (c) 2019 Inria + * Copyright (c) 1999-2008 Mark D. Hill and David A. Wood + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are + * met: redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer; + * redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution; + * neither the name of the copyright holders nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + * Authors: Daniel Carvalho + */ + +#ifndef __BASE_FILTERS_BASE_HH__ +#define __BASE_FILTERS_BASE_HH__ + +#include <vector> + +#include "base/intmath.hh" +#include "base/types.hh" +#include "params/BloomFilterBase.hh" +#include "sim/sim_object.hh" + +namespace BloomFilter { + +class Base : public SimObject +{ + protected: + /** Number of LSB bits to ignore from the the addresses. */ + const unsigned offsetBits; + + /** The filter itself. */ + std::vector<int> filter; + + /** Number of bits needed to represent the size of the filter. */ + const int sizeBits; + + /** Threshold at which a filter entry starts being considered as set. */ + const int setThreshold; + + public: + /** + * Create and clear the filter. + */ + Base(const BloomFilterBaseParams* p) + : SimObject(p), offsetBits(p->offset_bits), filter(p->size), + sizeBits(floorLog2(p->size)), setThreshold(p->threshold) + { + clear(); + } + virtual ~Base() {}; + + /** + * Clear the filter by resetting all values. + */ + virtual void clear() + { + for (auto& entry : filter) { + entry = 0; + } + } + + /** + * Merges the contents of both filters into this' (Bloom Filter union). + * Both must have the same number of entries. + * + * @param other The other bloom filter to merge with. + */ + virtual void + merge(const Base* other) + { + assert(filter.size() == other->filter.size()); + for (int i = 0; i < filter.size(); ++i){ + filter[i] |= other->filter[i]; + } + } + + /** + * Perform the filter specific function to set the corresponding + * entries (can be multiple) of an address. + * + * @param addr The address being parsed. + */ + virtual void set(Addr addr) = 0; + + /** + * Perform the filter specific function to clear the corresponding + * entries (can be multiple) of an address. By default a bloom + * filter does not support element deletion. + * + * @param addr The address being parsed. + */ + virtual void unset(Addr addr) {}; + + /** + * Check if the corresponding filter entries of an address should be + * considered as set. + * + * @param addr The address being parsed. + * @return Whether the respective filter entry is set. + */ + virtual bool + isSet(Addr addr) const + { + return getCount(addr) >= setThreshold; + } + + /** + * Get the value stored in the corresponding filter entry of an address. + * + * @param addr The address being parsed. + * @param Get the value stored in the respective filter entry. + */ + virtual int getCount(Addr addr) const { return 0; } + + /** + * Get the total value stored in the filter entries. + * + * @return The sum of all filter entries. + */ + virtual int getTotalCount() const + { + int count = 0; + for (const auto& entry : filter) { + count += entry; + } + return count; + } +}; + +} // namespace BloomFilter + +#endif // __BASE_FILTERS_BASE_HH__ |