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/*
* 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__