base.hh

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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
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 */

#ifndef __BASE_FILTERS_BASE_HH__
#define __BASE_FILTERS_BASE_HH__

#include <vector>

#include "base/intmath.hh"
#include "base/sat_counter.hh"
#include "base/types.hh"
#include "params/BloomFilterBase.hh"
#include "sim/sim_object.hh"

namespace BloomFilter {

class Base : public SimObject
{
  protected:
    const unsigned offsetBits;

    std::vector<SatCounter> filter;

    const int sizeBits;

    const int setThreshold;

  public:
    Base(const BloomFilterBaseParams* p)
        : SimObject(p), offsetBits(p->offset_bits),
          filter(p->size, SatCounter(p->num_bits)),
          sizeBits(floorLog2(p->size)), setThreshold(p->threshold)
    {
        clear();
    }
    virtual ~Base() {};

    virtual void clear()
    {
        for (auto& entry : filter) {
            entry.reset();
        }
    }

    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];
        }
    }

    virtual void set(Addr addr) = 0;

    virtual void unset(Addr addr) {};

    virtual bool
    isSet(Addr addr) const
    {
        return getCount(addr) >= setThreshold;
    }

    virtual int getCount(Addr addr) const { return 0; }

    virtual int getTotalCount() const
    {
        int count = 0;
        for (const auto& entry : filter) {
            count += entry;
        }
        return count;
    }
};

} // namespace BloomFilter

#endif // __BASE_FILTERS_BASE_HH__