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/*
*
* (C) 2013-22 - ntop.org
*
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software Foundation,
* Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*
*/
#ifndef _BLOOM_H_
#define _BLOOM_H_
/**
* @file Bloom.h
*
* @brief Bloom class implementation.
* @details A Bloom instance represents a bitmask that can be used as bloom filter for strings.
*/
#include "ntop_includes.h"
class Bloom {
private:
Bitmask *bitmask; /**< The bitmask */
u_int32_t num_bloom_bits; /**< The bitmask size */
u_int32_t mask; /**< The mask to be used for the hash */
u_int32_t ntophash(char *str);
public:
Bloom(u_int32_t _num_bloom_bits);
~Bloom();
/**
* Adds a new value to the bloom setting the relative bit in the bitmask.
* @param str The value to set.
*/
inline void setBit(char *str) { bitmask->set_bit(ntophash(str)); }
/**
* Removes a value to the bloom unsetting the relative bit in the bitmask.
* This is not the best thing that we could do with a bloom even though
* if the user is aware of the limitation it can be used safely
* @param str The value to set.
*/
inline void unsetBit(char *str) { bitmask->clear_bit(ntophash(str)); }
/**
* Checks if a value is set in the bloom filter.
* @param str The value to check.
* @return True is the hash for the provided value is set, false otherwise.
*/
inline bool isSetBit(char *str) { return(bitmask->is_set_bit(ntophash(str))); }
};
#endif /* _BLOOM_H_ */
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