bloom_parameters( unsigned long long int cnt, double fprate = 0.0001, unsigned long long int seed = 0xA5A5A5A55A5A5A5AULL ):
minimum_size(1),
maximum_size(std::numeric_limits<unsigned long long int>::max()),
minimum_number_of_hashes(1),
maximum_number_of_hashes(std::numeric_limits<unsigned int>::max() )
{
projected_element_count = cnt ;
false_positive_probability = fprate ;
random_seed = seed ;
compute_optimal_parameters() ;
}
/*
create a bloom filter according to the estimated number of inserted elements and desired false
positive probability. It will calculate the optimal value of the table size.
*/
bloom_filter(const large_integer projected_element_count,double false_positive_probability)
{
inserted_element_count_ = 0;
hash_count_ = 0;
table_size_ = 0;
raw_table_size_ = 0;
compute_optimal_parameters(projected_element_count,false_positive_probability);
//hash_range_ = (integer)(ceil(log(table_size_)));
raw_table_size_ = table_size_ / bits_per_char;
bit_table_ = new bitmap[static_cast<std::size_t>(raw_table_size_)];
std::fill_n(bit_table_,raw_table_size_,0x00);
//hash_ = new HashFunc[hash_count_];
// allocate memory
hash_ = static_cast<HashFunc*>(::operator new(sizeof(HashFunc) * hash_count_));
generate_independent_hashes();
}
