bloom_filter

Classes
class	etl::bloom_filter< Desired_Width, THash1, THash2, THash3 >

Detailed Description

A Bloom filter

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Class Documentation

etl::bloom_filter

class etl::bloom_filter

template<size_t Desired_Width, typename THash1, typename THash2 = private_bloom_filter::null_hash, typename THash3 = private_bloom_filter::null_hash>
class etl::bloom_filter< Desired_Width, THash1, THash2, THash3 >

An implementation of a bloom filter. Allows up to three hashes to be defined. Hashes must support the () operator and define 'argument_type'.

Template Parameters

Desired_Width	The desired number of hash results that can be stored. Rounded up to best fit the underlying bitset.
THash1	The first hash generator class.
THash2	The second hash generator class. If omitted, uses the null hash.
THash3	The third hash generator class. If omitted, uses the null hash. The hash classes must define argument_type.

Public Types
enum	{ WIDTH = etl::bitset<Desired_Width>::Allocated_Bits }
Public Member Functions
void	clear ()
	Clears the bloom filter of all entries.
void	add (parameter_t key)
bool	exists (parameter_t key) const
size_t	width () const
	Returns the width of the Bloom filter.
size_t	usage () const
	Returns the percentage of usage. Range 0 to 100.
size_t	count () const
	Returns the number of filter flags set.

Member Function Documentation

add()

template<size_t Desired_Width, typename THash1, typename THash2 = private_bloom_filter::null_hash, typename THash3 = private_bloom_filter::null_hash>

void etl::bloom_filter< Desired_Width, THash1, THash2, THash3 >::add ( parameter_t key )

inline

Adds a key to the filter.

Parameters

key	The key to add.

exists()

template<size_t Desired_Width, typename THash1, typename THash2 = private_bloom_filter::null_hash, typename THash3 = private_bloom_filter::null_hash>

bool etl::bloom_filter< Desired_Width, THash1, THash2, THash3 >::exists ( parameter_t key ) const

inline

Tests a key to see if it exists in the filter.

Parameters

key	The key to test.

Returns

true if the key exists in the filter.