#include <lsh_table.h>

Public Types
typedef std::map< BucketKey, Bucket >	BucketsSpace

typedef std::vector< Bucket >	BucketsSpeed

Public Member Functions
void	add (const std::vector< std::pair< size_t, ElementType * > > &features)

void	add (unsigned int value, const ElementType *feature)

const Bucket *	getBucketFromKey (BucketKey key) const

size_t	getKey (const ElementType *) const

size_t	getKey (const unsigned char *feature) const

LshStats	getStats () const

LshStats	getStats () const

	LshTable ()

	LshTable (unsigned int feature_size, unsigned int subsignature_size)

	LshTable (unsigned int, unsigned int)

Private Types
enum	SpeedLevel { kArray, kBitsetHash, kHash }

Private Member Functions
void	initialize (size_t key_size)

void	optimize ()

template<typename Archive >
void	serialize (Archive &ar)

Private Attributes
BucketsSpace	buckets_space_

BucketsSpeed	buckets_speed_

DynamicBitset	key_bitset_

unsigned int	key_size_

std::vector< size_t >	mask_

SpeedLevel	speed_level_

Friends
struct	serialization::access

Detailed Description

template<typename ElementType>
class rtflann::lsh::LshTable< ElementType >

Lsh hash table. As its key is a sub-feature, and as usually the size of it is pretty small, we keep it as a continuous memory array. The value is an index in the corpus of features (we keep it as an unsigned int for pure memory reasons, it could be a size_t)

Definition at line 186 of file lsh_table.h.

Member Typedef Documentation

◆ BucketsSpace

template<typename ElementType >

typedef std::map<BucketKey, Bucket> rtflann::lsh::LshTable< ElementType >::BucketsSpace

A container of all the feature indices. Optimized for space

Definition at line 194 of file lsh_table.h.

◆ BucketsSpeed

template<typename ElementType >

typedef std::vector<Bucket> rtflann::lsh::LshTable< ElementType >::BucketsSpeed

A container of all the feature indices. Optimized for speed

Definition at line 199 of file lsh_table.h.

Member Enumeration Documentation

◆ SpeedLevel

template<typename ElementType >

enum rtflann::lsh::LshTable::SpeedLevel

private

defines the speed fo the implementation kArray uses a vector for storing data kBitsetHash uses a hash map but checks for the validity of a key with a bitset kHash uses a hash map only

Enumerator
kArray
kBitsetHash
kHash

Definition at line 313 of file lsh_table.h.

Constructor & Destructor Documentation

◆ LshTable() [1/3]

template<typename ElementType >

rtflann::lsh::LshTable< ElementType >::LshTable ( )

inline

Default constructor

Definition at line 203 of file lsh_table.h.

◆ LshTable() [2/3]

template<typename ElementType >

rtflann::lsh::LshTable< ElementType >::LshTable	(	unsigned int	,
		unsigned int
	)

inline

Default constructor Create the mask and allocate the memory

Parameters

feature_size	is the size of the feature (considered as a ElementType[])
key_size	is the number of bits that are turned on in the feature

Definition at line 212 of file lsh_table.h.

◆ LshTable() [3/3]

rtflann::lsh::LshTable< unsigned char >::LshTable	(	unsigned int	feature_size,
		unsigned int	subsignature_size
	)

inline

Definition at line 419 of file lsh_table.h.

Member Function Documentation

◆ add() [1/2]

template<typename ElementType >

void rtflann::lsh::LshTable< ElementType >::add ( const std::vector< std::pair< size_t, ElementType * > > & features )

inline

Add a set of features to the table

Parameters

dataset the values to store

Definition at line 249 of file lsh_table.h.

◆ add() [2/2]

template<typename ElementType >

void rtflann::lsh::LshTable< ElementType >::add	(	unsigned int	value,
		const ElementType *	feature
	)

inline

Add a feature to the table

Parameters

value	the value to store for that feature
feature	the feature itself

Definition at line 222 of file lsh_table.h.

◆ getBucketFromKey()

template<typename ElementType >

const Bucket* rtflann::lsh::LshTable< ElementType >::getBucketFromKey ( BucketKey key ) const

inline

Get a bucket given the key

Parameters

key

Returns

Definition at line 266 of file lsh_table.h.

◆ getKey() [1/2]

template<typename ElementType >

size_t rtflann::lsh::LshTable< ElementType >::getKey ( const ElementType * ) const

inline

Compute the sub-signature of a feature

Definition at line 295 of file lsh_table.h.

◆ getKey() [2/2]

size_t rtflann::lsh::LshTable< unsigned char >::getKey ( const unsigned char * feature ) const

inline

Return the Subsignature of a feature

Parameters

feature the feature to analyze

Definition at line 462 of file lsh_table.h.

◆ getStats() [1/2]

template<typename ElementType >

LshStats rtflann::lsh::LshTable< ElementType >::getStats ( ) const

Get statistics about the table

Returns

◆ getStats() [2/2]

LshStats rtflann::lsh::LshTable< unsigned char >::getStats ( ) const

inline

Definition at line 495 of file lsh_table.h.

◆ initialize()

template<typename ElementType >

void rtflann::lsh::LshTable< ElementType >::initialize ( size_t key_size )

inlineprivate

Initialize some variables

Definition at line 320 of file lsh_table.h.

◆ optimize()

template<typename ElementType >

void rtflann::lsh::LshTable< ElementType >::optimize ( )

inlineprivate

Optimize the table for speed/space

Definition at line 328 of file lsh_table.h.

◆ serialize()

template<typename ElementType >

template<typename Archive >

void rtflann::lsh::LshTable< ElementType >::serialize ( Archive & ar )

inlineprivate

Definition at line 362 of file lsh_table.h.

Friends And Related Function Documentation

◆ serialization::access

template<typename ElementType >

friend struct serialization::access

friend

Definition at line 386 of file lsh_table.h.

Member Data Documentation

◆ buckets_space_

template<typename ElementType >

BucketsSpace rtflann::lsh::LshTable< ElementType >::buckets_space_

private

The hash table of all the buckets in case we cannot use the speed version

Definition at line 394 of file lsh_table.h.

◆ buckets_speed_

template<typename ElementType >

BucketsSpeed rtflann::lsh::LshTable< ElementType >::buckets_speed_

private

The vector of all the buckets if they are held for speed

Definition at line 390 of file lsh_table.h.

◆ key_bitset_

template<typename ElementType >

DynamicBitset rtflann::lsh::LshTable< ElementType >::key_bitset_

private

If the subkey is small enough, it will keep track of which subkeys are set through that bitset That is just a speedup so that we don't look in the hash table (which can be mush slower that checking a bitset)

Definition at line 402 of file lsh_table.h.

◆ key_size_

template<typename ElementType >

unsigned int rtflann::lsh::LshTable< ElementType >::key_size_

private

The size of the sub-signature in bits

Definition at line 406 of file lsh_table.h.

◆ mask_

template<typename ElementType >

std::vector<size_t> rtflann::lsh::LshTable< ElementType >::mask_

private

The mask to apply to a feature to get the hash key Only used in the unsigned char case

Definition at line 412 of file lsh_table.h.

◆ speed_level_

template<typename ElementType >

SpeedLevel rtflann::lsh::LshTable< ElementType >::speed_level_

private

What is used to store the data

Definition at line 397 of file lsh_table.h.

The documentation for this class was generated from the following file:

lsh_table.h

Public Types

Public Member Functions

Private Types

Private Member Functions

Private Attributes

Friends

Detailed Description

template<typename ElementType> class rtflann::lsh::LshTable< ElementType >

Member Typedef Documentation

◆ BucketsSpace

◆ BucketsSpeed

Member Enumeration Documentation

◆ SpeedLevel

Constructor & Destructor Documentation

◆ LshTable() [1/3]

◆ LshTable() [2/3]

◆ LshTable() [3/3]

Member Function Documentation

◆ add() [1/2]

◆ add() [2/2]

◆ getBucketFromKey()

◆ getKey() [1/2]

◆ getKey() [2/2]

◆ getStats() [1/2]

◆ getStats() [2/2]

◆ initialize()

◆ optimize()

◆ serialize()

Friends And Related Function Documentation

◆ serialization::access

Member Data Documentation

◆ buckets_space_

◆ buckets_speed_

◆ key_bitset_

◆ key_size_

◆ mask_

◆ speed_level_

template<typename ElementType>
class rtflann::lsh::LshTable< ElementType >