Bitmap16 Class Reference
[Bitmap Processing]

A vertical representation of the data. More...

#include <Bitmap16.h>

Public Member Functions
	Bitmap16 (int numCustomers, unsigned short *&memory)
	Allocate the memory for Bitmap16 for this many customers.
	Bitmap16 (Bitmap16 &b, unsigned short *&memory)
	Copy constructor.
	~Bitmap16 ()
	Destructor (does nothing).
void	Deallocate (unsigned short *&memory)
	Pop this bitmap's memory from the global stack (allocation is done in the constructor, but deallocation is not done in the destructor.
void	FillEmptyPosition (int j)
	Fill in a 1 in a certain position.
void	Or (const Bitmap16 &b1, const Bitmap16 &b2)
	Bitwise OR 2 bitmaps and store the result.
void	And (const Bitmap16 &b1, const Bitmap16 &b2)
	Bitwise AND 2 bitmaps and store the result.
int	Count ()
	find the support of this bitmap in *number of customers*
void	CreateSBitmap (const Bitmap16 &iBitmap)
	Create a s-bitmap from an i-bitmap.
void	CreateCBitmap (const Bitmap16 &iBitmap)
	create a c-bitmap for compression
int	getIntSize () const
Static Public Member Functions
void	Init ()
	Initialize the counting tables.
void	Destroy ()
	deallocate counting tables
int	CalcSize (int numCust)
Static Public Attributes
int	_countOr = 0
	counters for performance measurements
int	_countAnd = 0
int	_countCount = 0
int	_countCreateSBitmap = 0
int	_countCreateCBitmap = 0
const int	_lookupTableSize = 0x10000
	lookup table for counting
int *	_sBitmapLookupTable = 0
	lookup table for creating a s-bitmap from an i-bitmap
int *	_cBitmapLookupTable = 0
	lookup table for creating a c-bitmap for compression
Private Attributes
unsigned short *	_memory
	where data is stored
int	_memSizeInt
	size of memory allocated in sizeof(int)
int	_memSizeShort
	size of memory allocated in sizeof(short)
int	_numCust
	number of customers
Friends
class	SeqBitmap

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Detailed Description

A vertical representation of the data.

It handles both uncompressed and compressed data.

This bitmap can represent customers with up to 16 transactions since it allocates exactly 16 bits per customer

Definition at line 56 of file Bitmap16.h.

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Constructor & Destructor Documentation

Bitmap16::Bitmap16 (  int  numCustomers, unsigned short *&  memory )  [inline]

Allocate the memory for Bitmap16 for this many customers. Parameters: numCustomers  # of customers memory  Definition at line 81 of file Bitmap16.h.

Bitmap16::Bitmap16 (  Bitmap16 &  b, unsigned short *&  memory )  [inline]

Copy constructor. Parameters: b  Bitmap to copy memory  Definition at line 103 of file Bitmap16.h.

Bitmap16::~Bitmap16 (   )  [inline]

Destructor (does nothing). Definition at line 118 of file Bitmap16.h.

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Member Function Documentation

void Bitmap16::And (  const Bitmap16 &  b1, const Bitmap16 &  b2 )

Bitwise AND 2 bitmaps and store the result. Parameters: b1  the first Bitmap16 b2  the second Bitmap16 Definition at line 146 of file Bitmap16.cpp. Referenced by SeqBitmap::And().

int Bitmap16::CalcSize (  int  numCust  )  [inline, static]

Definition at line 65 of file Bitmap16.h.

int Bitmap16::Count (   )

find the support of this bitmap in *number of customers* Returns: the number of customers that have some bit set among their 16 bits Definition at line 170 of file Bitmap16.cpp. Referenced by SeqBitmap::Count(), and SeqBitmap::PrintBitmap().

void Bitmap16::CreateCBitmap (  const Bitmap16 &  iBitmap  )

create a c-bitmap for compression Parameters: iBitmap  the bitmap16 from which we create c-bitmap Definition at line 224 of file Bitmap16.cpp. Referenced by SeqBitmap::CreateCBitmap().

void Bitmap16::CreateSBitmap (  const Bitmap16 &  iBitmap  )

Create a s-bitmap from an i-bitmap. Idea : Again, we go thru each element of _memory. For each element, if it is greater than 0, we look up the transformation table (postProcessTable) to find the corresponding value for the s-bitmap, and set the remaining SHORTs of the current custom to USHRT_MAX (i.e. all 1's). Note : For example, if the bitmap is [0001 | 1100 | 0011 | 1111 | 0000 | 0000] and [00001111 | 00011111 | 11111111]. Refer to the paper for details. Parameters: iBitmap  the bitmap from which we create s-bitmap Definition at line 203 of file Bitmap16.cpp. Referenced by SeqBitmap::CreateSBitmap().

void Bitmap16::Deallocate (  unsigned short *&  memory  )  [inline]

Pop this bitmap's memory from the global stack (allocation is done in the constructor, but deallocation is not done in the destructor. Definition at line 128 of file Bitmap16.h. Referenced by SeqBitmap::Deallocate().

void Bitmap16::Destroy (   )  [static]

deallocate counting tables Definition at line 105 of file Bitmap16.cpp. Referenced by SeqBitmap::Destroy().

void Bitmap16::FillEmptyPosition (  int  j  )  [inline]

Fill in a 1 in a certain position. Parameters: j  bit position in Bitmap to be changed Definition at line 138 of file Bitmap16.h. Referenced by SeqBitmap::FillEmptyPosition().

int Bitmap16::getIntSize (   )  const [inline]

Definition at line 173 of file Bitmap16.h. Referenced by SeqBitmap::printSizes().

void Bitmap16::Init (   )  [static]

Initialize the counting tables. Definition at line 57 of file Bitmap16.cpp. Referenced by SeqBitmap::Init().

void Bitmap16::Or (  const Bitmap16 &  b1, const Bitmap16 &  b2 )

Bitwise OR 2 bitmaps and store the result. Parameters: b1  the first Bitmap16 b2  the second Bitmap16 Definition at line 120 of file Bitmap16.cpp. Referenced by SeqBitmap::Or().

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Friends And Related Function Documentation

friend class SeqBitmap [friend]

Definition at line 58 of file Bitmap16.h.

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Field Documentation

int * Bitmap16::_cBitmapLookupTable = 0 [static]

lookup table for creating a c-bitmap for compression Definition at line 50 of file Bitmap16.cpp. Referenced by CreateCBitmap(), Destroy(), and Init().

int Bitmap16::_countAnd = 0 [static]

Definition at line 45 of file Bitmap16.cpp. Referenced by And().

int Bitmap16::_countCount = 0 [static]

Definition at line 46 of file Bitmap16.cpp. Referenced by Count().

int Bitmap16::_countCreateCBitmap = 0 [static]

Definition at line 48 of file Bitmap16.cpp. Referenced by CreateCBitmap().

int Bitmap16::_countCreateSBitmap = 0 [static]

Definition at line 47 of file Bitmap16.cpp. Referenced by CreateSBitmap().

int Bitmap16::_countOr = 0 [static]

counters for performance measurements Definition at line 44 of file Bitmap16.cpp. Referenced by Or().

const int Bitmap16::_lookupTableSize = 0x10000 [static]

lookup table for counting Definition at line 42 of file Bitmap16.cpp. Referenced by Init().

unsigned short* Bitmap16::_memory [private]

where data is stored Definition at line 180 of file Bitmap16.h. Referenced by And(), Bitmap16(), SeqBitmap::Compress16(), Count(), SeqBitmap::CountSmaller(), CreateCBitmap(), CreateSBitmap(), FillEmptyPosition(), Or(), and SeqBitmap::PrintBitmap().

int Bitmap16::_memSizeInt [private]

size of memory allocated in sizeof(int) Definition at line 181 of file Bitmap16.h. Referenced by And(), Bitmap16(), getIntSize(), SeqBitmap::memSize(), and Or().

int Bitmap16::_memSizeShort [private]

size of memory allocated in sizeof(short) Definition at line 182 of file Bitmap16.h. Referenced by Bitmap16(), SeqBitmap::Compress16(), Count(), SeqBitmap::CountSmaller(), CreateCBitmap(), CreateSBitmap(), Deallocate(), and SeqBitmap::PrintBitmap().

int Bitmap16::_numCust [private]

number of customers Definition at line 183 of file Bitmap16.h. Referenced by Bitmap16().

int * Bitmap16::_sBitmapLookupTable = 0 [static]

lookup table for creating a s-bitmap from an i-bitmap Definition at line 49 of file Bitmap16.cpp. Referenced by CreateSBitmap(), Destroy(), and Init().

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

• Bitmap16.h
• Bitmap16.cpp

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