temptable::Cell_calculator Class Reference

Utility to perform calculations for a cell. More...

#include <cell_calculator.h>

Public Member Functions
	Cell_calculator ()=default
	Default constructor used for std::array initialization in Index. More...
	Cell_calculator (const KEY_PART_INFO &mysql_key_part)
	Constructor to be used when creating calculators for indexed columns. More...
	Cell_calculator (const Field *mysql_field)
	Constructor to be used when creating calculators for columns when comparing table rows. More...
size_t	hash (const Cell &cell) const
	Calculate hash value for a cell. More...
int	compare (const Cell &lhs, const Cell &rhs) const
	Compare two cells. More...

Private Types
enum class	Mode : uint8_t { BINARY , CHARSET , CHARSET_AND_CHAR_LENGTH }

Static Private Member Functions
static const CHARSET_INFO *	field_charset (const Field &field)
static size_t	zero_hash ()
	Convenience function to get the hash value of 0.0. More...

Private Attributes
const Field *	m_mysql_field
	Field for which this calculator was created. More...
const CHARSET_INFO *	m_cs
	Charset used by calculator. More...
Mode	m_mode
	Calculation mode. More...
bool	m_is_floating_point
	True if the key is of type double or float. More...
bool	m_is_space_padded
	True if the cell is right-padded with spaces (CHAR column). More...
uint32_t	m_char_length
	Length in number of characters. More...

Static Private Attributes
static const size_t	s_zero_hash = Cell_calculator::zero_hash()
	This value is to be used for hashing 0 value for approximate types such as float or double. More...

Detailed Description

Utility to perform calculations for a cell.

It uses cell's contents and a stored context that describes how to interpret the data.

Member Enumeration Documentation

Mode

enum class temptable::Cell_calculator::Mode : uint8_t

strongprivate

Enumerator
BINARY
CHARSET
CHARSET_AND_CHAR_LENGTH

Constructor & Destructor Documentation

Cell_calculator() [1/3]

temptable::Cell_calculator::Cell_calculator ( )

default

Default constructor used for std::array initialization in Index.

Cell_calculator() [2/3]

temptable::Cell_calculator::Cell_calculator ( const KEY_PART_INFO &  mysql_key_part )

inlineexplicit

Constructor to be used when creating calculators for indexed columns.

Parameters

[in]

mysql_key_part

Key part (indexed column) for which calculator is created.

Cell_calculator() [3/3]

temptable::Cell_calculator::Cell_calculator ( const Field *  mysql_field )

inlineexplicit

Constructor to be used when creating calculators for columns when comparing table rows.

Parameters

[in]

mysql_field

Field (column) for which calculator is created.

Member Function Documentation

compare()

int temptable::Cell_calculator::compare ( const Cell &  lhs, const Cell &  rhs  ) const

inline

Compare two cells.

Return values

<0	if lhs < rhs
0	if lhs == rhs
>0	if lhs > rhs

Parameters

[in]	lhs	First cell to compare.
[in]	rhs	Second cell to compare.

field_charset()

const CHARSET_INFO * temptable::Cell_calculator::field_charset ( const Field &  field )

inlinestaticprivate

hash()

size_t temptable::Cell_calculator::hash ( const Cell &  cell ) const

inline

Calculate hash value for a cell.

Returns

a hash number

Parameters

[in]

cell

Cell for which hash is to be calculated.

zero_hash()

size_t temptable::Cell_calculator::zero_hash ( )

inlinestaticprivate

Convenience function to get the hash value of 0.0.

Member Data Documentation

m_char_length

uint32_t temptable::Cell_calculator::m_char_length

private

Length in number of characters.

Only used in CHARSET_AND_CHAR_LENGTH mode.

m_cs

const CHARSET_INFO* temptable::Cell_calculator::m_cs

private

Charset used by calculator.

NULL for binary mode.

m_is_floating_point

bool temptable::Cell_calculator::m_is_floating_point

private

True if the key is of type double or float.

m_is_space_padded

bool temptable::Cell_calculator::m_is_space_padded

private

True if the cell is right-padded with spaces (CHAR column).

m_mode

Mode temptable::Cell_calculator::m_mode

private

Calculation mode.

m_mysql_field

const Field* temptable::Cell_calculator::m_mysql_field

private

Field for which this calculator was created.

s_zero_hash

const size_t temptable::Cell_calculator::s_zero_hash = Cell_calculator::zero_hash()

staticprivate

This value is to be used for hashing 0 value for approximate types such as float or double.

Specifically, for such types we don't want to have separate hash entries for 0.0 and -0.0.

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

• storage/temptable/include/temptable/cell_calculator.h
• storage/temptable/src/row.cc