A column class that describes the metadata of a column. More...

#include <column.h>

Public Member Functions
	Column (const unsigned char *mysql_row, const TABLE &mysql_table TEMPTABLE_UNUSED_NODBUG, const Field &mysql_field)
	Constructor. More...

bool	read_is_null (const unsigned char *mysql_row) const
	Check if a particular cell is NULL. More...

void	write_is_null (bool is_null, unsigned char *mysql_row, size_t mysql_row_length) const
	Write the information that cell is NULL or not. More...

uint32_t	read_user_data_length (const unsigned char *mysql_row) const
	In MySQL write_row() format - the length of the actual user data of a cell in a given row. More...

void	write_user_data_length (uint32_t data_length, unsigned char *mysql_row, size_t mysql_row_length) const
	Write the length of user data stored in a cell. More...

const unsigned char *	get_user_data_ptr (const unsigned char *mysql_row) const
	Return pointer to user data in MySQL row. More...

void	read_user_data (unsigned char data, uint32_t data_length, const unsigned char mysql_row, size_t mysql_row_length) const
	Reads user data stored in a cell. More...

void	write_user_data (bool is_null, const unsigned char data, uint32_t data_length, unsigned char mysql_row, size_t mysql_row_length) const
	Write user data stored in a cell. More...

Private Member Functions
bool	is_nullable () const
	Check if the cells in this column can be NULL. More...

bool	is_blob () const
	Check this column stores blobs. More...

bool	is_fixed_size () const
	Check if different cells that belong to this column can have different size (eg VARCHAR). More...

void	read_std_user_data (unsigned char data, uint32_t data_length, const unsigned char mysql_row, size_t mysql_row_length TEMPTABLE_UNUSED_NODBUG) const
	Reads user data stored in a cell. More...

void	write_std_user_data (const unsigned char data, uint32_t data_length, unsigned char mysql_row, size_t mysql_row_length TEMPTABLE_UNUSED_NODBUG) const
	Write user data stored in a cell. More...

void	read_blob_user_data (unsigned char data, uint32_t data_length, const unsigned char mysql_row, size_t mysql_row_length TEMPTABLE_UNUSED_NODBUG) const
	Reads user data stored in a cell for columns stored as BLOBs. More...

void	write_blob_user_data (const unsigned char data, uint32_t data_length, unsigned char mysql_row, size_t mysql_row_length TEMPTABLE_UNUSED_NODBUG) const
	Write user data stored in a cell for columns stored as BLOBs. More...

const unsigned char *	calculate_user_data_ptr (const unsigned char *mysql_row) const
	Calculate pointer to user data in a MySQL row. More...

const unsigned char *	read_blob_data_ptr (const unsigned char *mysql_row) const
	Reads pointer to user data for a column stored as BLOB. More...

Private Attributes
bool	m_nullable
	True if can be NULL. More...

bool	m_is_blob
	True if it is a blob. More...

uint8_t	m_null_bitmask
	Bitmask to extract is is-NULL bit from the is-NULL byte. More...

uint8_t	m_length_bytes_size
	The number of bytes that indicate the length of the user data in the cell, for variable sized cells. More...

union {
uint32_t m_length
	Length of the user data of a cell. More...

uint32_t m_offset
	Offset of the bytes that indicate the user data length of a cell. More...

};

uint32_t	m_null_byte_offset
	The offset of the is-NULL byte from the start of the mysql row. More...

uint32_t	m_user_data_offset
	The offset of the user data from the start of the mysql row in bytes. More...

Detailed Description

A column class that describes the metadata of a column.

Constructor & Destructor Documentation

◆ Column()

temptable::Column::Column	(	const unsigned char *	mysql_row,
		const TABLE &mysql_table	TEMPTABLE_UNUSED_NODBUG,
		const Field &	mysql_field
	)

Constructor.

Parameters

[in]	mysql_row	A pointer to the row (user data).
[in]	TEMPTABLE_UNUSED_NODBUG	MySQL table that contains the column.
[in]	mysql_field	MySQL field (column/cell) that describes the columns.

Member Function Documentation

◆ calculate_user_data_ptr()

const unsigned char * temptable::Column::calculate_user_data_ptr ( const unsigned char * mysql_row ) const

inlineprivate

Calculate pointer to user data in a MySQL row.

Cannot be used for columns stored as BLOBs.

Returns: Pointer to user data stored in a cell.

Parameters

[in] mysql_row MySQL row buffer that stores the user data.

◆ get_user_data_ptr()

const unsigned char * temptable::Column::get_user_data_ptr ( const unsigned char * mysql_row ) const

inline

Return pointer to user data in MySQL row.

Returns: Pointer to user data.

◆ is_blob()

bool temptable::Column::is_blob ( ) const

inlineprivate

Check this column stores blobs.

Returns: true if it is a blob column.

◆ is_fixed_size()

bool temptable::Column::is_fixed_size ( ) const

inlineprivate

Check if different cells that belong to this column can have different size (eg VARCHAR).

Returns: true if all cells are the same size

◆ is_nullable()

bool temptable::Column::is_nullable ( ) const

inlineprivate

Check if the cells in this column can be NULL.

Returns: true if cells are allowed to be NULL.

◆ read_blob_data_ptr()

const unsigned char * temptable::Column::read_blob_data_ptr ( const unsigned char * mysql_row ) const

inlineprivate

Reads pointer to user data for a column stored as BLOB.

Returns: Pointer to user data stored in a BLOB field.

Parameters

[in] mysql_row MySQL row buffer that stores BLOB data pointer.

◆ read_blob_user_data()

void temptable::Column::read_blob_user_data	(	unsigned char *	data,
		uint32_t	data_length,
		const unsigned char *	mysql_row,
		size_t mysql_row_length	TEMPTABLE_UNUSED_NODBUG
	)		const

inlineprivate

Reads user data stored in a cell for columns stored as BLOBs.

Performs a deep copy of the data.

Parameters

[out]	data	Pointer to store user data.
[out]	data_length	Length of the data to read.
[in]	mysql_row	MySQL row buffer to read data from.
[in]	TEMPTABLE_UNUSED_NODBUG	Length of the row buffer.

◆ read_is_null()

bool temptable::Column::read_is_null ( const unsigned char * mysql_row ) const

inline

Check if a particular cell is NULL.

The cell is the intersection of this column with the provided row (in MySQL write_row() format).

Returns: true if the cell is NULL

Parameters

[in] mysql_row MySQL row that contains the cell to be checked.

◆ read_std_user_data()

void temptable::Column::read_std_user_data	(	unsigned char *	data,
		uint32_t	data_length,
		const unsigned char *	mysql_row,
		size_t mysql_row_length	TEMPTABLE_UNUSED_NODBUG
	)		const

inlineprivate

Reads user data stored in a cell.

Cannot be used for columns stored as BLOBs. Performs a deep copy of the data.

Parameters

[out]	data	Pointer to store user data.
[out]	data_length	Length of the data to read.
[in]	mysql_row	MySQL row buffer to read data from.
[in]	TEMPTABLE_UNUSED_NODBUG	Length of the row buffer.

◆ read_user_data()

void temptable::Column::read_user_data	(	unsigned char *	data,
		uint32_t	data_length,
		const unsigned char *	mysql_row,
		size_t	mysql_row_length
	)		const

inline

Reads user data stored in a cell.

Cannot be used for columns stored as BLOBs. Performs a deep copy of the data.

Parameters

[out]	data	Pointer to store user data.
[out]	data_length	Length of the data to read.
[in]	mysql_row	MySQL row buffer to read data from.
[in]	mysql_row_length	Length of the row buffer.

◆ read_user_data_length()

uint32_t temptable::Column::read_user_data_length ( const unsigned char * mysql_row ) const

inline

In MySQL write_row() format - the length of the actual user data of a cell in a given row.

Returns: user data length of the cell that corresponds to this column in the given row

Parameters

[in] mysql_row MySQL row buffer to read data from.

◆ write_blob_user_data()

void temptable::Column::write_blob_user_data	(	const unsigned char *	data,
		uint32_t data_length	TEMPTABLE_UNUSED,
		unsigned char *	mysql_row,
		size_t mysql_row_length	TEMPTABLE_UNUSED_NODBUG
	)		const

inlineprivate

Write user data stored in a cell for columns stored as BLOBs.

NOTE: Currently only pointer is stored, no data is copied and the length is ignored.

Parameters

[in]	data	Pointer to user data. Can be NULL for cells with NULL value.
[in]	TEMPTABLE_UNUSED	Length of user data.
[out]	mysql_row	MySQL row buffer to write data into.
[in]	TEMPTABLE_UNUSED_NODBUG	Length of the row buffer.

◆ write_is_null()

void temptable::Column::write_is_null	(	bool	is_null,
		unsigned char *	mysql_row,
		size_t mysql_row_length	TEMPTABLE_UNUSED_NODBUG
	)		const

inline

Write the information that cell is NULL or not.

Parameters

[in]	is_null	True if cell is NULL, false if it has value.
[out]	mysql_row	MySQL row buffer to write data into.
[in]	TEMPTABLE_UNUSED_NODBUG	Length of the row buffer.

◆ write_std_user_data()

void temptable::Column::write_std_user_data	(	const unsigned char *	data,
		uint32_t	data_length,
		unsigned char *	mysql_row,
		size_t mysql_row_length	TEMPTABLE_UNUSED_NODBUG
	)		const

inlineprivate

Write user data stored in a cell.

Cannot be used for columns stored as blobs.

Parameters

[in]	data	Pointer to used data.
[in]	data_length	Length of user data.
[out]	mysql_row	MySQL row buffer to write data into.
[in]	TEMPTABLE_UNUSED_NODBUG	Length of the row buffer.

◆ write_user_data()

void temptable::Column::write_user_data	(	bool	is_null,
		const unsigned char *	data,
		uint32_t	data_length,
		unsigned char *	mysql_row,
		size_t	mysql_row_length
	)		const

inline

Write user data stored in a cell.

Cannot be used for columns stored as blobs.

Parameters

[in]	is_null	True if cell is NULL, false if it has value.
[in]	data	Pointer to used data.
[in]	data_length	Length of user data.
[out]	mysql_row	MySQL row buffer to write data into.
[in]	mysql_row_length	Length of the row buffer.

◆ write_user_data_length()

void temptable::Column::write_user_data_length	(	uint32_t	data_length,
		unsigned char *	mysql_row,
		size_t mysql_row_length	TEMPTABLE_UNUSED_NODBUG
	)		const

inline

Write the length of user data stored in a cell.

Parameters

[in]	data_length	User data length.
[out]	mysql_row	MySQL row buffer to write data into.
[in]	TEMPTABLE_UNUSED_NODBUG	Length of the row buffer.

Member Data Documentation

◆

union { ... } temptable::Column::@200

◆ m_is_blob

bool temptable::Column::m_is_blob

private

True if it is a blob.

◆ m_length

uint32_t temptable::Column::m_length

Length of the user data of a cell.

It is for fixed size cells (when m_length_bytes_size == 0).

◆ m_length_bytes_size

uint8_t temptable::Column::m_length_bytes_size

private

The number of bytes that indicate the length of the user data in the cell, for variable sized cells.

If this is 0, then the cell is fixed size.

◆ m_null_bitmask

uint8_t temptable::Column::m_null_bitmask

private

Bitmask to extract is is-NULL bit from the is-NULL byte.

◆ m_null_byte_offset

uint32_t temptable::Column::m_null_byte_offset

private

The offset of the is-NULL byte from the start of the mysql row.

If m_null_bitmask is set in this byte and m_nullable is true, then that particular cell is NULL.

◆ m_nullable

bool temptable::Column::m_nullable

private

True if can be NULL.

◆ m_offset

uint32_t temptable::Column::m_offset

Offset of the bytes that indicate the user data length of a cell.

It is used for variable size cells (when m_length_bytes_size > 0).

◆ m_user_data_offset

uint32_t temptable::Column::m_user_data_offset

private

The offset of the user data from the start of the mysql row in bytes.

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

storage/temptable/include/temptable/column.h
storage/temptable/src/column.cc

Public Member Functions

Private Member Functions

Private Attributes

Detailed Description

Constructor & Destructor Documentation

◆ Column()

Member Function Documentation

◆ calculate_user_data_ptr()

◆ get_user_data_ptr()

◆ is_blob()

◆ is_fixed_size()

◆ is_nullable()

◆ read_blob_data_ptr()

◆ read_blob_user_data()

◆ read_is_null()

◆ read_std_user_data()

◆ read_user_data()

◆ read_user_data_length()

◆ write_blob_user_data()

◆ write_is_null()

◆ write_std_user_data()

◆ write_user_data()

◆ write_user_data_length()

Member Data Documentation

◆

◆ m_is_blob

◆ m_length

◆ m_length_bytes_size

◆ m_null_bitmask

◆ m_null_byte_offset

◆ m_nullable

◆ m_offset

◆ m_user_data_offset