Transaction undo log. More...

#include "data0type.h"
#include "page0page.h"
#include "trx0purge.h"

Functions
roll_ptr_t	trx_undo_build_roll_ptr (bool is_insert, space_id_t space_id, page_no_t page_no, ulint offset)
	Build a roll pointer. More...

void	trx_undo_decode_roll_ptr (roll_ptr_t roll_ptr, bool is_insert, ulint rseg_id, page_no_t page_no, ulint offset)
	Decodes a roll pointer. More...

static bool	trx_undo_roll_ptr_is_insert (roll_ptr_t roll_ptr)
	Returns true if the roll pointer is of the insert type. More...

static bool	trx_undo_trx_id_is_insert (const byte *trx_id)
	Returns true if the record is of the insert type. More...

static void	trx_write_roll_ptr (byte *ptr, roll_ptr_t roll_ptr)
	Writes a roll ptr to an index page. More...

static roll_ptr_t	trx_read_roll_ptr (const byte *ptr)
	Reads a roll ptr from an index page. More...

static page_t *	trx_undo_page_get (const page_id_t &page_id, const page_size_t &page_size, mtr_t *mtr)
	Gets an undo log page and x-latches it. More...

static page_t *	trx_undo_page_get_s_latched (const page_id_t &page_id, const page_size_t &page_size, mtr_t *mtr)
	Gets an undo log page and s-latches it. More...

static ulint	trx_undo_page_get_start (page_t *undo_page, page_no_t page_no, ulint offset)
	Returns the start offset of the undo log records of the specified undo log on the page. More...

static ulint	trx_undo_page_get_end (page_t *undo_page, page_no_t page_no, ulint offset)
	Returns the end offset of the undo log records of the specified undo log on the page. More...

static trx_undo_rec_t *	trx_undo_page_get_prev_rec (trx_undo_rec_t *rec, page_no_t page_no, ulint offset)
	Returns the previous undo record on the page in the specified log, or NULL if none exists. More...

static trx_undo_rec_t *	trx_undo_page_get_next_rec (trx_undo_rec_t *rec, page_no_t page_no, ulint offset)
	Returns the next undo log record on the page in the specified log, or NULL if none exists. More...

static trx_undo_rec_t *	trx_undo_page_get_last_rec (page_t *undo_page, page_no_t page_no, ulint offset)
	Returns the last undo record on the page in the specified undo log, or NULL if none exists. More...

static trx_undo_rec_t *	trx_undo_page_get_first_rec (page_t *undo_page, page_no_t page_no, ulint offset)
	Returns the first undo record on the page in the specified undo log, or NULL if none exists. More...

Detailed Description

Transaction undo log.

Created 3/26/1996 Heikki Tuuri

Function Documentation

◆ trx_read_roll_ptr()

static roll_ptr_t trx_read_roll_ptr ( const byte * ptr )

inlinestatic

Reads a roll ptr from an index page.

In case that the roll ptr size changes in some future version, this function should be used instead of mach_read_...

Returns: roll ptr

Parameters

ptr	in: pointer to memory from where to read

◆ trx_undo_build_roll_ptr()

roll_ptr_t trx_undo_build_roll_ptr	(	bool	is_insert,
		space_id_t	space_id,
		page_no_t	page_no,
		ulint	offset
	)

inline

Build a roll pointer.

Parameters

[in]	is_insert	true if insert undo log
[in]	space_id	space ID of the rollback segment
[in]	page_no	page number
[in]	offset	offset of the undo entry within page

Returns: roll pointer

◆ trx_undo_decode_roll_ptr()

void trx_undo_decode_roll_ptr	(	roll_ptr_t	roll_ptr,
		bool *	is_insert,
		ulint *	rseg_id,
		page_no_t *	page_no,
		ulint *	offset
	)

inline

Decodes a roll pointer.

Parameters

roll_ptr	in: roll pointer
is_insert	out: true if insert undo log
rseg_id	out: rollback segment id
page_no	out: page number
offset	out: offset of the undo entry within page

◆ trx_undo_page_get()

static page_t * trx_undo_page_get	(	const page_id_t &	page_id,
		const page_size_t &	page_size,
		mtr_t *	mtr
	)

inlinestatic

Gets an undo log page and x-latches it.

Parameters

[in]	page_id	Page id
[in]	page_size	Page size
[in,out]	mtr	Mini-transaction

Returns: pointer to page x-latched

◆ trx_undo_page_get_end()

static ulint trx_undo_page_get_end	(	page_t *	undo_page,
		page_no_t	page_no,
		ulint	offset
	)

inlinestatic

Returns the end offset of the undo log records of the specified undo log on the page.

Returns: end offset

Parameters

undo_page	in: undo log page
page_no	in: undo log header page number
offset	in: undo log header offset on page

◆ trx_undo_page_get_first_rec()

static trx_undo_rec_t * trx_undo_page_get_first_rec	(	page_t *	undo_page,
		page_no_t	page_no,
		ulint	offset
	)

inlinestatic

Returns the first undo record on the page in the specified undo log, or NULL if none exists.

Returns: pointer to record, NULL if none

Parameters

undo_page	in: undo log page
page_no	in: undo log header page number
offset	in: undo log header offset on page

◆ trx_undo_page_get_last_rec()

static trx_undo_rec_t * trx_undo_page_get_last_rec	(	page_t *	undo_page,
		page_no_t	page_no,
		ulint	offset
	)

inlinestatic

Returns the last undo record on the page in the specified undo log, or NULL if none exists.

Returns: pointer to record, NULL if none

Parameters

undo_page	in: undo log page
page_no	in: undo log header page number
offset	in: undo log header offset on page

◆ trx_undo_page_get_next_rec()

static trx_undo_rec_t * trx_undo_page_get_next_rec	(	trx_undo_rec_t *	rec,
		page_no_t	page_no,
		ulint	offset
	)

inlinestatic

Returns the next undo log record on the page in the specified log, or NULL if none exists.

Returns: pointer to record, NULL if none

Parameters

rec	in: undo log record
page_no	in: undo log header page number
offset	in: undo log header offset on page

◆ trx_undo_page_get_prev_rec()

static trx_undo_rec_t * trx_undo_page_get_prev_rec	(	trx_undo_rec_t *	rec,
		page_no_t	page_no,
		ulint	offset
	)

inlinestatic

Returns the previous undo record on the page in the specified log, or NULL if none exists.

Returns: pointer to record, NULL if none

Parameters

rec	in: undo log record
page_no	in: undo log header page number
offset	in: undo log header offset on page

◆ trx_undo_page_get_s_latched()

static page_t * trx_undo_page_get_s_latched	(	const page_id_t &	page_id,
		const page_size_t &	page_size,
		mtr_t *	mtr
	)

inlinestatic

Gets an undo log page and s-latches it.

Parameters

[in]	page_id	Page id
[in]	page_size	Page size
[in,out]	mtr	Mini-transaction

Returns: pointer to page s-latched

◆ trx_undo_page_get_start()

static ulint trx_undo_page_get_start	(	page_t *	undo_page,
		page_no_t	page_no,
		ulint	offset
	)

inlinestatic

Returns the start offset of the undo log records of the specified undo log on the page.

Returns: start offset

Parameters

undo_page	in: undo log page
page_no	in: undo log header page number
offset	in: undo log header offset on page

◆ trx_undo_roll_ptr_is_insert()

static bool trx_undo_roll_ptr_is_insert ( roll_ptr_t roll_ptr )

inlinestatic

Returns true if the roll pointer is of the insert type.

Returns: true if insert undo log

Parameters

roll_ptr in: roll pointer

◆ trx_undo_trx_id_is_insert()

static bool trx_undo_trx_id_is_insert ( const byte * trx_id )

inlinestatic

Returns true if the record is of the insert type.

Returns: true if the record was freshly inserted (not updated).

Parameters

trx_id in: DB_TRX_ID, followed by DB_ROLL_PTR

◆ trx_write_roll_ptr()

static void trx_write_roll_ptr	(	byte *	ptr,
		roll_ptr_t	roll_ptr
	)

inlinestatic

Writes a roll ptr to an index page.

In case that the size changes in some future version, this function should be used instead of mach_write_...

Parameters

ptr	in: pointer to memory where written
roll_ptr	in: roll ptr

Functions

Detailed Description

Function Documentation

◆ trx_read_roll_ptr()

◆ trx_undo_build_roll_ptr()

◆ trx_undo_decode_roll_ptr()

◆ trx_undo_page_get()

◆ trx_undo_page_get_end()

◆ trx_undo_page_get_first_rec()

◆ trx_undo_page_get_last_rec()

◆ trx_undo_page_get_next_rec()

◆ trx_undo_page_get_prev_rec()

◆ trx_undo_page_get_s_latched()

◆ trx_undo_page_get_start()

◆ trx_undo_roll_ptr_is_insert()

◆ trx_undo_trx_id_is_insert()

◆ trx_write_roll_ptr()