trx0rec.cc File Reference

Transaction undo log record. More...

#include "trx0rec.h"
#include <sys/types.h>
#include "fsp0fsp.h"
#include "mach0data.h"
#include "mtr0log.h"
#include "trx0undo.h"
#include "ut0dbg.h"
#include "dict0dict.h"
#include "fsp0sysspace.h"
#include "ha_prototypes.h"
#include "lob0index.h"
#include "lob0inf.h"
#include "lob0lob.h"
#include "que0que.h"
#include "read0read.h"
#include "row0ext.h"
#include "row0mysql.h"
#include "row0row.h"
#include "row0upd.h"
#include "trx0purge.h"
#include "trx0rseg.h"
#include "ut0mem.h"
#include "my_dbug.h"

Namespaces
namespace	dd
	The version of the current data dictionary table definitions.

Macros
#define	ATTRIB_USED_ONLY_IN_DEBUG

Functions
static void	trx_undof_page_add_undo_rec_log (page_t *undo_page, ulint old_free, ulint new_free, mtr_t *mtr)
	Writes the mtr log entry of the inserted undo log record on the undo log page. More...
const byte *	trx_undo_parse_add_undo_rec (const byte *ptr, const byte *end_ptr, page_t *page)
	Parses a redo log record of adding an undo log record. More...
static ulint	trx_undo_left (const page_t *page, const byte *ptr)
	Calculates the free space left for extending an undo log record. More...
size_t	trx_undo_max_free_space ()
	Get the max free space of undo log by assuming it's a fresh new page and the free space doesn't count for the undo log header too. More...
static ulint	trx_undo_page_set_next_prev_and_add (page_t *undo_page, byte *ptr, mtr_t *mtr)
	Set the next and previous pointers in the undo page for the undo record that was written to ptr. More...
bool	trx_undo_rec_is_multi_value (const byte *undo_rec)
	Decide if the following undo log record is a multi-value virtual column. More...
static byte *	trx_undo_log_v_idx (page_t *undo_page, const dict_table_t *table, ulint pos, byte *ptr, bool first_v_col)
	Write virtual column index info (index id and column position in index) to the undo log. More...
static const byte *	trx_undo_read_v_idx_low (const dict_table_t *table, const byte *ptr, ulint *col_pos)
	Read virtual column index from undo log, and verify the column is still indexed, and return its position. More...
const byte *	trx_undo_read_v_idx (const dict_table_t *table, const byte *ptr, bool first_v_col, bool *is_undo_log, ulint *field_no)
	Read virtual column index from undo log or online log if the log contains such info, and in the undo log case, verify the column is still indexed, and output its position. More...
static bool	trx_undo_store_multi_value (page_t *undo_page, const dfield_t *vfield, byte **ptr)
	Store the multi-value column information for undo log. More...
static bool	trx_undo_report_insert_virtual (page_t *undo_page, dict_table_t *table, const dtuple_t *row, byte **ptr)
	Reports in the undo log of an insert of virtual columns. More...
static ulint	trx_undo_page_report_insert (page_t *undo_page, trx_t *trx, dict_index_t *index, const dtuple_t *clust_entry, mtr_t *mtr)
	Reports in the undo log of an insert of a clustered index record. More...
const byte *	trx_undo_rec_get_pars (trx_undo_rec_t *undo_rec, ulint *type, ulint *cmpl_info, bool *updated_extern, undo_no_t *undo_no, table_id_t *table_id, type_cmpl_t &type_cmpl)
	Reads from an undo log record the general parameters. More...
table_id_t	trx_undo_rec_get_table_id (const trx_undo_rec_t *undo_rec)
	Reads from an undo log record the table ID. More...
const byte *	trx_undo_rec_get_multi_value (const byte *ptr, dfield_t *field, mem_heap_t *heap)
	Read from an undo log record of a multi-value virtual column. More...
const byte *	trx_undo_rec_get_col_val (const byte *ptr, const byte **field, ulint *len, ulint *orig_len)
	Read from an undo log record a non-virtual column value. More...
const byte *	trx_undo_rec_get_row_ref (const byte *ptr, dict_index_t *index, dtuple_t **ref, mem_heap_t *heap)
	Builds a row reference from an undo log record. More...
static const byte *	trx_undo_rec_skip_row_ref (const byte *ptr, const dict_index_t *index)
	Skips a row reference from an undo log record. More...
static byte *	trx_undo_page_fetch_ext (trx_t *trx, dict_index_t *index, byte *ext_buf, ulint prefix_len, const page_size_t &page_size, const byte *field, bool is_sdi, ulint *len)
	Fetch a prefix of an externally stored column, for writing to the undo log of an update or delete marking of a clustered index record. More...
static byte *	trx_undo_page_report_modify_ext_func (trx_t *trx, dict_index_t *index, byte *ptr, byte *ext_buf, ulint prefix_len, const page_size_t &page_size, const byte **field, ulint *len, bool is_sdi, spatial_status_t spatial_status)
	Writes to the undo log a prefix of an externally stored column. More...
static byte *	trx_undo_page_report_modify_ext (trx_t *trx, dict_index_t *index, byte *ptr, byte *ext_buf, ulint prefix_len, const page_size_t &page_size, const byte **field, ulint *len, bool is_sdi, spatial_status_t spatial_status)
static void	trx_undo_get_mbr_from_ext (trx_t *trx, dict_index_t *index, double *mbr, const page_size_t &page_size, const byte *field, ulint *len, const dd::Spatial_reference_system *srs)
	Get MBR from a Geometry column stored externally. More...
static const byte *	trx_undo_read_blob_update (const byte *undo_ptr, upd_field_t *uf, lob::undo_vers_t *lob_undo)
static byte *	trx_undo_report_blob_update (page_t *undo_page, dict_index_t *index, byte *undo_ptr, const byte *field, ulint flen, const upd_t *update, upd_field_t *fld, mtr_t *mtr)
	Write the partial update information about LOBs to the undo log record. More...
static ulint	trx_undo_page_report_modify (page_t *undo_page, trx_t *trx, dict_index_t *index, const rec_t *rec, const ulint *offsets, const upd_t *update, ulint cmpl_info, const dtuple_t *row, mtr_t *mtr)
	Reports in the undo log of an update or delete marking of a clustered index record. More...
const byte *	trx_undo_update_rec_get_sys_cols (const byte *ptr, trx_id_t *trx_id, roll_ptr_t *roll_ptr, ulint *info_bits)
	Reads from an undo log update record the system field values of the old version. More...
const byte *	trx_undo_update_rec_get_update (const byte *ptr, const dict_index_t *index, ulint type, trx_id_t trx_id, roll_ptr_t roll_ptr, ulint info_bits, mem_heap_t *heap, upd_t **upd, lob::undo_vers_t *lob_undo, type_cmpl_t &type_cmpl)
	Builds an update vector based on a remaining part of an undo log record. More...
const byte *	trx_undo_rec_get_partial_row (const byte *ptr, dict_index_t *index, dtuple_t **row, bool ignore_prefix, mem_heap_t *heap)
	Builds a partial row from an update undo log record, for purge. More...
static bool	trx_undo_erase_page_end (page_t *undo_page, mtr_t *mtr)
	Erases the unused undo log page end. More...
const byte *	trx_undo_parse_erase_page_end (const byte *ptr, const byte *end_ptr, page_t *page, mtr_t *mtr)
	Parses a redo log record of erasing of an undo page end. More...
dberr_t	trx_undo_report_row_operation (ulint flags, ulint op_type, que_thr_t *thr, dict_index_t *index, const dtuple_t *clust_entry, const upd_t *update, ulint cmpl_info, const rec_t *rec, const ulint *offsets, roll_ptr_t *roll_ptr)
	Writes information to an undo log about an insert, update, or a delete marking of a clustered index record. More...
static trx_undo_rec_t *	trx_undo_get_undo_rec_low (roll_ptr_t roll_ptr, mem_heap_t *heap, bool is_temp)
	Copies an undo record to heap. More...
static bool	trx_undo_get_undo_rec (roll_ptr_t roll_ptr, trx_id_t trx_id, mem_heap_t *heap, bool is_temp, const table_name_t &name, trx_undo_rec_t **undo_rec)
	Copies an undo record to heap. More...
bool	trx_undo_prev_version_build (const rec_t *index_rec, mtr_t *index_mtr, const rec_t *rec, const dict_index_t *const index, ulint *offsets, mem_heap_t *heap, rec_t **old_vers, mem_heap_t *v_heap, const dtuple_t **vrow, ulint v_status, lob::undo_vers_t *lob_undo)
	Build a previous version of a clustered index record. More...
void	trx_undo_read_v_cols (const dict_table_t *table, const byte *ptr, const dtuple_t *row, bool in_purge, bool online, const ulint *col_map, mem_heap_t *heap)
	Read virtual column value from undo log. More...

Variables
static const ulint	VIRTUAL_COL_UNDO_FORMAT_1 = 0xF1
	Virtual column undo log version. More...

Detailed Description

Transaction undo log record.

Created 3/26/1996 Heikki Tuuri

Macro Definition Documentation

ATTRIB_USED_ONLY_IN_DEBUG

#define ATTRIB_USED_ONLY_IN_DEBUG

Function Documentation

trx_undo_erase_page_end()

static bool trx_undo_erase_page_end ( page_t *  undo_page, mtr_t *  mtr  )

static

Erases the unused undo log page end.

Returns

true if the page contained something, false if it was empty

Parameters

undo_page	in/out: undo page whose end to erase
mtr	in/out: mini-transaction

trx_undo_get_mbr_from_ext()

static void trx_undo_get_mbr_from_ext ( trx_t *  trx, dict_index_t *  index, double *  mbr, const page_size_t &  page_size, const byte *  field, ulint *  len, const dd::Spatial_reference_system *  srs  )

static

Get MBR from a Geometry column stored externally.

Parameters

[in]	trx	transaction object
[in]	index	the clustered index object
[out]	mbr	MBR to fill
[in]	page_size	table pagesize
[in]	field	field contain the geometry data
[in,out]	len	length of field, in bytes
[in]	srs	Spatial reference system of R-tree.

trx_undo_get_undo_rec()

static bool trx_undo_get_undo_rec ( roll_ptr_t  roll_ptr, trx_id_t  trx_id, mem_heap_t *  heap, bool  is_temp, const table_name_t &  name, trx_undo_rec_t **  undo_rec  )

static

Copies an undo record to heap.

Parameters

[in]	roll_ptr	roll pointer to record
[in]	trx_id	id of the trx that generated the roll pointer: it points to an undo log of this transaction
[in]	heap	memory heap where copied
[in]	is_temp	true if temporary, no-redo rseg.
[in]	name	table name
[out]	undo_rec	own: copy of the record

Return values

true	if the undo log has been truncated and we cannot fetch the old version
false	if the undo log record is available NOTE: the caller must have latches on the clustered index page.

trx_undo_get_undo_rec_low()

static trx_undo_rec_t * trx_undo_get_undo_rec_low ( roll_ptr_t  roll_ptr, mem_heap_t *  heap, bool  is_temp  )

static

Copies an undo record to heap.

This function can be called if we know that the undo log record exists.

Returns

own: copy of the record

Parameters

roll_ptr	in: roll pointer to record
heap	in: memory heap where copied
is_temp	in: true if temp undo rec.

trx_undo_left()

static ulint trx_undo_left ( const page_t *  page, const byte *  ptr  )

inlinestatic

Calculates the free space left for extending an undo log record.

Returns

bytes left

Parameters

page	in: undo log page
ptr	in: pointer to page

trx_undo_log_v_idx()

static byte * trx_undo_log_v_idx ( page_t *  undo_page, const dict_table_t *  table, ulint  pos, byte *  ptr, bool  first_v_col  )

static

Write virtual column index info (index id and column position in index) to the undo log.

Parameters

[in,out]	undo_page	undo log page
[in]	table	the table
[in]	pos	the virtual column position
[in]	ptr	undo log record being written
[in]	first_v_col	whether this is the first virtual column which could start with a version marker

Returns

new undo log pointer

trx_undo_max_free_space()

size_t trx_undo_max_free_space

(

)

Get the max free space of undo log by assuming it's a fresh new page and the free space doesn't count for the undo log header too.

trx_undo_page_fetch_ext()

static byte * trx_undo_page_fetch_ext ( trx_t *  trx, dict_index_t *  index, byte *  ext_buf, ulint  prefix_len, const page_size_t &  page_size, const byte *  field, bool  is_sdi, ulint *  len  )

static

Fetch a prefix of an externally stored column, for writing to the undo log of an update or delete marking of a clustered index record.

Parameters

[in]	trx	transaction object
[in]	index	the clustered index object
[out]	ext_buf	buffer to hold the prefix data and BLOB pointer
[in]	prefix_len	prefix size to store in the undo log
[in]	page_size	page size
[in]	field	an externally stored column
[in]	is_sdi	true for SDI indexes
[in,out]	len	input: length of field; output: used length of ext_buf

Returns

ext_buf

trx_undo_page_report_insert()

static ulint trx_undo_page_report_insert ( page_t *  undo_page, trx_t *  trx, dict_index_t *  index, const dtuple_t *  clust_entry, mtr_t *  mtr  )

static

Reports in the undo log of an insert of a clustered index record.

Returns

offset of the inserted entry on the page if succeed, 0 if fail

Parameters

undo_page	in: undo log page
trx	in: transaction
index	in: clustered index
clust_entry	in: index entry which will be inserted to the clustered index
mtr	in: mtr

trx_undo_page_report_modify()

static ulint trx_undo_page_report_modify ( page_t *  undo_page, trx_t *  trx, dict_index_t *  index, const rec_t *  rec, const ulint *  offsets, const upd_t *  update, ulint  cmpl_info, const dtuple_t *  row, mtr_t *  mtr  )

static

Reports in the undo log of an update or delete marking of a clustered index record.

Returns

byte offset of the inserted undo log entry on the page if succeed, 0 if fail

Parameters

undo_page	in: undo log page
trx	in: transaction
index	in: clustered index where update or delete marking is done
rec	in: clustered index record which has NOT yet been modified
offsets	in: rec_get_offsets(rec, index)
update	in: update vector which tells the columns to be updated; in the case of a delete, this should be set to NULL
cmpl_info	in: compiler info on secondary index updates
row	in: clustered index row contains virtual column info
mtr	in: mtr

trx_undo_page_report_modify_ext()

static byte * trx_undo_page_report_modify_ext ( trx_t *  trx, dict_index_t *  index, byte *  ptr, byte *  ext_buf, ulint  prefix_len, const page_size_t &  page_size, const byte **  field, ulint *  len, bool  is_sdi, spatial_status_t  spatial_status  )

inlinestatic

trx_undo_page_report_modify_ext_func()

static byte * trx_undo_page_report_modify_ext_func ( trx_t *  trx, dict_index_t *  index, byte *  ptr, byte *  ext_buf, ulint  prefix_len, const page_size_t &  page_size, const byte **  field, ulint *  len, bool  is_sdi, spatial_status_t  spatial_status  )

static

Writes to the undo log a prefix of an externally stored column.

Parameters

[in]	trx	transaction object
[in]	index	the clustered index object
[out]	ptr	undo log position, at least 15 bytes must be available
[out]	ext_buf	a buffer of DICT_MAX_FIELD_LEN_BY_FORMAT() size, or NULL when should not fetch a longer prefix
[in]	prefix_len	prefix size to store in the undo log
[in]	page_size	page size
[in,out]	field	the locally stored part of the externally stored column
[in,out]	len	length of field, in bytes
[in]	is_sdi	true for SDI indexes
[in]	spatial_status	whether the column is used by spatial index or regular index

Returns

undo log position

trx_undo_page_set_next_prev_and_add()

static ulint trx_undo_page_set_next_prev_and_add ( page_t *  undo_page, byte *  ptr, mtr_t *  mtr  )

static

Set the next and previous pointers in the undo page for the undo record that was written to ptr.

Update the first free value by the number of bytes written for this undo record.

Returns

offset of the inserted entry on the page if succeeded, 0 if fail

< offset within undo_page

< offset within undo_page

Parameters

undo_page	in/out: undo log page
ptr	in: ptr up to where data has been written on this undo page.
mtr	in: mtr

trx_undo_parse_add_undo_rec()

const byte * trx_undo_parse_add_undo_rec	(	const byte *	ptr,
		const byte *	end_ptr,
		page_t *	page
	)

Parses a redo log record of adding an undo log record.

Returns

end of log record or NULL

Parameters

ptr	in: buffer
end_ptr	in: buffer end
page	in: page or NULL

trx_undo_parse_erase_page_end()

const byte * trx_undo_parse_erase_page_end	(	const byte *	ptr,
		const byte *	end_ptr,
		page_t *	page,
		mtr_t *	mtr
	)

Parses a redo log record of erasing of an undo page end.

Parameters

[in,out]	ptr	Buffer.
[in,out]	end_ptr	Buffer end.
[in,out]	page	Page or nullptr.
[in,out]	mtr	MTR or nullptr.

Returns

end of log record or nullptr

trx_undo_prev_version_build()

bool trx_undo_prev_version_build	(	const rec_t *	index_rec,
		mtr_t *	index_mtr,
		const rec_t *	rec,
		const dict_index_t *	index,
		ulint *	offsets,
		mem_heap_t *	heap,
		rec_t **	old_vers,
		mem_heap_t *	v_heap,
		const dtuple_t **	vrow,
		ulint	v_status,
		lob::undo_vers_t *	lob_undo
	)

Build a previous version of a clustered index record.

The caller must hold a latch on the index page of the clustered index record. If the vrow passed to this function is not null, then this function will store information about virtual columns from the requested version in vrow, unless the change did not affect any secondary index nor ordering field of clustered index (the change has UPD_NODE_NO_ORD_CHANGE flag) in which case the requested information can not be reconstructed from undo log, and the caller may assume that the (virtual) columns of secondary index have the same values they have in the more recent version (the one rec comes from). Equivalently, if the vrow is not returned, it is either because it was not requested, or not available due to UPD_NODE_NO_ORD_CHANGE. Obviously vrow is also not set in case rec is the oldest version in history, in which case we also set old_vers to NULL.

Parameters

[in]	index_rec	clustered index record in the index tree
[in]	index_mtr	mtr which contains the latch to index_rec page and purge_view
[in]	rec	version of a clustered index record
[in]	index	clustered index
[in,out]	offsets	rec_get_offsets(rec, index)
[in]	heap	memory heap from which the memory needed is allocated
[out]	old_vers	previous version, or NULL if rec is the first inserted version, or if history data has been deleted
[in]	v_heap	memory heap used to create vrow dtuple if it is not yet created. This heap diffs from "heap" above in that it could be prebuilt->old_vers_heap for selection
[out]	vrow	virtual column info, if any
[in]	v_status	status determine if it is going into this function by purge thread or not. And if we read "after image" of undo log has been rebuilt
[in]	lob_undo	LOB undo information.

Return values

true	if previous version was built, or if it was an insert or the table has been rebuilt
false	if the previous version is earlier than purge_view, or being purged, which means that it may have been removed

trx_undo_read_blob_update()

static const byte * trx_undo_read_blob_update ( const byte *  undo_ptr, upd_field_t *  uf, lob::undo_vers_t *  lob_undo  )

static

trx_undo_read_v_cols()

void trx_undo_read_v_cols	(	const dict_table_t *	table,
		const byte *	ptr,
		const dtuple_t *	row,
		bool	in_purge,
		bool	online,
		const ulint *	col_map,
		mem_heap_t *	heap
	)

Read virtual column value from undo log.

Parameters

[in]	table	the table
[in]	ptr	undo log pointer
[in,out]	row	the dtuple to fill
[in]	in_purge	called by purge thread
[in]	online	true if this is from online DDL log
[in]	col_map	online rebuild column map
[in,out]	heap	memory heap to keep value when necessary

trx_undo_read_v_idx()

const byte * trx_undo_read_v_idx	(	const dict_table_t *	table,
		const byte *	ptr,
		bool	first_v_col,
		bool *	is_undo_log,
		ulint *	field_no
	)

Read virtual column index from undo log or online log if the log contains such info, and in the undo log case, verify the column is still indexed, and output its position.

Parameters

[in]	table	the table
[in]	ptr	undo log pointer
[in]	first_v_col	if this is the first virtual column, which has the version marker
[in,out]	is_undo_log	this function is used to parse both undo log, and online log for virtual columns. So check to see if this is undo log. When first_v_col is true, is_undo_log is output, when first_v_col is false, is_undo_log is input
[in,out]	field_no	the column number

Returns

remaining part of undo log record after reading these values

trx_undo_read_v_idx_low()

static const byte * trx_undo_read_v_idx_low ( const dict_table_t *  table, const byte *  ptr, ulint *  col_pos  )

static

Read virtual column index from undo log, and verify the column is still indexed, and return its position.

Parameters

[in]	table	the table
[in]	ptr	undo log pointer
[out]	col_pos	the column number or ULINT_UNDEFINED if the column is not indexed any more

Returns

remaining part of undo log record after reading these values

trx_undo_rec_get_col_val()

const byte * trx_undo_rec_get_col_val	(	const byte *	ptr,
		const byte **	field,
		ulint *	len,
		ulint *	orig_len
	)

Read from an undo log record a non-virtual column value.

Parameters

[in,out]	ptr	pointer to remaining part of the undo record
[in,out]	field	stored field
[in,out]	len	length of the field, or UNIV_SQL_NULL
[in,out]	orig_len	original length of the locally stored part of an externally stored column, or 0

Returns

remaining part of undo log record after reading these values

trx_undo_rec_get_multi_value()

const byte * trx_undo_rec_get_multi_value	(	const byte *	ptr,
		dfield_t *	field,
		mem_heap_t *	heap
	)

Read from an undo log record of a multi-value virtual column.

Parameters

[in]	ptr	pointer to remaining part of the undo record
[in,out]	field	stored field, nullptr if the col is no longer indexed or existing, in the latter case, this function will only skip the log
[in,out]	heap	memory heap

Returns

remaining part of undo log record after reading these values

trx_undo_rec_get_pars()

const byte * trx_undo_rec_get_pars	(	trx_undo_rec_t *	undo_rec,
		ulint *	type,
		ulint *	cmpl_info,
		bool *	updated_extern,
		undo_no_t *	undo_no,
		table_id_t *	table_id,
		type_cmpl_t &	type_cmpl
	)

Reads from an undo log record the general parameters.

Returns

remaining part of undo log record after reading these values

Parameters

undo_rec	in: undo log record
type	out: undo record type: TRX_UNDO_INSERT_REC, ...
cmpl_info	out: compiler info, relevant only for update type records
updated_extern	out: true if we updated an externally stored fild
undo_no	out: undo log record number
table_id	out: table id
type_cmpl	out: type compilation info

trx_undo_rec_get_partial_row()

const byte * trx_undo_rec_get_partial_row	(	const byte *	ptr,
		dict_index_t *	index,
		dtuple_t **	row,
		bool	ignore_prefix,
		mem_heap_t *	heap
	)

Builds a partial row from an update undo log record, for purge.

It contains the columns which occur as ordering in any index of the table. Any missing columns are indicated by col->mtype == DATA_MISSING.

Returns

pointer to remaining part of undo record

Parameters

ptr	in: remaining part in update undo log record of a suitable type, at the start of the stored index columns; NOTE that this copy of the undo log record must be preserved as long as the partial row is used, as we do NOT copy the data in the record!
index	in: clustered index
row	out, own: partial row
ignore_prefix	in: flag to indicate if we expect blob prefixes in undo. Used only in the assertion.
heap	in: memory heap from which the memory needed is allocated

trx_undo_rec_get_row_ref()

const byte * trx_undo_rec_get_row_ref	(	const byte *	ptr,
		dict_index_t *	index,
		dtuple_t **	ref,
		mem_heap_t *	heap
	)

Builds a row reference from an undo log record.

Returns

pointer to remaining part of undo record

Parameters

ptr	in: remaining part of a copy of an undo log record, at the start of the row reference; NOTE that this copy of the undo log record must be preserved as long as the row reference is used, as we do NOT copy the data in the record!
index	in: clustered index
ref	out, own: row reference
heap	in: memory heap from which the memory needed is allocated

trx_undo_rec_get_table_id()

table_id_t trx_undo_rec_get_table_id

(

const trx_undo_rec_t *

undo_rec

)

Reads from an undo log record the table ID.

Parameters

[in]

undo_rec

Undo log record

Returns

the table ID

trx_undo_rec_is_multi_value()

bool trx_undo_rec_is_multi_value

(

const byte *

undo_rec

)

Decide if the following undo log record is a multi-value virtual column.

Parameters

[in]

undo_rec

undo log record

Returns

true if this is a multi-value virtual column log, otherwise false

trx_undo_rec_skip_row_ref()

static const byte * trx_undo_rec_skip_row_ref ( const byte *  ptr, const dict_index_t *  index  )

static

Skips a row reference from an undo log record.

Returns

pointer to remaining part of undo record

Parameters

ptr	in: remaining part in update undo log record, at the start of the row reference
index	in: clustered index

trx_undo_report_blob_update()

static byte * trx_undo_report_blob_update ( page_t *  undo_page, dict_index_t *  index, byte *  undo_ptr, const byte *  field, ulint  flen, const upd_t *  update, upd_field_t *  fld, mtr_t *  mtr  )

static

Write the partial update information about LOBs to the undo log record.

Parameters

[in]	undo_page	the undo page
[in]	index	the clustered index where LOBs are modified.
[in]	undo_ptr	the location within undo page where next part of undo record is to be written.
[in]	field	the LOB data
[in]	flen	length of LOB data in bytes
[in]	update	the update vector containing partial update information on LOBs.
[in]	fld	the field to which the LOB belongs.
[in]	mtr	the mini-transaction context.

Returns

the undo record pointer where new data can be written.

nullptr when there is not enough space in undo page.

trx_undo_report_insert_virtual()

static bool trx_undo_report_insert_virtual ( page_t *  undo_page, dict_table_t *  table, const dtuple_t *  row, byte **  ptr  )

static

Reports in the undo log of an insert of virtual columns.

Parameters

[in]	undo_page	undo log page
[in]	table	the table
[in]	row	dtuple contains the virtual columns
[in,out]	ptr	log ptr

Returns

true if write goes well, false if out of space

trx_undo_report_row_operation()

dberr_t trx_undo_report_row_operation	(	ulint	flags,
		ulint	op_type,
		que_thr_t *	thr,
		dict_index_t *	index,
		const dtuple_t *	clust_entry,
		const upd_t *	update,
		ulint	cmpl_info,
		const rec_t *	rec,
		const ulint *	offsets,
		roll_ptr_t *	roll_ptr
	)

Writes information to an undo log about an insert, update, or a delete marking of a clustered index record.

This information is used in a rollback of the transaction and in consistent reads that must look to the history of this transaction.

Returns

DB_SUCCESS or error code

Parameters

flags	in: if BTR_NO_UNDO_LOG_FLAG bit is set, does nothing
op_type	in: TRX_UNDO_INSERT_OP or TRX_UNDO_MODIFY_OP
thr	in: query thread
index	in: clustered index
clust_entry	in: in the case of an insert, index entry to insert into the clustered index, otherwise NULL
update	in: in the case of an update, the update vector, otherwise NULL
cmpl_info	in: compiler info on secondary index updates
rec	in: in case of an update or delete marking, the record in the clustered index, otherwise NULL
offsets	in: rec_get_offsets(rec)
roll_ptr	out: rollback pointer to the inserted undo log record, 0 if BTR_NO_UNDO_LOG flag was specified

trx_undo_store_multi_value()

static bool trx_undo_store_multi_value ( page_t *  undo_page, const dfield_t *  vfield, byte **  ptr  )

static

Store the multi-value column information for undo log.

Parameters

[in,out]	undo_page	undo page to store the information
[in]	vfield	multi-value field information
[in,out]	ptr	pointer where to store the information

Returns

true if stored successfully, false if space is not enough

trx_undo_update_rec_get_sys_cols()

const byte * trx_undo_update_rec_get_sys_cols	(	const byte *	ptr,
		trx_id_t *	trx_id,
		roll_ptr_t *	roll_ptr,
		ulint *	info_bits
	)

Reads from an undo log update record the system field values of the old version.

Returns

remaining part of undo log record after reading these values

Parameters

ptr	in: remaining part of undo log record after reading general parameters
trx_id	out: trx id
roll_ptr	out: roll ptr
info_bits	out: info bits state

trx_undo_update_rec_get_update()

const byte * trx_undo_update_rec_get_update	(	const byte *	ptr,
		const dict_index_t *	index,
		ulint	type,
		trx_id_t	trx_id,
		roll_ptr_t	roll_ptr,
		ulint	info_bits,
		mem_heap_t *	heap,
		upd_t **	upd,
		lob::undo_vers_t *	lob_undo,
		type_cmpl_t &	type_cmpl
	)

Builds an update vector based on a remaining part of an undo log record.

Parameters

[in]	ptr	Remaining part in update undo log record, after reading the row reference. NOTE that this copy of the undo log record must be preserved as long as the update vector is used, as we do NOT copy the data in the record!
[in]	index	Clustered index.
[in]	type	TRX_UNDO_UPD_EXIST_REC, TRX_UNDO_UPD_DEL_REC, or TRX_UNDO_DEL_MARK_REC; in the last case, only trx id and roll ptr fields are added to the update vector.
[in]	trx_id	Transaction id from this undo record.
[in]	roll_ptr	Roll pointer from this undo record.
[in]	info_bits	Info bits from this undo record.
[in]	heap	Memory heap from which the memory needed is allocated.
[out]	upd	Update vector.
[out]	lob_undo	LOB undo information.
[out]	type_cmpl	Type compilation info.

Returns

remaining part of the record, NULL if an error detected, which means that the record is corrupted.

trx_undof_page_add_undo_rec_log()

static void trx_undof_page_add_undo_rec_log ( page_t *  undo_page, ulint  old_free, ulint  new_free, mtr_t *  mtr  )

inlinestatic

Writes the mtr log entry of the inserted undo log record on the undo log page.

Parameters

undo_page	in: undo log page
old_free	in: start offset of the inserted entry
new_free	in: end offset of the entry
mtr	in: mtr

Variable Documentation

VIRTUAL_COL_UNDO_FORMAT_1

const ulint VIRTUAL_COL_UNDO_FORMAT_1 = 0xF1

static

Virtual column undo log version.

To distinguish it from a length value in 5.7.8 undo log, it starts with 0xF1