INFORMATION SCHEMA innodb_trx, innodb_locks and innodb_lock_waits tables cache structures and public functions. More...

#include <optional>
#include "dict0types.h"
#include "trx0types.h"
#include "univ.i"

Classes
struct	i_s_locks_row_t
	This structure represents INFORMATION_SCHEMA.innodb_locks row. More...

struct	i_s_trx_row_t
	This structure represents INFORMATION_SCHEMA.innodb_trx row. More...

Macros
#define	TRX_I_S_STRING_COPY(data, field, constraint, tcache)
	Safely copy strings in to the INNODB_TRX table's string based columns. More...

Enumerations
enum	i_s_table { I_S_INNODB_TRX }
	Auxiliary enum used by functions that need to select one of the INFORMATION_SCHEMA tables. More...

Functions
void	trx_i_s_cache_init (trx_i_s_cache_t *cache)
	Initialize INFORMATION SCHEMA trx related cache. More...

void	trx_i_s_cache_free (trx_i_s_cache_t *cache)
	Free the INFORMATION SCHEMA trx related cache. More...

void	trx_i_s_cache_start_read (trx_i_s_cache_t *cache)
	Issue a shared/read lock on the tables cache. More...

void	trx_i_s_cache_end_read (trx_i_s_cache_t *cache)
	Release a shared/read lock on the tables cache. More...

void	trx_i_s_cache_start_write (trx_i_s_cache_t *cache)
	Issue an exclusive/write lock on the tables cache. More...

void	trx_i_s_cache_end_write (trx_i_s_cache_t *cache)
	Release an exclusive/write lock on the tables cache. More...

ulint	trx_i_s_cache_get_rows_used (trx_i_s_cache_t *cache, enum i_s_table table)
	Retrieves the number of used rows in the cache for a given INFORMATION SCHEMA table. More...

void *	trx_i_s_cache_get_nth_row (trx_i_s_cache_t *cache, enum i_s_table table, ulint n)
	Retrieves the nth row in the cache for a given INFORMATION SCHEMA table. More...

int	trx_i_s_possibly_fetch_data_into_cache (trx_i_s_cache_t *cache)
	Update the transactions cache if it has not been read for some time. More...

bool	trx_i_s_cache_is_truncated (trx_i_s_cache_t *cache)
	Returns true if the data in the cache is truncated due to the memory limit posed by TRX_I_S_MEM_LIMIT. More...

char *	trx_i_s_create_lock_id (const i_s_locks_row_t &row, char *lock_id, size_t lock_id_size)
	Crafts a lock id string from a i_s_locks_row_t object. More...

void	p_s_fill_lock_data (const char *lock_data, const lock_t lock, ulint heap_no, PSI_server_data_lock_container *container)
	Fill performance schema lock data. More...

void	fill_locks_row (i_s_locks_row_t row, const lock_t lock, ulint heap_no)
	Fills i_s_locks_row_t object with data about the lock. More...

int	trx_i_s_parse_lock_id (const char lock_id, i_s_locks_row_t row)
	Parses lock id into row. More...

Variables
constexpr uint32_t	TRX_I_S_MEM_LIMIT = 16777216
	The maximum amount of memory that can be consumed by innodb_trx, innodb_locks and innodb_lock_waits information schema tables. More...

constexpr uint32_t	TRX_I_S_LOCK_DATA_MAX_LEN = 8192
	The maximum length of a string that can be stored in i_s_locks_row_t::lock_data. More...

constexpr uint32_t	TRX_I_S_TRX_QUERY_MAX_LEN = 1024
	The maximum length of a string that can be stored in i_s_trx_row_t::trx_query. More...

constexpr uint32_t	TRX_I_S_TRX_OP_STATE_MAX_LEN = 64
	The maximum length of a string that can be stored in i_s_trx_row_t::trx_operation_state. More...

constexpr uint32_t	TRX_I_S_TRX_FK_ERROR_MAX_LEN = 256
	The maximum length of a string that can be stored in i_s_trx_row_t::trx_foreign_key_error. More...

constexpr uint32_t	TRX_I_S_TRX_ISOLATION_LEVEL_MAX_LEN = 16
	The maximum length of a string that can be stored in i_s_trx_row_t::trx_isolation_level. More...

trx_i_s_cache_t *	trx_i_s_cache
	This is the intermediate buffer where data needed to fill the INFORMATION SCHEMA tables is fetched and later retrieved by the C++ code in handler/i_s.cc. More...

constexpr uint32_t	TRX_I_S_LOCK_ID_MAX_LEN = 20 * 6 + 5
	The maximum length of a resulting lock_id_size in trx_i_s_create_lock_id(), not including the terminating NUL. More...

Detailed Description

INFORMATION SCHEMA innodb_trx, innodb_locks and innodb_lock_waits tables cache structures and public functions.

Created July 17, 2007 Vasil Dimov

Macro Definition Documentation

◆ TRX_I_S_STRING_COPY

#define TRX_I_S_STRING_COPY	(	data,
		field,
		constraint,
		tcache
	)

Value:

  do {                                                                   \
    if (strlen(data) > constraint) {                                     \
      char buff[constraint + 1];                                         \
      strncpy(buff, data, constraint);                                   \
      buff[constraint] = '\0';                                           \
                                                                         \
      field = static_cast<const char *>(                                 \
          ha_storage_put_memlim((tcache)->storage, buff, constraint + 1, \
                                MAX_ALLOWED_FOR_STORAGE(tcache)));       \
    } else {                                                             \
      field = static_cast<const char *>(ha_storage_put_str_memlim(       \
          (tcache)->storage, data, MAX_ALLOWED_FOR_STORAGE(tcache)));    \
    }                                                                    \
  } while (0)

Safely copy strings in to the INNODB_TRX table's string based columns.

Enumeration Type Documentation

◆ i_s_table

enum i_s_table

Auxiliary enum used by functions that need to select one of the INFORMATION_SCHEMA tables.

Enumerator
I_S_INNODB_TRX	INFORMATION_SCHEMA.innodb_trx.

Function Documentation

◆ fill_locks_row()

void fill_locks_row	(	i_s_locks_row_t *	row,
		const lock_t *	lock,
		ulint	heap_no
	)

Fills i_s_locks_row_t object with data about the lock.

Parameters

[out]	row	Result object that's filled
[in]	lock	Lock to get data from
[in]	heap_no	Lock's record number or ULINT_UNDEFINED if the lock is a table lock

◆ p_s_fill_lock_data()

void p_s_fill_lock_data	(	const char **	lock_data,
		const lock_t *	lock,
		ulint	heap_no,
		PSI_server_data_lock_container *	container
	)

Fill performance schema lock data.

Create a string that represents the LOCK_DATA column, for a given lock record.

Parameters

[out]	lock_data	Lock data string
[in]	lock	Lock to inspect
[in]	heap_no	Lock heap number
[in]	container	Data container to fill

◆ trx_i_s_cache_end_read()

void trx_i_s_cache_end_read ( trx_i_s_cache_t * cache )

Release a shared/read lock on the tables cache.

in: cache

Parameters

cache in: cache

◆ trx_i_s_cache_end_write()

void trx_i_s_cache_end_write ( trx_i_s_cache_t * cache )

Release an exclusive/write lock on the tables cache.

in: cache

Parameters

cache in: cache

◆ trx_i_s_cache_free()

void trx_i_s_cache_free ( trx_i_s_cache_t * cache )

Free the INFORMATION SCHEMA trx related cache.

in/out: cache to free

Parameters

cache in, own: cache to free

◆ trx_i_s_cache_get_nth_row()

void * trx_i_s_cache_get_nth_row	(	trx_i_s_cache_t *	cache,
		enum i_s_table	table,
		ulint	n
	)

Retrieves the nth row in the cache for a given INFORMATION SCHEMA table.

Returns: row in: row number

Retrieves the nth row in the cache for a given INFORMATION SCHEMA table.

Returns: row

Parameters

cache	in: cache
table	in: which table
n	in: row number

◆ trx_i_s_cache_get_rows_used()

ulint trx_i_s_cache_get_rows_used	(	trx_i_s_cache_t *	cache,
		enum i_s_table	table
	)

Retrieves the number of used rows in the cache for a given INFORMATION SCHEMA table.

Returns: number of rows in: which table; number of rows

Parameters

cache	in: cache
table	in: which table

◆ trx_i_s_cache_init()

void trx_i_s_cache_init ( trx_i_s_cache_t * cache )

Initialize INFORMATION SCHEMA trx related cache.

out: cache to init

Parameters

cache out: cache to init

◆ trx_i_s_cache_is_truncated()

bool trx_i_s_cache_is_truncated ( trx_i_s_cache_t * cache )

Returns true if the data in the cache is truncated due to the memory limit posed by TRX_I_S_MEM_LIMIT.

Parameters

[in] cache The cache

Returns: true if truncated

◆ trx_i_s_cache_start_read()

void trx_i_s_cache_start_read ( trx_i_s_cache_t * cache )

Issue a shared/read lock on the tables cache.

in: cache

Parameters

cache in: cache

◆ trx_i_s_cache_start_write()

void trx_i_s_cache_start_write ( trx_i_s_cache_t * cache )

Issue an exclusive/write lock on the tables cache.

in: cache

Parameters

cache in: cache

◆ trx_i_s_create_lock_id()

char * trx_i_s_create_lock_id	(	const i_s_locks_row_t &	row,
		char *	lock_id,
		size_t	lock_id_size
	)

Crafts a lock id string from a i_s_locks_row_t object.

Returns its second argument. This function aborts if there is not enough space in lock_id. Be sure to provide at least TRX_I_S_LOCK_ID_MAX_LEN + 1 if you want to be 100% sure that it will not abort.

Parameters

[in]	row	The description of the lock sufficient to populate a row
[out]	lock_id	The buffer to store the resulting lock_id
[in]	lock_id_size	The size of the lock_id buffer

Returns: resulting lock id

◆ trx_i_s_parse_lock_id()

int trx_i_s_parse_lock_id	(	const char *	lock_id,
		i_s_locks_row_t *	row
	)

Parses lock id into row.

Parameters

[in]	lock_id	Lock id generated with trx_i_s_create_lock_id
[out]	row	Row to be filled in with data

Returns: LOCK_REC, LOCK_TABLE or 0 if failed to parse

◆ trx_i_s_possibly_fetch_data_into_cache()

int trx_i_s_possibly_fetch_data_into_cache ( trx_i_s_cache_t * cache )

Update the transactions cache if it has not been read for some time.

Returns: 0 - fetched, 1 - not in/out: cache

Called from handler/i_s.cc.

Returns: 0 - fetched, 1 - not

Parameters

cache in/out: cache

Variable Documentation

◆ trx_i_s_cache

trx_i_s_cache_t* trx_i_s_cache

extern

This is the intermediate buffer where data needed to fill the INFORMATION SCHEMA tables is fetched and later retrieved by the C++ code in handler/i_s.cc.

◆ TRX_I_S_LOCK_DATA_MAX_LEN

constexpr uint32_t TRX_I_S_LOCK_DATA_MAX_LEN = 8192

constexpr

The maximum length of a string that can be stored in i_s_locks_row_t::lock_data.

◆ TRX_I_S_LOCK_ID_MAX_LEN

constexpr uint32_t TRX_I_S_LOCK_ID_MAX_LEN = 20 * 6 + 5

constexpr

The maximum length of a resulting lock_id_size in trx_i_s_create_lock_id(), not including the terminating NUL.

"%lu:%lu:%lu:%lu:%lu:%lu" -> 20*6+5 chars

◆ TRX_I_S_MEM_LIMIT

constexpr uint32_t TRX_I_S_MEM_LIMIT = 16777216

constexpr

The maximum amount of memory that can be consumed by innodb_trx, innodb_locks and innodb_lock_waits information schema tables.

◆ TRX_I_S_TRX_FK_ERROR_MAX_LEN

constexpr uint32_t TRX_I_S_TRX_FK_ERROR_MAX_LEN = 256

constexpr

The maximum length of a string that can be stored in i_s_trx_row_t::trx_foreign_key_error.

◆ TRX_I_S_TRX_ISOLATION_LEVEL_MAX_LEN

constexpr uint32_t TRX_I_S_TRX_ISOLATION_LEVEL_MAX_LEN = 16

constexpr

The maximum length of a string that can be stored in i_s_trx_row_t::trx_isolation_level.

◆ TRX_I_S_TRX_OP_STATE_MAX_LEN

constexpr uint32_t TRX_I_S_TRX_OP_STATE_MAX_LEN = 64

constexpr

The maximum length of a string that can be stored in i_s_trx_row_t::trx_operation_state.

◆ TRX_I_S_TRX_QUERY_MAX_LEN

constexpr uint32_t TRX_I_S_TRX_QUERY_MAX_LEN = 1024

constexpr

The maximum length of a string that can be stored in i_s_trx_row_t::trx_query.

Classes

Macros

Enumerations

Functions

Variables

Detailed Description

Macro Definition Documentation

◆ TRX_I_S_STRING_COPY

Enumeration Type Documentation

◆ i_s_table

Function Documentation

◆ fill_locks_row()

◆ p_s_fill_lock_data()

◆ trx_i_s_cache_end_read()

◆ trx_i_s_cache_end_write()

◆ trx_i_s_cache_free()

◆ trx_i_s_cache_get_nth_row()

◆ trx_i_s_cache_get_rows_used()

◆ trx_i_s_cache_init()

◆ trx_i_s_cache_is_truncated()

◆ trx_i_s_cache_start_read()

◆ trx_i_s_cache_start_write()

◆ trx_i_s_create_lock_id()

◆ trx_i_s_parse_lock_id()

◆ trx_i_s_possibly_fetch_data_into_cache()

Variable Documentation

◆ trx_i_s_cache

◆ TRX_I_S_LOCK_DATA_MAX_LEN

◆ TRX_I_S_LOCK_ID_MAX_LEN

◆ TRX_I_S_MEM_LIMIT

◆ TRX_I_S_TRX_FK_ERROR_MAX_LEN

◆ TRX_I_S_TRX_ISOLATION_LEVEL_MAX_LEN

◆ TRX_I_S_TRX_OP_STATE_MAX_LEN

◆ TRX_I_S_TRX_QUERY_MAX_LEN