Public Member Functions
bool	open_table (THD thd, const LEX_STRING dbstr, const LEX_STRING tbstr, uint max_num_field, enum thr_lock_type lock_type, TABLE table, Open_tables_backup backup)
bool	close_table (THD thd, TABLE table, Open_tables_backup *backup, bool error)
enum enum_return_id	find_info (Rpl_info_values field_values, TABLE table)
enum enum_return_id	scan_info (TABLE *table, uint instance)
bool	count_info (TABLE table, uint counter)
bool	load_info_values (uint max_num_field, Field *fields, Rpl_info_values field_values)
bool	store_info_values (uint max_num_field, Field *fields, Rpl_info_values field_values)
THD *	create_thd ()
bool	drop_thd (THD *thd)

Member Function Documentation

bool Rpl_info_table_access::close_table	(	THD *	thd,
		TABLE *	table,
		Open_tables_backup *	backup,
		bool	error
	)

Commits the changes, unlocks the table and closes it. This method needs to be called even if the open_table fails, in order to ensure the lock info is properly restored.

Parameters:

[in]	thd	Thread requesting to close the table
[in]	table	Table to be closed
[in]	backup	Restore the lock info from here
[in]	error	If there was an error while updating the table

If there is an error, rolls back the current statement. Otherwise, commits it. However, if a new thread was created and there is an error, the transaction must be rolled back. Otherwise, it must be committed. In this case, the changes were not done on behalf of any user transaction and if not finished, there would be pending changes.

Returns:

Return values:

FALSE	No error
TRUE	Failure

bool Rpl_info_table_access::count_info	(	TABLE *	table,
		uint *	counter
	)

Returns the number of entries in table.

The code built on top of this function needs to ensure there is no concurrent threads trying to update the table. So if an error different from HA_ERR_END_OF_FILE is returned, we abort with an error because this implies that someone has manualy and concurrently changed something.

Parameters:

[in]	table	Table
[out]	counter	Registers the number of entries.

Returns:

Return values:

false	No error
true	Failure

THD * Rpl_info_table_access::create_thd ( )

Creates a new thread if necessary. In the bootstrap process or in the mysqld startup, a thread is created in order to be able to access a table. Otherwise, the current thread is used.

Returns:

Return values:

THD*	Pointer to thread structure

bool Rpl_info_table_access::drop_thd ( THD * thd )

Destroys the created thread if necessary and restores the system_thread information.

Parameters:

[in] thd Thread requesting to be destroyed

Returns:

Return values:

FALSE	No error
TRUE	Failure

enum enum_return_id Rpl_info_table_access::find_info	(	Rpl_info_values *	field_values,
		TABLE *	table
	)

Positions the internal pointer of `table` according to the primary key.

If the search succeeds, the table cursor points to the found row.

Parameters:

[in,out]	field_values	The sequence of values
[in,out]	table	Table

Returns:

Return values:

FOUND	The row was found.
NOT_FOUND	The row was not found.
ERROR	There was a failure.

bool Rpl_info_table_access::load_info_values	(	uint	max_num_field,
		Field **	fields,
		Rpl_info_values *	field_values
	)

Reads information from a sequence of fields into a set of LEX_STRING structures, where the sequence of values is specified through the object Rpl_info_values.

Parameters:

[in]	max_num_field	Maximum number of fields
[in]	fields	The sequence of fields
[in]	field_values	The sequence of values

Returns:

Return values:

FALSE	No error
TRUE	Failure

bool Rpl_info_table_access::open_table	(	THD *	thd,
		const LEX_STRING	dbstr,
		const LEX_STRING	tbstr,
		uint	max_num_field,
		enum thr_lock_type	lock_type,
		TABLE **	table,
		Open_tables_backup *	backup
	)

Opens and locks a table.

It's assumed that the caller knows what they are doing:

whether it was necessary to reset-and-backup the open tables state
whether the requested lock does not lead to a deadlock
whether this open mode would work under LOCK TABLES, or inside a stored function or trigger.

Note that if the table can't be locked successfully this operation will close it. Therefore it provides guarantee that it either opens and locks table or fails without leaving any tables open.

Parameters:

[in]	thd	Thread requesting to open the table
[in]	dbstr	Database where the table resides
[in]	tbstr	Table to be openned
[in]	max_num_field	Maximum number of fields
[in]	lock_type	How to lock the table
[out]	table	We will store the open table here
[out]	backup	Save the lock info. here

Returns:

Return values:

TRUE	open and lock failed - an error message is pushed into the stack
FALSE	success

enum enum_return_id Rpl_info_table_access::scan_info	(	TABLE *	table,
		uint	instance
	)

Positions the internal pointer of `table` to the n-instance row.

Parameters:

[in]	table	Reference to a table object.
[in]	instance	n-instance row.

The code built on top of this function needs to ensure there is no concurrent threads trying to update the table. So if an error different from HA_ERR_END_OF_FILE is returned, we abort with an error because this implies that someone has manualy and concurrently changed something.

Returns:

Return values:

FOUND	The row was found.
NOT_FOUND	The row was not found.
ERROR	There was a failure.

bool Rpl_info_table_access::store_info_values	(	uint	max_num_field,
		Field **	fields,
		Rpl_info_values *	field_values
	)

Stores information from a sequence of fields into a set of LEX_STRING structures, where the sequence of values is specified through the object Rpl_info_values.

Parameters:

[in]	max_num_field	Maximum number of fields
[in]	fields	The sequence of fields
[in]	field_values	The sequence of values

Returns:

Return values:

FALSE	No error
TRUE	Failure

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

rpl_info_table_access.h
rpl_info_table_access.cc

Public Member Functions

Member Function Documentation