#include <rpl_info_table_access.h>

Inheritance diagram for Rpl_info_table_access:

Public Member Functions
	Rpl_info_table_access ()

	~Rpl_info_table_access () override=default

void	before_open (THD *thd) override
	Prepares before opening table. More...

bool	close_table (THD thd, TABLE table, Open_tables_backup *backup, bool error)
	Commits the changes, unlocks the table and closes it. More...

enum enum_return_id	find_info (Rpl_info_values field_values, TABLE table)
	Positions the internal pointer of `table` according to the primary key. More...

enum enum_return_id	scan_info (TABLE *table, uint instance)
	Positions the internal pointer of `table` to the n-instance row. More...

std::pair< bool, bool >	is_table_in_use (TABLE *table)
	Returns if the table is being used, meaning it contains at least a line or some concurrency related error was returned when looking at the table. More...

bool	count_info (TABLE table, ulonglong counter)
	Returns the number of entries in table. More...

bool	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. More...

bool	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. More...

THD *	create_thd ()
	Creates a new thread if necessary. More...

void	drop_thd (THD *thd)
	Destroys the created thread if necessary and restores the system_thread information. More...

Public Member Functions inherited from System_table_access
virtual	~System_table_access ()=default

bool	open_table (THD thd, const LEX_CSTRING dbstr, const LEX_CSTRING tbstr, uint max_num_field, enum thr_lock_type lock_type, TABLE table, Open_tables_backup backup)
	Opens and locks a system table. More...

bool	open_table (THD thd, std::string dbstr, std::string tbstr, uint max_num_field, enum thr_lock_type lock_type, TABLE table, Open_tables_backup backup)
	Opens and locks a system table. More...

bool	close_table (THD thd, TABLE table, Open_tables_backup *backup, bool error, bool need_commit)
	Commits the changes, unlocks the table and closes it. More...

THD *	create_thd ()
	Creates a new thread in the bootstrap process or in the mysqld startup, a thread is created in order to be able to access a table. More...

void	drop_thd (THD *thd)
	Destroys the created thread and restores the system_thread information. More...

Private Member Functions
Rpl_info_table_access &	operator= (const Rpl_info_table_access &info)

	Rpl_info_table_access (const Rpl_info_table_access &info)

Private Attributes
bool	thd_created

Additional Inherited Members
Public Attributes inherited from System_table_access
uint	m_flags

Constructor & Destructor Documentation

◆ Rpl_info_table_access() [1/2]

Rpl_info_table_access::Rpl_info_table_access ( )

inline

◆ ~Rpl_info_table_access()

Rpl_info_table_access::~Rpl_info_table_access ( )

overridedefault

◆ Rpl_info_table_access() [2/2]

Rpl_info_table_access::Rpl_info_table_access ( const Rpl_info_table_access & info )

private

Member Function Documentation

◆ before_open()

void Rpl_info_table_access::before_open ( THD * thd )

overridevirtual

Prepares before opening table.

set flags
start lex and reset the part of THD responsible for the state of command processing if needed.

Parameters

[in] thd Thread requesting to open the table

Implements System_table_access.

◆ close_table()

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.

Return values

false	Success
true	Failure

◆ count_info()

bool Rpl_info_table_access::count_info	(	TABLE *	table,
		ulonglong *	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 access the table. So if an error different from HA_ERR_END_OF_FILE is returned, an error is returned meaning the count failed cause a deadlock or other issue was found

Parameters

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

Return values

false	No error
true	Failure

◆ create_thd()

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: THD* Pointer to thread structure

◆ drop_thd()

void 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

◆ find_info()

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

Return values

FOUND_ID	The row was found.
NOT_FOUND_ID	The row was not found.
ERROR_ID	There was a failure.

◆ is_table_in_use()

std::pair< bool, bool > Rpl_info_table_access::is_table_in_use ( TABLE * table )

Returns if the table is being used, meaning it contains at least a line or some concurrency related error was returned when looking at the table.

Parameters

[in] table Table

Return values

a	pair of booleans First element is true if an error occurred, false otherwise. Second element is true if the table is not empty or an access error occurred meaning someone else is accessing it. False if the table is empty.

◆ load_info_values()

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

Return values

false	No error
true	Failure

◆ operator=()

Rpl_info_table_access & Rpl_info_table_access::operator= ( const Rpl_info_table_access & info )

private

◆ scan_info()

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 manually and concurrently changed something.

Return values

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

◆ store_info_values()

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

Return values

false	No error
true	Failure

Member Data Documentation

◆ thd_created

bool Rpl_info_table_access::thd_created

private

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

sql/rpl_info_table_access.h
sql/rpl_info_table_access.cc

Public Member Functions

Private Member Functions

Private Attributes

Additional Inherited Members

Constructor & Destructor Documentation

◆ Rpl_info_table_access() [1/2]

◆ ~Rpl_info_table_access()

◆ Rpl_info_table_access() [2/2]

Member Function Documentation

◆ before_open()

◆ close_table()

◆ count_info()

◆ create_thd()

◆ drop_thd()

◆ find_info()

◆ is_table_in_use()

◆ load_info_values()

◆ operator=()

◆ scan_info()

◆ store_info_values()

Member Data Documentation

◆ thd_created