This class holds all information about triggers of a table. More...

#include <table_trigger_dispatcher.h>

Inheritance diagram for Table_trigger_dispatcher:

Public Member Functions
bool	check_n_load (THD *thd, const dd::Table &table)
	Load triggers for the table. More...

bool	reorder_57_list (MEM_ROOT mem_root, List< Trigger > triggers)

	~Table_trigger_dispatcher () override

bool	check_for_broken_triggers ()
	Checks if there is a broken trigger for this table. More...

bool	create_trigger (THD thd, String binlog_create_trigger_stmt, bool if_not_exists, bool &already_exists)
	Create trigger for table. More...

bool	process_triggers (THD *thd, enum_trigger_event_type event, enum_trigger_action_time_type action_time, bool old_row_is_record1)
	Execute trigger for given (event, time) pair. More...

Trigger_chain *	get_triggers (int event, int action_time)

const Trigger_chain *	get_triggers (int event, int action_time) const

Trigger *	find_trigger (const LEX_STRING &trigger_name)
	Get trigger object by trigger name. More...

bool	has_triggers (enum_trigger_event_type event, enum_trigger_action_time_type action_time) const

bool	has_update_triggers () const

bool	has_delete_triggers () const

bool	mark_fields (enum_trigger_event_type event)
	Mark fields of subject table which we read/set in its triggers as such. More...

bool	add_tables_and_routines_for_triggers (THD thd, Query_tables_list prelocking_ctx, Table_ref *table_list)
	Add triggers for table to the set of routines used by statement. More...

void	enable_fields_temporary_nullability (THD *thd)
	Mark all trigger fields as "temporary nullable" and remember the current THD::check_for_truncated_fields value. More...

void	disable_fields_temporary_nullability ()
	Reset "temporary nullable" flag from trigger fields. More...

void	print_upgrade_warnings (THD *thd)
	Iterate along triggers and print necessary upgrade warnings. More...

void	parse_triggers (THD thd, List< Trigger > triggers, bool is_upgrade)
	Parse trigger definition statements (CREATE TRIGGER). More...

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

Static Public Member Functions
static Table_trigger_dispatcher *	create (TABLE *subject_table)
	Create an instance of Table_trigger_dispatcher for the given subject table. More...

Private Member Functions
	Table_trigger_dispatcher (TABLE *subject_table)
	Private form of Table_trigger_dispatcher constructor. More...

Trigger_chain *	create_trigger_chain (MEM_ROOT *mem_root, enum_trigger_event_type event, enum_trigger_action_time_type action_time)
	Make sure there is a chain for the specified event and action time. More...

bool	prepare_record1_accessors ()
	Prepare array of Field objects referencing to TABLE::record[1] instead of record<a href="they will represent OLD. More...

void	set_parse_error_message (const char *error_message)
	Remember a parse error that occurred while parsing trigger definitions loaded from the Data Dictionary. More...

TABLE *	get_subject_table () override

Field *	get_trigger_variable_field (enum_trigger_variable_type v, int field_index) override

Private Attributes
TABLE *	m_subject_table
	TABLE instance for which this triggers list object was created. More...

Trigger_chain *	m_trigger_map [TRG_EVENT_MAX][TRG_ACTION_MAX]
	Triggers grouped by event, action_time. More...

Field **	m_record1_field
	Copy of TABLE::Field array with field pointers set to TABLE::record[1] buffer instead of TABLE::record[0] (used for OLD values in on UPDATE trigger and DELETE trigger when it is called for REPLACE). More...

Field **	m_new_field
	During execution of trigger m_new_field and m_old_field should point to the array of fields representing new or old version of row correspondingly (so it can point to TABLE::field or to Table_trigger_dispatcher::m_record1_field). More...

Field **	m_old_field

bool	m_has_unparseable_trigger
	This flag indicates that one of the triggers was not parsed successfully, and as a precaution the object has entered the state where all trigger operations result in errors until all the table triggers are dropped. More...

char	m_parse_error_message [MYSQL_ERRMSG_SIZE]
	This error will be displayed when the user tries to manipulate or invoke triggers on a table that has broken triggers. More...

Detailed Description

This class holds all information about triggers of a table.

Constructor & Destructor Documentation

◆ Table_trigger_dispatcher()

Table_trigger_dispatcher::Table_trigger_dispatcher ( TABLE * subject_table )

private

Private form of Table_trigger_dispatcher constructor.

In order to construct an instance of Table_trigger_dispatcher with a valid pointer to the subject table, use Table_trigger_dispatcher::create().

◆ ~Table_trigger_dispatcher()

Table_trigger_dispatcher::~Table_trigger_dispatcher ( )

override

Member Function Documentation

◆ add_tables_and_routines_for_triggers()

bool Table_trigger_dispatcher::add_tables_and_routines_for_triggers	(	THD *	thd,
		Query_tables_list *	prelocking_ctx,
		Table_ref *	table_list
	)

Add triggers for table to the set of routines used by statement.

Add tables used by them to statement table list. Do the same for routines used by triggers.

Parameters

thd	Thread context.
prelocking_ctx	Prelocking context of the statement.
table_list	Table list element for table with trigger.

Returns: Operation status.

Return values

false	Success
true	Failure

◆ check_for_broken_triggers()

bool Table_trigger_dispatcher::check_for_broken_triggers ( )

inline

Checks if there is a broken trigger for this table.

Return values

false	if all triggers are Ok.
true	in case there is at least one broken trigger (a trigger which SQL-definition can not be parsed) for this table.

◆ check_n_load()

bool Table_trigger_dispatcher::check_n_load	(	THD *	thd,
		const dd::Table &	table
	)

Load triggers for the table.

Parameters

thd	current thread context
table	table object.

Returns: Operation status.

Return values

false	Success
true	Failure

◆ create()

Table_trigger_dispatcher * Table_trigger_dispatcher::create ( TABLE * subject_table )

static

Create an instance of Table_trigger_dispatcher for the given subject table.

Parameters

subject_table valid (not fake!) TABLE-object representing the subject table

Returns: a pointer to a new Table_trigger_dispatcher instance.

◆ create_trigger()

bool Table_trigger_dispatcher::create_trigger	(	THD *	thd,
		String *	binlog_create_trigger_stmt,
		bool	if_not_exists,
		bool &	already_exists
	)

Create trigger for table.

Parameters

	thd	Thread context
[out]	binlog_create_trigger_stmt	Well-formed CREATE TRIGGER statement for putting into binlog (after successful execution)
	if_not_exists	True if 'IF NOT EXISTS' clause was specified
[out]	already_exists	Set to true if trigger already exists on the same table

Note

Assumes that trigger name is fully qualified.
NULL-string means the following LEX_STRING instance: { str = 0; length = 0 }.
In other words, definer_user and definer_host should contain simultaneously NULL-strings (non-SUID/old trigger) or valid strings (SUID/new trigger).

Returns: Operation status.

Return values

false	Success
true	Failure

◆ create_trigger_chain()

Trigger_chain * Table_trigger_dispatcher::create_trigger_chain	(	MEM_ROOT *	mem_root,
		enum_trigger_event_type	event,
		enum_trigger_action_time_type	action_time
	)

private

Make sure there is a chain for the specified event and action time.

Returns: A pointer to newly created Trigger_chain object, NULL in case of OOM error.

◆ disable_fields_temporary_nullability()

void Table_trigger_dispatcher::disable_fields_temporary_nullability ( )

Reset "temporary nullable" flag from trigger fields.

◆ enable_fields_temporary_nullability()

void Table_trigger_dispatcher::enable_fields_temporary_nullability ( THD * thd )

Mark all trigger fields as "temporary nullable" and remember the current THD::check_for_truncated_fields value.

Parameters

thd	Thread context.

◆ find_trigger()

Trigger * Table_trigger_dispatcher::find_trigger ( const LEX_STRING & trigger_name )

Get trigger object by trigger name.

Parameters

[in] trigger_name trigger name

Returns: a pointer to Trigger object, NULL if the trigger not found.

◆ get_subject_table()

TABLE * Table_trigger_dispatcher::get_subject_table ( )

inlineoverrideprivatevirtual

Implements Table_trigger_field_support.

◆ get_trigger_variable_field()

Field * Table_trigger_dispatcher::get_trigger_variable_field	(	enum_trigger_variable_type	v,
		int	field_index
	)

inlineoverrideprivatevirtual

Implements Table_trigger_field_support.

◆ get_triggers() [1/2]

Trigger_chain * Table_trigger_dispatcher::get_triggers	(	int	event,
		int	action_time
	)

inline

◆ get_triggers() [2/2]

const Trigger_chain * Table_trigger_dispatcher::get_triggers	(	int	event,
		int	action_time
	)		const

inline

◆ has_delete_triggers()

bool Table_trigger_dispatcher::has_delete_triggers ( ) const

inline

◆ has_triggers()

bool Table_trigger_dispatcher::has_triggers	(	enum_trigger_event_type	event,
		enum_trigger_action_time_type	action_time
	)		const

inline

◆ has_update_triggers()

bool Table_trigger_dispatcher::has_update_triggers ( ) const

inline

◆ mark_fields()

bool Table_trigger_dispatcher::mark_fields ( enum_trigger_event_type event )

Mark fields of subject table which we read/set in its triggers as such.

This method marks fields of subject table which are read/set in its triggers as such (by properly updating TABLE::read_set/write_set) and thus informs handler that values for these fields should be retrieved/stored during execution of statement.

Parameters

event Type of event triggers for which we are going to inspect

Returns: false if success, true if error

◆ parse_triggers()

void Table_trigger_dispatcher::parse_triggers	(	THD *	thd,
		List< Trigger > *	triggers,
		bool	is_upgrade
	)

Parse trigger definition statements (CREATE TRIGGER).

Parameters

[in]	thd	Thread context
[in]	is_upgrade	Flag to indicate that trigger being parsed is read from .TRG file in case of upgrade.
[in]	triggers	List of triggers to parse

◆ prepare_record1_accessors()

bool Table_trigger_dispatcher::prepare_record1_accessors ( )

private

Prepare array of Field objects referencing to TABLE::record[1] instead of record<a href="they will represent OLD.

row values in ON UPDATE trigger and in ON DELETE trigger which will be called during REPLACE execution" >0.

Returns: Operation status.

Return values

false	Success
true	Failure

◆ print_upgrade_warnings()

void Table_trigger_dispatcher::print_upgrade_warnings ( THD * thd )

Iterate along triggers and print necessary upgrade warnings.

Now it prints the warning about missing 'CREATED' attribute.

Parameters

thd	Thread context.

◆ process_triggers()

bool Table_trigger_dispatcher::process_triggers	(	THD *	thd,
		enum_trigger_event_type	event,
		enum_trigger_action_time_type	action_time,
		bool	old_row_is_record1
	)

Execute trigger for given (event, time) pair.

The operation executes trigger for the specified event (insert, update, delete) and time (after, before) if it is set.

Parameters

thd	Thread handle
event	Insert, update or delete
action_time	Before or after
old_row_is_record1	If record1 contains old or new field.

Returns: Operation status.

Return values

false	Success
true	Failure

◆ reorder_57_list()

bool Table_trigger_dispatcher::reorder_57_list	(	MEM_ROOT *	mem_root,
		List< Trigger > *	triggers
	)

◆ set_parse_error_message()

void Table_trigger_dispatcher::set_parse_error_message ( const char * error_message )

inlineprivate

Remember a parse error that occurred while parsing trigger definitions loaded from the Data Dictionary.

This makes the Table_trigger_dispatcher enter the error state flagged by m_has_unparseable_trigger == true. The error message will be used whenever a statement invoking or manipulating triggers is issued against the Table_trigger_dispatcher's table.

Parameters

error_message The error message thrown by the parser.

Member Data Documentation

◆ m_has_unparseable_trigger

bool Table_trigger_dispatcher::m_has_unparseable_trigger

private

This flag indicates that one of the triggers was not parsed successfully, and as a precaution the object has entered the state where all trigger operations result in errors until all the table triggers are dropped.

It is not safe to add triggers since it is unknown if the broken trigger has the same name or event type. Nor is it safe to invoke any trigger. The only safe operations are drop_trigger() and drop_all_triggers().

We can't use the value of m_parse_error_message as a flag to inform that a trigger has a parse error since for multi-byte locale the first byte of message can be 0 but the message still be meaningful. It means that just a comparison against m_parse_error_message[0] can not be done safely.

See also: Table_trigger_dispatcher::set_parse_error()

◆ m_new_field

Field** Table_trigger_dispatcher::m_new_field

private

During execution of trigger m_new_field and m_old_field should point to the array of fields representing new or old version of row correspondingly (so it can point to TABLE::field or to Table_trigger_dispatcher::m_record1_field).

◆ m_old_field

Field** Table_trigger_dispatcher::m_old_field

private

◆ m_parse_error_message

char Table_trigger_dispatcher::m_parse_error_message[MYSQL_ERRMSG_SIZE]

private

This error will be displayed when the user tries to manipulate or invoke triggers on a table that has broken triggers.

It is set once per statement and thus will contain the first parse error encountered in the trigger file.

◆ m_record1_field

Field** Table_trigger_dispatcher::m_record1_field

private

Copy of TABLE::Field array with field pointers set to TABLE::record[1] buffer instead of TABLE::record[0] (used for OLD values in on UPDATE trigger and DELETE trigger when it is called for REPLACE).

◆ m_subject_table

TABLE* Table_trigger_dispatcher::m_subject_table

private

TABLE instance for which this triggers list object was created.

◆ m_trigger_map

Trigger_chain* Table_trigger_dispatcher::m_trigger_map[TRG_EVENT_MAX][TRG_ACTION_MAX]

private

Triggers grouped by event, action_time.

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

Public Member Functions

Static Public Member Functions

Private Member Functions

Private Attributes

Detailed Description

Constructor & Destructor Documentation

◆ Table_trigger_dispatcher()

◆ ~Table_trigger_dispatcher()

Member Function Documentation

◆ add_tables_and_routines_for_triggers()

◆ check_for_broken_triggers()

◆ check_n_load()

◆ create()

◆ create_trigger()

◆ create_trigger_chain()

◆ disable_fields_temporary_nullability()

◆ enable_fields_temporary_nullability()

◆ find_trigger()

◆ get_subject_table()

◆ get_trigger_variable_field()

◆ get_triggers() [1/2]

◆ get_triggers() [2/2]

◆ has_delete_triggers()

◆ has_triggers()

◆ has_update_triggers()

◆ mark_fields()

◆ parse_triggers()

◆ prepare_record1_accessors()

◆ print_upgrade_warnings()

◆ process_triggers()

◆ reorder_57_list()

◆ set_parse_error_message()

Member Data Documentation

◆ m_has_unparseable_trigger

◆ m_new_field

◆ m_old_field

◆ m_parse_error_message

◆ m_record1_field

◆ m_subject_table

◆ m_trigger_map