#include <sp_rcontext.h>

Classes
class	Handler_call_frame
	This class represents a call frame of SQL-handler (one invocation of a handler). More...

class	sp_handler_entry
	This is an auxiliary class to store entering instruction pointer for an SQL-handler. More...

Public Member Functions
	~sp_rcontext ()

bool	set_variable (THD thd, bool standalone, uint var_idx, Item *value)

Item *	get_item (uint var_idx) const

Item **	get_item_addr (uint var_idx) const

Field *	get_return_field () const

bool	set_return_value (THD thd, bool standalone, Item *return_value_item)

bool	is_return_value_set () const

bool	push_handler (sp_handler *handler, uint first_ip)
	Create a new sp_handler_entry instance and push it to the handler call stack. More...

void	pop_handlers (sp_pcontext *current_scope)
	Pop and delete given number of sp_handler_entry instances from the handler call stack. More...

Handler_call_frame *	current_handler_frame () const
	Get the Handler_call_frame representing the currently active handler. More...

bool	handle_sql_condition (THD thd, uint ip, const sp_instr *cur_spi)
	Handle current SQL condition (if any). More...

void	exit_handler (THD thd, sp_pcontext target_scope)
	Handle return from SQL-handler. More...

uint	get_last_handler_continue_ip () const

bool	push_cursor (sp_instr_cpush *i)
	Create a new sp_cursor instance and push it to the cursor stack. More...

void	pop_cursors (uint count)
	Pop and delete given number of sp_cursor instance from the cursor stack. More...

void	pop_all_cursors ()

sp_cursor *	get_cursor (uint i) const

bool	set_case_expr (THD thd, bool standalone, int case_expr_id, Item *case_expr_item_ptr)
	Set CASE expression to the specified value. More...

Item *	get_case_expr (int case_expr_id) const

Item **	get_case_expr_addr (int case_expr_id) const

Static Public Member Functions
static sp_rcontext *	create (THD thd, const sp_pcontext root_parsing_ctx, Field *return_value_fld)
	Construct and properly initialize a new sp_rcontext instance. More...

Public Attributes
Query_arena *	callers_arena
	Arena used to (re) allocate items on. More...

bool	end_partial_result_set
	Flag to end an open result set before start executing an SQL-handler (if one is found). More...

sp_head *	sp
	The stored program for which this runtime context is created. More...

Private Member Functions
	sp_rcontext (const sp_pcontext root_parsing_ctx, Field return_value_fld, bool in_sub_stmt)

	sp_rcontext (const sp_rcontext &)

void	operator= (sp_rcontext &)

bool	alloc_arrays (THD *thd)
	Internal function to allocate memory for arrays. More...

bool	init_var_table (THD *thd)
	Create and initialize a table to store SP-variables. More...

bool	init_var_items (THD *thd)
	Create and initialize an Item-adapter (Item_field) for each SP-var field. More...

Item_cache *	create_case_expr_holder (THD thd, const Item item) const
	Create an instance of appropriate Item_cache class depending on the specified type in the callers arena. More...

bool	set_variable (THD thd, bool standalone, Field field, Item **value)

void	pop_handler_frame (THD *thd)
	Pop the Handler_call_frame on top of the stack of active handlers. More...

Private Attributes
const sp_pcontext *	m_root_parsing_ctx
	Top-level (root) parsing context for this runtime context. More...

TABLE *	m_var_table
	Virtual table for storing SP-variables. More...

Bounds_checked_array< Item * >	m_var_items
	Collection of Item_field proxies, each of them points to the corresponding field in m_var_table. More...

Field *	m_return_value_fld
	This is a pointer to a field, which should contain return value for stored functions (only). More...

bool	m_return_value_set
	Indicates whether the return value (in m_return_value_fld) has been set during execution. More...

bool	m_in_sub_stmt
	Flag to tell if the runtime context is created for a sub-statement. More...

Prealloced_array< sp_handler_entry *, 16 >	m_visible_handlers
	Stack of visible handlers. More...

Prealloced_array< Handler_call_frame *, 16 >	m_activated_handlers
	Stack of caught SQL conditions. More...

Bounds_checked_array< sp_cursor * >	m_cstack
	Stack of cursors. More...

uint	m_ccount
	Current number of cursors in m_cstack. More...

Bounds_checked_array< Item_cache * >	m_case_expr_holders
	Array of CASE expression holders. More...

Constructor & Destructor Documentation

◆ ~sp_rcontext()

sp_rcontext::~sp_rcontext ( )

◆ sp_rcontext() [1/2]

sp_rcontext::sp_rcontext	(	const sp_pcontext *	root_parsing_ctx,
		Field *	return_value_fld,
		bool	in_sub_stmt
	)

private

◆ sp_rcontext() [2/2]

sp_rcontext::sp_rcontext ( const sp_rcontext & )

private

Member Function Documentation

◆ alloc_arrays()

bool sp_rcontext::alloc_arrays ( THD * thd )

private

Internal function to allocate memory for arrays.

Parameters

thd	Thread handle.

Returns: error flag: false on success, true in case of failure.

◆ create()

sp_rcontext * sp_rcontext::create	(	THD *	thd,
		const sp_pcontext *	root_parsing_ctx,
		Field *	return_value_fld
	)

static

Construct and properly initialize a new sp_rcontext instance.

The static create-function is needed because we need a way to return an error from the constructor.

Parameters

thd	Thread handle.
root_parsing_ctx	Top-level parsing context for this stored program.
return_value_fld	Field object to store the return value (for stored functions only).

Returns: valid sp_rcontext object or NULL in case of OOM-error.

◆ create_case_expr_holder()

Item_cache * sp_rcontext::create_case_expr_holder	(	THD *	thd,
		const Item *	item
	)		const

private

Create an instance of appropriate Item_cache class depending on the specified type in the callers arena.

Note: We should create cache items in the callers arena, as they are used between in several instructions.

Parameters

thd	Thread handler.
item	Item to get the expression type.

Returns: Pointer to valid object on success, or NULL in case of error.

◆ current_handler_frame()

Handler_call_frame * sp_rcontext::current_handler_frame ( ) const

inline

Get the Handler_call_frame representing the currently active handler.

◆ exit_handler()

void sp_rcontext::exit_handler	(	THD *	thd,
		sp_pcontext *	target_scope
	)

Handle return from SQL-handler.

Parameters

thd	Thread handle.
target_scope	The BEGIN..END block, containing the target (next) instruction.

◆ get_case_expr()

Item * sp_rcontext::get_case_expr ( int case_expr_id ) const

inline

◆ get_case_expr_addr()

Item ** sp_rcontext::get_case_expr_addr ( int case_expr_id ) const

inline

◆ get_cursor()

sp_cursor * sp_rcontext::get_cursor ( uint i ) const

inline

◆ get_item()

Item * sp_rcontext::get_item ( uint var_idx ) const

inline

◆ get_item_addr()

Item ** sp_rcontext::get_item_addr ( uint var_idx ) const

inline

◆ get_last_handler_continue_ip()

uint sp_rcontext::get_last_handler_continue_ip ( ) const

inline

Returns: the continue instruction pointer of the last activated CONTINUE handler. This function must not be called for the EXIT handlers.

◆ get_return_field()

Field * sp_rcontext::get_return_field ( ) const

inline

◆ handle_sql_condition()

bool sp_rcontext::handle_sql_condition	(	THD *	thd,
		uint *	ip,
		const sp_instr *	cur_spi
	)

Handle current SQL condition (if any).

This is the public-interface function to handle SQL conditions in stored routines.

Parameters

	thd	Thread handle.
[out]	ip	Instruction pointer to the first handler instruction.
	cur_spi	Current SP instruction.

Return values

true	if an SQL-handler has been activated. That means, all of the following conditions are satisfied: the SP-instruction raised SQL-condition(s), and there is an SQL-handler to process at least one of those SQL-conditions, and that SQL-handler has been activated. Note, that the return value has nothing to do with "error flag" semantics.
false	otherwise.

◆ init_var_items()

bool sp_rcontext::init_var_items ( THD * thd )

private

Create and initialize an Item-adapter (Item_field) for each SP-var field.

param thd Thread handle.

Returns: error flag.

Return values

false	on success.
true	on error.

◆ init_var_table()

bool sp_rcontext::init_var_table ( THD * thd )

private

Create and initialize a table to store SP-variables.

param thd Thread handle.

Returns: error flag.

Return values

false	on success.
true	on error.

◆ is_return_value_set()

bool sp_rcontext::is_return_value_set ( ) const

inline

◆ operator=()

void sp_rcontext::operator= ( sp_rcontext & )

private

◆ pop_all_cursors()

void sp_rcontext::pop_all_cursors ( )

inline

◆ pop_cursors()

void sp_rcontext::pop_cursors ( uint count )

Pop and delete given number of sp_cursor instance from the cursor stack.

Parameters

count Number of cursors to pop & delete.

◆ pop_handler_frame()

void sp_rcontext::pop_handler_frame ( THD * thd )

private

Pop the Handler_call_frame on top of the stack of active handlers.

Also pop the matching Diagnostics Area and transfer conditions.

◆ pop_handlers()

void sp_rcontext::pop_handlers ( sp_pcontext * current_scope )

Pop and delete given number of sp_handler_entry instances from the handler call stack.

Parameters

current_scope The current BEGIN..END block.

◆ push_cursor()

bool sp_rcontext::push_cursor ( sp_instr_cpush * i )

Create a new sp_cursor instance and push it to the cursor stack.

Parameters

i	Cursor-push instruction.

Returns: error flag.

Return values

false	on success.
true	on error.

◆ push_handler()

bool sp_rcontext::push_handler	(	sp_handler *	handler,
		uint	first_ip
	)

Create a new sp_handler_entry instance and push it to the handler call stack.

Parameters

handler	SQL-handler object.
first_ip	First instruction pointer of the handler.

Returns: error flag.

Return values

false	on success.
true	on error.

◆ set_case_expr()

bool sp_rcontext::set_case_expr	(	THD *	thd,
		bool	standalone,
		int	case_expr_id,
		Item **	case_expr_item_ptr
	)

Set CASE expression to the specified value.

Parameters

thd	Thread handler.
standalone	Whether instruction is a standalone query expr.
case_expr_id	The CASE expression identifier.
case_expr_item_ptr	The CASE expression value

Returns: false on success, true on error

Note: The idea is to reuse Item_cache for the expression of the one CASE statement. This optimization takes place when there is CASE statement inside of a loop. So, in other words, we will use the same object on each iteration instead of creating a new one for each iteration.

TODO Hypothetically, a type of CASE expression can be different for each iteration. For instance, this can happen if the expression contains a session variable (something like @VAR) and its type is changed from one iteration to another.

In order to cope with this problem, we check type each time, when we use already created object. If the type does not match, we re-create Item. This also can (should?) be optimized.

◆ set_return_value()

bool sp_rcontext::set_return_value	(	THD *	thd,
		bool	standalone,
		Item **	return_value_item
	)

◆ set_variable() [1/2]

bool sp_rcontext::set_variable	(	THD *	thd,
		bool	standalone,
		Field *	field,
		Item **	value
	)

private

◆ set_variable() [2/2]

bool sp_rcontext::set_variable	(	THD *	thd,
		bool	standalone,
		uint	var_idx,
		Item **	value
	)

inline

Member Data Documentation

◆ callers_arena

Query_arena* sp_rcontext::callers_arena

Arena used to (re) allocate items on.

E.g. reallocate INOUT/OUT SP-variables when they don't fit into prealloced items. This is common situation with String items. It is used mainly in sp_eval_func_item().

◆ end_partial_result_set

bool sp_rcontext::end_partial_result_set

Flag to end an open result set before start executing an SQL-handler (if one is found).

Otherwise the client will hang due to a violation of the client/server protocol.

◆ m_activated_handlers

Prealloced_array<Handler_call_frame *, 16> sp_rcontext::m_activated_handlers

private

Stack of caught SQL conditions.

◆ m_case_expr_holders

Bounds_checked_array<Item_cache *> sp_rcontext::m_case_expr_holders

private

Array of CASE expression holders.

◆ m_ccount

uint sp_rcontext::m_ccount

private

Current number of cursors in m_cstack.

◆ m_cstack

Bounds_checked_array<sp_cursor *> sp_rcontext::m_cstack

private

Stack of cursors.

◆ m_in_sub_stmt

bool sp_rcontext::m_in_sub_stmt

private

Flag to tell if the runtime context is created for a sub-statement.

◆ m_return_value_fld

Field* sp_rcontext::m_return_value_fld

private

This is a pointer to a field, which should contain return value for stored functions (only).

For stored procedures, this pointer is NULL.

◆ m_return_value_set

bool sp_rcontext::m_return_value_set

private

Indicates whether the return value (in m_return_value_fld) has been set during execution.

◆ m_root_parsing_ctx

const sp_pcontext* sp_rcontext::m_root_parsing_ctx

private

Top-level (root) parsing context for this runtime context.

◆ m_var_items

Bounds_checked_array<Item *> sp_rcontext::m_var_items

private

Collection of Item_field proxies, each of them points to the corresponding field in m_var_table.

◆ m_var_table

TABLE* sp_rcontext::m_var_table

private

Virtual table for storing SP-variables.

◆ m_visible_handlers

Prealloced_array<sp_handler_entry *, 16> sp_rcontext::m_visible_handlers

private

Stack of visible handlers.

◆ sp

sp_head* sp_rcontext::sp

The stored program for which this runtime context is created.

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

sql/sp_rcontext.h
sql/sp_rcontext.cc

Classes

Public Member Functions

Static Public Member Functions

Public Attributes

Private Member Functions

Private Attributes

Constructor & Destructor Documentation

◆ ~sp_rcontext()

◆ sp_rcontext() [1/2]

◆ sp_rcontext() [2/2]

Member Function Documentation

◆ alloc_arrays()

◆ create()

◆ create_case_expr_holder()

◆ current_handler_frame()

◆ exit_handler()

◆ get_case_expr()

◆ get_case_expr_addr()

◆ get_cursor()

◆ get_item()

◆ get_item_addr()

◆ get_last_handler_continue_ip()

◆ get_return_field()

◆ handle_sql_condition()

◆ init_var_items()

◆ init_var_table()

◆ is_return_value_set()

◆ operator=()

◆ pop_all_cursors()

◆ pop_cursors()

◆ pop_handler_frame()

◆ pop_handlers()

◆ push_cursor()

◆ push_handler()

◆ set_case_expr()

◆ set_return_value()

◆ set_variable() [1/2]

◆ set_variable() [2/2]

Member Data Documentation

◆ callers_arena

◆ end_partial_result_set

◆ m_activated_handlers

◆ m_case_expr_holders

◆ m_ccount

◆ m_cstack

◆ m_in_sub_stmt

◆ m_return_value_fld

◆ m_return_value_set

◆ m_root_parsing_ctx

◆ m_var_items

◆ m_var_table

◆ m_visible_handlers

◆ sp