anonymous_namespace{item_create.cc}::Function_factory< Instantiator_fn > Class Template Reference

Factory for creating function objects. More...

Inheritance diagram for anonymous_namespace{item_create.cc}::Function_factory< Instantiator_fn >:

Public Member Functions
Item *	create_func (THD *thd, LEX_STRING function_name, PT_item_list *item_list) override
	The builder create method. More...

Static Public Attributes
static Function_factory< Instantiator_fn >	s_singleton

Private Member Functions
	Function_factory ()=default

Private Attributes
Instantiator_fn	m_instantiator

Additional Inherited Members
Protected Member Functions inherited from Create_func
	Create_func ()=default
virtual	~Create_func ()=default

Detailed Description

template<typename Instantiator_fn>
class anonymous_namespace{item_create.cc}::Function_factory< Instantiator_fn >

Factory for creating function objects.

Performs validation check that the number of arguments is correct, then calls upon the instantiator function to instantiate the function object.

Template Parameters

Instantiator_fn

A class that is expected to contain the following:

• Min_argcount: The minimal number of arguments required to call the function. If the parameter count is less, an SQL error is raised and nullptr is returned.
• Max_argcount: The maximum number of arguments required to call the function. If the parameter count is greater, an SQL error is raised and nullptr is returned.
• Item *instantiate(THD *, PT_item_list *): Should construct an Item.

Constructor & Destructor Documentation

Function_factory()

template<typename Instantiator_fn >

anonymous_namespace{item_create.cc}::Function_factory< Instantiator_fn >::Function_factory ( )

privatedefault

Member Function Documentation

create_func()

template<typename Instantiator_fn >

Item * anonymous_namespace{item_create.cc}::Function_factory< Instantiator_fn >::create_func ( THD *  thd, LEX_STRING  name, PT_item_list *  item_list  )

inlineoverridevirtual

The builder create method.

Given the function name and list or arguments, this method creates an Item that represents the function call. In case or errors, a NULL item is returned, and an error is reported. Note that the thd object may be modified by the builder. In particular, the following members/methods can be set/called, depending on the function called and the function possible side effects.

• thd->lex->binlog_row_based_if_mixed
• thd->lex->current_context()
• thd->lex->safe_to_cache_query
• thd->lex->uncacheable(UNCACHEABLE_SIDEEFFECT)
• thd->lex->uncacheable(UNCACHEABLE_RAND)
• thd->lex->add_time_zone_tables_to_query_tables(thd)

Parameters

thd	The current thread
name	The function name
item_list	The list of arguments to the function, can be NULL

Returns

An item representing the parsed function call, or NULL

Implements Create_func.

Member Data Documentation

m_instantiator

template<typename Instantiator_fn >

Instantiator_fn anonymous_namespace{item_create.cc}::Function_factory< Instantiator_fn >::m_instantiator

private

s_singleton

template<typename Instantiator_fn >

Function_factory< Instantiator_fn > anonymous_namespace{item_create.cc}::Function_factory< Instantiator_fn >::s_singleton

static

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

• sql/item_create.cc