Opt_trace_stmt Class Reference

The trace of one statement. More...

Public Member Functions
	Opt_trace_stmt (Opt_trace_context *ctx_arg)
	Constructor, starts a trace for information_schema and dbug. More...
void	end ()
	Ends a trace; destruction may not be possible immediately as we may have to keep the trace in case the user later reads it from I_S. More...
bool	has_ended () const
void	set_allowed_mem_size (size_t size)
	Sets the quantity of allowed memory for this trace. More...
void	set_query (const char *query, size_t length, const CHARSET_INFO *charset)
bool	open_struct (const char *key, Opt_trace_struct *ots, bool wants_disable_I_S, char opening_bracket)
	When creating an Opt_trace_struct: adds a key and the opening bracket to the trace buffer, updates current_struct. More...
void	close_struct (const char *saved_key, bool has_disabled_I_S, char closing_bracket)
	When closing an Opt_trace_struct: More...
void	separator ()
	Put optional comma, newline and indentation. More...
void	next_line ()
	Put newline and indentation. More...
void	add (const char *key, const char *val, size_t val_length, bool quotes, bool escape)
	Adds a key/value pair to the trace buffer. More...
void	fill_info (Opt_trace_info *info) const
	Fills user-level information. More...
size_t	alloced_length () const
void	assert_current_struct (const Opt_trace_struct *s) const
void	missing_privilege ()
bool	support_I_S () const
void	disable_I_S ()
	Temporarily disables I_S output for this statement. More...
void	restore_I_S ()
	Restores I_S support to what it was before the previous call to disable_I_S(). More...
const char *	make_unknown_key ()
	Generate a dummy unique key, and return pointer to it. More...

Private Attributes
bool	ended
	Whether end() has been called on this instance. More...
int	I_S_disabled
	0 <=> this trace should be in information_schema. More...
bool	missing_priv
	whether user lacks privilege to see this trace More...
Opt_trace_context *	ctx
	context More...
Opt_trace_struct *	current_struct
	current open structure More...
Prealloced_array< Opt_trace_struct *, 16 >	stack_of_current_structs
	Same logic as Opt_trace_context::stack_of_current_stmts. More...
Buffer	trace_buffer
	Where the trace is accumulated. More...
Buffer	query_buffer
	Where the original query is put. More...
uint	unknown_key_count
	Counter which serves to have unique autogenerated keys, needed if we autogenerate more than one key in a single object. More...
char	unknown_key [24]
	Space for last autogenerated key. More...

Detailed Description

The trace of one statement.

For example, executing a stored procedure containing 3 sub-statements will produce 4 traces (one for the CALL statement, one for each sub-statement), so 4 Opt_trace_stmt linked together into Opt_trace_context's lists.

Constructor & Destructor Documentation

Opt_trace_stmt()

Opt_trace_stmt::Opt_trace_stmt

(

Opt_trace_context *

ctx_arg

)

Constructor, starts a trace for information_schema and dbug.

Parameters

ctx_arg

context

Member Function Documentation

add()

void Opt_trace_stmt::add	(	const char *	key,
		const char *	val,
		size_t	val_length,
		bool	quotes,
		bool	escape
	)

Adds a key/value pair to the trace buffer.

Parameters

key	key or NULL
val	representation of value as string
val_length	length of value
quotes	should value be delimited with '"' (false when the value is the representation of a number, boolean or null)
escape	does value need escaping (has special characters)

Note

Structures prepare a string representation of their value-to-add and call this function.

alloced_length()

size_t Opt_trace_stmt::alloced_length ( ) const

inline

Returns

total memory used by this trace

assert_current_struct()

void Opt_trace_stmt::assert_current_struct ( const Opt_trace_struct *  s ) const

inline

close_struct()

void Opt_trace_stmt::close_struct	(	const char *	saved_key,
		bool	has_disabled_I_S,
		char	closing_bracket
	)

When closing an Opt_trace_struct:

• adds the closing bracket and optionally the key to the trace buffer
• re-enables I_S output if the dying structure had disabled it
• updates current_struct.

  Parameters

  saved_key	key or NULL
  has_disabled_I_S	whether structure had disabled I_S output
  closing_bracket	closing bracket to use

disable_I_S()

void Opt_trace_stmt::disable_I_S ( )

inline

Temporarily disables I_S output for this statement.

end()

void Opt_trace_stmt::end

(

void

)

Ends a trace; destruction may not be possible immediately as we may have to keep the trace in case the user later reads it from I_S.

fill_info()

void Opt_trace_stmt::fill_info

(

Opt_trace_info *

info

)

const

Fills user-level information.

See also

Opt_trace_iterator

has_ended()

bool Opt_trace_stmt::has_ended ( ) const

inline

Returns

whether end() has been called on this instance.

make_unknown_key()

const char * Opt_trace_stmt::make_unknown_key

(

)

Generate a dummy unique key, and return pointer to it.

The pointed data has the lifetime of Opt_trace_stmt, and is overwritten by the next call to this function.

missing_privilege()

void Opt_trace_stmt::missing_privilege

(

)

See also

Opt_trace_context::missing_privilege()

next_line()

void Opt_trace_stmt::next_line

(

)

Put newline and indentation.

open_struct()

bool Opt_trace_stmt::open_struct	(	const char *	key,
		Opt_trace_struct *	ots,
		bool	wants_disable_I_S,
		char	opening_bracket
	)

When creating an Opt_trace_struct: adds a key and the opening bracket to the trace buffer, updates current_struct.

Parameters

key	key or NULL
ots	structure being created
wants_disable_I_S	whether structure wants to disable I_S output
opening_bracket	opening bracket to use

Return values

false	ok
true	error, Opt_trace_struct must set itself to dummy; trace may have been written to, will likely be invalid JSON.

restore_I_S()

void Opt_trace_stmt::restore_I_S ( )

inline

Restores I_S support to what it was before the previous call to disable_I_S().

separator()

void Opt_trace_stmt::separator

(

)

Put optional comma, newline and indentation.

set_allowed_mem_size()

void Opt_trace_stmt::set_allowed_mem_size

(

size_t

size

)

Sets the quantity of allowed memory for this trace.

set_query()

void Opt_trace_stmt::set_query	(	const char *	query,
		size_t	length,
		const CHARSET_INFO *	charset
	)

See also

Opt_trace_context::set_query()

support_I_S()

bool Opt_trace_stmt::support_I_S ( ) const

inline

Member Data Documentation

ctx

Opt_trace_context* Opt_trace_stmt::ctx

private

context

current_struct

Opt_trace_struct* Opt_trace_stmt::current_struct

private

current open structure

ended

bool Opt_trace_stmt::ended

private

Whether end() has been called on this instance.

I_S_disabled

int Opt_trace_stmt::I_S_disabled

private

0 <=> this trace should be in information_schema.

In the life of an Opt_trace_stmt, support for I_S may be temporarily disabled. Once disabled, it must stay disabled until re-enabled at the same stack frame. This: Opt_trace_object1 // disables I_S Opt_trace_object2 // re-enables I_S is impossible (the top object wins). So it is sufficient, to keep track of the current state, to have a counter incremented each time we get a request to disable I_S.

missing_priv

bool Opt_trace_stmt::missing_priv

private

whether user lacks privilege to see this trace

query_buffer

Buffer Opt_trace_stmt::query_buffer

private

Where the original query is put.

stack_of_current_structs

Prealloced_array<Opt_trace_struct *, 16> Opt_trace_stmt::stack_of_current_structs

private

Same logic as Opt_trace_context::stack_of_current_stmts.

trace_buffer

Buffer Opt_trace_stmt::trace_buffer

private

Where the trace is accumulated.

unknown_key

char Opt_trace_stmt::unknown_key[24]

private

Space for last autogenerated key.

unknown_key_count

uint Opt_trace_stmt::unknown_key_count

private

Counter which serves to have unique autogenerated keys, needed if we autogenerate more than one key in a single object.

See also

Opt_trace_struct::check_key() and

Opt_trace_stmt::add() .

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

• sql/opt_trace.cc