sp_lex_branch_instr Class Reference

#include <sp_instr.h>

Inheritance diagram for sp_lex_branch_instr:

List of all members.

Public Member Functions
void	set_cont_dest (uint cont_dest)
virtual uint	opt_mark (sp_head *sp, List< sp_instr > *leads)
virtual void	opt_move (uint dst, List< sp_branch_instr > *ibp)
virtual uint	get_cont_dest () const
virtual bool	is_invalid () const
virtual void	invalidate ()
virtual LEX_STRING	get_expr_query () const
virtual void	set_destination (uint old_dest, uint new_dest)
virtual void	backpatch (uint dest)
Protected Member Functions
	sp_lex_branch_instr (uint ip, sp_pcontext *ctx, LEX *lex, Item *expr_item, LEX_STRING expr_query)
	sp_lex_branch_instr (uint ip, sp_pcontext *ctx, LEX *lex, Item *expr_item, LEX_STRING expr_query, uint dest)
Protected Attributes
uint	m_dest
	Where we will go.
uint	m_cont_dest
	Where continue handlers will go.
sp_instr *	m_optdest
sp_instr *	m_cont_optdest
Item *	m_expr_item
	Expression item.
LEX_STRING	m_expr_query
	SQL-query corresponding to the expression.

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Detailed Description

sp_lex_branch_instr is a base class for SP-instructions, which might perform conditional jump depending on the value of an SQL-expression.

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Member Function Documentation

virtual void sp_lex_branch_instr::backpatch

(

uint

dest

)

[inline, virtual]

Update all instruction with the given label in the backpatch list to the specified instruction pointer.

Parameters:

dest	destination instruction pointer.

Implements sp_branch_instr.

Reimplemented in sp_instr_set_case_expr.

virtual uint sp_lex_branch_instr::get_cont_dest

(

)

const [inline, virtual]

Get the continuation destination (instruction pointer for the CONTINUE HANDLER) of this instruction.

Returns:

the continuation destination

Reimplemented from sp_instr.

virtual LEX_STRING sp_lex_branch_instr::get_expr_query

(

)

const [inline, virtual]

Returns:

the expression query string. This string can not be passed directly to the parser as it is most likely not a valid SQL-statement.

Note:

as it can be seen in the get_query() implementation, get_expr_query() might return EMPTY_STR. EMPTY_STR means that no query-expression is available. That happens when class provides different implementation of get_query(). Strictly speaking, this is a drawback of the current class hierarchy.

Reimplemented from sp_lex_instr.

virtual void sp_lex_branch_instr::invalidate

(

)

[inline, virtual]

Invalidate the object.

Implements sp_lex_instr.

Reimplemented in sp_instr_jump_case_when.

virtual bool sp_lex_branch_instr::is_invalid

(

)

const [inline, virtual]

Return values:

false	if the object (i.e. LEX-object) is valid and exec_core() can be just called.
true	if the object is not valid any longer, exec_core() can not be called. The original query string should be re-parsed and a new LEX-object should be used.

Implements sp_lex_instr.

uint sp_lex_branch_instr::opt_mark	(	sp_head *	sp,
		List< sp_instr > *	leads
	)		[virtual]

Mark this instruction as reachable during optimization and return the index to the next instruction. Jump instruction will add their destination to the leads list.

Reimplemented from sp_instr.

Reimplemented in sp_instr_set_case_expr.

void sp_lex_branch_instr::opt_move	(	uint	dst,
		List< sp_branch_instr > *	ibp
	)		[virtual]

Inform the instruction that it has been moved during optimization. Most instructions will simply update its index, but jump instructions must also take care of their destination pointers. Forward jumps get pushed to the backpatch list 'ibp'.

Reimplemented from sp_instr.

Reimplemented in sp_instr_set_case_expr.

virtual void sp_lex_branch_instr::set_destination	(	uint	old_dest,
		uint	new_dest
	)		[inline, virtual]

Update the destination; used by the SP-instruction-optimizer.

Parameters:

old_dest	current (old) destination (instruction pointer).
new_dest	new destination (instruction pointer).

Implements sp_branch_instr.

Reimplemented in sp_instr_set_case_expr.

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

• sp_instr.h
• sp_instr.cc