XPath stack optimization: Reduce stack usage during parsing by sharing scratch buffer for variable/number parsing (we only need one per parser)

git-svn-id: http://pugixml.googlecode.com/svn/trunk@928 99668b35-9821-0410-8761-19e4c4f06640
This commit is contained in:
arseny.kapoulkine@gmail.com 2012-11-17 21:52:02 +00:00
parent 971fd96764
commit ed30b95a42

View File

@ -6440,10 +6440,8 @@ PUGI__NS_BEGIN
#endif #endif
} }
PUGI__FN bool convert_string_to_number(const char_t* begin, const char_t* end, double* out_result) PUGI__FN bool convert_string_to_number(char_t (&buffer)[32], const char_t* begin, const char_t* end, double* out_result)
{ {
char_t buffer[32];
size_t length = static_cast<size_t>(end - begin); size_t length = static_cast<size_t>(end - begin);
char_t* scratch = buffer; char_t* scratch = buffer;
@ -6736,10 +6734,8 @@ PUGI__NS_BEGIN
} }
} }
PUGI__FN xpath_variable* get_variable(xpath_variable_set* set, const char_t* begin, const char_t* end) PUGI__FN xpath_variable* get_variable(char_t (&buffer)[32], xpath_variable_set* set, const char_t* begin, const char_t* end)
{ {
char_t buffer[32];
size_t length = static_cast<size_t>(end - begin); size_t length = static_cast<size_t>(end - begin);
char_t* scratch = buffer; char_t* scratch = buffer;
@ -8730,6 +8726,8 @@ PUGI__NS_BEGIN
xpath_parse_result* _result; xpath_parse_result* _result;
char_t _scratch[32];
#ifdef PUGIXML_NO_EXCEPTIONS #ifdef PUGIXML_NO_EXCEPTIONS
jmp_buf _error_handler; jmp_buf _error_handler;
#endif #endif
@ -9018,7 +9016,7 @@ PUGI__NS_BEGIN
if (!_variables) if (!_variables)
throw_error("Unknown variable: variable set is not provided"); throw_error("Unknown variable: variable set is not provided");
xpath_variable* var = get_variable(_variables, name.begin, name.end); xpath_variable* var = get_variable(_scratch, _variables, name.begin, name.end);
if (!var) if (!var)
throw_error("Unknown variable: variable set does not contain the given name"); throw_error("Unknown variable: variable set does not contain the given name");
@ -9056,7 +9054,7 @@ PUGI__NS_BEGIN
{ {
double value = 0; double value = 0;
if (!convert_string_to_number(_lexer.contents().begin, _lexer.contents().end, &value)) if (!convert_string_to_number(_scratch, _lexer.contents().begin, _lexer.contents().end, &value))
throw_error_oom(); throw_error_oom();
xpath_ast_node* n = new (alloc_node()) xpath_ast_node(ast_number_constant, xpath_type_number, value); xpath_ast_node* n = new (alloc_node()) xpath_ast_node(ast_number_constant, xpath_type_number, value);