Don't create tons of locales when parsing URIs

csk-ableton · csk-ableton · commit 10dc45b54279 · 2018-07-23T15:44:20.000+02:00
This is a major performance bottleneck when parsing URIs as creating locales
is quite expensive.
diff --git a/src/detail/grammar.hpp b/src/detail/grammar.hpp
@@ -17,7 +17,7 @@ namespace detail {
 inline bool isalnum(string_view::const_iterator &it,
                     string_view::const_iterator last) {
   if (it != last) {
-    if (std::isalnum(*it, std::locale("C"))) {
+    if (std::isalnum(*it, std::locale::classic())) {
       ++it;
       return true;
     }
@@ -28,7 +28,7 @@ inline bool isalnum(string_view::const_iterator &it,
 inline bool isdigit(string_view::const_iterator &it,
                     string_view::const_iterator last) {
   if (it != last) {
-    if (std::isdigit(*it, std::locale("C"))) {
+    if (std::isdigit(*it, std::locale::classic())) {
       ++it;
       return true;
     }
@@ -91,14 +91,14 @@ inline bool is_pct_encoded(string_view::const_iterator &it,
     }
   }
 
-  if (std::isxdigit(*it_copy, std::locale("C"))) {
+  if (std::isxdigit(*it_copy, std::locale::classic())) {
     ++it_copy;
     if (it_copy == last) {
       return false;
     }
   }
 
-  if (std::isxdigit(*it_copy, std::locale("C"))) {
+  if (std::isxdigit(*it_copy, std::locale::classic())) {
     ++it_copy;
     it = it_copy;
     return true;

Original file line number	Diff line number	Diff line change
`@@ -17,7 +17,7 @@ namespace detail {`
`17`	`17`	`inline bool isalnum(string_view::const_iterator &it,`
`18`	`18`	`string_view::const_iterator last) {`
`19`	`19`	`if (it != last) {`
`20`		`- if (std::isalnum(*it, std::locale("C"))) {`
	`20`	`+ if (std::isalnum(*it, std::locale::classic())) {`
`21`	`21`	`++it;`
`22`	`22`	`return true;`
`23`	`23`	`}`
`@@ -28,7 +28,7 @@ inline bool isalnum(string_view::const_iterator &it,`
`28`	`28`	`inline bool isdigit(string_view::const_iterator &it,`
`29`	`29`	`string_view::const_iterator last) {`
`30`	`30`	`if (it != last) {`
`31`		`- if (std::isdigit(*it, std::locale("C"))) {`
	`31`	`+ if (std::isdigit(*it, std::locale::classic())) {`
`32`	`32`	`++it;`
`33`	`33`	`return true;`
`34`	`34`	`}`
`@@ -91,14 +91,14 @@ inline bool is_pct_encoded(string_view::const_iterator &it,`
`91`	`91`	`}`
`92`	`92`	`}`
`93`	`93`
`94`		`- if (std::isxdigit(*it_copy, std::locale("C"))) {`
	`94`	`+ if (std::isxdigit(*it_copy, std::locale::classic())) {`
`95`	`95`	`++it_copy;`
`96`	`96`	`if (it_copy == last) {`
`97`	`97`	`return false;`
`98`	`98`	`}`
`99`	`99`	`}`
`100`	`100`
`101`		`- if (std::isxdigit(*it_copy, std::locale("C"))) {`
	`101`	`+ if (std::isxdigit(*it_copy, std::locale::classic())) {`
`102`	`102`	`++it_copy;`
`103`	`103`	`it = it_copy;`
`104`	`104`	`return true;`