http/httpguts: eliminate bounds checks in IsTokenRune

jub0bs · jub0bs · commit edec33714c86 · 2024-04-10T15:00:15.000+02:00
diff --git a/http/httpguts/httplex.go b/http/httpguts/httplex.go
@@ -12,7 +12,7 @@ import (
 	"golang.org/x/net/idna"
 )
 
-var isTokenTable = [127]bool{
+var isTokenTable = [256]bool{
 	'!':  true,
 	'#':  true,
 	'$':  true,
@@ -93,8 +93,7 @@ var isTokenTable = [127]bool{
 }
 
 func IsTokenRune(r rune) bool {
-	i := int(r)
-	return i < len(isTokenTable) && isTokenTable[i]
+	return r < utf8.RuneSelf && isTokenTable[byte(r)]
 }
 
 // HeaderValuesContainsToken reports whether any string in values

Original file line number	Diff line number	Diff line change
`@@ -12,7 +12,7 @@ import (`
`12`	`12`	`"golang.org/x/net/idna"`
`13`	`13`	`)`
`14`	`14`
`15`		`-var isTokenTable = [127]bool{`
	`15`	`+var isTokenTable = [256]bool{`
`16`	`16`	`'!': true,`
`17`	`17`	`'#': true,`
`18`	`18`	`'$': true,`
`@@ -93,8 +93,7 @@ var isTokenTable = [127]bool{`
`93`	`93`	`}`
`94`	`94`
`95`	`95`	`func IsTokenRune(r rune) bool {`
`96`		`- i := int(r)`
`97`		`- return i < len(isTokenTable) && isTokenTable[i]`
	`96`	`+ return r < utf8.RuneSelf && isTokenTable[byte(r)]`
`98`	`97`	`}`
`99`	`98`
`100`	`99`	`// HeaderValuesContainsToken reports whether any string in values`