chore: improve titleCasedName performance (#1691)

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Signed-off-by: Bo-Yi Wu <appleboy.tw@gmail.com>

chore: improve titleCasedName performance

Signed-off-by: Bo-Yi Wu <appleboy.tw@gmail.com>

Co-authored-by: Bo-Yi Wu <appleboy.tw@gmail.com>
Reviewed-on: https://gitea.com/xorm/xorm/pulls/1691

names/mapper.go

@@ -103,27 +103,28 @@ func (mapper SnakeMapper) Obj2Table(name string) string {
 }
 
 func titleCasedName(name string) string {
-	newstr := make([]rune, 0)
+	newstr := make([]byte, 0, len(name))
 	upNextChar := true
 
 	name = strings.ToLower(name)
 
-	for _, chr := range name {
+	for i := 0; i < len(name); i++ {
+		c := name[i]
 		switch {
 		case upNextChar:
 			upNextChar = false
-			if 'a' <= chr && chr <= 'z' {
-				chr -= ('a' - 'A')
+			if 'a' <= c && c <= 'z' {
+				c -= 'a' - 'A'
 			}
-		case chr == '_':
+		case c == '_':
 			upNextChar = true
 			continue
 		}
 
-		newstr = append(newstr, chr)
+		newstr = append(newstr, c)
 	}
 
-	return string(newstr)
+	return b2s(newstr)
 }
 
 func (mapper SnakeMapper) Table2Obj(name string) string {

names/mapper_test.go

@@ -58,3 +58,13 @@ func BenchmarkSnakeCasedName(b *testing.B) {
 		_ = snakeCasedName(s)
 	}
 }
+
+func BenchmarkTitleCasedName(b *testing.B) {
+	b.ReportAllocs()
+	b.ResetTimer()
+
+	s := strings.Repeat("foo_bar", 32)
+	for i := 0; i < b.N; i++ {
+		_ = titleCasedName(s)
+	}
+}