Move some regexp out of functions (#25430)

/cc @KN4CK3R
https://github.com/go-gitea/gitea/pull/25294#discussion_r1237425343

I also searched the codebase and found a few more.

---------

Signed-off-by: jolheiser <john.olheiser@gmail.com>

modules/repository/generate.go

@@ -372,12 +372,12 @@ func GenerateRepository(ctx context.Context, doer, owner *user_model.User, templ
 	return generateRepo, nil
 }
 
+var fileNameSanitizeRegexp = regexp.MustCompile(`(?i)\.\.|[<>:\"/\\|?*\x{0000}-\x{001F}]|^(con|prn|aux|nul|com\d|lpt\d)$`)
+
 // Sanitize user input to valid OS filenames
 //
 //		Based on https://github.com/sindresorhus/filename-reserved-regex
 //	 Adds ".." to prevent directory traversal
 func fileNameSanitize(s string) string {
-	re := regexp.MustCompile(`(?i)\.\.|[<>:\"/\\|?*\x{0000}-\x{001F}]|^(con|prn|aux|nul|com\d|lpt\d)$`)
-
-	return strings.TrimSpace(re.ReplaceAllString(s, "_"))
+	return strings.TrimSpace(fileNameSanitizeRegexp.ReplaceAllString(s, "_"))
 }

modules/util/path.go

@@ -222,6 +222,8 @@ func isOSWindows() bool {
 	return runtime.GOOS == "windows"
 }
 
+var driveLetterRegexp = regexp.MustCompile("/[A-Za-z]:/")
+
 // FileURLToPath extracts the path information from a file://... url.
 func FileURLToPath(u *url.URL) (string, error) {
 	if u.Scheme != "file" {
@@ -235,8 +237,7 @@ func FileURLToPath(u *url.URL) (string, error) {
 	}
 
 	// If it looks like there's a Windows drive letter at the beginning, strip off the leading slash.
-	re := regexp.MustCompile("/[A-Za-z]:/")
-	if re.MatchString(path) {
+	if driveLetterRegexp.MatchString(path) {
 		return path[1:], nil
 	}
 	return path, nil

services/lfs/server.go

@@ -77,6 +77,8 @@ func CheckAcceptMediaType(ctx *context.Context) {
 	}
 }
 
+var rangeHeaderRegexp = regexp.MustCompile(`bytes=(\d+)\-(\d*).*`)
+
 // DownloadHandler gets the content from the content store
 func DownloadHandler(ctx *context.Context) {
 	rc := getRequestContext(ctx)
@@ -92,8 +94,7 @@ func DownloadHandler(ctx *context.Context) {
 	toByte = meta.Size - 1
 	statusCode := http.StatusOK
 	if rangeHdr := ctx.Req.Header.Get("Range"); rangeHdr != "" {
-		regex := regexp.MustCompile(`bytes=(\d+)\-(\d*).*`)
-		match := regex.FindStringSubmatch(rangeHdr)
+		match := rangeHeaderRegexp.FindStringSubmatch(rangeHdr)
 		if len(match) > 1 {
 			statusCode = http.StatusPartialContent
 			fromByte, _ = strconv.ParseInt(match[1], 10, 32)