chore: improve subscription userinfo parsing (MetaCubeX#781)

do not use regex parsing for `Subscription-UserInfo` header field

adapter/provider/subscription_info.go

@@ -1,7 +1,6 @@
 package provider
 
 import (
-	"github.com/dlclark/regexp2"
 	"strconv"
 	"strings"
 )
@@ -13,45 +12,24 @@ type SubscriptionInfo struct {
 	Expire   int64
 }
 
-func NewSubscriptionInfo(str string) (si *SubscriptionInfo, err error) {
-	si = &SubscriptionInfo{}
-	str = strings.ToLower(str)
-	reTraffic := regexp2.MustCompile("upload=(\\d+); download=(\\d+); total=(\\d+)", 0)
-	reExpire := regexp2.MustCompile("expire=(\\d+)", 0)
-
-	match, err := reTraffic.FindStringMatch(str)
-	if err != nil || match == nil {
-		return nil, err
-	}
-	group := match.Groups()
-	si.Upload, err = str2uint64(group[1].String())
-	if err != nil {
-		return nil, err
-	}
-
-	si.Download, err = str2uint64(group[2].String())
-	if err != nil {
-		return nil, err
-	}
-
-	si.Total, err = str2uint64(group[3].String())
-	if err != nil {
-		return nil, err
-	}
-
-	match, _ = reExpire.FindStringMatch(str)
-	if match != nil {
-		group = match.Groups()
-		si.Expire, err = str2uint64(group[1].String())
+func NewSubscriptionInfo(userinfo string) (si *SubscriptionInfo, err error) {
+	userinfo = strings.ToLower(userinfo)
+	userinfo = strings.ReplaceAll(userinfo, " ", "")
+	si = new(SubscriptionInfo)
+	for _, field := range strings.Split(userinfo, ";") {
+		switch name, value, _ := strings.Cut(field, "="); name {
+		case "upload":
+			si.Upload, err = strconv.ParseInt(value, 10, 64)
+		case "download":
+			si.Download, err = strconv.ParseInt(value, 10, 64)
+		case "total":
+			si.Total, err = strconv.ParseInt(value, 10, 64)
+		case "expire":
+			si.Expire, err = strconv.ParseInt(value, 10, 64)
+		}
 		if err != nil {
-			return nil, err
+			return
 		}
 	}
-
 	return
 }
-
-func str2uint64(str string) (int64, error) {
-	i, err := strconv.ParseInt(str, 10, 64)
-	return i, err
-}