fix: GeoIP side-load

component/mmdb/mmdb.go

@@ -54,7 +54,7 @@ func Verify() bool {
 	return err == nil
 }
 
-func DefaultInstance() Reader {
+func Instance() Reader {
 	once.Do(func() {
 		mmdbPath := C.Path.MMDB()
 		log.Debugln("Load MMDB file: %s", mmdbPath)

component/mmdb/patch.go

@@ -2,30 +2,19 @@ package mmdb
 
 import (
 	C "github.com/Dreamacro/clash/constant"
-	"github.com/Dreamacro/clash/log"
-	"github.com/oschwald/geoip2-golang"
+
 	"github.com/oschwald/maxminddb-golang"
 )
 
-var overrideMmdb *geoip2.Reader
-
-func InstallOverride(override *geoip2.Reader) {
-	overrideMmdb = overrideMmdb
-}
-
-func Instance() Reader {
-	once.Do(func() {
-		mmdb, err := maxminddb.Open(C.Path.MMDB())
-		if err != nil {
-			log.Fatalln("Can't load mmdb: %s", err.Error())
-		}
-		reader = Reader{Reader: mmdb}
-		if mmdb.Metadata.DatabaseType == "sing-geoip" {
-			reader.databaseType = typeSing
-		} else {
-			reader.databaseType = typeMaxmind
-		}
-	})
-
-	return reader
+func InstallOverride(override *maxminddb.Reader) {
+	newReader := Reader{Reader: override}
+	switch override.Metadata.DatabaseType {
+	case "sing-geoip":
+		reader.databaseType = typeSing
+	case "Meta-geoip0":
+		reader.databaseType = typeMetaV0
+	default:
+		reader.databaseType = typeMaxmind
+	}
+	reader = newReader
 }