From 1e7b5abbe2768418f0f2eac26d2788443a716bdf Mon Sep 17 00:00:00 2001
From: gVisor bot <gvisor-bot@google.com>
Date: Wed, 1 Aug 2018 00:18:29 +0800
Subject: [PATCH] Improve: lazy load mmdb

---
 rules/geoip.go | 22 +++++++++++++---------
 1 file changed, 13 insertions(+), 9 deletions(-)

diff --git a/rules/geoip.go b/rules/geoip.go
index 9ee8691e..f79f26f0 100644
--- a/rules/geoip.go
+++ b/rules/geoip.go
@@ -1,21 +1,18 @@
 package rules
 
 import (
+	"sync"
+
 	C "github.com/Dreamacro/clash/constant"
 
 	"github.com/oschwald/geoip2-golang"
 	log "github.com/sirupsen/logrus"
 )
 
-var mmdb *geoip2.Reader
-
-func init() {
-	var err error
-	mmdb, err = geoip2.Open(C.MMDBPath)
-	if err != nil {
-		log.Fatalf("Can't load mmdb: %s", err.Error())
-	}
-}
+var (
+	mmdb *geoip2.Reader
+	once sync.Once
+)
 
 type GEOIP struct {
 	country string
@@ -43,6 +40,13 @@ func (g *GEOIP) Payload() string {
 }
 
 func NewGEOIP(country string, adapter string) *GEOIP {
+	once.Do(func() {
+		var err error
+		mmdb, err = geoip2.Open(C.MMDBPath)
+		if err != nil {
+			log.Fatalf("Can't load mmdb: %s", err.Error())
+		}
+	})
 	return &GEOIP{
 		country: country,
 		adapter: adapter,