support redis as a global var in lua scripts (#289)

by supporting both ledis and redis as the global lua script var,
we keep ledis support as it is, while also supporting redis clients,
which will be sending scripts, whilst assuming redis is the global

server/script.go

@@ -182,6 +182,22 @@ func (app *App) openScript() {
 	w.l = l
 	s.c.resp = w
 
+	setGlobalDBScriptVar(l, "ledis")
+	setGlobalDBScriptVar(l, "redis")
+
+	setMapState(l, s)
+}
+
+func (app *App) closeScript() {
+	app.script.l.Close()
+	delMapState(app.script.l)
+	app.script = nil
+}
+
+var mapState = map[*lua.State]*script{}
+var stateLock sync.Mutex
+
+func setGlobalDBScriptVar(l *lua.State, name string) {
 	l.NewTable()
 	l.PushString("call")
 	l.PushGoFunction(luaCall)
@@ -203,20 +219,9 @@ func (app *App) openScript() {
 	l.PushGoFunction(luaStatusReply)
 	l.SetTable(-3)
 
-	l.SetGlobal("ledis")
-
-	setMapState(l, s)
+	l.SetGlobal(name)
 }
 
-func (app *App) closeScript() {
-	app.script.l.Close()
-	delMapState(app.script.l)
-	app.script = nil
-}
-
-var mapState = map[*lua.State]*script{}
-var stateLock sync.Mutex
-
 func setMapState(l *lua.State, s *script) {
 	stateLock.Lock()
 	defer stateLock.Unlock()