fix: add user to blacklist when it's banned or deleted, and make deletion soft (close #473, close #791)

common/blacklist/main.go

@@ -0,0 +1,29 @@
+package blacklist
+
+import (
+	"fmt"
+	"sync"
+)
+
+var blackList sync.Map
+
+func init() {
+	blackList = sync.Map{}
+}
+
+func userId2Key(id int) string {
+	return fmt.Sprintf("userid_%d", id)
+}
+
+func BanUser(id int) {
+	blackList.Store(userId2Key(id), true)
+}
+
+func UnbanUser(id int) {
+	blackList.Delete(userId2Key(id))
+}
+
+func IsUserBanned(id int) bool {
+	_, ok := blackList.Load(userId2Key(id))
+	return ok
+}