hible

cache add function
// IncrBy increase counter by num.
IncrBy(key string, num int)
// DecrBy decrease counter by num.
DecrBy(key string, num int)

cache/redis/redis.go

@@ -128,12 +128,30 @@ func (rc *Cache) Incr(key string) error {
 	return err
 }
 
+// IncrBy increase counter in redis by num.
+func (rc *Cache) IncrBy(key string, num int) error {
+	if num < 1 {
+		return errors.New("increase num should be a positive number")
+	}
+	_, err := redis.Bool(rc.do("INCRBY", key, num))
+	return err
+}
+
 // Decr decrease counter in redis.
 func (rc *Cache) Decr(key string) error {
 	_, err := redis.Bool(rc.do("INCRBY", key, -1))
 	return err
 }
 
+// DecrBy decrease counter in redis by num.
+func (rc *Cache) DecrBy(key string, num int) error {
+	if num < 1 {
+		return errors.New("decrease num should be a positive number")
+	}
+	_, err := redis.Bool(rc.do("DECRBY", key, num))
+	return err
+}
+
 // ClearAll clean all cache in redis. delete this redis collection.
 func (rc *Cache) ClearAll() error {
 	c := rc.p.Get()