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()

cache/redis/redis_test.go

@@ -56,6 +56,22 @@ func TestRedisCache(t *testing.T) {
 		t.Error("get err")
 	}
 
+	if err = bm.IncrBy("astaxie", 2); err != nil {
+		t.Error("Incr Error", err)
+	}
+
+	if v, _ := redis.Int(bm.Get("astaxie"), err); v != 4 {
+		t.Error("get err")
+	}
+
+	if err = bm.DecrBy("astaxie", 2); err != nil {
+		t.Error("Decr Error", err)
+	}
+
+	if v, _ := redis.Int(bm.Get("astaxie"), err); v != 2 {
+		t.Error("get err")
+	}
+
 	if err = bm.Decr("astaxie"); err != nil {
 		t.Error("Decr Error", err)
 	}
@@ -63,6 +79,7 @@ func TestRedisCache(t *testing.T) {
 	if v, _ := redis.Int(bm.Get("astaxie"), err); v != 1 {
 		t.Error("get err")
 	}
+
 	bm.Delete("astaxie")
 	if bm.IsExist("astaxie") {
 		t.Error("delete err")