Re-struct pkg/api, pkg/database

pkg/api/check.go

@@ -0,0 +1,17 @@
+package api
+
+import (
+	"errors"
+	"log"
+	"net/http"
+)
+
+func (api *API) CheckLimit(w http.ResponseWriter, r *http.Request, limit int64) error {
+	if limit <= 0 || limit > 10 {
+		log.Println("[api] [Warning] Limit error", limit)
+		err := errors.New(`"limit" can't be zero or more than 10`)
+		api.HandleError(w, r, err)
+		return err
+	}
+	return nil
+}