         }
         
         if let attributes = previousAttributes {
-            self.size -= attributes.fileSize()
+            substractSize(attributes.fileSize())
         }
         self.size += UInt64(data.length)
         self.controlCapacity()

            }
        }
    }
}

private func isNoSuchFileError(error : NSError?) -> Bool {

            let fileSize = attributes.fileSize()
            do {
                try fileManager.removeItemAtPath(path)
                substractSize(fileSize)
            } catch {
                Log.error("Failed to remove file", error as NSError)
            }
