Struct
This data structure contains information on a message just received from the network.
刚从网络接收的数据的相关信息会被保存到这个结构中。
It reveals where it came from, what time it was send and what network view sent it.
它揭示了从哪里来(数据源),什么时间发送和什么网络视图发送;其中包括:数据源、发送时间、网络视图。