The data that is eventually written to the FDS bucket is as follows:
| Message header | Message content |
|---|---|
| Length of message bytes, maximum length of 4 bytes | Bytes array of message content, referring to the message content sent by the user. The length is the actual length of the message, and corresponds to the length of the message header record. |
When a user processes an FDS file, the 4-byte message header is read to obtain the length of the message. The message is then read based on the length of the message.