3.2. Network Protocol¶
checkpoint, size, version, and session_id are sent as 64-bit little-endian numbers.
3.2.1. Client to Server¶
| Prefix | Data | Description |
|---|---|---|
| joedb | client_version | first message, sent at connection time |
| P | checkpoint | pull |
| L | checkpoint | lock-pull |
| p | checkpoint size data | locked-push |
| U | checkpoint size data | push-unlock |
| u | unlock | |
| H | checkpoint hash (32 bytes) | check SHA-256 hash code |
| i | ping (used to keep the connection alive) | |
| Q | quit |
3.2.2. Server to Client¶
| Prefix | Data | Description |
|---|---|---|
| joedb | server_version session_id checkpoint | reply to joedb.
server_version = 0 means client_version is rejected.
|
| P | checkpoint size data | reply to P |
| L | checkpoint size data | reply to L |
| U | reply to U or p when the push succeeded | |
| C | reply to U or p when the push failed (conflict) | |
| R | reply to U or p when the push failed (read-only) | |
| u | reply to u (no timeout) | |
| t | reply to u, U, or p in case of timeout | |
| H | reply to H, hash is matching | |
| h | reply to H, hash mismatch | |
| i | reply to i |