cloud-save
Cloud save
Cloud synchronization reconciles already-valid local save generations. It does not replace save-systems atomic persistence or save-integrity trust classes.
Modes
| Mode | Reconciliation |
|---|---|
| single-authoritative | one server/backend revision is authoritative and clients submit against a known base |
| prompt-conflict | divergent descendants require a player/operator choice |
| deterministic-merge | only fields with an explicit domain-safe merge rule combine automatically |
Blind last-write-wins is not a safe default for divergent progress.
Revision model
Every synchronized generation carries a stable slot/profile ID plus a monotonic revision/generation and, when supported, the base version/ancestor it was derived from. Uploads use compare-and-set/precondition semantics where the backend permits them.
If local and remote share an ancestor and only one side advanced, fast-forward. If both advanced from the same base, classify it as a conflict unless every changed field has a declared deterministic merge rule. Playtime, timestamp, or file size alone do not decide which progress is correct.