fix(rust_brain): preserve HLC on snapshot restore and gossip receive#25
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restore_from_file dropped hlc fields added in v0.6.0, assigning fresh timestamps on restore. Post-crash causal writes and gossip replays with pre-crash HLC were rejected (silent data loss), while gossip events without HLC could overwrite fresher data. - Add _parse_hlc() for snapshot/wire normalisation with legacy fallback - restore_from_file: restore hlc and advance global _hlc per node - bulk_write: pass through hlc from row payloads - gossip.receive: apply hlc, reject stale updates, skip missing-hlc overwrites on existing keys - Tests: snapshot HLC round-trip, gossip stale/new/missing-hlc cases Co-authored-by: Daniel <DJLougen@users.noreply.github.com>
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Bug and impact
Critical data-loss bug in distributed memory paths.
restore_from_file()andgossip.receive()did not preserve or apply Hybrid Logical Clock (HLC) timestamps introduced in v0.6.0. After a snapshot restore:_hlcwas not advanced to match restored state.Concrete trigger: Node crashes, restores from snapshot, peer gossips a causal update with the original HLC →
TimestampRegressionis raised and the update is dropped.Root cause
v0.6.0 (
07a1c75) switched monotonic enforcement fromts_nstohlc, butrestore_from_file()andgossip.receive()were never updated to read/applyhlcfields. Snapshots stored HLC in JSON viato_dict(), but restore ignored them.Fix
_parse_hlc()for snapshot/wire normalisation with legacyts_nsfallback.restore_from_file: restorehlcper node and call_hlc.update()to advance the process clock.bulk_write: pass throughhlcfrom row payloads.gossip.receive: applyhlc, update clock, reject stale overwrites, skip missing-HLC updates on existing keys.Validation
test_restore_preserves_hlc_for_replication, gossip stale/new/missing-hlc cases.