fix(rust_brain): preserve HLC on snapshot restore and gossip receive#53
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restore_from_file() dropped HLC timestamps from snapshots, assigning fresh (wall, 0, uuid) values instead. After disaster recovery, any causal successor write with the pre-crash HLC was rejected with TimestampRegression, causing silent data loss on replay/gossip. - Add _parse_hlc() for wire/snapshot normalisation with legacy fallback - restore_from_file: restore hlc, update global _hlc, hold lock during restore - bulk_write: pass through hlc from row payloads - gossip.receive: apply hlc, reject stale overwrites, skip missing-hlc updates Regression tests cover snapshot round-trip and gossip HLC ordering. Co-authored-by: Daniel <DJLougen@users.noreply.github.com>
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Bug and impact
restore_from_file()andgossip.receive()dropped Hybrid Logical Clock (HLC) timestamps introduced in v0.6.0. After disaster recovery from a snapshot, restored nodes received fresh(wall, 0, uuid)HLCs instead of their original causal timestamps. Any subsequent write or gossip replay using the pre-crash HLC was rejected withTimestampRegression, causing silent data loss on recovery and cross-node sync.Concrete trigger: Node writes
remember("k", "v1", hlc=(5000, 10, "nodeA")), snapshots, crashes, restores. A causal successorremember("k", "v2", hlc=(5000, 11, "nodeA"))raisesTimestampRegressionbecause restore assigned a newer wall-clock HLC.Root cause
restore_from_file()constructedMemoryNodewithout passinghlcfrom the snapshot dict (defaulting to a fresh HLC).gossip.receive()similarly omittedhlc/ts_nswhen callingremember(). The global_hlcwas never advanced to the max restored timestamp.Fix
_parse_hlc()helper with legacyts_nsfallback for pre-v0.6.0 snapshotsrestore_from_file: restorehlc, call_hlc.update()per node, hold lock during restorebulk_write: pass throughhlcfrom row payloadsgossip.receive: applyhlc, reject stale overwrites, skip missing-HLC updates on existing keysValidation
test_restore_preserves_hlc_for_replication, gossip HLC ordering tests