Every ISerializable carried SerializedThread/SerializedPosition/SerializedLength
so WriteSnapshot could gather each entity's bytes from the worker heaps in
dictionary order. The idx records absolute positions, so bin order is free -
the snapshot can be written in worker-heap order instead, and the join inverts:
- Chunks are persistence-homogeneous: SerializeAll declares the owner at each
boundary, publishing the partial chunk on change.
- Workers log segments (owner, slot range, heap start) plus one length per
record as they serialize. Positions are implicit because a worker's writes
are contiguous; identity comes from re-walking the same snapshot slots in
the same order (guaranteed stable - mutations divert to the pending queues
until PostWorldSave), or from an entities log on the fallback path.
- WriteSnapshot routes segments by owner, emits idx entries during the
re-walk, and writes each segment's heap bytes as a single span instead of
one copy per entity, which also speeds up the background write phase.
- Persistence self-payloads keep placement as three private fields on the
~dozens of persistence instances; PushSingle is now typed accordingly.
Net effect: 9 bytes (plus padding) of resident state removed from every item,
mobile, guild, and account on every shard; three interface-property stores
per entity leave the drain hot path (stamping dirtied one cache line per
entity mid-freeze - the lengths log is a single sequential stream); and the
vestigial loader-side length stamp is gone. The transient cost is ~4 bytes
per entity in pooled per-worker logs that are released after each write.
The save format is unchanged (idx v3, same loader); only the write-side
mechanics moved. Adds an end-to-end round-trip test that drives real workers
through the chunk source, snapshots from the segment logs, and reloads.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
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