42 lines
2.2 KiB
Text
42 lines
2.2 KiB
Text
# net_sync.ludic — N2: @Sync replication codegen (NETWORKING-DESIGN §6.1, §13 N2).
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#
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# Replication is opt-in at the field level and per model use-site. All three
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# granularities here:
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# @Sync property Position — every field of Position is replicable
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# Health { @Sync hp, max } — only hp is replicable; max never is
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# @Sync Position in Player — Position participates → x, y replicate
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# Position in Prop — not @Sync here → Prop's Position does NOT replicate
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#
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# The compiler generates per-model serialize/apply over exactly the replicable-
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# and-participating fields, plus by-kind dispatchers: sync_size(e) / serialize(e,
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# buf) / apply(e, buf, len). This snapshots a Player's synced fields, mutates all
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# of them, then applies the snapshot: synced fields (x, y, hp) restore; the
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# unsynced one (max) keeps its mutation. Prints 12 (bytes) / 3 4 50 999.
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program NetSync {
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@Sync property Position { x: int = 0, y: int = 0 } # all fields replicable
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property Health { @Sync hp: int = 0, max: int = 0 } # only hp replicable
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@Owned model Player { @Sync Position, @Sync Health }
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model Prop { Position } # Position not @Sync here → no replication
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entry {
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spawn Player { Position { x: 3, y: 4 }, Health { hp: 50, max: 100 } }
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unsafe { # a raw snapshot buffer on purpose: built with --unsafe (L7)
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for (Position, Health) in query [Position, Health, {Player}] {
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let e = self()
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let buf = bytes(64)
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print(sync_size(e)) # 12 = Position(x,y)=8 + Health.hp=4
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let n = serialize(e, buf) # snapshot the synced fields
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Position.x = 99 # mutate everything
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Position.y = 88
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Health.hp = 7
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Health.max = 999 # max is NOT synced
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apply(e, buf, n) # restore from the snapshot
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print(Position.x) # 3 — restored
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print(Position.y) # 4 — restored
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print(Health.hp) # 50 — restored
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print(Health.max) # 999 — kept (unsynced)
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}
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}
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}
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}
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