Artifact d489bfd517759021e4f006355c1b9f99717ceda2068739eb3a9f84e291a95a89:
- File
src/delta.zig
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2026-08-04 13:30:54
— part of check-in
[bfb63af209]
on branch sub-manifest
— delta: replace the encoder's hash map with a fixed-capacity index
wapp import, user CPU: safe 1076s -> 540s, fast 95s -> 53s. Byte-identical output; the 14 pinned vectors are unchanged.
std.AutoHashMap(u64,u32) + Wyhash is gone. The window is now a comptime 16-byte array read through readInt, and the table is open-addressed with capacity from a bounded counter, so it is never more than half full -- that is the probe's termination argument, asserted rather than assumed.
Most of the safe-side win is not bounds checks. Wyhash.init declares a 48-byte buf as undefined, which runtime_safety poison-fills on every call, and the encoder hashed twice per position -- once for the window, once again inside the map on the resulting key. Removing the map removed both.
The probe's explicit bound sits inside `if (std.debug.runtime_safety)`: present in ReleaseSafe where it can trap, compiled out of ReleaseFast. Written unconditionally it cost 12.2% of the fast import; gated it costs nothing in either mode. (user: dmestas, size: 23706) [annotate] [blame] [check-ins using]
- 2026-08-14 12:21:34 — part of check-in [8a45a021f9] on branch trunk — merge sub-manifest: delta-manifest dialect, R cards, diff hunks, server identity, stash, open/log resolution, clone remote+progress, timestamp names; e2e expectations updated (user: dmestas, size: 23706) [annotate] [blame] [check-ins using]
-
2026-08-04 13:30:54
— part of check-in
[bfb63af209]
on branch sub-manifest
— delta: replace the encoder's hash map with a fixed-capacity index