LL perf (Textures/assets): Mesh: the whole cache file is pre-filled with zeros on header receipt #303

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opened 2026-10-04 14:09:14 +00:00 by sky_line · 0 comments

sky_line commented

2026-10-04 14:09:14 +00:00

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From the LL-origin inefficiency audit (finding T8). File/line references are from commit 0229f8872c; re-locate them before working.

Mesh: the whole cache file is pre-filled with zeros on header receipt

Where: llmeshrepository.cpp:3812-3842.
Cost: allocates and writes every LOD's worth of zeros, even though most LODs are never fetched. The "never written" detection checks the first 1 KB for zeros (:2088-2093).
Fix: sparse file or ftruncate, plus a per-LOD presence bitmap.
Confirmed. S, risk L-M (cache format).

Verify the cost (profile or timer) before and after changing it.

From the LL-origin inefficiency audit (finding T8). File/line references are from commit 0229f8872c; re-locate them before working. **Mesh: the whole cache file is pre-filled with zeros on header receipt** - **Where:** `llmeshrepository.cpp:3812-3842`. - **Cost:** allocates and writes every LOD's worth of zeros, even though most LODs are never fetched. The "never written" detection checks the first 1 KB for zeros (`:2088-2093`). - **Fix:** sparse file or `ftruncate`, plus a per-LOD presence bitmap. - Confirmed. S, risk L-M (cache format). Verify the cost (profile or timer) before and after changing it.

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