{"v":1,"run":"browser-perf-2026-07-16","workstream":"S21 experiential / S18 graphics — browser chrome-parity ratchet","title":"Nishi browser — the paint-cliff and big-page fixes (eaglercraft + full Wikipedia now load)","date":"2026-07-16","verdict":"Two hard blockers eaten — and one honest limit made visible. (1) PAINT CLIFF: the Eaglercraft page went from >170s (killed, never finished) to 2s — root cause was every CSS lookup scanning the whole computed-decl array per box per ancestor (O(boxes x ancestors x ncomp)); fixed with a per-box decl index, proven a PURE accelerator by a gate (same answers on every box x 4 resolvers, buckets bounded). (2) BIG-PAGE FETCH: the full Wikipedia /wiki/Computer article returned ZERO bytes (the fetch response buffer capped at 512KB, the page is ~1MB); raised to 4MB across the fetch/dechunk/charset/GUI buffers — it now fetches 966,758 bytes and renders a 27,465px page in 3s. THE HONEST LIMIT: Eaglercraft is a 100 percent JS/WASM app, so with the hang gone the Nishi browser paints its background and NOTHING ELSE (the launcher you see in Chrome is drawn entirely by scripts the Nishi engine does not execute yet). So this run proves the paint cliff is dead (by TIMING + a gate), not that we render the launcher. The real VISUAL proof of the paint fix is the Wikipedia render below.","artifacts":[{"file":"comp_eagler.png","caption":"Eaglercraft launcher — Chrome (left, full launcher) vs Nishi (right, blank dark page). This is the honest picture: Eaglercraft is entirely JS/WASM, so the Nishi browser correctly fetches, lays out and paints in 2 seconds (was an infinite hang) but there is no static content to show — the launcher is 100 percent script-drawn and the Nishi engine does not run page scripts yet. The paint-cliff win is real but it is proven by the 2s timing and the equivalence gate, NOT by these pixels."},{"file":"wiki_computer_nishi.png","caption":"Full Wikipedia \"Computer\" article, first screen, rendered by the Nishi browser — THIS is the visual proof of both fixes. The page previously could not load at all (fetch returned 0 bytes at the old 512KB cap); it now fetches ~1MB and the paint index lets it lay out 27,465px of real article (body text, headings, links) in 3 seconds instead of hanging."}],"metrics":[{"name":"Eaglercraft paint time","value":">170s (killed) -> 2s","note":"Per-box computed-decl index (br_cidx): CSS lookups scan only that box's bucket, not the whole array"},{"name":"Index correctness","value":"nx_cidx_equiv_gate GREEN","note":"300 boxes x 4 resolvers (bg/border/color/font-size): bucketed answer == full-scan answer, 0 divergences; can-fail control confirms buckets are genuinely bounded (max 9 vs ncomp 667)"},{"name":"Wikipedia /Computer fetch","value":"0 bytes -> 966,758 bytes","note":"Response/dechunk/charset/GUI buffers 512KB/1MB/2MB -> 4MB uniformly"},{"name":"Wikipedia /Computer render","value":"27,465px page in 3s","note":"The largest real page the engine has laid out; no hang, no truncation"},{"name":"Regression check","value":"203KB baseline page unchanged (203,464 bytes); bg-cascade + fontsize-frac + inline-vec-measure gates all GREEN","note":"The buffer + index changes are additive; every prior gate re-run passed"},{"name":"honest gap","value":"Eaglercraft game UI (JS/WASM) not executed","note":"Static-shell paint only; JS execution is a separate, larger arc (the engine has a JS VM but the browser does not yet run page scripts in the shot lane)"}]}