mirror of
https://github.com/heygen-com/hyperframes.git
synced 2026-09-14 18:01:20 +08:00
Miguel Angel Simon Sierra
3327b12d50
The row virtualization stack made the timeline publish a viewport snapshot on every scroll frame and swap `renderClipContent` across every mounted clip at gesture start and settle. Both are windowing concessions, and neither was gated on the flag, so the build users actually run paid for them while mounting all 1,000 clips anyway. Measured on a 3,000-clip project: median scroll step 16.6ms to 76.9ms, p95 17.9ms to 189.4ms, 40 long tasks to 247. Gate both on the row virtualization flag. The scroll path now stops at the door when the flag is off, so `isScrolling` stays false and resize-driven and programmatic syncs still publish through the immediate path. The flag moves into its own module: the scroll-viewport hook needs to read it, and the virtualization hook already imports the viewport snapshot type back, which would have closed an import cycle. Also release the perf fixture lease from the fixture rather than from the test-hook effect. Loading a fixture writes player state, which changed that effect's dependency identities and tore it down on the next frame, so the lease was revoked moments after it was taken and live iframe discovery overwrote the fixture before the gate could measure it. The e2e gate gains a flag-off arm (`test:timeline-default`, 1,000 elements) next to the existing flag-on one. It refuses the 50,000-element combination, verifies from the mounted DOM that the server under test matches the requested flag, and skips the DOM-size budgets for the unvirtualized build rather than relaxing them, so a skipped budget never reads as a passed one. Verified against a live Studio dev server on the fixture project: flag off, before: interactionP95 303.1ms, longest task 194ms, 0/5 runs pass flag off, after: interactionP95 33.6ms, longest task 0ms, 5/5 runs pass flag on, after: interactionP95 33.2ms, 4/5 runs pass, exit 0 The flag-on arm's fourth run reproducibly reports a 55-58ms long task against a 50ms budget. That is the residual tail of the window swap itself, tracked separately and not addressed here.