Every undoable edit keeps the previous project for undo, so the comp it touches
is shared and Arc::make_mut deep-copies it: every layer and every keyframe. An
edit therefore costs time in proportion to the comp's size, and a script that
sets many keyframes in a big comp goes quadratic (a 1,600-layer build with
~100k sampled keys took ~45 minutes).
Comp::layers is now a Layers collection backed by Vec<Arc<Layer>>: copying the
stack copies pointers, and only the layer an edit changes is copied. The API
mirrors Vec<Layer>; serialized form is unchanged (a list of layers).
Comp::layer_mut and the iter_mut().filter/find call sites use find_mut /
iter_mut_where so they copy only the layers they actually change.
- prop.addKey in a 400-layer comp: 1.36 ms -> 0.16 ms per key (flat in comp size)
- the 1,600-layer script build: ~45 min -> 47 s, frames pixel-identical
- regression tests: an edit leaves the other layers shared with undo; layers
round-trip as a plain list
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VkpGcKfWyCudfSsQNiWAaG
Conflicts came from upstream splitting crates/project/src/lib.rs and moving the
frames tests. Re-applied the branch's change in the new places:
- Layer::same_pixels_with now in crates/project/src/layer.rs
- Comp::same_pixels_with, same_settings(o, with_markers), pixel_form_with and the
timing-marker helpers in crates/project/src/comp.rs (same_pixels_ignoring_markers
stays removed)
- Project::reads_markers in crates/project/src/item.rs
- crates/ui-egui/src/frames.rs uses reads_markers/same_pixels_with; the branch's
two marker tests replace the old ones in crates/ui-egui/src/frames/tests.rs
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
bflatastic