perf: cache parsed flags and let the raster cache retain them - #1
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perf: cache parsed flags and let the raster cache retain them#1ik-make wants to merge 2 commits into
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ScalableImageWidget.fromSISource falls back to a zero-size cache when none is supplied, so every flag scrolling out of view is evicted immediately and re-parsed on the way back. In a long scrolling list this also releases the native Path objects that already-queued pictures still reference, and Flutter web (Skwasm) then traps with "memory access out of bounds". Share one ScalableImageCache across all _FlagImage instances, sized to hold the whole flag pack. Co-authored-by: Cursor <cursoragent@cursor.com>
CustomPaint.isComplex defaults to false, so the raster cache never retains a flag and the whole compact image is replayed on every frame. Several flags carry a coat of arms (rs.si is ~500KB, pe.si ~127KB), which makes that replay expensive during a scroll and churns a large number of short-lived native Path objects. Co-authored-by: Cursor <cursoragent@cursor.com>
ik-make
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IMHO it's unlikely to be a jovial_svg bug. Rather, it appears to be a bug in the Skwasm renderer that you were able to work around (partially?) in jovial_svg. See zathras/jovial_svg#143 . |
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Found while chasing a Skwasm renderer crash in a 145-row language picker on Flutter 3.47.2 (
--wasm, single-threaded skwasm). The crash itself turned out to be a jovial_svg bug, not acountry_flagsbug — it is fixed separately in zathras/jovial_svg#142. These two changes are pure performance work, verified not to be required for the crash fix.1. Share a
ScalableImageCache_FlagImagecallsScalableImageWidget.fromSISourcewithout acache:. Per jovial_svg's docs on that constructor:So every flag that scrolls out of view is evicted immediately and re-parsed when it scrolls back. Some assets in this pack are large (
rs.si~500KB,pe.si~127KB,es.si~77KB), so a scroll repeatedly re-parses hundreds of KB on the main thread.A single static cache, sized to hold the whole pack, removes that.
2.
isComplex: trueCustomPaint.isComplexdefaults to false, so the raster cache never retains a painted flag and the whole compact image is replayed every frame. Flags are detailed vector art (several carry a coat of arms), which is exactly the caseisComplexexists for.Notes
No API change, no asset change. Both are opt-out-free improvements for any consumer rendering many flags at once.