nightshift/perf: cache decoded images to eliminate repeated disk reads#3
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nightshift/perf: cache decoded images to eliminate repeated disk reads#3
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loadImage(for:) called NSImage(contentsOf:) on every SwiftUI render pass, doing synchronous disk I/O on the main thread for each visible image snippet. Add a simple NSCache so the file is read at most once per session; cache entries are evicted automatically on memory pressure. Invalidate the relevant entry on delete and on addImage so callers always see the current image.
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Summary
SnippetStore.loadImage(for:)calledNSImage(contentsOf:)on every SwiftUI render pass — synchronous disk I/O on the main thread for every visible image snippet, on every frame. With several image snippets in the list this causes measurable jank while scrolling or resizing the panel.Changes
NSCache<NSString, NSImage>toSnippetStoreloadImage(for:)now returns the cached image when available; falls back to disk and populates the cache on the first loadaddImage(_:)primes the cache with the already-decodedNSImageso the first render after a paste is also free of disk I/Odelete(_:)evicts the cache entry alongside removing the file, preventing stale dataNSCacheis used rather than a plainDictionaryso the OS can reclaim memory automatically under pressure without any manual eviction logic needed.Expected impact
NSCacheeviction policy