diff --git a/.jules/bolt.md b/.jules/bolt.md index b2c1128..0d99566 100644 --- a/.jules/bolt.md +++ b/.jules/bolt.md @@ -28,3 +28,6 @@ ## 2025-10-24 - Bulk Disk I/O Parallelization and Thread Pool Starvation **Learning:** Both `withTaskGroup` and `Task.detached` schedule their work on Swift's cooperative thread pool, which has only as many threads as the CPU has cores. Running synchronous blocking I/O (like `FileManager.removeItem`) directly inside such tasks ties up cooperative threads — when every thread is parked in a syscall there is nothing left to advance other Swift Concurrency work, which manifests as starvation and (with self-referential `await` chains) outright deadlock. `Task.detached` does not help here: "detached" means unstructured/independent, not "off the cooperative pool." **Action:** To parallelize bulk blocking I/O, combine a sliding-window `withThrowingTaskGroup` (e.g., `maxConcurrency` of 8) with a per-item handoff to a GCD queue: wrap the blocking call in `withCheckedThrowingContinuation` and dispatch it via `DispatchQueue.global(qos: .userInitiated).async { ... continuation.resume(...) }`. The cooperative-pool task only `await`s the continuation, so it never holds a thread while the syscall runs. +## 2026-04-05 - Lazy Filter Chains in SwiftUI Computed Properties +**Learning:** Eager `.filter` operations in SwiftUI computed properties execute on every view re-render, allocating temporary intermediate arrays that cause unnecessary memory churn. +**Action:** Chain `.lazy.filter` before terminal operations like `.count` or `.sorted()` in UI components to avoid intermediate array allocations during rapid state updates. diff --git a/Sources/Cacheout/Views/CleanConfirmation.swift b/Sources/Cacheout/Views/CleanConfirmation.swift index 58f679b..6fe1ef8 100644 --- a/Sources/Cacheout/Views/CleanConfirmation.swift +++ b/Sources/Cacheout/Views/CleanConfirmation.swift @@ -36,7 +36,8 @@ struct CleanConfirmationSheet: View { Text("Clean Selected Caches?") .font(.title2.bold()) - Text("This will remove \(viewModel.formattedTotalSelectedSize) from \(viewModel.selectedResults.count + viewModel.nodeModulesItems.filter(\.isSelected).count) items.") + // PERF: Use .lazy.filter before .count to prevent intermediate array allocation + Text("This will remove \(viewModel.formattedTotalSelectedSize) from \(viewModel.selectedResults.count + viewModel.nodeModulesItems.lazy.filter(\.isSelected).count) items.") .font(.body) .foregroundStyle(.secondary) .multilineTextAlignment(.center) diff --git a/Sources/Cacheout/Views/MenuBarView.swift b/Sources/Cacheout/Views/MenuBarView.swift index 9084b59..03fb005 100644 --- a/Sources/Cacheout/Views/MenuBarView.swift +++ b/Sources/Cacheout/Views/MenuBarView.swift @@ -154,7 +154,8 @@ struct MenuBarView: View { Spacer() statPill( label: "Categories", - value: "\(viewModel.scanResults.filter { !$0.isEmpty }.count)", + // PERF: Use .lazy.filter before .count to prevent intermediate array allocation + value: "\(viewModel.scanResults.lazy.filter { !$0.isEmpty }.count)", color: .blue ) } @@ -177,7 +178,9 @@ struct MenuBarView: View { // MARK: - Top Categories private var topCategories: some View { + // PERF: Chain .lazy.filter before .sorted() to prevent intermediate array allocation let top = viewModel.scanResults + .lazy .filter { !$0.isEmpty } .sorted { $0.sizeBytes > $1.sizeBytes } .prefix(5)