From ec8a4a259b34b7d0fdae06607406f001bb878b8c Mon Sep 17 00:00:00 2001 From: "google-labs-jules[bot]" <161369871+google-labs-jules[bot]@users.noreply.github.com> Date: Wed, 10 Jun 2026 05:28:33 +0000 Subject: [PATCH] =?UTF-8?q?=E2=9A=A1=20Bolt:=20[performance=20improvement]?= =?UTF-8?q?=20Eliminate=20eager=20array=20allocations=20in=20computed=20pr?= =?UTF-8?q?operties?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Replaced eager `.filter` calls with `.lazy.filter` and `.contains(where:)` in `CacheoutViewModel` and `MenuBarView`. Calling `.filter` followed by `.isEmpty` or `.count` allocates a complete array just to check boolean state or get a count, causing memory churn in frequently evaluated SwiftUI computed properties. Additionally, checking `selectedNodeModulesSize > 0` forced a full iteration over node modules instead of short-circuiting. Reduces intermediate array allocations during rendering and O(N) operations to O(1) short-circuiting when checking selections, improving frame rates. Co-authored-by: acebytes <2820910+acebytes@users.noreply.github.com> --- .jules/bolt.md | 3 +++ Sources/Cacheout/ViewModels/CacheoutViewModel.swift | 4 ++-- Sources/Cacheout/Views/MenuBarView.swift | 4 ++-- 3 files changed, 7 insertions(+), 4 deletions(-) diff --git a/.jules/bolt.md b/.jules/bolt.md index b2c1128..772f73c 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. +## 2025-11-01 - Eager Filtering in Computed Properties +**Learning:** Calling `.isEmpty` on an eagerly filtered array (e.g., `!selectedResults.isEmpty` where `selectedResults` uses `.filter`) allocates a complete intermediate array just to evaluate a boolean state, causing memory churn in SwiftUI computed properties. Additionally, checking sizes greater than zero (e.g., `selectedNodeModulesSize > 0`) forces full iteration. +**Action:** Use `.contains(where:)` for boolean checks to short-circuit iteration without allocation, and chain `.lazy.filter` before `.reduce`, `.count`, or `.sorted`. diff --git a/Sources/Cacheout/ViewModels/CacheoutViewModel.swift b/Sources/Cacheout/ViewModels/CacheoutViewModel.swift index 27de41a..4097202 100644 --- a/Sources/Cacheout/ViewModels/CacheoutViewModel.swift +++ b/Sources/Cacheout/ViewModels/CacheoutViewModel.swift @@ -106,7 +106,7 @@ class CacheoutViewModel: ObservableObject { } var selectedSize: Int64 { - selectedResults.reduce(0) { $0 + $1.sizeBytes } + scanResults.lazy.filter(\.isSelected).reduce(0) { $0 + $1.sizeBytes } } var formattedSelectedSize: String { @@ -118,7 +118,7 @@ class CacheoutViewModel: ObservableObject { } var hasResults: Bool { !scanResults.isEmpty || !nodeModulesItems.isEmpty } - var hasSelection: Bool { !selectedResults.isEmpty || selectedNodeModulesSize > 0 } + var hasSelection: Bool { scanResults.contains(where: \.isSelected) || nodeModulesItems.contains(where: \.isSelected) } // MARK: - Node Modules computed properties diff --git a/Sources/Cacheout/Views/MenuBarView.swift b/Sources/Cacheout/Views/MenuBarView.swift index 9084b59..c6bd622 100644 --- a/Sources/Cacheout/Views/MenuBarView.swift +++ b/Sources/Cacheout/Views/MenuBarView.swift @@ -154,7 +154,7 @@ struct MenuBarView: View { Spacer() statPill( label: "Categories", - value: "\(viewModel.scanResults.filter { !$0.isEmpty }.count)", + value: "\(viewModel.scanResults.lazy.filter { !$0.isEmpty }.count)", color: .blue ) } @@ -178,7 +178,7 @@ struct MenuBarView: View { private var topCategories: some View { let top = viewModel.scanResults - .filter { !$0.isEmpty } + .lazy.filter { !$0.isEmpty } .sorted { $0.sizeBytes > $1.sizeBytes } .prefix(5)