Improve projection performance

2026-06-01 08:48:50 -05:00 · 2026-06-01 08:48:50 -05:00 · b5046a16c2
commit b5046a16c2
parent d2617a25ff
4 changed files with 116 additions and 30 deletions
--- a/Minecraft/Services/Sources/Core/SourceLibrary.swift
+++ b/Minecraft/Services/Sources/Core/SourceLibrary.swift
@ -26,7 +26,11 @@ final class SourceLibrary: ObservableObject, SourceScanSessionHosting, SourcePer
        category: "ConnectedDevicePerformance"
    )

-    @Published var sources: [MinecraftSource] = []
+    @Published var sources: [MinecraftSource] = [] {
+        didSet {
+            rebuildLookupIndexes()
+        }
+    }
    @Published var connectedDevices: [ConnectedDeviceSidebarEntry] = []
    @Published var isRestoringPersistedSources = true

@ -40,6 +44,8 @@ final class SourceLibrary: ObservableObject, SourceScanSessionHosting, SourcePer
    private let notificationService: ScanNotificationServicing
    private let itemActionService: ContentItemActionService
    private let connectedDeviceSourceFactory = ConnectedDeviceSourceFactory()
+    private var sourceIndexByID: [URL: Int] = [:]
+    private var sourceIDByItemID: [URL: URL] = [:]
    var lastMatchedConnectedSourceIDs: Set<URL> = []
    var cachedDeviceDiscoveryByUDID: [String: CachedConnectedDeviceDiscovery] = [:]
    var isShuttingDown = false
@ -90,6 +96,14 @@ final class SourceLibrary: ObservableObject, SourceScanSessionHosting, SourcePer
        visibleSources
    }

+    func sourceID(forItemID itemID: URL) -> URL? {
+        sourceIDByItemID[itemID]
+    }
+
+    func containsItem(withID itemID: URL) -> Bool {
+        sourceIDByItemID[itemID] != nil
+    }
+
    func shutdown() {
        guard !isShuttingDown else {
            return
@ -189,7 +203,11 @@ final class SourceLibrary: ObservableObject, SourceScanSessionHosting, SourcePer
    }

    func source(withID sourceID: URL) -> MinecraftSource? {
-        sources.first(where: { $0.id == sourceID })
+        guard let index = sourceIndexByID[sourceID], sources.indices.contains(index) else {
+            return nil
+        }
+
+        return sources[index]
    }

    func rescanSource(withID sourceID: URL) {
@ -499,6 +517,18 @@ final class SourceLibrary: ObservableObject, SourceScanSessionHosting, SourcePer
        )
    }

+    private func rebuildLookupIndexes() {
+        sourceIndexByID = Dictionary(uniqueKeysWithValues: sources.enumerated().map { ($0.element.id, $0.offset) })
+
+        var itemIndex: [URL: URL] = [:]
+        for source in sources {
+            for item in source.items {
+                itemIndex[item.id] = source.id
+            }
+        }
+        sourceIDByItemID = itemIndex
+    }
+
    @discardableResult
    func updateAvailability(for sourceID: URL, to newAvailability: SourceAvailability) -> (previous: SourceAvailability, becameAvailable: Bool) {
        SourceSyncRuntime.updateAvailability(for: sourceID, to: newAvailability, on: self)
--- a/Minecraft/UI/List/ItemListColumnViews.swift
+++ b/Minecraft/UI/List/ItemListColumnViews.swift
@ -33,7 +33,7 @@ struct ItemListColumnView<MenuContent: View>: View {
    let subtitle: String
    let showsSubtitle: Bool
    let isRefreshing: Bool
-    let isUpdatingProjection: Bool
+    let showsProjectionLoadingState: Bool
    let items: [MinecraftContentItem]
    let searchPrompt: String
    let chooseFolderAction: () -> Void
@ -58,7 +58,7 @@ struct ItemListColumnView<MenuContent: View>: View {
                }
                .listStyle(.inset)
                .overlay {
-                    if isUpdatingProjection && items.isEmpty {
+                    if showsProjectionLoadingState && items.isEmpty {
                        ItemListLoadingOverlay()
                    }
                }
@ -73,7 +73,7 @@ struct ItemListColumnView<MenuContent: View>: View {
                    subtitle: subtitle,
                    showsSubtitle: showsSubtitle,
                    isRefreshing: isRefreshing,
-                    isUpdatingProjection: isUpdatingProjection
+                    showsProjectionLoadingState: showsProjectionLoadingState
                )
            }
        }
@ -106,7 +106,7 @@ private struct ItemListHeaderView: View {
    let subtitle: String
    let showsSubtitle: Bool
    let isRefreshing: Bool
-    let isUpdatingProjection: Bool
+    let showsProjectionLoadingState: Bool

    var body: some View {
        VStack(alignment: .leading, spacing: 8) {
@ -121,13 +121,13 @@ private struct ItemListHeaderView: View {
                    .font(.title2.weight(.semibold))
                    .lineLimit(2)

-                if isRefreshing || isUpdatingProjection {
+                if isRefreshing || showsProjectionLoadingState {
                    ProgressView()
                        .appActivityIndicatorStyle(.small)
                }
            }

-            if showsSubtitle || isUpdatingProjection {
+            if showsSubtitle || showsProjectionLoadingState {
                Text(displaySubtitle)
                    .appTextStyle(.supporting)
            }
@ -140,7 +140,7 @@ private struct ItemListHeaderView: View {
    }

    private var displaySubtitle: String {
-        if isUpdatingProjection {
+        if showsProjectionLoadingState {
            return "Loading items..."
        }

--- a/Minecraft/UI/Preview/PreviewFixtures.swift
+++ b/Minecraft/UI/Preview/PreviewFixtures.swift
@ -323,7 +323,7 @@ struct ItemListColumnPreviewContainer: View {
                subtitle: "5 items in Kid iPad Imports",
                showsSubtitle: false,
                isRefreshing: false,
-                isUpdatingProjection: false,
+                showsProjectionLoadingState: false,
                items: PreviewFixtures.primarySource.displayItems,
                searchPrompt: "Search Worlds",
                chooseFolderAction: {},
--- a/Minecraft/UI/Root/ContentView.swift
+++ b/Minecraft/UI/Root/ContentView.swift
@ -20,6 +20,7 @@ struct ContentView: View {
    @State private var isShowingDeviceSourceSheet = false
    @State private var sortMode: ItemSortMode = .name
    @State private var directoryPreviewContents: [DirectoryEntry] = []
+    @State private var showsProjectionLoadingState = false
    @State private var itemListProjection = ItemCollectionProjection.placeholder(
        for: ItemCollectionProjectionRequest(
            selection: nil,
@ -33,6 +34,7 @@ struct ContentView: View {
    private let deviceSourceFactory: ConnectedDeviceSourceFactory
    private let itemActionService: ContentItemActionService
    private let directoryPreviewLimit = 12
+    private let projectionLoadingDelay: Duration = .milliseconds(150)

    init() {
        let dependencies = ContentViewDependencies.makeDefault()
@ -53,15 +55,25 @@ struct ContentView: View {
            sortMode: sortMode,
            source: resolvedCurrentSource
        )
+        let fastPathProjection = fastProjection(for: currentProjectionRequest, previousRequest: itemListProjection.request)
        let reusesCurrentProjectedItems =
            itemListProjection.request.selection == currentProjectionRequest.selection &&
            itemListProjection.request.source?.id == currentProjectionRequest.source?.id
-        let isUpdatingItemListProjection = itemListProjection.request != currentProjectionRequest
-        let resolvedItemListProjection = itemListProjection.request == currentProjectionRequest
-            ? itemListProjection
-            : ItemCollectionProjection.placeholder(for: currentProjectionRequest)
+        let resolvedItemListProjection = if let fastPathProjection {
+            fastPathProjection
+        } else if itemListProjection.request == currentProjectionRequest {
+            itemListProjection
+        } else {
+            ItemCollectionProjection.placeholder(for: currentProjectionRequest)
+        }
        let resolvedCurrentSelectedItem = currentSelectedItem(in: resolvedCurrentSource)
-        let resolvedDisplayedItems = reusesCurrentProjectedItems ? itemListProjection.items : []
+        let resolvedDisplayedItems: [MinecraftContentItem] = if let fastPathProjection {
+            fastPathProjection.items
+        } else if reusesCurrentProjectedItems {
+            itemListProjection.items
+        } else {
+            []
+        }

        NavigationSplitView(columnVisibility: $columnVisibility) {
            SourcesSidebarView(
@ -94,9 +106,9 @@ struct ContentView: View {
                showsSourceName: !isSidebarVisible,
                title: resolvedItemListProjection.title,
                subtitle: resolvedItemListProjection.subtitle,
-                showsSubtitle: isSearching || isUpdatingItemListProjection,
+                showsSubtitle: isSearching || showsProjectionLoadingState,
                isRefreshing: resolvedCurrentSource?.isScanning == true,
-                isUpdatingProjection: isUpdatingItemListProjection,
+                showsProjectionLoadingState: showsProjectionLoadingState,
                items: resolvedDisplayedItems,
                searchPrompt: resolvedItemListProjection.searchPrompt,
                chooseFolderAction: pickFolder,
@ -180,14 +192,41 @@ struct ContentView: View {
        }
        .task(id: currentProjectionRequest) {
            let request = currentProjectionRequest
+            if let fastPathProjection = fastProjection(for: request, previousRequest: itemListProjection.request) {
+                showsProjectionLoadingState = false
+                itemListProjection = fastPathProjection
+                return
+            }
+
            let projection = await Task.detached(priority: .userInitiated) {
                ItemCollectionProjector.makeProjection(for: request)
            }.value
            guard !Task.isCancelled else {
                return
            }
+            showsProjectionLoadingState = false
            itemListProjection = projection
        }
+        .task(id: currentProjectionRequest) {
+            showsProjectionLoadingState = false
+
+            guard itemListProjection.request != currentProjectionRequest else {
+                return
+            }
+
+            guard fastProjection(for: currentProjectionRequest, previousRequest: itemListProjection.request) == nil else {
+                return
+            }
+
+            try? await Task.sleep(for: projectionLoadingDelay)
+            guard !Task.isCancelled else {
+                return
+            }
+
+            if itemListProjection.request != currentProjectionRequest {
+                showsProjectionLoadingState = true
+            }
+        }
        .task(id: resolvedCurrentSelectedItem?.id) {
            await refreshDirectoryPreviewContents()
        }
@ -224,10 +263,9 @@ struct ContentView: View {
            return item
        }

-        for source in library.visibleSources {
-            if let item = source.items.first(where: { $0.id == selectedItemID }) {
-                return item
-            }
+        if let sourceID = library.sourceID(forItemID: selectedItemID),
+           let source = library.source(withID: sourceID) {
+            return source.items.first(where: { $0.id == selectedItemID })
        }

        return nil
@ -558,18 +596,17 @@ struct ContentView: View {
        }

        if let selectedItemID {
-            let itemStillExists = library.visibleSources
-                .flatMap(\.items)
-                .contains(where: { $0.id == selectedItemID })
-
-            if !itemStillExists {
+            if !library.containsItem(withID: selectedItemID) {
                self.selectedItemID = nil
            }
        }
    }

    private func areFileActionsEnabled(for item: MinecraftContentItem) -> Bool {
-        guard let source = library.visibleSources.first(where: { $0.items.contains(where: { $0.id == item.id }) }) else {
+        guard
+            let sourceID = library.sourceID(forItemID: item.id),
+            let source = library.source(withID: sourceID)
+        else {
            return false
        }

@ -577,9 +614,28 @@ struct ContentView: View {
    }

    private func sourceForItem(_ item: MinecraftContentItem) -> MinecraftSource? {
-        library.visibleSources.first(where: { source in
-            source.items.contains(where: { $0.id == item.id })
-        })
+        guard let sourceID = library.sourceID(forItemID: item.id) else {
+            return nil
+        }
+
+        return library.source(withID: sourceID)
+    }
+
+    private func fastProjection(
+        for request: ItemCollectionProjectionRequest,
+        previousRequest: ItemCollectionProjectionRequest
+    ) -> ItemCollectionProjection? {
+        guard
+            let sourceID = request.source?.id,
+            sourceID == previousRequest.source?.id,
+            request.searchText == previousRequest.searchText,
+            request.sortMode == previousRequest.sortMode,
+            request.selection != previousRequest.selection
+        else {
+            return nil
+        }
+
+        return ItemCollectionProjector.makeProjection(for: request)
    }

    private func saveItem(_ item: MinecraftContentItem) {