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Run synchronous mutations ahead of all async mutations.

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george-signal 2023-01-11 15:48:38 -08:00 committed by GitHub
parent e8788abc19
commit fb3225c9fb
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4 changed files with 57 additions and 26 deletions
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6
Signal/src/ViewControllers/MediaGallery/MediaGallery.swift
View File

@ -425,6 +425,7 @@ class MediaGallery: Dependencies {
async: Bool = false,
userData: MediaGalleryUpdateUserData? = nil,
completion: ((_ newSections: IndexSet) -> Void)? = nil) {
Logger.info("")
let anchorItem: MediaGalleryItem? = sections.loadedItem(at: IndexPath(item: itemIndex, section: sectionIndex))
// May include a negative start location.
@ -461,6 +462,7 @@ class MediaGallery: Dependencies {
}()
if async {
Logger.info("will ensure loaded asynchronously")
mutateAsync { sections, callback in
sections.asyncEnsureItemsLoaded(in: naiveRequestRange,
relativeToSection: sectionIndex,
@ -471,6 +473,7 @@ class MediaGallery: Dependencies {
completion?(newlyLoadedSections)
}
} else {
Logger.info("will ensure loaded synchronously")
let newlyLoadedSections = mutate { sections in
sections.ensureItemsLoaded(in: naiveRequestRange,
relativeToSection: sectionIndex,
@ -497,6 +500,7 @@ class MediaGallery: Dependencies {
}
internal func ensureLoadedForDetailView(focusedAttachment: TSAttachment) -> MediaGalleryItem? {
Logger.info("")
let newItem: MediaGalleryItem? = databaseStorage.read { transaction in
guard let focusedItem = buildGalleryItem(attachment: focusedAttachment, transaction: transaction) else {
return nil
@ -527,10 +531,12 @@ class MediaGallery: Dependencies {
// For a speedy load, we only fetch a few items on either side of
// the initial message
Logger.info("ensureGalleryItemsLoaded: will call")
ensureGalleryItemsLoaded(.around,
item: focusedItem,
amount: kGallerySwipeLoadBatchSize * 2,
shouldLoadAlbumRemainder: true)
Logger.info("ensureGalleryItemsLoaded: finished")
return focusedItem
}

71
Signal/src/ViewControllers/MediaGallery/MediaGallerySections.swift
View File

@ -499,7 +499,7 @@ internal struct MediaGallerySections<Loader: MediaGallerySectionLoader, UpdateUs
/// always be before and/or after the existing sections, never interleaving.
internal mutating func ensureItemsLoaded(request: LoadItemsRequest,
transaction: SDSAnyReadTransaction) -> IndexSet {
return Bench(title: "fetching gallery items") {
return Bench(title: "ensureItemsLoaded") {
guard let naiveRange = resolveLoadItemsRequest(request) else {
return IndexSet()
}
@ -703,27 +703,29 @@ internal struct MediaGallerySections<Loader: MediaGallerySectionLoader, UpdateUs
}
private class SnapshotManager: Dependencies {
let queue: DispatchQueue
private var mutableState: State
private var snapshot: State
private(set) var pendingUpdate = AtomicValue(Update.noop, lock: AtomicLock())
private var highPriorityStack: AtomicArray<() -> Void> = AtomicArray()
private var lowPriorityStack: AtomicArray<() -> Void> = AtomicArray()
// We use an operation queue because we need to prioritize user-initiated actions over others,
// such as eager fetching. OperationQueue gives us this for free.
private let operationQueue = OperationQueue()
var state: State {
dispatchPrecondition(condition: .onQueue(.main))
return snapshot
}
init(_ queue: DispatchQueue, state: State) {
self.queue = queue
init(state: State) {
operationQueue.maxConcurrentOperationCount = 1
self.mutableState = state
self.snapshot = state
}
// Runs on the operation queue.
private func _mutate<T>(userData: UpdateUserData?, _ block: (inout State) -> (T)) -> T {
dispatchPrecondition(condition: .onQueue(queue))
let result = block(&mutableState)
let updatedState = mutableState
let changes = mutableState.itemsBySection.takeJournal()
@ -737,10 +739,27 @@ internal struct MediaGallerySections<Loader: MediaGallerySectionLoader, UpdateUs
return result
}
private var depthReport: String {
return "H=\(highPriorityStack.count) L=\(lowPriorityStack.count)"
}
func mutate<T>(userData: UpdateUserData?, _ block: (inout State) -> (T)) -> T {
dispatchPrecondition(condition: .onQueue(.main))
return queue.sync {
return _mutate(userData: userData, block)
return Bench(title: "Sync mutation [\(depthReport)]", logInProduction: true) {
dispatchPrecondition(condition: .onQueue(.main))
var result: T!
withoutActuallyEscaping(block) { escapingClosure in
// This is used to trick Swift into believing that escapingClosure doesn't escape.
var sneakyClosure: ((inout State) -> T)?
sneakyClosure = escapingClosure
let operation = BlockOperation {
result = self._mutate(userData: userData, sneakyClosure!)
}
operation.queuePriority = .veryHigh
operationQueue.addOperation(operation)
operation.waitUntilFinished()
sneakyClosure = nil
}
return result
}
}
@ -752,7 +771,7 @@ internal struct MediaGallerySections<Loader: MediaGallerySectionLoader, UpdateUs
}
}
/// Runs `block` on the mutation queue and then runs `completion` on the main queue, but the main queue is not
/// Runs `block` on the operation queue and then runs `completion` on the main queue, but the main queue is not
/// blocked while waiting for `block` to complete.
///
/// Note that mutations go on a stack rather than a queue. The last call to `mutateAsync` will be the first one to run after any current operation completes.
@ -760,6 +779,7 @@ internal struct MediaGallerySections<Loader: MediaGallerySectionLoader, UpdateUs
/// All `highPriority` mutations will occur before any low-priority mutation. Clients are advised to treat user-initiated updates as high-priority.
func mutateAsync<T>(userData: UpdateUserData?,
highPriority: Bool,
title: String?,
_ block: @escaping (inout State) -> (T),
completion: @escaping (T) -> Void) {
dispatchPrecondition(condition: .onQueue(.main))
@ -767,26 +787,30 @@ internal struct MediaGallerySections<Loader: MediaGallerySectionLoader, UpdateUs
guard let self else {
return
}
let result = self._mutate(userData: userData, block)
DispatchQueue.main.async {
completion(result)
Bench(title: "Async mutation of \(title ?? "untitled") [\(self.depthReport)]", logInProduction: true) {
let result = self._mutate(userData: userData, block)
DispatchQueue.main.async {
completion(result)
}
}
}
(highPriority ? highPriorityStack : lowPriorityStack).pushTail(closure)
queue.async { [weak self] in
guard let self else {
return
let operation = BlockOperation { [weak self] in
if let self {
let closure = self.highPriorityStack.popTail() ?? self.lowPriorityStack.popTail()
closure?()
}
let closure = self.highPriorityStack.popTail() ?? self.lowPriorityStack.popTail()
closure?()
}
operation.queuePriority = .normal
operationQueue.addOperation(operation)
}
func mutateAsync<T>(userData: UpdateUserData?,
highPriority: Bool,
title: String? = nil,
_ block: @escaping (inout State, SDSAnyReadTransaction) -> (T),
completion: @escaping (T) -> Void) {
mutateAsync(userData: userData, highPriority: highPriority) { mutableState in
mutateAsync(userData: userData, highPriority: highPriority, title: title) { mutableState in
return Self.databaseStorage.read { transaction in
block(&mutableState, transaction)
}
@ -798,10 +822,9 @@ internal struct MediaGallerySections<Loader: MediaGallerySectionLoader, UpdateUs
private var snapshotManager: SnapshotManager
private var state: State { snapshotManager.state }
private let mutationQueue = DispatchQueue(label: "org.signal.media-gallery-sections-mutation")
internal init(loader: Loader) {
snapshotManager = SnapshotManager(mutationQueue, state: State(loader: loader))
snapshotManager = SnapshotManager(state: State(loader: loader))
}
/// Executes `closure` with exclusive access to the pending update. It must not escape the
@ -830,7 +853,7 @@ internal struct MediaGallerySections<Loader: MediaGallerySectionLoader, UpdateUs
highPriority: Bool,
userData: UpdateUserData? = nil,
completion: ((Int) -> Void)?) {
snapshotManager.mutateAsync(userData: userData, highPriority: highPriority) { state, transaction in
snapshotManager.mutateAsync(userData: userData, highPriority: highPriority, title: "load earlier section") { state, transaction in
return state.loadEarlierSections(batchSize: batchSize, transaction: transaction)
} completion: { numberOfSectionsLoaded in
completion?(numberOfSectionsLoaded)
@ -846,7 +869,7 @@ internal struct MediaGallerySections<Loader: MediaGallerySectionLoader, UpdateUs
internal mutating func asyncLoadLaterSections(batchSize: Int,
userData: UpdateUserData? = nil,
completion: ((Int) -> Void)?) {
snapshotManager.mutateAsync(userData: userData, highPriority: true) { state, transaction in
snapshotManager.mutateAsync(userData: userData, highPriority: true, title: "load later sections") { state, transaction in
return state.loadLaterSections(batchSize: batchSize, transaction: transaction)
} completion: { numberOfSectionsLoaded in
completion?(numberOfSectionsLoaded)
@ -1100,7 +1123,7 @@ internal struct MediaGallerySections<Loader: MediaGallerySectionLoader, UpdateUs
}
return
}
snapshotManager.mutateAsync(userData: userData, highPriority: true) { state, transaction in
snapshotManager.mutateAsync(userData: userData, highPriority: true, title: "ensure \(naiveRange.count) items loaded") { state, transaction in
return state.ensureItemsLoaded(request: request,
transaction: transaction)
} completion: { newlyLoadedSectionIndexes in

2
Signal/src/ViewControllers/MediaGallery/MediaPageViewController.swift
View File

@ -92,7 +92,9 @@ class MediaPageViewController: UIPageViewController, UIPageViewControllerDataSou
delegate = self
transitioningDelegate = self
Logger.info("will ensureLoadedForDetailView")
let galleryItem = mediaGallery.ensureLoadedForDetailView(focusedAttachment: initialMediaAttachment)
Logger.info("ensureLoadedForDetailView done")
guard let initialItem = galleryItem else {
owsFailDebug("unexpectedly failed to build initialDetailItem.")

4
Signal/src/ViewControllers/MediaGallery/MediaTileViewController.swift
View File

@ -277,7 +277,7 @@ public class MediaTileViewController: UICollectionViewController, MediaGalleryDe
}
override public func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
Logger.debug("")
Logger.info("")
guard let gridCell = self.collectionView(collectionView, cellForItemAt: indexPath) as? PhotoGridViewCell else {
owsFailDebug("galleryCell was unexpectedly nil")
@ -796,7 +796,7 @@ public class MediaTileViewController: UICollectionViewController, MediaGalleryDe
// MARK: Lazy Loading
var isFetchingMoreData = false
let kLoadBatchSize: Int = 1024
let kLoadBatchSize: Int = 100
let kLoadOlderSectionIdx: Int = 0
var loadNewerSectionIdx: Int {