async/awaitの性能をDartとSwiftとの比較で読み解く

iOSDC 2021 のプレゼン資料
「async/awaitの性能をDartとSwiftとの比較で読み解く」

Transcript

1. async/awaitͷੑೳΛ
   DartͱSwiftͱͷൺֱͰಡΈղ͘
   iOSDC 2021
   Tamappe
   @tamapppe
   

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2. I N T R O D U C T I O N
   Tamappe
   ϞόΠϧΞϓϦΤϯδχΞ
   2014೥-2019೥3݄·ͰϑϦʔϥϯεͱͯ͠׆ಈ
   2019೥4݄ΑΓϨΞδϣϒʹϞόΠϧΞϓϦΤϯδχΞͱͯ͠ೖࣾ
   झຯ: ϒϩάͷߋ৽ɺσΟζχʔ८Γ(ίϩφʹΑΓࣗॗ)
   Qiita: https://qiita.com/tamappe
   Blog: https://tamappe.com
   Twitter: https://twitter.com/tamapppe
   01
   גࣜձࣾϨΞδϣϒ
   

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3. ຊ೔ͷςʔϚ
   async/await
   SwiftͱDartͷൺֱ
   

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4. ͖͔͚ͬ…
   WWDC 2021Ͱasync/awaitൃද
   

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5. ͖͔͚ͬ…
   ɾfunctionͰ࢖͑Δ
   ɾError handling Ͱ΋࢖͑Δ
   ɾfor จ(Async sequences)Ͱ΋࢖͑Δͷʁ
   ɾgetterͰ΋࢖͑Δ΍Μʁʁ
   

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6. ˎasync/await͸ͲͷݴޠͰ΋ૉ੖Β͍͠Ͱ͢
   SwiftͰͷasync/await
   ΊͬͪΌੌ͍΍Μ
   ݁࿦...
   

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7. Ajenda
   1. async/await ൺֱ
   2. SwiftͰͷasync/await
   3. SwiftͰͷӨڹൣғ
   4. DartͰͷasync/await
   5. DartͰͷϝϦοτɾσϝϦοτ
   6. ·ͱΊ
   

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8. async/await ൺֱ
   02
   Swift Dart
   Function ○ ○
   Error handling ○ ○
   Property(getter) ○ ×
   Parameter × ○
   Async sequences ○ ×
   

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9. async/await is …
   03
   1.Simple
   2.Easy
   3.Safe
   

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10. 04
    SwiftͰͷasync/await
    

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11. SwiftͰͷasync/await
    05
    Function
    WWDC 2021 Meet async/await in Swift
    

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12. SwiftͰͷasync/await
    06
    Function
    func asyncFetchData() async throws -> Data {
    
    
    let url = URL(string: "https://jsonplaceholder.typicode.com/todos/1")!
    
    
    let request = URLRequest(url: url)
    
    
    let (data, response) = try await URLSession.shared.data(for: request,
    
    
    delegate: nil)
    
    
    guard (response as? HTTPURLResponse)?.statusCode == 200 else {
    
    
    throw NSError(domain: "error", code: -1, userInfo: nil)
    
    
    }
    
    
    return data
    
    
    }
    

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13. SwiftͰͷasync/await
    07
    Property (getter)
    WWDC 2021 Meet async/await in Swift
    

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14. SwiftͰͷasync/await
    08
    Property (getter)
    extension UIImage {
    
    
    var thumbnail: UIImage? {
    
    
    get async {
    
    
    let size = CGSize(width: 40, height: 40)
    
    
    return await self.byPreparingThumbnail(ofSize: size)
    
    
    }
    
    
    }
    
    
    }
    

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15. SwiftͰͷasync/await
    09
    Async sequences (for loop)
    WWDC 2021 Meet async/await in Swift
    

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16. SwiftͰͷasync/await
    10
    sync to async
    WWDC 2021 Meet async/await in Swift
    

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17. SwiftͰͷasync/await
    11
    sync to async
    func doSomething() {
    
    
    async {
    
    
    let data = try await asyncFetchData()
    
    
    }
    
    
    }
    

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18. 12
    SwiftͰͷӨڹൣғ
    

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19. SwiftͰͷӨڹൣғ
    13
    1. ίʔϧόοΫ
    - ίʔϧόοΫ(ωετ)஍ࠈ͔Βͷղ์
    - weakSelf͔Βͷղ์
    2. Thread
    - actorʹΑΓMainActorͰϝΠϯεϨουͰ࣮ߦ
    3. CoreData
    - contextͰͷ΍ΓͱΓ
    

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20. SwiftͰͷӨڹൣғ (ίʔϧόοΫ)
    14
    class SampleRequest: NSObject {
    
    
    
    
    func fetchSomethingA(id: Int, compeltion: (Int) -> Void) { }
    
    
    func fetchSomethingB(id: Int, compeltion: (Int) -> Void) { }
    
    
    
    
    func fetchSomethingC(id: Int, compeltion: (Int) -> Void) { }
    
    
    
    
    }
    

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21. SwiftͰͷӨڹൣғ (ίʔϧόοΫ)
    15
    class SampleRequest: NSObject {
    
    
    
    
    // தུ
    
    
    
    
    func requestSomething() {
    
    
    fetchSomethingA(id: 1, compeltion: { [weak self] a in
    
    
    // ॲཧΛॻ͘
    
    
    self?.fetchSomethingB(id: a, compeltion: { [weak self] b in
    
    
    // ॲཧΛॻ͘
    
    
    self?.fetchSomethingC(id: b, compeltion: { c in
    
    
    // ॲཧΛॻ͘
    
    
    })
    
    
    })
    
    
    })
    
    
    }
    
    
    }
    

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22. ίʔϧόοΫ is …
    16
    not Simple
    not Easy
    not Safe
    

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23. SwiftͰͷӨڹൣғ (ίʔϧόοΫ)
    17
    class SampleRequest: NSObject {
    
    
    
    
    func fetchSomethingA(id: Int) async -> Int {
    
    
    return 1
    
    
    }
    
    
    func fetchSomethingB(id: Int) async -> Int {
    
    
    return 2
    
    
    }
    
    
    func fetchSomethingC(id: Int) async -> Int {
    
    
    return 3
    
    
    }
    
    
    
    
    }
    

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24. SwiftͰͷӨڹൣғ (ίʔϧόοΫ)
    18
    class SampleRequest: NSObject {
    
    
    
    
    // தུ
    
    
    
    
    func requestSomething() async {
    
    
    let a = await fetchSomethingA(id: 1)
    
    
    let b = await fetchSomethingB(id: a)
    
    
    let c = await fetchSomethingC(id: b)
    
    
    // ॲཧΛॻ͘
    
    
    
    
    }
    
    
    
    
    }
    

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25. SwiftͰͷӨڹൣғ (ίʔϧόοΫ)
    19
    1.Simple
    2.Easy
    3.Safe
    

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26. SwiftͰͷӨڹൣғ (Thread)
    20
    εϨουૢ࡞͸Ͳ͏ͳΔ͔
    - UITableView
    - UICollectionView
    - Viewͷߋ৽ॲཧ
    

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27. SwiftͰͷӨڹൣғ (Thread)
    21
    class SampleViewController: UIViewController {
    
    
    @IBOutlet weak var collectionView: UICollectionView!
    
    
    
    
    func update() {
    
    
    // APIͰσʔλΛऔಘޙʹUIͷߋ৽
    
    
    DispatchQueue.main.async {
    
    
    self.collectionView.reloadData()
    
    
    }
    
    
    }
    
    
    }
    

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28. SwiftͰͷӨڹൣғ (Thread)
    22
    ɾactor
    ɾMainActor
    

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29. SwiftͰͷӨڹൣғ (Thread)
    23
    class SampleRequest: NSObject {
    
    
    var number: Int = 0
    
    
    // தུ
    
    
    
    
    func requestSomething() async {
    
    
    let a = await fetchSomethingA(id: 1)
    
    
    let b = await fetchSomethingB(id: a)
    
    
    let c = await fetchSomethingC(id: b)
    
    
    
    
    // ॲཧΛॻ͘
    
    
    Task.detached(priority: nil, operation: { @MainActor in
    
    
    // @MainActor ͰϝΠϯεϨουͰߋ৽Ͱ͖Δʁ
    
    
    self.number = c
    
    
    })
    
    
    }
    
    
    
    
    }
    

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30. SwiftͰͷӨڹൣғ (CoreData)
    24
    synchronous functions (ಉظॲཧ) asynchronous functions (ඇಉظॲཧ)
    .performAndWait await perform
    .perform await perform(.enqueued)
    

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31. SwiftͰͷӨڹൣғ (CoreData)
    25
    func executePerform() {
    
    
    let persistentContainer = NSPersistentContainer(name: "XXX")
    
    
    let context = persistentContainer.newBackgroundContext()
    
    
    context.perform {
    
    
    // ॲཧ
    
    
    context.perform {
    
    
    // ॲཧ
    
    
    context.perform {
    
    
    // ॲཧ
    
    
    }
    
    
    try? context.save()
    
    
    }
    
    
    }
    
    
    }
    

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32. SwiftͰͷӨڹൣғ (CoreData)
    26
    func asyncExecutePerform() async {
    
    
    let persistentContainer = NSPersistentContainer(name: "XXX")
    
    
    let context = persistentContainer.newBackgroundContext()
    
    
    await context.perform {
    
    
    // ॲཧ
    
    
    }
    
    
    
    
    await context.perform {
    
    
    // ॲཧ
    
    
    try? context.save()
    
    
    }
    
    
    await context.perform {
    
    
    // ॲཧ
    
    
    }
    
    
    }
    

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33. 27
    DartͰͷasync/await
    

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34. DartͰͷasync/await
    28
    1. ؔ਺ʹasyncΛએݴ͢Δ
    2. ݺͼग़࣌͠ʹawaitΛએݴ
    3. ύϥϝʔλʔ͸Futureܕ
    ˎCombine.frameworkͷFutureͱ͍ۙ
    

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35. DartͰͷasync/await
    29
    Example: synchronous functions (ಉظॲཧ)
    String createOrderMessage() {
    var order = fetchUserOrder();
    return 'Your order is: $order';
    }
    Future fetchUserOrder() =>
    Future.delayed(const Duration(seconds: 2), () => 'Large Latte',);
    void main() {
    print('Fetching user order...');
    print(createOrderMessage());
    }
    

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36. DartͰͷasync/await
    30
    Future createOrderMessage() async {
    var order = await fetchUserOrder();
    return 'Your order is: $order';
    }
    Future fetchUserOrder() =>
    Future.delayed(const Duration(seconds: 2), () => 'Large Latte',);
    Future main() async {
    print('Fetching user order...');
    print(await createOrderMessage());
    }
    Example: asynchronous functions (ඇಉظॲཧ)
    

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37. DartͰͷasync/await
    31
    https://dart.dev/codelabs/async-await
    

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38. DartͰͷasync/await (then ݺͼग़͠)
    32
    Future hello() async {
    var order = await fetchHello();
    return order;
    }
    Future fetchHello() =>
    Future.delayed(const Duration(seconds: 2), () => 'Hello world',);
    main() async {
    hello()
    .then((value) {
    // thenͰܨ͛Δ
    print(value);
    });
    }
    

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39. DartͰͷasync/await (Error handling)
    33
    main() async {
    hello()
    .then((value) {
    // thenͰܨ͛Δ
    print(value);
    })
    .catchError((error) {
    // catchError Ͱܨ͛Δ
    print(error);
    });
    }
    

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40. DartͰͷϝϦοτɾσϝϦοτ
    34
    ϝϦοτ
    ɾDartͷඪ४Ͱasync/await͕࢖͑Δ
    ɾFutureܕ͕͋Δ
    ɾiOS ͷ৚݅ʹറΓ͕ͳ͍
    

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41. DartͰͷϝϦοτɾσϝϦοτ
    35
    σϝϦοτ
    ɾจ๏͕JavaϥΠΫͰݹ͍ॻ͖ํ
    ɾenum͕SwiftΑΓ΋ॊೈʹॻ͚ͳ͍
    

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42. Dartͷenum (͓·͚)
    36
    Swift Dart
    Normal (Int Value) ○ ○
    Iterating over Enumeration Cases ○ ×
    Associated Values ○ ×
    Implicitly Assigned Raw Values ○ ×
    Recursive Enumerations ○ ×
    https://docs.swift.org/swift-book/LanguageGuide/Enumerations.html
    

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43. Dartͷenum (͓·͚)
    37
    // Value͸ int
    enum Type {
    First,
    Second,
    Third,
    Fourth
    }
    // Dartͷ֦ுؔ਺͸ on ͱϥϕϦϯά͕ඞཁ
    extension TypeExtension on Type {
    String parseString() {
    switch (this) {
    case Type.First:
    return "First";
    case Type.Second:
    return "Second";
    case Type.Third:
    return "Third";
    case Type.Fourth:
    return "Fourth";
    }
    }
    }
    

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44. ·ͱΊ
    38
    Swift Dart
    Function ○ ○
    Error handling ○ ○
    Property(getter) ○ ×
    Parameter × ○
    Async sequences ○ ×
    

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45. Ҿ༻ 1
    Asynchronous programming
    https://dart.dev/codelabs/async-await
    Futures and error handling
    https://dart.dev/guides/libraries/futures-error-handling
    WWDC 2021 Meet async/await in Swift
    https://developer.apple.com/videos/play/wwdc2021/10132
    WWDC 2021 Meet AsyncSequence
    https://developer.apple.com/videos/play/wwdc2021/10058
    WWDC 2021 Use async/await with URLSession
    https://developer.apple.com/videos/play/wwdc2021/10095
    WWDC 2021 Bring CoreData concurrency to Swift and SwiftUI
    https://developer.apple.com/videos/play/wwdc2021/10017
    

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46. Ҿ༻ 2
    Async/Await and the Future of Combine
    https://benscheirman.com/2021/06/async-await-and-the-future-of-combine/
    URLsessionΛ༻͍ͨHTTPϦΫΤετͷํ๏(Swift, Xcode)
    https://qiita.com/shungo_m/items/64564fd822a7558ac7b1
    Core DataΛόοΫάϥ΢ϯυͰ࢖͏
    https://www.2nd-walker.com/2020/10/09/swift-using-coredata-in-background/
    {JSON} Placeholder
    https://jsonplaceholder.typicode.com/
    

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47. Thank you!
    

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