Paywalls: warm-up image cache

RevenueCat.xcodeproj/project.pbxproj

@@ -227,6 +227,7 @@
 		4F6ABC782A81595900250E63 /* PaywallCacheWarming.swift in Sources */ = {isa = PBXBuildFile; fileRef = 4F6ABC772A81595900250E63 /* PaywallCacheWarming.swift */; };
 		4F6ABC7A2A81649800250E63 /* MockPaywallCacheWarming.swift in Sources */ = {isa = PBXBuildFile; fileRef = 4F6ABC792A81649800250E63 /* MockPaywallCacheWarming.swift */; };
 		4F6ABC7C2A81673F00250E63 /* PaywallCacheWarmingTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 4F6ABC7B2A81673F00250E63 /* PaywallCacheWarmingTests.swift */; };
+		4F6ABC7E2A81700900250E63 /* PaywallsStrings.swift in Sources */ = {isa = PBXBuildFile; fileRef = 4F6ABC7D2A81700900250E63 /* PaywallsStrings.swift */; };
 		4F6BED592A26A14400CD9322 /* DebugView.swift in Sources */ = {isa = PBXBuildFile; fileRef = 4F6BED582A26A14400CD9322 /* DebugView.swift */; };
 		4F6BEDD92A26B55C00CD9322 /* DebugViewModel.swift in Sources */ = {isa = PBXBuildFile; fileRef = 4F6BEDD82A26B55C00CD9322 /* DebugViewModel.swift */; };
 		4F6BEDE02A26B65900CD9322 /* DebugViewSheetPresentation.swift in Sources */ = {isa = PBXBuildFile; fileRef = 4F6BEDDF2A26B65900CD9322 /* DebugViewSheetPresentation.swift */; };
@@ -970,6 +971,7 @@
 		4F6ABC772A81595900250E63 /* PaywallCacheWarming.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = PaywallCacheWarming.swift; sourceTree = "<group>"; };
 		4F6ABC792A81649800250E63 /* MockPaywallCacheWarming.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = MockPaywallCacheWarming.swift; sourceTree = "<group>"; };
 		4F6ABC7B2A81673F00250E63 /* PaywallCacheWarmingTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = PaywallCacheWarmingTests.swift; sourceTree = "<group>"; };
+		4F6ABC7D2A81700900250E63 /* PaywallsStrings.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = PaywallsStrings.swift; sourceTree = "<group>"; };
 		4F6BED582A26A14400CD9322 /* DebugView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = DebugView.swift; sourceTree = "<group>"; };
 		4F6BEDD82A26B55C00CD9322 /* DebugViewModel.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = DebugViewModel.swift; sourceTree = "<group>"; };
 		4F6BEDDF2A26B65900CD9322 /* DebugViewSheetPresentation.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = DebugViewSheetPresentation.swift; sourceTree = "<group>"; };
@@ -1526,6 +1528,7 @@
 				9A65E07A2591977500DE00B0 /* NetworkStrings.swift */,
 				9A65E09F2591A23200DE00B0 /* OfferingStrings.swift */,
 				57488BE729CB7FB60000EE7E /* OfflineEntitlementsStrings.swift */,
+				4F6ABC7D2A81700900250E63 /* PaywallsStrings.swift */,
 				9A65E0A42591A23500DE00B0 /* PurchaseStrings.swift */,
 				5791FCF22992D3EC00F1FEDA /* SigningStrings.swift */,
 				F5C0196826E880800005D61E /* StoreKitStrings.swift */,
@@ -3401,6 +3404,7 @@
 				B34605D1279A6E600031CA74 /* CustomerAPI.swift in Sources */,
 				2DDF41A224F6F331005BC22D /* ProductsManager.swift in Sources */,
 				57CCC6EC2984496D001CE9B6 /* Box.swift in Sources */,
+				4F6ABC7E2A81700900250E63 /* PaywallsStrings.swift in Sources */,
 				575137CF27F50D2F0064AB2C /* HTTPResponseBody.swift in Sources */,
 				573E7F092819B989007C9128 /* StoreKitWorkarounds.swift in Sources */,
 				5791FCF32992D3EC00F1FEDA /* SigningStrings.swift in Sources */,

Sources/Logging/Strings/EligibilityStrings.swift

@@ -24,7 +24,7 @@ enum EligibilityStrings {
     case check_eligibility_no_identifiers
     case check_eligibility_failed(productIdentifier: String, error: Error)
     case sk2_intro_eligibility_too_slow
-    case warming_up_eligibility_cache(products: Set<String>)
+
 }
 
 extension EligibilityStrings: LogMessage {
@@ -53,9 +53,6 @@ extension EligibilityStrings: LogMessage {
 
         case .sk2_intro_eligibility_too_slow:
             return "StoreKit 2 intro eligibility took longer than expected to determine"
-
-        case let .warming_up_eligibility_cache(products):
-            return "Warming up intro eligibility cache for \(products.count) products"
         }
     }
 

Sources/Logging/Strings/PaywallsStrings.swift

@@ -0,0 +1,43 @@
+//
+//  Copyright RevenueCat Inc. All Rights Reserved.
+//
+//  Licensed under the MIT License (the "License");
+//  you may not use this file except in compliance with the License.
+//  You may obtain a copy of the License at
+//
+//      https://opensource.org/licenses/MIT
+//
+//  PaywallsStrings.swift
+//
+//  Created by Nacho Soto on 08/7/23.
+
+import Foundation
+
+// swiftlint:disable identifier_name
+
+enum PaywallsStrings {
+
+    case warming_up_eligibility_cache(products: Set<String>)
+    case warming_up_images(imageURLs: Set<URL>)
+    case error_prefetching_image(URL, Error)
+
+}
+
+extension PaywallsStrings: LogMessage {
+
+    var description: String {
+        switch self {
+        case let .warming_up_eligibility_cache(products):
+            return "Warming up intro eligibility cache for \(products.count) products"
+
+        case let .warming_up_images(imageURLs):
+            return "Warming up paywall images cache: \(imageURLs)"
+
+        case let .error_prefetching_image(url, error):
+            return "Error pre-fetching paywall image '\(url)': \((error as NSError).description)"
+        }
+    }
+
+    var category: String { return "paywalls" }
+
+}

Sources/Logging/Strings/Strings.swift

@@ -26,6 +26,7 @@ enum Strings {
     static let network = NetworkStrings.self
     static let offering = OfferingStrings.self
     static let offlineEntitlements = OfflineEntitlementsStrings.self
+    static let paywalls = PaywallsStrings.self
     static let purchase = PurchaseStrings.self
     static let receipt = ReceiptStrings.self
     static let signing = SigningStrings.self

Sources/Paywalls/PaywallCacheWarming.swift

@@ -16,30 +16,94 @@ import Foundation
 protocol PaywallCacheWarmingType: Sendable {
 
     func warmUpEligibilityCache(offerings: Offerings)
+    func warmUpPaywallImagesCache(offerings: Offerings)
+
+}
+
+protocol PaywallImageFetcherType: Sendable {
+
+    @available(iOS 15.0, macOS 12.0, watchOS 8.0, tvOS 15.0, *)
+    func downloadImage(_ url: URL) async throws
 
 }
 
 final class PaywallCacheWarming: PaywallCacheWarmingType {
 
     private let introEligibiltyChecker: TrialOrIntroPriceEligibilityCheckerType
+    private let imageFetcher: PaywallImageFetcherType
+
+    convenience init(introEligibiltyChecker: TrialOrIntroPriceEligibilityCheckerType) {
+        final class Fetcher: PaywallImageFetcherType {
+            @available(iOS 15.0, macOS 12.0, watchOS 8.0, tvOS 15.0, *)
+            func downloadImage(_ url: URL) async throws {
+                _ = try await URLSession.shared.data(from: url)
+            }
+        }
 
-    init(introEligibiltyChecker: TrialOrIntroPriceEligibilityCheckerType) {
+        self.init(introEligibiltyChecker: introEligibiltyChecker, imageFetcher: Fetcher())
+    }
+
+    init(introEligibiltyChecker: TrialOrIntroPriceEligibilityCheckerType, imageFetcher: PaywallImageFetcherType) {
         self.introEligibiltyChecker = introEligibiltyChecker
+        self.imageFetcher = imageFetcher
+
+        // SwiftUI's `AsyncImage` uses `URLSession.shared` for internal caching.
+        URLCache.shared.memoryCapacity = 50_000_000 // 50M
+        URLCache.shared.diskCapacity = 200_000_000 // 200MB
     }
 
     func warmUpEligibilityCache(offerings: Offerings) {
-        let productIdentifiers = Set<String>(
-            offerings
+        let productIdentifiers = offerings.allProductIdentifiersInPaywalls
+        guard !productIdentifiers.isEmpty else { return }
+
+        Logger.debug(Strings.paywalls.warming_up_eligibility_cache(products: productIdentifiers))
+        self.introEligibiltyChecker.checkEligibility(productIdentifiers: productIdentifiers) { _ in }
+    }
+
+    func warmUpPaywallImagesCache(offerings: Offerings) {
+        guard #available(iOS 15.0, macOS 12.0, watchOS 8.0, tvOS 15.0, *) else { return }
+
+        let imageURLs = offerings.allImagesInPaywalls
+        guard !imageURLs.isEmpty else { return }
+
+        Logger.verbose(Strings.paywalls.warming_up_images(imageURLs: imageURLs))
+
+        Task<Void, Never> {
+            for url in imageURLs {
+                do {
+                    try await self.imageFetcher.downloadImage(url)
+                } catch {
+                    Logger.error(Strings.paywalls.error_prefetching_image(url, error))
+                }
+            }
+        }
+    }
+
+}
+
+// MARK: - Extensions
+
+private extension Offerings {
+
+    var allProductIdentifiersInPaywalls: Set<String> {
+        return .init(
+            self
                 .all
                 .values
                 .lazy
                 .flatMap(\.productIdentifiersInPaywall)
         )
+    }
 
-        guard !productIdentifiers.isEmpty else { return }
-
-        Logger.debug(Strings.eligibility.warming_up_eligibility_cache(products: productIdentifiers))
-        self.introEligibiltyChecker.checkEligibility(productIdentifiers: productIdentifiers) { _ in }
+    var allImagesInPaywalls: Set<URL> {
+        return .init(
+            self
+                .all
+                .values
+                .lazy
+                .compactMap(\.paywall)
+                .flatMap(\.allImageURLs)
+        )
     }
 
 }
@@ -59,3 +123,26 @@ private extension Offering {
     }
 
 }
+
+private extension PaywallData {
+
+    var allImageURLs: [URL] {
+        return self.config.images
+            .allImageNames
+            .map { self.assetBaseURL.appendingPathComponent($0) }
+    }
+
+}
+
+private extension PaywallData.Configuration.Images {
+
+    var allImageNames: [String] {
+        return [
+            self.header,
+            self.background,
+            self.icon
+        ]
+            .compactMap { $0 }
+    }
+
+}

Sources/Purchasing/Purchases/Purchases.swift

@@ -1624,6 +1624,7 @@ private extension Purchases {
             if let offerings = offerings.value {
                 self.operationDispatcher.dispatchOnWorkerThread {
                     cache.warmUpEligibilityCache(offerings: offerings)
+                    cache.warmUpPaywallImagesCache(offerings: offerings)
                 }
             }
         }

Tests/UnitTests/Mocks/MockPaywallCacheWarming.swift

@@ -23,7 +23,6 @@ final class MockPaywallCacheWarming: PaywallCacheWarmingType {
         get { return self._invokedWarmUpEligibilityCache.value }
         set { self._invokedWarmUpEligibilityCache.value = newValue }
     }
-
     var invokedWarmUpEligibilityCacheOfferings: Offerings? {
         get { return self._invokedWarmUpEligibilityCacheOfferings.value }
         set { self._invokedWarmUpEligibilityCacheOfferings.value = newValue }
@@ -34,4 +33,23 @@ final class MockPaywallCacheWarming: PaywallCacheWarmingType {
         self.invokedWarmUpEligibilityCacheOfferings = offerings
     }
 
+    // MARK: -
+
+    private let _invokedWarmUpPaywallImagesCache: Atomic<Bool> = false
+    private let _invokedWarmUpPaywallImagesCacheOfferings: Atomic<Offerings?> = nil
+
+    var invokedWarmUpPaywallImagesCache: Bool {
+        get { return self._invokedWarmUpPaywallImagesCache.value }
+        set { self._invokedWarmUpPaywallImagesCache.value = newValue }
+    }
+    var invokedWarmUpPaywallImagesCacheOfferings: Offerings? {
+        get { return self._invokedWarmUpPaywallImagesCacheOfferings.value }
+        set { self._invokedWarmUpPaywallImagesCacheOfferings.value = newValue }
+    }
+
+    func warmUpPaywallImagesCache(offerings: Offerings) {
+        self.invokedWarmUpPaywallImagesCache = true
+        self.invokedWarmUpPaywallImagesCacheOfferings = offerings
+    }
+
 }

Tests/UnitTests/Paywalls/PaywallCacheWarmingTests.swift

@@ -18,13 +18,16 @@ import XCTest
 class PaywallCacheWarmingTests: TestCase {
 
     private var eligibilityChecker: MockTrialOrIntroPriceEligibilityChecker!
+    private var imageFetcher: MockPaywallImageFetcher!
     private var cache: PaywallCacheWarmingType!
 
     override func setUp() {
         super.setUp()
 
         self.eligibilityChecker = .init()
-        self.cache = PaywallCacheWarming(introEligibiltyChecker: self.eligibilityChecker)
+        self.imageFetcher = .init()
+        self.cache = PaywallCacheWarming(introEligibiltyChecker: self.eligibilityChecker,
+                                         imageFetcher: self.imageFetcher)
     }
 
     func testOfferingsWithNoPaywallsDoesNotCheckEligibility() throws {
@@ -76,12 +79,33 @@ class PaywallCacheWarmingTests: TestCase {
         ]
 
         self.logger.verifyMessageWasLogged(
-            Strings.eligibility.warming_up_eligibility_cache(products: ["product_1", "product_3"]),
+            Strings.paywalls.warming_up_eligibility_cache(products: ["product_1", "product_3"]),
             level: .debug,
             expectedCount: 1
         )
     }
 
+    func testWarmsUpImages() throws {
+        let paywall = try Self.loadPaywall("PaywallData-Sample1")
+        let offerings = try Self.createOfferings([
+            Self.createOffering(
+                identifier: Self.offeringIdentifier,
+                paywall: paywall,
+                products: []
+            )
+        ])
+
+        let expectedURLs: Set<String> = [
+            "https://rc-paywalls.s3.amazonaws.com/header.jpg",
+            "https://rc-paywalls.s3.amazonaws.com/background.jpg",
+            "https://rc-paywalls.s3.amazonaws.com/icon.jpg"
+        ]
+
+        self.cache.warmUpPaywallImagesCache(offerings: offerings)
+
+        expect(self.imageFetcher.images).toEventually(equal(expectedURLs))
+    }
+
 }
 
 private extension PaywallCacheWarmingTests {
@@ -132,3 +156,18 @@ private extension PaywallCacheWarmingTests {
     static let offeringIdentifier = "offering"
 
 }
+
+private final class MockPaywallImageFetcher: PaywallImageFetcherType {
+
+    let downloadedImages: Atomic<Set<URL>> = .init([])
+
+    var images: Set<String> {
+        return Set(self.downloadedImages.value.map(\.absoluteString))
+    }
+
+    @available(iOS 15.0, macOS 12.0, watchOS 8.0, tvOS 15.0, *)
+    func downloadImage(_ url: URL) async throws {
+        self.downloadedImages.modify { $0.insert(url) }
+    }
+
+}

Tests/UnitTests/Purchasing/Purchases/PurchasesGetOfferingsTests.swift

@@ -99,7 +99,7 @@ class PurchasesGetOfferingsTests: BasePurchasesTests {
         expect(self.deviceCache.clearOfferingsCacheTimestampCount) == 0
     }
 
-    func testWarmsUpEligibilityCache() throws {
+    func testWarmsUpPaywallsCache() throws {
         let bundle = Bundle(for: Self.self)
         let offeringsURL = try XCTUnwrap(bundle.url(forResource: "Offerings",
                                                     withExtension: "json",
@@ -126,8 +126,13 @@ class PurchasesGetOfferingsTests: BasePurchasesTests {
         self.setupPurchases()
 
         expect(self.mockOfferingsManager.invokedUpdateOfferingsCacheCount).toEventually(equal(1))
+        expect(self.mockOfferingsManager.invokedUpdateOfferingsCacheCount).toEventually(equal(1))
+
         expect(self.paywallCache.invokedWarmUpEligibilityCache) == true
         expect(self.paywallCache.invokedWarmUpEligibilityCacheOfferings) == offerings
+
+        expect(self.paywallCache.invokedWarmUpPaywallImagesCache) == true
+        expect(self.paywallCache.invokedWarmUpPaywallImagesCacheOfferings) == offerings
     }
 
 }