Remove Cache library

.gitmodules

@@ -1,6 +1,3 @@
-[submodule "Cache"]
-	path = Cache
-	url = git@github.com:hyperoslo/Cache.git
 [submodule "Gifu"]
 	path = Gifu
 	url = git://github.com/kaishin/Gifu.git

Cache

@@ -1 +0,0 @@
-Subproject commit 8c42c575cf28b2ff0e780c9728721e9a8891c92e

Tusker.xcodeproj/project.pbxproj

@@ -14,8 +14,6 @@
 		0450531F22B0097E00100BA2 /* Timline+UI.swift in Sources */ = {isa = PBXBuildFile; fileRef = 0450531E22B0097E00100BA2 /* Timline+UI.swift */; };
 		04586B4122B2FFB10021BD04 /* PreferencesView.swift in Sources */ = {isa = PBXBuildFile; fileRef = 04586B4022B2FFB10021BD04 /* PreferencesView.swift */; };
 		04586B4322B301470021BD04 /* AppearancePrefsView.swift in Sources */ = {isa = PBXBuildFile; fileRef = 04586B4222B301470021BD04 /* AppearancePrefsView.swift */; };
-		0461A3902163CBAE00C0A807 /* Cache.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = 0461A38F2163CBAE00C0A807 /* Cache.framework */; };
-		0461A3912163CBAE00C0A807 /* Cache.framework in Embed Frameworks */ = {isa = PBXBuildFile; fileRef = 0461A38F2163CBAE00C0A807 /* Cache.framework */; settings = {ATTRIBUTES = (CodeSignOnCopy, RemoveHeadersOnCopy, ); }; };
 		04D14BB022B34A2800642648 /* GalleryViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = 04D14BAE22B34A2800642648 /* GalleryViewController.swift */; };
 		04DACE8C212CB14B009840C4 /* MainTabBarViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = 04DACE8B212CB14B009840C4 /* MainTabBarViewController.swift */; };
 		04DACE8E212CC7CC009840C4 /* ImageCache.swift in Sources */ = {isa = PBXBuildFile; fileRef = 04DACE8D212CC7CC009840C4 /* ImageCache.swift */; };
@@ -113,7 +111,6 @@
 		D62D2426217ABF63005076CC /* UserActivityType.swift in Sources */ = {isa = PBXBuildFile; fileRef = D62D2425217ABF63005076CC /* UserActivityType.swift */; };
 		D62FF04823D7CDD700909D6E /* AttributedStringHelperTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = D62FF04723D7CDD700909D6E /* AttributedStringHelperTests.swift */; };
 		D6311C5025B3765B00B27539 /* ImageDataCache.swift in Sources */ = {isa = PBXBuildFile; fileRef = D6311C4F25B3765B00B27539 /* ImageDataCache.swift */; };
-		D6311C5625B4CEA000B27539 /* CachingDiskStorage.swift in Sources */ = {isa = PBXBuildFile; fileRef = D6311C5525B4CEA000B27539 /* CachingDiskStorage.swift */; };
 		D6333B372137838300CE884A /* AttributedString+Helpers.swift in Sources */ = {isa = PBXBuildFile; fileRef = D6333B362137838300CE884A /* AttributedString+Helpers.swift */; };
 		D6333B792139AEFD00CE884A /* Date+TimeAgo.swift in Sources */ = {isa = PBXBuildFile; fileRef = D6333B782139AEFD00CE884A /* Date+TimeAgo.swift */; };
 		D63569E023908A8D003DD353 /* StatusState.swift in Sources */ = {isa = PBXBuildFile; fileRef = D60A4FFB238B726A008AC647 /* StatusState.swift */; };
@@ -228,6 +225,9 @@
 		D6A5BB2F23BBAC97003BF21D /* DelegatingResponse.swift in Sources */ = {isa = PBXBuildFile; fileRef = D6A5BB2E23BBAC97003BF21D /* DelegatingResponse.swift */; };
 		D6A5BB3123BBAD87003BF21D /* JSONResponse.swift in Sources */ = {isa = PBXBuildFile; fileRef = D6A5BB3023BBAD87003BF21D /* JSONResponse.swift */; };
 		D6A6C10525B6138A00298D0F /* StatusTablePrefetching.swift in Sources */ = {isa = PBXBuildFile; fileRef = D6A6C10425B6138A00298D0F /* StatusTablePrefetching.swift */; };
+		D6A6C10F25B62D2400298D0F /* DiskCache.swift in Sources */ = {isa = PBXBuildFile; fileRef = D6A6C10E25B62D2400298D0F /* DiskCache.swift */; };
+		D6A6C11525B62E9700298D0F /* CacheExpiry.swift in Sources */ = {isa = PBXBuildFile; fileRef = D6A6C11425B62E9700298D0F /* CacheExpiry.swift */; };
+		D6A6C11B25B63CEE00298D0F /* MemoryCache.swift in Sources */ = {isa = PBXBuildFile; fileRef = D6A6C11A25B63CEE00298D0F /* MemoryCache.swift */; };
 		D6AC956723C4347E008C9946 /* MainSceneDelegate.swift in Sources */ = {isa = PBXBuildFile; fileRef = D6AC956623C4347E008C9946 /* MainSceneDelegate.swift */; };
 		D6ACE1AC240C3BAD004EA8E2 /* Ambassador.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = D65F613023AE99E000F3CFD3 /* Ambassador.framework */; };
 		D6ACE1AD240C3BAD004EA8E2 /* Embassy.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = D65F612D23AE990C00F3CFD3 /* Embassy.framework */; };
@@ -304,7 +304,6 @@
 		D6EE63FB2551F7F60065485C /* StatusCollapseButton.swift in Sources */ = {isa = PBXBuildFile; fileRef = D6EE63FA2551F7F60065485C /* StatusCollapseButton.swift */; };
 		D6F0B12B24A3071C001E48C3 /* MainSplitViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = D6F0B12A24A3071C001E48C3 /* MainSplitViewController.swift */; };
 		D6F0B17524A3A1AA001E48C3 /* MainSidebarViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = D6F0B17424A3A1AA001E48C3 /* MainSidebarViewController.swift */; };
-		D6F1F84D2193B56E00F5FE67 /* Cache.swift in Sources */ = {isa = PBXBuildFile; fileRef = D6F1F84C2193B56E00F5FE67 /* Cache.swift */; };
 		D6F2E965249E8BFD005846BB /* CrashReporterViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = D6F2E963249E8BFD005846BB /* CrashReporterViewController.swift */; };
 		D6F2E966249E8BFD005846BB /* CrashReporterViewController.xib in Resources */ = {isa = PBXBuildFile; fileRef = D6F2E964249E8BFD005846BB /* CrashReporterViewController.xib */; };
 		D6F953F021251A2900CF0F2B /* MastodonController.swift in Sources */ = {isa = PBXBuildFile; fileRef = D6F953EF21251A2900CF0F2B /* MastodonController.swift */; };
@@ -358,7 +357,6 @@
 			files = (
 				D61099C12144B0CC00432DC2 /* Pachyderm.framework in Embed Frameworks */,
 				D6BC874621961F73006163F1 /* Gifu.framework in Embed Frameworks */,
-				0461A3912163CBAE00C0A807 /* Cache.framework in Embed Frameworks */,
 			);
 			name = "Embed Frameworks";
 			runOnlyForDeploymentPostprocessing = 0;
@@ -472,7 +470,6 @@
 		D62D2425217ABF63005076CC /* UserActivityType.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = UserActivityType.swift; sourceTree = "<group>"; };
 		D62FF04723D7CDD700909D6E /* AttributedStringHelperTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = AttributedStringHelperTests.swift; sourceTree = "<group>"; };
 		D6311C4F25B3765B00B27539 /* ImageDataCache.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ImageDataCache.swift; sourceTree = "<group>"; };
-		D6311C5525B4CEA000B27539 /* CachingDiskStorage.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = CachingDiskStorage.swift; sourceTree = "<group>"; };
 		D6333B362137838300CE884A /* AttributedString+Helpers.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "AttributedString+Helpers.swift"; sourceTree = "<group>"; };
 		D6333B782139AEFD00CE884A /* Date+TimeAgo.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "Date+TimeAgo.swift"; sourceTree = "<group>"; };
 		D63661BF2381C144004B9E16 /* PreferencesNavigationController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = PreferencesNavigationController.swift; sourceTree = "<group>"; };
@@ -589,6 +586,9 @@
 		D6A5BB2E23BBAC97003BF21D /* DelegatingResponse.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = DelegatingResponse.swift; sourceTree = "<group>"; };
 		D6A5BB3023BBAD87003BF21D /* JSONResponse.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = JSONResponse.swift; sourceTree = "<group>"; };
 		D6A6C10425B6138A00298D0F /* StatusTablePrefetching.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = StatusTablePrefetching.swift; sourceTree = "<group>"; };
+		D6A6C10E25B62D2400298D0F /* DiskCache.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = DiskCache.swift; sourceTree = "<group>"; };
+		D6A6C11425B62E9700298D0F /* CacheExpiry.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = CacheExpiry.swift; sourceTree = "<group>"; };
+		D6A6C11A25B63CEE00298D0F /* MemoryCache.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = MemoryCache.swift; sourceTree = "<group>"; };
 		D6AC956623C4347E008C9946 /* MainSceneDelegate.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = MainSceneDelegate.swift; sourceTree = "<group>"; };
 		D6AEBB3D2321638100E5038B /* UIActivity+Types.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "UIActivity+Types.swift"; sourceTree = "<group>"; };
 		D6AEBB402321642700E5038B /* SendMesasgeActivity.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = SendMesasgeActivity.swift; sourceTree = "<group>"; };
@@ -668,7 +668,6 @@
 		D6EE63FA2551F7F60065485C /* StatusCollapseButton.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = StatusCollapseButton.swift; sourceTree = "<group>"; };
 		D6F0B12A24A3071C001E48C3 /* MainSplitViewController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = MainSplitViewController.swift; sourceTree = "<group>"; };
 		D6F0B17424A3A1AA001E48C3 /* MainSidebarViewController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = MainSidebarViewController.swift; sourceTree = "<group>"; };
-		D6F1F84C2193B56E00F5FE67 /* Cache.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = Cache.swift; sourceTree = "<group>"; };
 		D6F2E963249E8BFD005846BB /* CrashReporterViewController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = CrashReporterViewController.swift; sourceTree = "<group>"; };
 		D6F2E964249E8BFD005846BB /* CrashReporterViewController.xib */ = {isa = PBXFileReference; lastKnownFileType = file.xib; path = CrashReporterViewController.xib; sourceTree = "<group>"; };
 		D6F953EF21251A2900CF0F2B /* MastodonController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = MastodonController.swift; sourceTree = "<group>"; };
@@ -699,7 +698,6 @@
 				D6B0539F23BD2BA300A066FA /* SheetController in Frameworks */,
 				D69CCBBF249E6EFD000AF167 /* CrashReporter in Frameworks */,
 				D6BC874521961F73006163F1 /* Gifu.framework in Frameworks */,
-				0461A3902163CBAE00C0A807 /* Cache.framework in Frameworks */,
 				D60CFFDB24A290BA00D00083 /* SwiftSoup in Frameworks */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
@@ -1498,10 +1496,11 @@
 		D6F1F84E2193B9BE00F5FE67 /* Caching */ = {
 			isa = PBXGroup;
 			children = (
-				D6F1F84C2193B56E00F5FE67 /* Cache.swift */,
+				D6A6C11425B62E9700298D0F /* CacheExpiry.swift */,
-				04DACE8D212CC7CC009840C4 /* ImageCache.swift */,
+				D6A6C10E25B62D2400298D0F /* DiskCache.swift */,
+				D6A6C11A25B63CEE00298D0F /* MemoryCache.swift */,
 				D6311C4F25B3765B00B27539 /* ImageDataCache.swift */,
-				D6311C5525B4CEA000B27539 /* CachingDiskStorage.swift */,
+				04DACE8D212CC7CC009840C4 /* ImageCache.swift */,
 			);
 			path = Caching;
 			sourceTree = "<group>";
@@ -1880,7 +1879,6 @@
 				D6A3BC8A2321F79B00FD64D5 /* AccountTableViewCell.swift in Sources */,
 				D66A77BB233838DC0058F1EC /* UIFont+Traits.swift in Sources */,
 				D68FEC4F232C5BC300C84F23 /* SegmentedPageViewController.swift in Sources */,
-				D6311C5625B4CEA000B27539 /* CachingDiskStorage.swift in Sources */,
 				D62275AA24F1E01C00B82A16 /* ComposeTextView.swift in Sources */,
 				0450531F22B0097E00100BA2 /* Timline+UI.swift in Sources */,
 				D667E5F52135BCD50057A976 /* ConversationTableViewController.swift in Sources */,
@@ -1921,6 +1919,7 @@
 				D677284A24ECBDF400C732D3 /* ComposeCurrentAccount.swift in Sources */,
 				D62D2424217ABF3F005076CC /* NSUserActivity+Extensions.swift in Sources */,
 				D6B30E09254BAF63009CAEE5 /* ImageGrayscalifier.swift in Sources */,
+				D6A6C10F25B62D2400298D0F /* DiskCache.swift in Sources */,
 				D6E426812532814100C02E1C /* MaybeLazyStack.swift in Sources */,
 				D6B81F3C2560365300F6E31D /* RefreshableViewController.swift in Sources */,
 				D646C958213B367000269FB5 /* LargeImageShrinkAnimationController.swift in Sources */,
@@ -1944,6 +1943,7 @@
 				D6AEBB4823216B1D00E5038B /* AccountActivity.swift in Sources */,
 				04ED00B121481ED800567C53 /* SteppedProgressView.swift in Sources */,
 				D677284C24ECBE9100C732D3 /* ComposeAvatarImageView.swift in Sources */,
+				D6A6C11B25B63CEE00298D0F /* MemoryCache.swift in Sources */,
 				D6BC9DDA232D8BE5002CA326 /* SearchResultsViewController.swift in Sources */,
 				D627FF7F217E95E000CC0648 /* DraftTableViewCell.swift in Sources */,
 				D6B17255254F88B800128392 /* OppositeCollapseKeywordsView.swift in Sources */,
@@ -2020,6 +2020,7 @@
 				D670F8B62537DC890046588A /* EmojiPickerWrapper.swift in Sources */,
 				D6B81F442560390300F6E31D /* MenuController.swift in Sources */,
 				D65234E12561AA68001AF9CF /* NotificationsTableViewController.swift in Sources */,
+				D6A6C11525B62E9700298D0F /* CacheExpiry.swift in Sources */,
 				D67C57AF21E28EAD00C3118B /* Array+Uniques.swift in Sources */,
 				D6945C3223AC4D36005C403C /* HashtagTimelineViewController.swift in Sources */,
 				D647D92824257BEB0005044F /* AttachmentPreviewViewController.swift in Sources */,
@@ -2045,7 +2046,6 @@
 				D6757A7C2157E01900721E32 /* XCBManager.swift in Sources */,
 				D65234D325618EFA001AF9CF /* TimelineTableViewController.swift in Sources */,
 				D68E6F5F253C9B2D001A1B4C /* BaseEmojiLabel.swift in Sources */,
-				D6F1F84D2193B56E00F5FE67 /* Cache.swift in Sources */,
 				D6F0B12B24A3071C001E48C3 /* MainSplitViewController.swift in Sources */,
 				0427037C22B316B9000D31B6 /* SilentActionPrefs.swift in Sources */,
 				D6AEBB3E2321638100E5038B /* UIActivity+Types.swift in Sources */,

Tusker.xcworkspace/contents.xcworkspacedata

@@ -7,9 +7,6 @@
    <FileRef
       location = "group:BlankSlate.xcappdata">
    </FileRef>
-   <FileRef
-      location = "group:Cache/Cache.xcodeproj">
-   </FileRef>
    <FileRef
       location = "group:Gifu/Gifu.xcodeproj">
    </FileRef>

Tusker/Caching/Cache.swift

@@ -1,62 +0,0 @@
-//
-//  Cache.swift
-//  Tusker
-//
-//  Created by Shadowfacts on 11/7/18.
-//  Copyright © 2018 Shadowfacts. All rights reserved.
-//
-
-import Foundation
-import Cache
-
-/// Wrapper around Cache library that provides an API for transparently using any storage type
-enum Cache<T> {
-    case memory(MemoryStorage<T>)
-    case disk(DiskStorage<T>)
-    case hybrid(HybridStorage<T>)
-    
-    @available(*, deprecated, message: "disk-based caches synchronously interact with the file system. Avoid using if possible.")
-    func existsObject(forKey key: String) throws -> Bool {
-        switch self {
-        case let .memory(memory):
-            return try memory.existsObject(forKey: key)
-        case let .disk(disk):
-            return try disk.existsObject(forKey: key)
-        case let .hybrid(hybrid):
-            return try hybrid.existsObject(forKey: key)
-        }
-    }
-    
-    func object(forKey key: String) throws -> T {
-        switch self {
-        case let .memory(memory):
-            return try memory.object(forKey: key)
-        case let .disk(disk):
-            return try disk.object(forKey: key)
-        case let .hybrid(hybrid):
-            return try hybrid.object(forKey: key)
-        }
-    }
-    
-    func setObject(_ object: T, forKey key: String, expiry: Expiry? = nil) throws {
-        switch self {
-        case let .memory(memory):
-            memory.setObject(object, forKey: key, expiry: expiry)
-        case let .disk(disk):
-            try disk.setObject(object, forKey: key, expiry: expiry)
-        case let .hybrid(hybrid):
-            try hybrid.setObject(object, forKey: key, expiry: expiry)
-        }
-    }
-    
-    func removeAll() throws {
-        switch self {
-        case let .memory(memory):
-            memory.removeAll()
-        case let .disk(disk):
-            try disk.removeAll()
-        case let .hybrid(hybrid):
-            try hybrid.removeAll()
-        }
-    }
-}

Tusker/Caching/CacheExpiry.swift

@@ -0,0 +1,30 @@
+//
+//  CacheExpiry.swift
+//  Tusker
+//
+//  Created by Shadowfacts on 1/18/21.
+//  Copyright © 2021 Shadowfacts. All rights reserved.
+//
+
+import Foundation
+
+enum CacheExpiry {
+    case never
+    case seconds(TimeInterval)
+    case date(Date)
+    
+    var date: Date {
+        switch self {
+        case .never:
+            return .distantFuture
+        case let .seconds(seconds):
+            return Date().addingTimeInterval(seconds)
+        case let .date(date):
+            return date
+        }
+    }
+    
+    var isExpired: Bool {
+        return date.timeIntervalSinceNow < 0
+    }
+}

Tusker/Caching/CachingDiskStorage.swift

@@ -1,71 +0,0 @@
-//
-//  CachingDiskStorage.swift
-//  Tusker
-//
-//  Created by Shadowfacts on 1/17/21.
-//  Copyright © 2021 Shadowfacts. All rights reserved.
-//
-
-import Foundation
-import Cache
-
-/// This class wraps a `DiskStorage` and maintains an in-memory cache of whether objects
-/// exist on disk to avoid unnecessary disk I/O when calling synchronous methods like
-/// `existsObject(forKey:)`.
-class CachingDiskStorage<T>: StorageAware {
-    
-    private let storage: DiskStorage<T>
-    private var files = [String: FileState]()
-    
-    init(config: DiskConfig, transformer: Transformer<T>) throws {
-        storage = try DiskStorage(config: config, transformer: transformer)
-    }
-    
-    private func state(for key: String) -> FileState {
-        return files[key] ?? .unknown
-    }
-    
-    func entry(forKey key: String) throws -> Entry<T> {
-        if state(for: key) == .doesNotExist {
-            throw StorageError.notFound
-        }
-        return try storage.entry(forKey: key)
-    }
-    
-    func existsObject(forKey key: String) throws -> Bool {
-        switch state(for: key) {
-        case .unknown:
-            return try storage.existsObject(forKey: key)
-        case .exists:
-            return true
-        case .doesNotExist:
-            return false
-        }
-    }
-    
-    func removeObject(forKey key: String) throws {
-        try storage.removeObject(forKey: key)
-        files[key] = .doesNotExist
-    }
-    
-    func setObject(_ object: T, forKey key: String, expiry: Expiry? = nil) throws {
-        try storage.setObject(object, forKey: key, expiry: expiry)
-        files[key] = .exists
-    }
-    
-    func removeAll() throws {
-        try storage.removeAll()
-        files.removeAll()
-    }
-    
-    func removeExpiredObjects() throws {
-        try storage.removeExpiredObjects()
-    }
-    
-}
-
-extension CachingDiskStorage {
-    private enum FileState {
-        case unknown, exists, doesNotExist
-    }
-}

Tusker/Caching/DiskCache.swift

@@ -0,0 +1,143 @@
+//
+//  DiskCache.swift
+//  Tusker
+//
+//  Created by Shadowfacts on 1/18/21.
+//  Copyright © 2021 Shadowfacts. All rights reserved.
+//
+
+import Foundation
+import CryptoKit
+
+struct DiskCacheTransformer<T> {
+    let toData: (T) throws -> Data
+    let fromData: (Data) throws -> T
+}
+
+class DiskCache<T> {
+    
+    let fileManager: FileManager
+    let path: String
+    let defaultExpiry: CacheExpiry
+    let transformer: DiskCacheTransformer<T>
+    
+    private var fileStates = [String: FileState]()
+    
+    init(name: String, defaultExpiry: CacheExpiry, transformer: DiskCacheTransformer<T>, fileManager: FileManager = .default) throws {
+        self.defaultExpiry = defaultExpiry
+        self.transformer = transformer
+        self.fileManager = fileManager
+        
+        let cacheDir = try fileManager.url(for: .cachesDirectory, in: .userDomainMask, appropriateFor: nil, create: true)
+        
+        self.path = cacheDir.appendingPathComponent(name, isDirectory: true).path
+        
+        try createDirectory()
+    }
+    
+    private func createDirectory() throws {
+        if !fileManager.fileExists(atPath: path) {
+            try fileManager.createDirectory(atPath: path, withIntermediateDirectories: true, attributes: nil)
+        }
+    }
+    
+    private func makeFileName(for key: String) -> String {
+        let ext = (key as NSString).pathExtension
+        
+        let digest = Insecure.MD5.hash(data: key.data(using: .utf8)!)
+        let hash = digest.map { String($0, radix: 16) }.joined()
+        
+        if ext.isEmpty {
+            return hash
+        } else {
+            return "\(hash).\(ext)"
+        }
+    }
+    
+    private func makeFilePath(for key: String) -> String {
+        return (path as NSString).appendingPathComponent(makeFileName(for: key))
+    }
+    
+    private func fileState(forKey key: String) -> FileState {
+        return fileStates[key] ?? .unknown
+    }
+    
+    func setObject(_ object: T, forKey key: String) throws {
+        let data = try transformer.toData(object)
+        let path = makeFilePath(for: key)
+        guard fileManager.createFile(atPath: path, contents: data, attributes: [.modificationDate: defaultExpiry.date]) else {
+            throw Error.couldNotCreateFile
+        }
+        fileStates[key] = .exists
+    }
+    
+    func removeObject(forKey key: String) throws {
+        let path = makeFilePath(for: key)
+        try fileManager.removeItem(atPath: path)
+        fileStates[key] = .doesNotExist
+    }
+    
+    func existsObject(forKey key: String) throws -> Bool {
+        switch fileState(forKey: key) {
+        case .exists:
+            return true
+        case .doesNotExist:
+            return false
+        case .unknown:
+            let path = makeFilePath(for: key)
+            guard fileManager.fileExists(atPath: path) else {
+                return false
+            }
+            let attributes = try fileManager.attributesOfItem(atPath: path)
+            guard let date = attributes[.modificationDate] as? Date else {
+                throw Error.malformedFileAttributes
+            }
+            return date.timeIntervalSinceNow >= 0
+        }
+    }
+    
+    func object(forKey key: String) throws -> T {
+        let path = makeFilePath(for: key)
+        let attributes = try fileManager.attributesOfItem(atPath: path)
+        
+        guard let date = attributes[.modificationDate] as? Date else {
+            throw Error.malformedFileAttributes
+        }
+        guard date.timeIntervalSinceNow >= 0 else {
+            try fileManager.removeItem(atPath: path)
+            fileStates[key] = .doesNotExist
+            throw Error.expired
+        }
+        
+        let data = try Data(contentsOf: URL(fileURLWithPath: path, isDirectory: false))
+        let object = try transformer.fromData(data)
+        return object
+    }
+    
+    func removeAll() throws {
+        try fileManager.removeItem(atPath: path)
+        try createDirectory()
+        fileStates.removeAll()
+    }
+    
+}
+
+extension DiskCache {
+    enum Error: Swift.Error {
+        case malformedFileAttributes
+        case couldNotCreateFile
+        case expired
+    }
+}
+
+extension DiskCache {
+    enum FileState {
+        case exists, doesNotExist, unknown
+    }
+}
+
+extension DiskCache where T == Data {
+    convenience init(name: String, defaultExpiry: CacheExpiry) throws {
+        try self.init(name: name, defaultExpiry: defaultExpiry, transformer: DiskCacheTransformer(toData: { $0 }, fromData: { $0 }))
+    }
+}

Tusker/Caching/ImageCache.swift

@@ -28,7 +28,7 @@ class ImageCache {
     
     private var backgroundQueue = DispatchQueue(label: "ImageCache completion queue", qos: .default)
     
-    init(name: String, memoryExpiry: Expiry, diskExpiry: Expiry? = nil, desiredSize: CGSize? = nil) {
+    init(name: String, memoryExpiry: CacheExpiry, diskExpiry: CacheExpiry? = nil, desiredSize: CGSize? = nil) {
         // todo: might not always want to use UIScreen.main for this, e.g. Catalyst?
         let pixelSize = desiredSize?.applying(.init(scaleX: UIScreen.main.scale, y: UIScreen.main.scale))
         self.cache = ImageDataCache(name: name, memoryExpiry: memoryExpiry, diskExpiry: diskExpiry, storeOriginalDataInMemory: diskExpiry == nil, desiredPixelSize: pixelSize)

Tusker/Caching/ImageDataCache.swift

@@ -11,19 +11,17 @@ import Cache
 
 class ImageDataCache {
     
-    private let memory: MemoryStorage<Entry>
+    private let memory: MemoryCache<Entry>
-    private let disk: CachingDiskStorage<Data>?
+    private let disk: DiskCache<Data>?
     
     private let storeOriginalDataInMemory: Bool
     private let desiredPixelSize: CGSize?
     
-    init(name: String, memoryExpiry: Expiry, diskExpiry: Expiry?, storeOriginalDataInMemory: Bool, desiredPixelSize: CGSize?) {
+    init(name: String, memoryExpiry: CacheExpiry, diskExpiry: CacheExpiry?, storeOriginalDataInMemory: Bool, desiredPixelSize: CGSize?) {
-        let memoryConfig = MemoryConfig(expiry: memoryExpiry)
+        self.memory = MemoryCache(defaultExpiry: memoryExpiry)
-        self.memory = MemoryStorage(config: memoryConfig)
         
         if let diskExpiry = diskExpiry {
-            let diskConfig = DiskConfig(name: name, expiry: diskExpiry)
+            self.disk = try! DiskCache(name: name, defaultExpiry: diskExpiry)
-            self.disk = try! CachingDiskStorage(config: diskConfig, transformer: TransformerFactory.forData())
         } else {
             self.disk = nil
         }
@@ -33,7 +31,7 @@ class ImageDataCache {
     }
     
     func has(_ key: String) throws -> Bool {
-        if try memory.existsObject(forKey: key) {
+        if memory.existsObject(forKey: key) {
             return true
         } else if let disk = self.disk,
                   try disk.existsObject(forKey: key) {

Tusker/Caching/MemoryCache.swift

@@ -0,0 +1,69 @@
+//
+//  MemoryCache.swift
+//  Tusker
+//
+//  Created by Shadowfacts on 1/18/21.
+//  Copyright © 2021 Shadowfacts. All rights reserved.
+//
+
+import Foundation
+
+class MemoryCache<T> {
+ 
+    private let cache = NSCache<NSString, Entry>()
+    private let defaultExpiry: CacheExpiry
+    
+    init(defaultExpiry: CacheExpiry) {
+        self.defaultExpiry = defaultExpiry
+    }
+    
+    
+    func setObject(_ object: T, forKey key: String) {
+        let entry = Entry(expiresAt: defaultExpiry.date, object: object)
+        cache.setObject(entry, forKey: key as NSString)
+    }
+    
+    func removeObject(forKey key: String) {
+        cache.removeObject(forKey: key as NSString)
+    }
+    
+    func existsObject(forKey key: String) -> Bool {
+        return cache.object(forKey: key as NSString) != nil
+    }
+    
+    func object(forKey key: String) throws -> T {
+        guard let entry = cache.object(forKey: key as NSString) else {
+            throw Error.notFound
+        }
+        
+        guard entry.expiresAt.timeIntervalSinceNow >= 0 else {
+            cache.removeObject(forKey: key as NSString)
+            throw Error.expired
+        }
+        
+        return entry.object
+    }
+    
+    func removeAll() {
+        cache.removeAllObjects()
+    }
+}
+
+extension MemoryCache {
+    enum Error: Swift.Error {
+        case notFound
+        case expired
+    }
+}
+
+extension MemoryCache {
+    class Entry {
+        let expiresAt: Date
+        let object: T
+        
+        init(expiresAt: Date, object: T) {
+            self.expiresAt = expiresAt
+            self.object = object
+        }
+    }
+}