Adds cache to store expensive frame data

Classes/Archival/Archive.swift

@@ -0,0 +1,52 @@
+//
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at https://mozilla.org/MPL/2.0/.
+//
+
+/// The class containing an image or video and associated data (an encoded representation of the edits).
+class Archive: NSObject, NSSecureCoding {
+    static var supportsSecureCoding: Bool = true
+
+    let image: UIImage?
+    let video: URL?
+    let data: Data?
+
+    init(image: UIImage, data: Data?) {
+        self.image = image
+        self.data = data
+        self.video = nil
+    }
+
+    init(video: URL, data: Data?) {
+        self.video = video
+        self.data = data
+        self.image = nil
+    }
+
+    private enum CodingKeys: String {
+        case image
+        case video
+        case data
+    }
+
+    func encode(with coder: NSCoder) {
+        coder.encode(image, forKey: CodingKeys.image.rawValue)
+        coder.encode(video?.absoluteString, forKey: CodingKeys.video.rawValue)
+        coder.encode(data?.base64EncodedString(), forKey: CodingKeys.data.rawValue)
+    }
+
+    required init?(coder: NSCoder) {
+        image = coder.decodeObject(of: UIImage.self, forKey: CodingKeys.image.rawValue)
+        if let urlString = coder.decodeObject(of: NSString.self, forKey: CodingKeys.video.rawValue) as String? {
+            video = URL(string: urlString)
+        } else {
+            video = nil
+        }
+        if let dataString = coder.decodeObject(of: NSString.self, forKey: CodingKeys.data.rawValue) as String? {
+            data = Data(base64Encoded: dataString)
+        } else {
+            data = nil
+        }
+    }
+}

Classes/Camera/MediaArchiver.swift

@@ -61,21 +61,50 @@ class MediaArchiver {
                 } else {
                     originalURL = nil
                 }
-                return KanvasMedia(image: image, url: url, original: originalURL, info: export.info)
+                let archiveURL = self.archive(media: .image(original), archive: export.archive, to: url.deletingPathExtension().lastPathComponent)
+                return KanvasMedia(image: image, url: url, original: originalURL, info: export.info, archive: archiveURL)
             } else {
                 return nil
             }
         case (.video(let url), .video(let original)):
+            let archiveURL = self.archive(media: .video(original), archive: export.archive, to: url.deletingPathExtension().lastPathComponent)
             os_log(.debug, log: log, "Original video URL: %@", original.absoluteString)
             let asset = AVURLAsset(url: url)
-            return KanvasMedia(asset: asset, original: original, info: export.info)
+            return KanvasMedia(asset: asset, original: original, info: export.info, archive: archiveURL)
         default:
             return nil
         }
     }
+
+    private func archive(media: EditorViewController.Media, archive data: Data, to path: String) -> URL? {
+
+        let archive: Archive
+
+        switch media {
+        case .image(let image):
+            archive = Archive(image: image, data: data)
+        case .video(let url):
+            archive = Archive(video: url, data: data)
+        }
+
+        let archiveURL: URL?
+        if let saveDirectory = saveDirectory {
+            do {
+                let data = try NSKeyedArchiver.archivedData(withRootObject: archive, requiringSecureCoding: true)
+                archiveURL = try data.save(to: path, in: saveDirectory, ext: "")
+            } catch let error {
+                archiveURL = nil
+                print("Failed to archive \(error)")
+            }
+        } else {
+            archiveURL = nil
+        }
+
+        return archiveURL
+    }
 }
 
-private extension Data {
+extension Data {
     func save(to filename: String, in directory: URL, ext fileExtension: String) throws -> URL {
         let fileURL = directory.appendingPathComponent(filename).appendingPathExtension(fileExtension)
         try write(to: fileURL, options: .atomic)

Classes/Editor/EditorView.swift

@@ -171,11 +171,7 @@ final class EditorView: UIView, MovableViewCanvasDelegate, MediaPlayerViewDelega
         )
     }()
 
-    lazy var movableViewCanvas: MovableViewCanvas = {
-        let canvas = MovableViewCanvas()
-        canvas.delegate = self
-        return canvas
-    }()
+    var movableViewCanvas: MovableViewCanvas
 
     private lazy var movableViewCanvasConstraints = {
         return FullViewConstraints(
@@ -219,7 +215,8 @@ final class EditorView: UIView, MovableViewCanvasDelegate, MediaPlayerViewDelega
          showBlogSwitcher: Bool,
          quickBlogSelectorCoordinator: KanvasQuickBlogSelectorCoordinating?,
          tagCollection: UIView?,
-         metalContext: MetalContext?) {
+         metalContext: MetalContext?,
+         movableViewCanvas: MovableViewCanvas?) {
         self.delegate = delegate
         self.mainActionMode = mainActionMode
         self.showSaveButton = showSaveButton
@@ -232,7 +229,10 @@ final class EditorView: UIView, MovableViewCanvasDelegate, MediaPlayerViewDelega
         self.quickBlogSelectorCoordinator = quickBlogSelectorCoordinator
         self.tagCollection = tagCollection
         self.metalContext = metalContext
+        self.movableViewCanvas = movableViewCanvas ?? MovableViewCanvas()
+
         super.init(frame: .zero)
+        self.movableViewCanvas.delegate = self
         setupViews()
     }
 
@@ -277,7 +277,7 @@ final class EditorView: UIView, MovableViewCanvasDelegate, MediaPlayerViewDelega
         setupOverlay()
         setupOverlayLabel()
     }
-    
+
     // MARK: - views
 
     private func setupPlayer() {
@@ -299,7 +299,7 @@ final class EditorView: UIView, MovableViewCanvasDelegate, MediaPlayerViewDelega
         addSubview(movableViewCanvas)
         movableViewCanvasConstraints.activate()
     }
-    
+
     /// Container that holds the back button and the bottom menu
     private func setupNavigationContainer() {
         navigationContainer.accessibilityIdentifier = "Navigation Container"