Shared media update

submodules/DirectMediaImageCache/Sources/DirectMediaImageCache.swift

@@ -0,0 +1,134 @@
+import Foundation
+import SwiftSignalKit
+import Postbox
+import TelegramCore
+import UIKit
+import TinyThumbnail
+import Display
+import FastBlur
+
+private func generateBlurredThumbnail(image: UIImage) -> UIImage? {
+    let thumbnailContextSize = CGSize(width: 32.0, height: 32.0)
+    let thumbnailContext = DrawingContext(size: thumbnailContextSize, scale: 1.0)
+
+    let filledSize = image.size.aspectFilled(thumbnailContextSize)
+    let imageRect = CGRect(origin: CGPoint(x: (thumbnailContextSize.width - filledSize.width) / 2.0, y: (thumbnailContextSize.height - filledSize.height) / 2.0), size: filledSize)
+
+    thumbnailContext.withFlippedContext { c in
+        c.draw(image.cgImage!, in: imageRect)
+    }
+    telegramFastBlurMore(Int32(thumbnailContextSize.width), Int32(thumbnailContextSize.height), Int32(thumbnailContext.bytesPerRow), thumbnailContext.bytes)
+
+    return thumbnailContext.generateImage()
+}
+
+public final class DirectMediaImageCache {
+    public final class GetMediaResult {
+        public let image: UIImage?
+        public let loadSignal: Signal<UIImage?, NoError>?
+
+        init(image: UIImage?, loadSignal: Signal<UIImage?, NoError>?) {
+            self.image = image
+            self.loadSignal = loadSignal
+        }
+    }
+
+    private enum ImageType {
+        case blurredThumbnail
+        case square(width: Int)
+    }
+
+    private let account: Account
+
+    public init(account: Account) {
+        self.account = account
+    }
+
+    private func getCachePath(resourceId: MediaResourceId, imageType: ImageType) -> String {
+        let representationId: String
+        switch imageType {
+        case .blurredThumbnail:
+            representationId = "blurred32"
+        case let .square(width):
+            representationId = "shm\(width)"
+        }
+        return self.account.postbox.mediaBox.cachedRepresentationPathForId(resourceId.stringRepresentation, representationId: representationId, keepDuration: .general)
+    }
+
+    private func getLoadSignal(resource: MediaResourceReference, width: Int) -> Signal<UIImage?, NoError>? {
+        let cachePath = self.getCachePath(resourceId: resource.resource.id, imageType: .square(width: width))
+        return Signal { subscriber in
+            let fetch = fetchedMediaResource(mediaBox: self.account.postbox.mediaBox, reference: resource).start()
+            let data = (self.account.postbox.mediaBox.resourceData(resource.resource)
+            |> filter { data in
+                return data.complete
+            }
+            |> take(1)).start(next: { data in
+                if let dataValue = try? Data(contentsOf: URL(fileURLWithPath: data.path)), let image = UIImage(data: dataValue) {
+                    if let scaledImage = generateImage(CGSize(width: CGFloat(width), height: CGFloat(width)), contextGenerator: { size, context in
+                        let filledSize = image.size.aspectFilled(size)
+                        let imageRect = CGRect(origin: CGPoint(x: (size.width - filledSize.width) / 2.0, y: (size.height - filledSize.height) / 2.0), size: filledSize)
+                        context.draw(image.cgImage!, in: imageRect)
+                    }, scale: 1.0) {
+                        if let resultData = scaledImage.jpegData(compressionQuality: 0.7) {
+                            let _ = try? resultData.write(to: URL(fileURLWithPath: cachePath))
+                            subscriber.putNext(scaledImage)
+                            subscriber.putCompletion()
+                        }
+                    }
+                }
+            })
+
+            return ActionDisposable {
+                fetch.dispose()
+                data.dispose()
+            }
+        }
+    }
+
+    private func getResource(message: Message, image: TelegramMediaImage) -> MediaResourceReference? {
+        guard let representation = image.representations.last else {
+            return nil
+        }
+        return MediaReference.message(message: MessageReference(message), media: image).resourceReference(representation.resource)
+    }
+
+    private func getResource(message: Message, file: TelegramMediaFile) -> MediaResourceReference? {
+        if let representation = file.previewRepresentations.last {
+            return MediaReference.message(message: MessageReference(message), media: file).resourceReference(representation.resource)
+        } else {
+            return nil
+        }
+    }
+
+    public func getImage(message: Message, media: Media, width: Int) -> GetMediaResult? {
+        var immediateThumbnailData: Data?
+        var resource: MediaResourceReference?
+        if let image = media as? TelegramMediaImage {
+            immediateThumbnailData = image.immediateThumbnailData
+            resource = self.getResource(message: message, image: image)
+        } else if let file = media as? TelegramMediaFile {
+            immediateThumbnailData = file.immediateThumbnailData
+            resource = self.getResource(message: message, file: file)
+        }
+
+        if let resource = resource {
+            if let data = try? Data(contentsOf: URL(fileURLWithPath: self.getCachePath(resourceId: resource.resource.id, imageType: .square(width: width)))), let image = UIImage(data: data) {
+                return GetMediaResult(image: image, loadSignal: nil)
+            }
+
+            var blurredImage: UIImage?
+            if let data = try? Data(contentsOf: URL(fileURLWithPath: self.getCachePath(resourceId: resource.resource.id, imageType: .blurredThumbnail))), let image = UIImage(data: data) {
+                blurredImage = image
+            } else if let data = immediateThumbnailData.flatMap(decodeTinyThumbnail), let image = UIImage(data: data) {
+                if let blurredImageValue = generateBlurredThumbnail(image: image) {
+                    blurredImage = blurredImageValue
+                }
+            }
+
+            return GetMediaResult(image: blurredImage, loadSignal: self.getLoadSignal(resource: resource, width: width))
+        } else {
+            return nil
+        }
+    }
+}