0.10.6

Sources/Shared/Services/ChatMediaImageCache.swift

@@ -0,0 +1,35 @@
+import Foundation
+
+#if os(iOS)
+import UIKit
+typealias ChatMediaPlatformImage = UIImage
+#elseif os(macOS)
+import AppKit
+typealias ChatMediaPlatformImage = NSImage
+#endif
+
+/// SwiftUI can evaluate every visible bubble repeatedly during scrolling.
+/// Keep decoded thumbnails in a bounded native-image cache so those passes do
+/// not repeatedly decompress JPEG/HEIC data on the main actor.
+@MainActor
+enum ChatMediaImageCache {
+    private static let cache: NSCache<NSString, ChatMediaPlatformImage> = {
+        let cache = NSCache<NSString, ChatMediaPlatformImage>()
+        cache.countLimit = 160
+        cache.totalCostLimit = 48 * 1_024 * 1_024
+        return cache
+    }()
+
+    static func image(
+        for message: ChatMessage,
+        data: Data
+    ) -> ChatMediaPlatformImage? {
+        let cacheKey = "\(message.conversationID)\u{1F}\(message.id)" as NSString
+        if let cached = cache.object(forKey: cacheKey) {
+            return cached
+        }
+        guard let image = ChatMediaPlatformImage(data: data) else { return nil }
+        cache.setObject(image, forKey: cacheKey, cost: data.count)
+        return image
+    }
+}