Fix the issue when using thumbnailPixelSize and optionsProcessor

SDWebImageSwiftUI/Classes/ImageManager.swift

@@ -106,18 +106,20 @@ public final class ImageManager : ObservableObject {
         }
     }
     
-    /// Prefetch the initial state of image
-    internal func prefetch() {
-        let key = manager.cacheKey(for: url)
-        if let imageCache = manager.imageCache as? SDImageCache {
-            self.image = imageCache.imageFromMemoryCache(forKey: key)
-        } else {
-            // generic API
-            manager.imageCache.containsImage(forKey: key, cacheType: .memory) { [unowned self] (cacheType) in
-                if cacheType == .memory {
-                    self.manager.imageCache.queryImage(forKey: key, options: self.options, context: self.context) { [unowned self] (image, data, cacheType) in
-                        self.image = image
-                    }
+    /// Prefetch the initial state of image, currently query the memory cache only
+    func prefetch() {
+        // Use the options processor if provided
+        var context = self.context
+        if let result = manager.optionsProcessor?.processedResult(for: url, options: options, context: context) {
+            context = result.context
+        }
+        // TODO: before SDWebImage 5.7.0, this is the SPI. Remove later
+        let key = manager.perform(Selector(("cacheKeyForURL:context:")), with: url, with: context)?.takeUnretainedValue() as? String
+        // This callback is synchronzied
+        manager.imageCache.containsImage(forKey: key, cacheType: .memory) { [unowned self] (cacheType) in
+            if cacheType == .memory {
+                self.manager.imageCache.queryImage(forKey: key, options: self.options, context: self.context) { [unowned self] (image, data, cacheType) in
+                    self.image = image
                 }
             }
         }