Fix and make SDScaledImageForPath extensible

SDWebImage/SDImageCache.m

@@ -164,8 +164,7 @@ static const NSInteger kDefaultCacheMaxCacheAge = 60 * 60 * 24 * 7; // 1 week
     }
     
     // Second check the disk cache...
-    UIImage *diskImage = [UIImage decodedImageWithImage:SDScaledImageForPath(key, [NSData dataWithContentsOfFile:[self cachePathForKey:key]])];
+    UIImage *diskImage = [self diskImageForKey:key];
-    
     if (diskImage)
     {
         CGFloat cost = diskImage.size.height * diskImage.size.width * diskImage.scale;
@@ -175,6 +174,27 @@ static const NSInteger kDefaultCacheMaxCacheAge = 60 * 60 * 24 * 7; // 1 week
     return diskImage;
 }
 
+- (UIImage *)diskImageForKey:(NSString *)key
+{
+    NSString *path = [self cachePathForKey:key];
+    NSData *data = [NSData dataWithContentsOfFile:path];
+    if (data)
+    {
+        UIImage *image = [[UIImage alloc] initWithData:data];
+        UIImage *scaledImage = [self scaledImageForKey:key image:image];
+        return [UIImage decodedImageWithImage:scaledImage];
+    }
+    else
+    {
+        return nil;
+    }
+}
+
+- (UIImage *)scaledImageForKey:(NSString *)key image:(UIImage *)image
+{
+    return SDScaledImageForKey(key, image);
+}
+
 - (void)queryDiskCacheForKey:(NSString *)key done:(void (^)(UIImage *image, SDImageCacheType cacheType))doneBlock
 {
     if (!doneBlock) return;
@@ -197,8 +217,7 @@ static const NSInteger kDefaultCacheMaxCacheAge = 60 * 60 * 24 * 7; // 1 week
     {
         @autoreleasepool
         {
-            UIImage *diskImage = [UIImage decodedImageWithImage:SDScaledImageForPath(key, [NSData dataWithContentsOfFile:[self cachePathForKey:key]])];
+            UIImage *diskImage = [self diskImageForKey:key];
-
             if (diskImage)
             {
                 CGFloat cost = diskImage.size.height * diskImage.size.width * diskImage.scale;

SDWebImage/SDWebImageCompat.h

@@ -37,4 +37,4 @@
     #define SDDispatchQueueSetterSementics assign
 #endif
 
-extern inline UIImage *SDScaledImageForPath(NSString *path, NSObject *imageOrData);
+extern inline UIImage *SDScaledImageForKey(NSString *key, UIImage *image);

SDWebImage/SDWebImageCompat.m

@@ -12,34 +12,15 @@
 #error SDWebImage is ARC only. Either turn on ARC for the project or use -fobjc-arc flag
 #endif
 
-inline UIImage *SDScaledImageForPath(NSString *path, NSObject *imageOrData)
+inline UIImage *SDScaledImageForKey(NSString *key, UIImage *image)
 {
-    if (!imageOrData)
-    {
-        return nil;
-    }
-
-    UIImage *image = nil;
-    if ([imageOrData isKindOfClass:[NSData class]])
-    {
-        image = [[UIImage alloc] initWithData:(NSData *)imageOrData];
-    }
-    else if ([imageOrData isKindOfClass:[UIImage class]])
-    {
-        image = (UIImage *)imageOrData;
-    }
-    else
-    {
-        return nil;
-    }
-
     if ([[UIScreen mainScreen] respondsToSelector:@selector(scale)])
     {
         CGFloat scale = 1.0;
-        if (path.length >= 8)
+        if (key.length >= 8)
         {
             // Search @2x. at the end of the string, before a 3 to 4 extension length (only if key len is 8 or more @2x. + 4 len ext)
-            NSRange range = [path rangeOfString:@"@2x." options:0 range:NSMakeRange(path.length - 8, 5)];
+            NSRange range = [key rangeOfString:@"@2x." options:0 range:NSMakeRange(key.length - 8, 5)];
             if (range.location != NSNotFound)
             {
                 scale = 2.0;
@@ -49,6 +30,5 @@ inline UIImage *SDScaledImageForPath(NSString *path, NSObject *imageOrData)
         UIImage *scaledImage = [[UIImage alloc] initWithCGImage:image.CGImage scale:scale orientation:image.imageOrientation];
         image = scaledImage;
     }
-
     return image;
 }

SDWebImage/SDWebImageDownloaderOperation.m

@@ -225,7 +225,9 @@
 
             if (partialImageRef)
             {
-                UIImage *image = [UIImage decodedImageWithImage:SDScaledImageForPath(self.request.URL.absoluteString, [UIImage imageWithCGImage:partialImageRef])];
+                UIImage *image = [UIImage imageWithCGImage:partialImageRef];
+                UIImage *scaledImage = [self scaledImageForKey:self.request.URL.absoluteString image:image];
+                image = [UIImage decodedImageWithImage:scaledImage];
                 CGImageRelease(partialImageRef);
                 dispatch_async(dispatch_get_main_queue(), ^
                 {
@@ -248,6 +250,11 @@
     }
 }
 
+- (UIImage *)scaledImageForKey:(NSString *)key image:(UIImage *)image
+{
+    return SDScaledImageForKey(key, image);
+}
+
 - (void)connectionDidFinishLoading:(NSURLConnection *)aConnection
 {
     CFRunLoopStop(CFRunLoopGetCurrent());
@@ -267,7 +274,9 @@
         }
         else
         {
-            UIImage *image = [UIImage decodedImageWithImage:SDScaledImageForPath(self.request.URL.absoluteString, self.imageData)];
+            UIImage *image = [[UIImage alloc] initWithData:self.imageData];
+            UIImage *scaledImage = [self scaledImageForKey:self.request.URL.absoluteString image:image];
+            image = [UIImage decodedImageWithImage:scaledImage];
             if (CGSizeEqualToSize(image.size, CGSizeZero))
             {
                 completionBlock(nil, nil, [NSError errorWithDomain:@"SDWebImageErrorDomain" code:0 userInfo:@{NSLocalizedDescriptionKey: @"Downloaded image has 0 pixels"}], YES);