Implemented progress callbacks and related fixes.

@@ -13,8 +13,8 @@
 NSString *const SDWebImageDownloadStartNotification = @"SDWebImageDownloadStartNotification";
 NSString *const SDWebImageDownloadStopNotification = @"SDWebImageDownloadStopNotification";
 
-NSString *const kProgressCallbackKey = @"completed";
-NSString *const kCompletedCallbackKey = @"completed";
+static NSString *const kProgressCallbackKey = @"progress";
+static NSString *const kCompletedCallbackKey = @"completed";
 
 @interface SDWebImageDownloader ()
 
@@ -107,7 +107,7 @@ NSString *const kCompletedCallbackKey = @"completed";
         {
             if (!wself) return;
             SDWebImageDownloader *sself = wself;
-            NSArray *callbacksForURL = [sself callbacksForURL:url remove:YES];
+            NSArray *callbacksForURL = [sself callbacksForURL:url remove:NO];
             for (NSDictionary *callbacks in callbacksForURL)
             {
                 SDWebImageDownloaderProgressBlock callback = callbacks[kProgressCallbackKey];

@@ -148,6 +148,10 @@
         {
             self.expectedSize = response.expectedContentLength > 0 ? (NSUInteger)response.expectedContentLength : 0;
             self.imageData = [NSMutableData.alloc initWithCapacity:self.expectedSize];
+            if (self.progressBlock)
+            {
+                self.progressBlock(0, self.expectedSize);
+            }
         });
     }
     else
@@ -234,6 +238,10 @@
 
             CFRelease(imageSource);
         }
+        if (self.progressBlock)
+        {
+            self.progressBlock(self.imageData.length, self.expectedSize);
+        }
     });
 }
 

@@ -97,7 +97,14 @@
             SDWebImageDownloaderOptions downloaderOptions = 0;
             if (options & SDWebImageLowPriority) downloaderOptions |= SDWebImageDownloaderLowPriority;
             if (options & SDWebImageProgressiveDownload) downloaderOptions |= SDWebImageDownloaderProgressiveDownload;
-            __block id<SDWebImageOperation> subOperation = [self.imageDownloader downloadImageWithURL:url options:downloaderOptions progress:progressBlock completed:^(UIImage *downloadedImage, NSData *data, NSError *error, BOOL finished)
+            __block id<SDWebImageOperation> subOperation = [self.imageDownloader downloadImageWithURL:url options:downloaderOptions progress:^(NSUInteger receivedSize, long long expectedSize)
+            {
+                dispatch_async(dispatch_get_main_queue(), ^
+                {
+                    progressBlock(receivedSize, expectedSize);
+                });
+            }
+            completed:^(UIImage *downloadedImage, NSData *data, NSError *error, BOOL finished)
             {
                 dispatch_async(dispatch_get_main_queue(), ^
                 {