1 @protocol SDWebImagePrefetcherDelegate <NSObject>
 2 
 3 @optional
 4 
 5 /**
 6  * Called when an image was prefetched.
 7  *
 8  * @param imagePrefetcher The current image prefetcher
 9  * @param imageURL        The image url that was prefetched
10  * @param finishedCount   The total number of images that were prefetched (successful or not)
11  * @param totalCount      The total number of images that were to be prefetched
12  */
13 - (void)imagePrefetcher:(nonnull SDWebImagePrefetcher *)imagePrefetcher didPrefetchURL:(nullable NSURL *)imageURL finishedCount:(NSUInteger)finishedCount totalCount:(NSUInteger)totalCount;
14 
15 /**
16  * Called when all images are prefetched.
17  * @param imagePrefetcher The current image prefetcher
18  * @param totalCount      The total number of images that were prefetched (whether successful or not)
19  * @param skippedCount    The total number of images that were skipped
20  */
21 - (void)imagePrefetcher:(nonnull SDWebImagePrefetcher *)imagePrefetcher didFinishWithTotalCount:(NSUInteger)totalCount skippedCount:(NSUInteger)skippedCount;
22 
23 @end

1 typedef void(^SDWebImagePrefetcherProgressBlock)(NSUInteger noOfFinishedUrls, NSUInteger noOfTotalUrls);
2 typedef void(^SDWebImagePrefetcherCompletionBlock)(NSUInteger noOfFinishedUrls, NSUInteger noOfSkippedUrls);

 1 /**
 2  *  The web image manager
 3  */
 4 @property (strong, nonatomic, readonly, nonnull) SDWebImageManager *manager;
 5 
 6 /**
 7  * Maximum number of URLs to prefetch at the same time. Defaults to 3.
 8  */
 9 @property (nonatomic, assign) NSUInteger maxConcurrentDownloads;
10 
11 /**
12  * SDWebImageOptions for prefetcher. Defaults to SDWebImageLowPriority.
13  */
14 @property (nonatomic, assign) SDWebImageOptions options;
15 
16 /**
17  * Queue options for Prefetcher. Defaults to Main Queue.
18  */
19 @property (nonatomic, assign, nonnull) dispatch_queue_t prefetcherQueue;
20 
21 @property (weak, nonatomic, nullable) id <SDWebImagePrefetcherDelegate> delegate;