Add custom cache setter

Reviewed By: donyu

Differential Revision: D3622912

fbshipit-source-id: 675b3135212c73808cb18702c2cbf5684816df87

Libraries/Image/RCTImageCache.h

@@ -11,5 +11,5 @@
 
 #import "RCTImageLoader.h"
 
-@interface RCTImageCache : NSObject <RCTImageCacheDelegate>
+@interface RCTImageCache : NSObject <RCTImageCache>
 @end

Libraries/Image/RCTImageLoader.h

@@ -17,6 +17,26 @@ typedef void (^RCTImageLoaderProgressBlock)(int64_t progress, int64_t total);
 typedef void (^RCTImageLoaderCompletionBlock)(NSError *error, UIImage *image);
 typedef dispatch_block_t RCTImageLoaderCancellationBlock;
 
+/**
+ * Provides an interface to use for providing a image caching strategy.
+ */
+@protocol RCTImageCache <NSObject>
+
+- (UIImage *)imageForUrl:(NSString *)url
+                    size:(CGSize)size
+                   scale:(CGFloat)scale
+              resizeMode:(RCTResizeMode)resizeMode
+            responseDate:(NSString *)responseDate;
+
+- (void)addImageToCache:(UIImage *)image
+                    URL:(NSString *)url
+                   size:(CGSize)size
+                  scale:(CGFloat)scale
+             resizeMode:(RCTResizeMode)resizeMode
+           responseDate:(NSString *)responseDate;
+
+@end
+
 @interface UIImage (React)
 
 @property (nonatomic, copy) CAKeyframeAnimation *reactKeyframeAnimation;
@@ -92,6 +112,13 @@ typedef dispatch_block_t RCTImageLoaderCancellationBlock;
 - (RCTImageLoaderCancellationBlock)getImageSizeForURLRequest:(NSURLRequest *)imageURLRequest
                                                        block:(void(^)(NSError *error, CGSize size))completionBlock;
 
+/**
+ * Allows developers to set their own caching implementation for
+ * decoded images as long as it conforms to the RCTImageCacheDelegate
+ * protocol. This method should be called in bridgeDidInitializeModule.
+ */
+- (void)setImageCache:(id<RCTImageCache>)cache;
+
 @end
 
 @interface RCTBridge (RCTImageLoader)
@@ -198,24 +225,3 @@ typedef dispatch_block_t RCTImageLoaderCancellationBlock;
 - (float)decoderPriority;
 
 @end
-
-/**
- * Provides an interface to use for providing a image caching strategy.
- */
-
-@protocol RCTImageCacheDelegate <NSObject>
-
-- (UIImage *)imageForUrl:(NSString *)url
-                    size:(CGSize)size
-                   scale:(CGFloat)scale
-              resizeMode:(RCTResizeMode)resizeMode
-            responseDate:(NSString *)responseDate;
-
-- (void)addImageToCache:(UIImage *)image
-                    URL:(NSString *)url
-                   size:(CGSize)size
-                  scale:(CGFloat)scale
-             resizeMode:(RCTResizeMode)resizeMode
-           responseDate:(NSString *)responseDate;
-
-@end

Libraries/Image/RCTImageLoader.m

@@ -43,7 +43,7 @@
   NSArray<id<RCTImageDataDecoder>> *_decoders;
   NSOperationQueue *_imageDecodeQueue;
   dispatch_queue_t _URLRequestQueue;
-  id<RCTImageCacheDelegate> _imageCache;
+  id<RCTImageCache> _imageCache;
   NSMutableArray *_pendingTasks;
   NSInteger _activeTasks;
   NSMutableArray *_pendingDecodes;
@@ -65,20 +65,28 @@ RCT_EXPORT_MODULE()
   _URLRequestQueue = dispatch_queue_create("com.facebook.react.ImageLoaderURLRequestQueue", DISPATCH_QUEUE_SERIAL);
 }
 
-- (id<RCTImageCacheDelegate>)getImageCache
-{
-    if (!_imageCache) {
-        //set up with default cache
-        _imageCache = [RCTImageCache new];
-    }
-    return _imageCache;
-}
-
 - (float)handlerPriority
 {
   return 1;
 }
 
+- (id<RCTImageCache>)imageCache
+{
+  if (!_imageCache) {
+    //set up with default cache
+    _imageCache = [RCTImageCache new];
+  }
+  return _imageCache;
+}
+
+- (void)setImageCache:(id<RCTImageCache>)cache
+{
+  if (_imageCache) {
+    RCTLogWarn(@"RCTImageCache was already set and has now been overriden.");
+  }
+  _imageCache = cache;
+}
+
 - (id<RCTImageURLLoader>)imageURLLoaderForURL:(NSURL *)URL
 {
   if (!_maxConcurrentLoadingTasks) {
@@ -500,7 +508,7 @@ static UIImage *RCTResizeImageIfNeeded(UIImage *image,
 
     // Check decoded image cache
     if (cacheResult) {
-      UIImage *image = [[strongSelf getImageCache] imageForUrl:imageURLRequest.URL.absoluteString
+      UIImage *image = [[strongSelf imageCache] imageForUrl:imageURLRequest.URL.absoluteString
                                                           size:size
                                                          scale:scale
                                                     resizeMode:resizeMode
@@ -514,7 +522,7 @@ static UIImage *RCTResizeImageIfNeeded(UIImage *image,
     // Store decoded image in cache
     RCTImageLoaderCompletionBlock cacheResultHandler = ^(NSError *error_, UIImage *image) {
       if (image) {
-        [[strongSelf getImageCache] addImageToCache:image
+        [[strongSelf imageCache] addImageToCache:image
                                                 URL:imageURLRequest.URL.absoluteString
                                                size:size
                                               scale:scale