Enhance image freshness check before stored into cache (#23226)

Summary:
This is a re-submit of D13895627 which got landed but didn't include a fix to Instagram's code. The sheriffs were unsure how it got landed without running the build.

Currently, before we store the image to cache, we only respect `Cache-Control`, actually, we also may need to check `Expires`、`Last-Modified`, refer to [MDN docs](https://developer.mozilla.org/en-US/docs/Web/HTTP/Caching#Freshness), and  [okhttp](https://github.com/square/okhttp/blob/568a91c44a118b2c2ba62d310a331582c567b24a/okhttp/src/main/java/okhttp3/internal/cache/CacheStrategy.java#L268) respect the `MDN`, so in iOS, we can also respect this.

[iOS] [Fixed] - Respect `MDN` cache strategy before cache the image.

Reviewed By: shergin

Differential Revision: D13896822

Pulled By: cpojer

fbshipit-source-id: 8c1714f4a17ad40496146806cff3e188a60be93c

Author: zhongwuzw

Libraries/Image/RCTImageCache.m

@@ -106,33 +106,49 @@ - (void)addImageToCache:(UIImage *)image
                    size:(CGSize)size
                   scale:(CGFloat)scale
              resizeMode:(RCTResizeMode)resizeMode
-           responseDate:(NSString *)responseDate
-           cacheControl:(NSString *)cacheControl
+               response:(NSURLResponse *)response
 {
-  NSString *cacheKey = RCTCacheKeyForImage(url, size, scale, resizeMode);
-  BOOL shouldCache = YES;
-  NSDate *staleTime;
-  NSArray<NSString *> *components = [cacheControl componentsSeparatedByString:@","];
-  for (NSString *component in components) {
-    if ([component containsString:@"no-cache"] || [component containsString:@"no-store"] || [component hasSuffix:@"max-age=0"]) {
-      shouldCache = NO;
-      break;
-    } else {
-      NSRange range = [component rangeOfString:@"max-age="];
-      if (range.location != NSNotFound) {
-        NSInteger seconds = [[component substringFromIndex:range.location + range.length] integerValue];
-        NSDate *originalDate = [self dateWithHeaderString:responseDate];
-        staleTime = [originalDate dateByAddingTimeInterval:(NSTimeInterval)seconds];
+  if ([response isKindOfClass:[NSHTTPURLResponse class]]) {
+    NSString *cacheKey = RCTCacheKeyForImage(url, size, scale, resizeMode);
+    BOOL shouldCache = YES;
+    NSString *responseDate = ((NSHTTPURLResponse *)response).allHeaderFields[@"Date"];
+    NSDate *originalDate = [self dateWithHeaderString:responseDate];
+    NSString *cacheControl = ((NSHTTPURLResponse *)response).allHeaderFields[@"Cache-Control"];
+    NSDate *staleTime;
+    NSArray<NSString *> *components = [cacheControl componentsSeparatedByString:@","];
+    for (NSString *component in components) {
+      if ([component containsString:@"no-cache"] || [component containsString:@"no-store"] || [component hasSuffix:@"max-age=0"]) {
+        shouldCache = NO;
+        break;
+      } else {
+        NSRange range = [component rangeOfString:@"max-age="];
+        if (range.location != NSNotFound) {
+          NSInteger seconds = [[component substringFromIndex:range.location + range.length] integerValue];
+          staleTime = [originalDate dateByAddingTimeInterval:(NSTimeInterval)seconds];
+        }
       }
     }
-  }
-  if (shouldCache) {
-    if (staleTime) {
-      @synchronized(_cacheStaleTimes) {
-        _cacheStaleTimes[cacheKey] = staleTime;
+    if (shouldCache) {
+      if (!staleTime && originalDate) {
+        NSString *expires = ((NSHTTPURLResponse *)response).allHeaderFields[@"Expires"];
+        NSString *lastModified = ((NSHTTPURLResponse *)response).allHeaderFields[@"Last-Modified"];
+        if (expires) {
+          staleTime = [self dateWithHeaderString:expires];
+        } else if (lastModified) {
+          NSDate *lastModifiedDate = [self dateWithHeaderString:lastModified];
+          if (lastModifiedDate) {
+            NSTimeInterval interval = [originalDate timeIntervalSinceDate:lastModifiedDate] / 10;
+            staleTime = [originalDate dateByAddingTimeInterval:interval];
+          }
+        }
+      }
+      if (staleTime) {
+        @synchronized(_cacheStaleTimes) {
+          _cacheStaleTimes[cacheKey] = staleTime;
+        }
       }
+      return [self addImageToCache:image forKey:cacheKey];
     }
-    return [self addImageToCache:image forKey:cacheKey];
   }
 }
 

Libraries/Image/RCTImageLoader.h

@@ -31,8 +31,7 @@ typedef dispatch_block_t RCTImageLoaderCancellationBlock;
                    size:(CGSize)size
                   scale:(CGFloat)scale
              resizeMode:(RCTResizeMode)resizeMode
-           responseDate:(NSString *)responseDate
-           cacheControl:(NSString *)cacheControl;
+               response:(NSURLResponse *)response;
 
 @end
 

Libraries/Image/RCTImageLoader.m

@@ -346,7 +346,7 @@ - (RCTImageLoaderCancellationBlock)_loadImageOrDataWithURLRequest:(NSURLRequest
                                                        resizeMode:(RCTResizeMode)resizeMode
                                                     progressBlock:(RCTImageLoaderProgressBlock)progressHandler
                                                  partialLoadBlock:(RCTImageLoaderPartialLoadBlock)partialLoadHandler
-                                                  completionBlock:(void (^)(NSError *error, id imageOrData, BOOL cacheResult, NSString *fetchDate, NSString *cacheControl))completionBlock
+                                                  completionBlock:(void (^)(NSError *error, id imageOrData, BOOL cacheResult, NSURLResponse *response))completionBlock
 {
     {
         NSMutableURLRequest *mutableRequest = [request mutableCopy];
@@ -375,7 +375,7 @@ - (RCTImageLoaderCancellationBlock)_loadImageOrDataWithURLRequest:(NSURLRequest
     __block atomic_bool cancelled = ATOMIC_VAR_INIT(NO);
     // TODO: Protect this variable shared between threads.
     __block dispatch_block_t cancelLoad = nil;
-    void (^completionHandler)(NSError *, id, NSString *, NSString *) = ^(NSError *error, id imageOrData, NSString *fetchDate, NSString *cacheControl) {
+    void (^completionHandler)(NSError *, id, NSURLResponse *) = ^(NSError *error, id imageOrData, NSURLResponse *response) {
         cancelLoad = nil;
 
         // If we've received an image, we should try to set it synchronously,
@@ -385,11 +385,11 @@ - (RCTImageLoaderCancellationBlock)_loadImageOrDataWithURLRequest:(NSURLRequest
             // expecting it, and may do expensive post-processing in the callback
             dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
                 if (!atomic_load(&cancelled)) {
-                    completionBlock(error, imageOrData, cacheResult, fetchDate, cacheControl);
+                    completionBlock(error, imageOrData, cacheResult, response);
                 }
             });
         } else if (!atomic_load(&cancelled)) {
-            completionBlock(error, imageOrData, cacheResult, fetchDate, cacheControl);
+            completionBlock(error, imageOrData, cacheResult, response);
         }
     };
 
@@ -403,7 +403,7 @@ - (RCTImageLoaderCancellationBlock)_loadImageOrDataWithURLRequest:(NSURLRequest
                             progressHandler:progressHandler
                          partialLoadHandler:partialLoadHandler
                           completionHandler:^(NSError *error, UIImage *image){
-                              completionHandler(error, image, nil, nil);
+                              completionHandler(error, image, nil);
                           }];
     }
 
@@ -427,7 +427,7 @@ - (RCTImageLoaderCancellationBlock)_loadImageOrDataWithURLRequest:(NSURLRequest
                                       progressHandler:progressHandler
                                    partialLoadHandler:partialLoadHandler
                                     completionHandler:^(NSError *error, UIImage *image) {
-                                        completionHandler(error, image, nil, nil);
+                                        completionHandler(error, image, nil);
                                     }];
         } else {
             UIImage *image;
@@ -439,7 +439,7 @@ - (RCTImageLoaderCancellationBlock)_loadImageOrDataWithURLRequest:(NSURLRequest
             }
 
             if (image) {
-                completionHandler(nil, image, nil, nil);
+                completionHandler(nil, image, nil);
             } else {
                 // Use networking module to load image
                 cancelLoad = [strongSelf _loadURLRequest:request
@@ -464,7 +464,7 @@ - (RCTImageLoaderCancellationBlock)_loadImageOrDataWithURLRequest:(NSURLRequest
 
 - (RCTImageLoaderCancellationBlock)_loadURLRequest:(NSURLRequest *)request
                                      progressBlock:(RCTImageLoaderProgressBlock)progressHandler
-                                   completionBlock:(void (^)(NSError *error, id imageOrData, NSString *fetchDate, NSString *cacheControl))completionHandler
+                                   completionBlock:(void (^)(NSError *error, id imageOrData, NSURLResponse *response))completionHandler
 {
     // Check if networking module is available
     if (RCT_DEBUG && ![_bridge respondsToSelector:@selector(networking)]) {
@@ -486,36 +486,31 @@ - (RCTImageLoaderCancellationBlock)_loadURLRequest:(NSURLRequest *)request
     RCTURLRequestCompletionBlock processResponse = ^(NSURLResponse *response, NSData *data, NSError *error) {
         // Check for system errors
         if (error) {
-            completionHandler(error, nil, nil, nil);
+            completionHandler(error, nil, response);
             return;
         } else if (!response) {
-            completionHandler(RCTErrorWithMessage(@"Response metadata error"), nil, nil, nil);
+            completionHandler(RCTErrorWithMessage(@"Response metadata error"), nil, response);
             return;
         } else if (!data) {
-            completionHandler(RCTErrorWithMessage(@"Unknown image download error"), nil, nil, nil);
+            completionHandler(RCTErrorWithMessage(@"Unknown image download error"), nil, response);
             return;
         }
 
         // Check for http errors
-        NSString *responseDate;
-        NSString *cacheControl;
         if ([response isKindOfClass:[NSHTTPURLResponse class]]) {
             NSInteger statusCode = ((NSHTTPURLResponse *)response).statusCode;
             if (statusCode != 200) {
                 NSString *errorMessage = [NSString stringWithFormat:@"Failed to load %@", response.URL];
                 NSDictionary *userInfo = @{NSLocalizedDescriptionKey: errorMessage};
                 completionHandler([[NSError alloc] initWithDomain:NSURLErrorDomain
                                                              code:statusCode
-                                                         userInfo:userInfo], nil, nil, nil);
+                                                         userInfo:userInfo], nil, response);
                 return;
             }
-
-            responseDate = ((NSHTTPURLResponse *)response).allHeaderFields[@"Date"];
-            cacheControl = ((NSHTTPURLResponse *)response).allHeaderFields[@"Cache-Control"];
         }
 
         // Call handler
-        completionHandler(nil, data, responseDate, cacheControl);
+        completionHandler(nil, data, response);
     };
 
     // Download image
@@ -537,7 +532,7 @@ - (RCTImageLoaderCancellationBlock)_loadURLRequest:(NSURLRequest *)request
                                } else {
                                    someError = RCTErrorWithMessage(@"Unknown image download error");
                                }
-                               completionHandler(someError, nil, nil, nil);
+                               completionHandler(someError, nil, response);
                                [strongSelf dequeueTasks];
                                return;
                            }
@@ -603,7 +598,7 @@ - (RCTImageLoaderCancellationBlock)loadImageWithURLRequest:(NSURLRequest *)image
     };
 
     __weak RCTImageLoader *weakSelf = self;
-    void (^completionHandler)(NSError *, id, BOOL, NSString *, NSString *) = ^(NSError *error, id imageOrData, BOOL cacheResult, NSString *fetchDate, NSString *cacheControl) {
+    void (^completionHandler)(NSError *, id, BOOL, NSURLResponse *) = ^(NSError *error, id imageOrData, BOOL cacheResult, NSURLResponse *response) {
         __typeof(self) strongSelf = weakSelf;
         if (atomic_load(&cancelled) || !strongSelf) {
             return;
@@ -623,8 +618,7 @@ - (RCTImageLoaderCancellationBlock)loadImageWithURLRequest:(NSURLRequest *)image
                                                     size:size
                                                    scale:scale
                                               resizeMode:resizeMode
-                                            responseDate:fetchDate
-                                            cacheControl:cacheControl];
+                                                response:response];
             }
 
             cancelLoad = nil;
@@ -758,7 +752,7 @@ - (RCTImageLoaderCancellationBlock)decodeImageData:(NSData *)data
 - (RCTImageLoaderCancellationBlock)getImageSizeForURLRequest:(NSURLRequest *)imageURLRequest
                                                        block:(void(^)(NSError *error, CGSize size))callback
 {
-    void (^completion)(NSError *, id, BOOL, NSString *, NSString *) = ^(NSError *error, id imageOrData, BOOL cacheResult, NSString *fetchDate, NSString *cacheControl) {
+    void (^completion)(NSError *, id, BOOL, NSURLResponse *) = ^(NSError *error, id imageOrData, BOOL cacheResult, NSURLResponse *response) {
         CGSize size;
         if ([imageOrData isKindOfClass:[NSData class]]) {
             NSDictionary *meta = RCTGetImageMetadata(imageOrData);