react-native/Libraries/Image/RCTImageLoader.m
Adam Comella 23423774ba iOS: Fix an image loader crash
Summary:
Fixes #10433

The code didn't account for the fact that cancelLoad is set by two different threads. It gets set on the URL request queue when the request completes successfully and it gets set on the UI queue during cancelation. This oversight lead to a couple of different kinds of crashes.

1. Attempt to invoke a nil function -- We check that cancelLoad is non-nil and on the next line we call it. However, cancelLoad could have been set to nil by the other thread between the time it was verified to be non-nil and the time it was called. Consequently, the program will attempt to call nil and crash.

2. Block deallocated while it's executing -- Suppose cancelLoad points to a block, it is verified to be non-nil, and it is successfully invoked. In the middle of executing the block, cancelLoad, the last reference to the block, is set to nil. This causes the block to be deallocated and its captured values to be freed. However, the block continues executing and the next time it attempts to use a captured value
Closes https://github.com/facebook/react-native/pull/11145

Differential Revision: D4261499

Pulled By: javache

fbshipit-source-id: 46424c6dd8cfa085cef32d945308de07798040bc
2016-12-01 21:28:33 -08:00

788 lines
28 KiB
Objective-C

/**
* Copyright (c) 2015-present, Facebook, Inc.
* All rights reserved.
*
* This source code is licensed under the BSD-style license found in the
* LICENSE file in the root directory of this source tree. An additional grant
* of patent rights can be found in the PATENTS file in the same directory.
*/
#import <libkern/OSAtomic.h>
#import <objc/runtime.h>
#import <ImageIO/ImageIO.h>
#import <React/RCTConvert.h>
#import <React/RCTDefines.h>
#import <React/RCTImageLoader.h>
#import <React/RCTLog.h>
#import <React/RCTNetworking.h>
#import <React/RCTUtils.h>
#import "RCTImageCache.h"
#import "RCTImageUtils.h"
@implementation UIImage (React)
- (CAKeyframeAnimation *)reactKeyframeAnimation
{
return objc_getAssociatedObject(self, _cmd);
}
- (void)setReactKeyframeAnimation:(CAKeyframeAnimation *)reactKeyframeAnimation
{
objc_setAssociatedObject(self, @selector(reactKeyframeAnimation), reactKeyframeAnimation, OBJC_ASSOCIATION_COPY_NONATOMIC);
}
@end
@implementation RCTImageLoader
{
NSArray<id<RCTImageURLLoader>> *_loaders;
NSArray<id<RCTImageDataDecoder>> *_decoders;
NSOperationQueue *_imageDecodeQueue;
dispatch_queue_t _URLRequestQueue;
id<RCTImageCache> _imageCache;
NSMutableArray *_pendingTasks;
NSInteger _activeTasks;
NSMutableArray *_pendingDecodes;
NSInteger _scheduledDecodes;
NSUInteger _activeBytes;
}
@synthesize bridge = _bridge;
RCT_EXPORT_MODULE()
- (void)setUp
{
// Set defaults
_maxConcurrentLoadingTasks = _maxConcurrentLoadingTasks ?: 4;
_maxConcurrentDecodingTasks = _maxConcurrentDecodingTasks ?: 2;
_maxConcurrentDecodingBytes = _maxConcurrentDecodingBytes ?: 30 * 1024 * 1024; // 30MB
_URLRequestQueue = dispatch_queue_create("com.facebook.react.ImageLoaderURLRequestQueue", DISPATCH_QUEUE_SERIAL);
}
- (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) {
[self setUp];
}
if (!_loaders) {
// Get loaders, sorted in reverse priority order (highest priority first)
RCTAssert(_bridge, @"Bridge not set");
_loaders = [[_bridge modulesConformingToProtocol:@protocol(RCTImageURLLoader)] sortedArrayUsingComparator:^NSComparisonResult(id<RCTImageURLLoader> a, id<RCTImageURLLoader> b) {
float priorityA = [a respondsToSelector:@selector(loaderPriority)] ? [a loaderPriority] : 0;
float priorityB = [b respondsToSelector:@selector(loaderPriority)] ? [b loaderPriority] : 0;
if (priorityA > priorityB) {
return NSOrderedAscending;
} else if (priorityA < priorityB) {
return NSOrderedDescending;
} else {
return NSOrderedSame;
}
}];
}
if (RCT_DEBUG) {
// Check for handler conflicts
float previousPriority = 0;
id<RCTImageURLLoader> previousLoader = nil;
for (id<RCTImageURLLoader> loader in _loaders) {
float priority = [loader respondsToSelector:@selector(loaderPriority)] ? [loader loaderPriority] : 0;
if (previousLoader && priority < previousPriority) {
return previousLoader;
}
if ([loader canLoadImageURL:URL]) {
if (previousLoader) {
if (priority == previousPriority) {
RCTLogError(@"The RCTImageURLLoaders %@ and %@ both reported that"
" they can load the URL %@, and have equal priority"
" (%g). This could result in non-deterministic behavior.",
loader, previousLoader, URL, priority);
}
} else {
previousLoader = loader;
previousPriority = priority;
}
}
}
return previousLoader;
}
// Normal code path
for (id<RCTImageURLLoader> loader in _loaders) {
if ([loader canLoadImageURL:URL]) {
return loader;
}
}
return nil;
}
- (id<RCTImageDataDecoder>)imageDataDecoderForData:(NSData *)data
{
if (!_maxConcurrentLoadingTasks) {
[self setUp];
}
if (!_decoders) {
// Get decoders, sorted in reverse priority order (highest priority first)
RCTAssert(_bridge, @"Bridge not set");
_decoders = [[_bridge modulesConformingToProtocol:@protocol(RCTImageDataDecoder)] sortedArrayUsingComparator:^NSComparisonResult(id<RCTImageDataDecoder> a, id<RCTImageDataDecoder> b) {
float priorityA = [a respondsToSelector:@selector(decoderPriority)] ? [a decoderPriority] : 0;
float priorityB = [b respondsToSelector:@selector(decoderPriority)] ? [b decoderPriority] : 0;
if (priorityA > priorityB) {
return NSOrderedAscending;
} else if (priorityA < priorityB) {
return NSOrderedDescending;
} else {
return NSOrderedSame;
}
}];
}
if (RCT_DEBUG) {
// Check for handler conflicts
float previousPriority = 0;
id<RCTImageDataDecoder> previousDecoder = nil;
for (id<RCTImageDataDecoder> decoder in _decoders) {
float priority = [decoder respondsToSelector:@selector(decoderPriority)] ? [decoder decoderPriority] : 0;
if (previousDecoder && priority < previousPriority) {
return previousDecoder;
}
if ([decoder canDecodeImageData:data]) {
if (previousDecoder) {
if (priority == previousPriority) {
RCTLogError(@"The RCTImageDataDecoders %@ and %@ both reported that"
" they can decode the data <NSData %p; %tu bytes>, and"
" have equal priority (%g). This could result in"
" non-deterministic behavior.",
decoder, previousDecoder, data, data.length, priority);
}
} else {
previousDecoder = decoder;
previousPriority = priority;
}
}
}
return previousDecoder;
}
// Normal code path
for (id<RCTImageDataDecoder> decoder in _decoders) {
if ([decoder canDecodeImageData:data]) {
return decoder;
}
}
return nil;
}
static UIImage *RCTResizeImageIfNeeded(UIImage *image,
CGSize size,
CGFloat scale,
RCTResizeMode resizeMode)
{
if (CGSizeEqualToSize(size, CGSizeZero) ||
CGSizeEqualToSize(image.size, CGSizeZero) ||
CGSizeEqualToSize(image.size, size)) {
return image;
}
CAKeyframeAnimation *animation = image.reactKeyframeAnimation;
CGRect targetSize = RCTTargetRect(image.size, size, scale, resizeMode);
CGAffineTransform transform = RCTTransformFromTargetRect(image.size, targetSize);
image = RCTTransformImage(image, size, scale, transform);
image.reactKeyframeAnimation = animation;
return image;
}
- (RCTImageLoaderCancellationBlock)loadImageWithURLRequest:(NSURLRequest *)imageURLRequest
callback:(RCTImageLoaderCompletionBlock)callback
{
return [self loadImageWithURLRequest:imageURLRequest
size:CGSizeZero
scale:1
clipped:YES
resizeMode:RCTResizeModeStretch
progressBlock:nil
partialLoadBlock:nil
completionBlock:callback];
}
- (void)dequeueTasks
{
dispatch_async(_URLRequestQueue, ^{
// Remove completed tasks
for (RCTNetworkTask *task in self->_pendingTasks.reverseObjectEnumerator) {
switch (task.status) {
case RCTNetworkTaskFinished:
[self->_pendingTasks removeObject:task];
self->_activeTasks--;
break;
case RCTNetworkTaskPending:
break;
case RCTNetworkTaskInProgress:
// Check task isn't "stuck"
if (task.requestToken == nil) {
RCTLogWarn(@"Task orphaned for request %@", task.request);
[self->_pendingTasks removeObject:task];
self->_activeTasks--;
[task cancel];
}
break;
}
}
// Start queued decode
NSInteger activeDecodes = self->_scheduledDecodes - self->_pendingDecodes.count;
while (activeDecodes == 0 || (self->_activeBytes <= self->_maxConcurrentDecodingBytes &&
activeDecodes <= self->_maxConcurrentDecodingTasks)) {
dispatch_block_t decodeBlock = self->_pendingDecodes.firstObject;
if (decodeBlock) {
[self->_pendingDecodes removeObjectAtIndex:0];
decodeBlock();
} else {
break;
}
}
// Start queued tasks
for (RCTNetworkTask *task in self->_pendingTasks) {
if (MAX(self->_activeTasks, self->_scheduledDecodes) >= self->_maxConcurrentLoadingTasks) {
break;
}
if (task.status == RCTNetworkTaskPending) {
[task start];
self->_activeTasks++;
}
}
});
}
/**
* This returns either an image, or raw image data, depending on the loading
* path taken. This is useful if you want to skip decoding, e.g. when preloading
* the image, or retrieving metadata.
*/
- (RCTImageLoaderCancellationBlock)_loadImageOrDataWithURLRequest:(NSURLRequest *)request
size:(CGSize)size
scale:(CGFloat)scale
resizeMode:(RCTResizeMode)resizeMode
progressBlock:(RCTImageLoaderProgressBlock)progressHandler
partialLoadBlock:(RCTImageLoaderPartialLoadBlock)partialLoadHandler
completionBlock:(void (^)(NSError *error, id imageOrData, BOOL cacheResult, NSString *fetchDate))completionBlock
{
{
NSMutableURLRequest *mutableRequest = [request mutableCopy];
[NSURLProtocol setProperty:@"RCTImageLoader"
forKey:@"trackingName"
inRequest:mutableRequest];
// Add missing png extension
if (request.URL.fileURL && request.URL.pathExtension.length == 0) {
mutableRequest.URL = [NSURL fileURLWithPath:[request.URL.path stringByAppendingPathExtension:@"png"]];
}
request = mutableRequest;
}
// Find suitable image URL loader
id<RCTImageURLLoader> loadHandler = [self imageURLLoaderForURL:request.URL];
BOOL requiresScheduling = [loadHandler respondsToSelector:@selector(requiresScheduling)] ?
[loadHandler requiresScheduling] : YES;
__block volatile uint32_t cancelled = 0;
__block dispatch_block_t cancelLoad = nil;
void (^completionHandler)(NSError *, id, NSString *) = ^(NSError *error, id imageOrData, NSString *fetchDate) {
cancelLoad = nil;
BOOL cacheResult = [loadHandler respondsToSelector:@selector(shouldCacheLoadedImages)] ?
[loadHandler shouldCacheLoadedImages] : YES;
// If we've received an image, we should try to set it synchronously,
// if it's data, do decoding on a background thread.
if (RCTIsMainQueue() && ![imageOrData isKindOfClass:[UIImage class]]) {
// Most loaders do not return on the main thread, so caller is probably not
// expecting it, and may do expensive post-processing in the callback
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
if (!cancelled) {
completionBlock(error, imageOrData, cacheResult, fetchDate);
}
});
} else if (!cancelled) {
completionBlock(error, imageOrData, cacheResult, fetchDate);
}
};
// If the loader doesn't require scheduling we call it directly on
// the main queue.
if (loadHandler && !requiresScheduling) {
return [loadHandler loadImageForURL:request.URL
size:size
scale:scale
resizeMode:resizeMode
progressHandler:progressHandler
partialLoadHandler:partialLoadHandler
completionHandler:^(NSError *error, UIImage *image){
completionHandler(error, image, nil);
}];
}
// All access to URL cache must be serialized
if (!_URLRequestQueue) {
[self setUp];
}
__weak RCTImageLoader *weakSelf = self;
dispatch_async(_URLRequestQueue, ^{
__typeof(self) strongSelf = weakSelf;
if (cancelled || !strongSelf) {
return;
}
if (loadHandler) {
cancelLoad = [loadHandler loadImageForURL:request.URL
size:size
scale:scale
resizeMode:resizeMode
progressHandler:progressHandler
partialLoadHandler:partialLoadHandler
completionHandler:^(NSError *error, UIImage *image) {
completionHandler(error, image, nil);
}];
} else {
// Use networking module to load image
cancelLoad = [strongSelf _loadURLRequest:request
progressBlock:progressHandler
completionBlock:completionHandler];
}
});
return ^{
dispatch_block_t cancelLoadLocal = cancelLoad;
cancelLoad = nil;
if (cancelLoadLocal && !cancelled) {
cancelLoadLocal();
}
OSAtomicOr32Barrier(1, &cancelled);
};
}
- (RCTImageLoaderCancellationBlock)_loadURLRequest:(NSURLRequest *)request
progressBlock:(RCTImageLoaderProgressBlock)progressHandler
completionBlock:(void (^)(NSError *error, id imageOrData, NSString *fetchDate))completionHandler
{
// Check if networking module is available
if (RCT_DEBUG && ![_bridge respondsToSelector:@selector(networking)]) {
RCTLogError(@"No suitable image URL loader found for %@. You may need to "
" import the RCTNetwork library in order to load images.",
request.URL.absoluteString);
return NULL;
}
RCTNetworking *networking = [_bridge networking];
// Check if networking module can load image
if (RCT_DEBUG && ![networking canHandleRequest:request]) {
RCTLogError(@"No suitable image URL loader found for %@", request.URL.absoluteString);
return NULL;
}
// Use networking module to load image
RCTURLRequestCompletionBlock processResponse = ^(NSURLResponse *response, NSData *data, NSError *error) {
// Check for system errors
if (error) {
completionHandler(error, nil, nil);
return;
} else if (!response) {
completionHandler(RCTErrorWithMessage(@"Response metadata error"), nil, nil);
return;
} else if (!data) {
completionHandler(RCTErrorWithMessage(@"Unknown image download error"), nil, nil);
return;
}
// Check for http errors
NSString *responseDate;
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);
return;
}
responseDate = ((NSHTTPURLResponse *)response).allHeaderFields[@"Date"];
}
// Call handler
completionHandler(nil, data, responseDate);
};
// Download image
__weak __typeof(self) weakSelf = self;
__block RCTNetworkTask *task =
[networking networkTaskWithRequest:request
completionBlock:^(NSURLResponse *response, NSData *data, NSError *error) {
__typeof(self) strongSelf = weakSelf;
if (!strongSelf) {
return;
}
if (error || !response || !data) {
NSError *someError = nil;
if (error) {
someError = error;
} else if (!response) {
someError = RCTErrorWithMessage(@"Response metadata error");
} else {
someError = RCTErrorWithMessage(@"Unknown image download error");
}
completionHandler(someError, nil, nil);
[strongSelf dequeueTasks];
return;
}
dispatch_async(strongSelf->_URLRequestQueue, ^{
// Process image data
processResponse(response, data, nil);
// Prepare for next task
[strongSelf dequeueTasks];
});
}];
task.downloadProgressBlock = ^(int64_t progress, int64_t total) {
if (progressHandler) {
progressHandler(progress, total);
}
};
if (task) {
if (!_pendingTasks) {
_pendingTasks = [NSMutableArray new];
}
[_pendingTasks addObject:task];
[self dequeueTasks];
}
return ^{
__typeof(self) strongSelf = weakSelf;
if (!strongSelf || !task) {
return;
}
dispatch_async(strongSelf->_URLRequestQueue, ^{
[task cancel];
task = nil;
});
[strongSelf dequeueTasks];
};
}
- (RCTImageLoaderCancellationBlock)loadImageWithURLRequest:(NSURLRequest *)imageURLRequest
size:(CGSize)size
scale:(CGFloat)scale
clipped:(BOOL)clipped
resizeMode:(RCTResizeMode)resizeMode
progressBlock:(RCTImageLoaderProgressBlock)progressBlock
partialLoadBlock:(RCTImageLoaderPartialLoadBlock)partialLoadBlock
completionBlock:(RCTImageLoaderCompletionBlock)completionBlock
{
__block volatile uint32_t cancelled = 0;
__block dispatch_block_t cancelLoad = nil;
dispatch_block_t cancellationBlock = ^{
dispatch_block_t cancelLoadLocal = cancelLoad;
if (cancelLoadLocal && !cancelled) {
cancelLoadLocal();
}
OSAtomicOr32Barrier(1, &cancelled);
};
__weak RCTImageLoader *weakSelf = self;
void (^completionHandler)(NSError *, id, BOOL, NSString *) = ^(NSError *error, id imageOrData, BOOL cacheResult, NSString *fetchDate) {
__typeof(self) strongSelf = weakSelf;
if (cancelled || !strongSelf) {
return;
}
if (!imageOrData || [imageOrData isKindOfClass:[UIImage class]]) {
cancelLoad = nil;
completionBlock(error, imageOrData);
return;
}
// Check decoded image cache
if (cacheResult) {
UIImage *image = [[strongSelf imageCache] imageForUrl:imageURLRequest.URL.absoluteString
size:size
scale:scale
resizeMode:resizeMode
responseDate:fetchDate];
if (image) {
cancelLoad = nil;
completionBlock(nil, image);
return;
}
}
RCTImageLoaderCompletionBlock decodeCompletionHandler = ^(NSError *error_, UIImage *image) {
if (cacheResult && image) {
// Store decoded image in cache
[[strongSelf imageCache] addImageToCache:image
URL:imageURLRequest.URL.absoluteString
size:size
scale:scale
resizeMode:resizeMode
responseDate:fetchDate];
}
cancelLoad = nil;
completionBlock(error_, image);
};
cancelLoad = [strongSelf decodeImageData:imageOrData
size:size
scale:scale
clipped:clipped
resizeMode:resizeMode
completionBlock:decodeCompletionHandler];
};
cancelLoad = [self _loadImageOrDataWithURLRequest:imageURLRequest
size:size
scale:scale
resizeMode:resizeMode
progressBlock:progressBlock
partialLoadBlock:partialLoadBlock
completionBlock:completionHandler];
return cancellationBlock;
}
- (RCTImageLoaderCancellationBlock)decodeImageData:(NSData *)data
size:(CGSize)size
scale:(CGFloat)scale
clipped:(BOOL)clipped
resizeMode:(RCTResizeMode)resizeMode
completionBlock:(RCTImageLoaderCompletionBlock)completionBlock
{
if (data.length == 0) {
completionBlock(RCTErrorWithMessage(@"No image data"), nil);
return ^{};
}
__block volatile uint32_t cancelled = 0;
void (^completionHandler)(NSError *, UIImage *) = ^(NSError *error, UIImage *image) {
if (RCTIsMainQueue()) {
// Most loaders do not return on the main thread, so caller is probably not
// expecting it, and may do expensive post-processing in the callback
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
if (!cancelled) {
completionBlock(error, clipped ? RCTResizeImageIfNeeded(image, size, scale, resizeMode) : image);
}
});
} else if (!cancelled) {
completionBlock(error, clipped ? RCTResizeImageIfNeeded(image, size, scale, resizeMode) : image);
}
};
id<RCTImageDataDecoder> imageDecoder = [self imageDataDecoderForData:data];
if (imageDecoder) {
return [imageDecoder decodeImageData:data
size:size
scale:scale
resizeMode:resizeMode
completionHandler:completionHandler] ?: ^{};
} else {
dispatch_block_t decodeBlock = ^{
// Calculate the size, in bytes, that the decompressed image will require
NSInteger decodedImageBytes = (size.width * scale) * (size.height * scale) * 4;
// Mark these bytes as in-use
self->_activeBytes += decodedImageBytes;
// Do actual decompression on a concurrent background queue
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
if (!cancelled) {
// Decompress the image data (this may be CPU and memory intensive)
UIImage *image = RCTDecodeImageWithData(data, size, scale, resizeMode);
#if RCT_DEV
CGSize imagePixelSize = RCTSizeInPixels(image.size, image.scale);
CGSize screenPixelSize = RCTSizeInPixels(RCTScreenSize(), RCTScreenScale());
if (imagePixelSize.width * imagePixelSize.height >
screenPixelSize.width * screenPixelSize.height) {
RCTLogInfo(@"[PERF ASSETS] Loading image at size %@, which is larger "
"than the screen size %@", NSStringFromCGSize(imagePixelSize),
NSStringFromCGSize(screenPixelSize));
}
#endif
if (image) {
completionHandler(nil, image);
} else {
NSString *errorMessage = [NSString stringWithFormat:@"Error decoding image data <NSData %p; %tu bytes>", data, data.length];
NSError *finalError = RCTErrorWithMessage(errorMessage);
completionHandler(finalError, nil);
}
}
// We're no longer retaining the uncompressed data, so now we'll mark
// the decoding as complete so that the loading task queue can resume.
dispatch_async(self->_URLRequestQueue, ^{
self->_scheduledDecodes--;
self->_activeBytes -= decodedImageBytes;
[self dequeueTasks];
});
});
};
if (!_URLRequestQueue) {
[self setUp];
}
dispatch_async(_URLRequestQueue, ^{
// The decode operation retains the compressed image data until it's
// complete, so we'll mark it as having started, in order to block
// further image loads from happening until we're done with the data.
self->_scheduledDecodes++;
if (!self->_pendingDecodes) {
self->_pendingDecodes = [NSMutableArray new];
}
NSInteger activeDecodes = self->_scheduledDecodes - self->_pendingDecodes.count - 1;
if (activeDecodes == 0 || (self->_activeBytes <= self->_maxConcurrentDecodingBytes &&
activeDecodes <= self->_maxConcurrentDecodingTasks)) {
decodeBlock();
} else {
[self->_pendingDecodes addObject:decodeBlock];
}
});
return ^{
OSAtomicOr32Barrier(1, &cancelled);
};
}
}
- (RCTImageLoaderCancellationBlock)getImageSizeForURLRequest:(NSURLRequest *)imageURLRequest
block:(void(^)(NSError *error, CGSize size))callback
{
void (^completion)(NSError *, id, BOOL, NSString *) = ^(NSError *error, id imageOrData, BOOL cacheResult, NSString *fetchDate) {
CGSize size;
if ([imageOrData isKindOfClass:[NSData class]]) {
NSDictionary *meta = RCTGetImageMetadata(imageOrData);
size = (CGSize){
[meta[(id)kCGImagePropertyPixelWidth] doubleValue],
[meta[(id)kCGImagePropertyPixelHeight] doubleValue],
};
} else {
UIImage *image = imageOrData;
size = (CGSize){
image.size.width * image.scale,
image.size.height * image.scale,
};
}
callback(error, size);
};
return [self _loadImageOrDataWithURLRequest:imageURLRequest
size:CGSizeZero
scale:1
resizeMode:RCTResizeModeStretch
progressBlock:NULL
partialLoadBlock:NULL
completionBlock:completion];
}
#pragma mark - RCTURLRequestHandler
- (BOOL)canHandleRequest:(NSURLRequest *)request
{
NSURL *requestURL = request.URL;
for (id<RCTImageURLLoader> loader in _loaders) {
// Don't use RCTImageURLLoader protocol for modules that already conform to
// RCTURLRequestHandler as it's inefficient to decode an image and then
// convert it back into data
if (![loader conformsToProtocol:@protocol(RCTURLRequestHandler)] &&
[loader canLoadImageURL:requestURL]) {
return YES;
}
}
return NO;
}
- (id)sendRequest:(NSURLRequest *)request withDelegate:(id<RCTURLRequestDelegate>)delegate
{
__block RCTImageLoaderCancellationBlock requestToken;
requestToken = [self loadImageWithURLRequest:request callback:^(NSError *error, UIImage *image) {
if (error) {
[delegate URLRequest:requestToken didCompleteWithError:error];
return;
}
NSString *mimeType = nil;
NSData *imageData = nil;
if (RCTImageHasAlpha(image.CGImage)) {
mimeType = @"image/png";
imageData = UIImagePNGRepresentation(image);
} else {
mimeType = @"image/jpeg";
imageData = UIImageJPEGRepresentation(image, 1.0);
}
NSURLResponse *response = [[NSURLResponse alloc] initWithURL:request.URL
MIMEType:mimeType
expectedContentLength:imageData.length
textEncodingName:nil];
[delegate URLRequest:requestToken didReceiveResponse:response];
[delegate URLRequest:requestToken didReceiveData:imageData];
[delegate URLRequest:requestToken didCompleteWithError:nil];
}];
return requestToken;
}
- (void)cancelRequest:(id)requestToken
{
if (requestToken) {
((RCTImageLoaderCancellationBlock)requestToken)();
}
}
@end
@implementation RCTBridge (RCTImageLoader)
- (RCTImageLoader *)imageLoader
{
return [self moduleForClass:[RCTImageLoader class]];
}
@end