react-native/Libraries/Image/RCTImageLoader.m
Nick Lockwood b49633e020 Fixed image test flakiness by tying decoded image cache to module lifecycle
Summary: The decoded image cache was previously static, meaning that cached images could persist beyond the lifetime of the module. This resulted in some flakiness in the RCTImageLoaderTests due to the loader returning cached image instanced from previous tests instead of the correct instance.

Reviewed By: bestander

Differential Revision: D3346329

fbshipit-source-id: 375af8894cef1c5b6303c6cdfd7eb57ebcfe3251
2016-05-25 06:58:23 -07:00

792 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 "RCTImageLoader.h"
#import <libkern/OSAtomic.h>
#import <UIKit/UIKit.h>
#import <ImageIO/ImageIO.h>
#import "RCTConvert.h"
#import "RCTDefines.h"
#import "RCTImageUtils.h"
#import "RCTLog.h"
#import "RCTNetworking.h"
#import "RCTUtils.h"
static NSString *const RCTErrorInvalidURI = @"E_INVALID_URI";
static NSString *const RCTErrorPrefetchFailure = @"E_PREFETCH_FAILURE";
static const NSUInteger RCTMaxCachableDecodedImageSizeInBytes = 1048576; // 1MB
static NSString *RCTCacheKeyForImage(NSString *imageTag, CGSize size,
CGFloat scale, RCTResizeMode resizeMode)
{
return [NSString stringWithFormat:@"%@|%g|%g|%g|%zd",
imageTag, size.width, size.height, scale, resizeMode];
}
@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 _URLCacheQueue;
NSURLCache *_URLCache;
NSCache *_decodedImageCache;
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
_URLCacheQueue = dispatch_queue_create("com.facebook.react.ImageLoaderURLCacheQueue", DISPATCH_QUEUE_SERIAL);
_decodedImageCache = [NSCache new];
_decodedImageCache.totalCostLimit = 5 * 1024 * 1024; // 5MB
// Clear cache in the event of a memory warning, or if app enters background
[[NSNotificationCenter defaultCenter] addObserver:_decodedImageCache selector:@selector(removeAllObjects) name:UIApplicationDidReceiveMemoryWarningNotification object:nil];
[[NSNotificationCenter defaultCenter] addObserver:_decodedImageCache selector:@selector(removeAllObjects) name:UIApplicationWillResignActiveNotification object:nil];
}
- (void)dealloc
{
[[NSNotificationCenter defaultCenter] removeObserver:_decodedImageCache];
}
- (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)loadImageWithTag:(NSString *)imageTag
callback:(RCTImageLoaderCompletionBlock)callback
{
return [self loadImageWithTag:imageTag
size:CGSizeZero
scale:1
resizeMode:RCTResizeModeStretch
progressBlock:nil
completionBlock:callback];
}
- (void)dequeueTasks
{
dispatch_async(_URLCacheQueue, ^{
// Remove completed tasks
for (RCTNetworkTask *task in _pendingTasks.reverseObjectEnumerator) {
switch (task.status) {
case RCTNetworkTaskFinished:
[_pendingTasks removeObject:task];
_activeTasks--;
break;
case RCTNetworkTaskPending:
case RCTNetworkTaskInProgress:
// Do nothing
break;
}
}
// Start queued decode
NSInteger activeDecodes = _scheduledDecodes - _pendingDecodes.count;
while (activeDecodes == 0 || (_activeBytes <= _maxConcurrentDecodingBytes &&
activeDecodes <= _maxConcurrentDecodingTasks)) {
dispatch_block_t decodeBlock = _pendingDecodes.firstObject;
if (decodeBlock) {
[_pendingDecodes removeObjectAtIndex:0];
decodeBlock();
} else {
break;
}
}
// Start queued tasks
for (RCTNetworkTask *task in _pendingTasks) {
if (MAX(_activeTasks, _scheduledDecodes) >= _maxConcurrentLoadingTasks) {
break;
}
if (task.status == RCTNetworkTaskPending) {
[task start];
_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)loadImageOrDataWithTag:(NSString *)imageTag
size:(CGSize)size
scale:(CGFloat)scale
resizeMode:(RCTResizeMode)resizeMode
progressBlock:(RCTImageLoaderProgressBlock)progressHandler
completionBlock:(void (^)(NSError *error, id imageOrData))completionBlock
{
__block volatile uint32_t cancelled = 0;
__block void(^cancelLoad)(void) = nil;
__weak RCTImageLoader *weakSelf = self;
void (^completionHandler)(NSError *error, id imageOrData) = ^(NSError *error, id imageOrData) {
if ([NSThread isMainThread]) {
// 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);
}
});
} else if (!cancelled) {
completionBlock(error, imageOrData);
}
};
if (imageTag.length == 0) {
completionHandler(RCTErrorWithMessage(@"source.uri should not be an empty string"), nil);
return ^{};
}
// All access to URL cache must be serialized
if (!_URLCacheQueue) {
[self setUp];
}
dispatch_async(_URLCacheQueue, ^{
if (!_URLCache) {
_URLCache = [[NSURLCache alloc] initWithMemoryCapacity:5 * 1024 * 1024 // 5MB
diskCapacity:200 * 1024 * 1024 // 200MB
diskPath:@"React/RCTImageDownloader"];
}
RCTImageLoader *strongSelf = weakSelf;
if (cancelled || !strongSelf) {
return;
}
// Find suitable image URL loader
NSURLRequest *request = [RCTConvert NSURLRequest:imageTag];
id<RCTImageURLLoader> loadHandler = [strongSelf imageURLLoaderForURL:request.URL];
if (loadHandler) {
cancelLoad = [loadHandler loadImageForURL:request.URL
size:size
scale:scale
resizeMode:resizeMode
progressHandler:progressHandler
completionHandler:completionHandler] ?: ^{};
return;
}
// 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.",
imageTag);
return;
}
// Check if networking module can load image
if (RCT_DEBUG && ![_bridge.networking canHandleRequest:request]) {
RCTLogError(@"No suitable image URL loader found for %@", imageTag);
return;
}
// Use networking module to load image
RCTURLRequestCompletionBlock processResponse =
^(NSURLResponse *response, NSData *data, NSError *error) {
// Check for system errors
if (error) {
completionHandler(error, nil);
return;
} else if (!data) {
completionHandler(RCTErrorWithMessage(@"Unknown image download error"), nil);
return;
}
// Check for http errors
if ([response isKindOfClass:[NSHTTPURLResponse class]]) {
NSInteger statusCode = ((NSHTTPURLResponse *)response).statusCode;
if (statusCode != 200) {
completionHandler([[NSError alloc] initWithDomain:NSURLErrorDomain
code:statusCode
userInfo:nil], nil);
return;
}
}
// Call handler
completionHandler(nil, data);
};
// Add missing png extension
if (request.URL.fileURL && request.URL.pathExtension.length == 0) {
NSMutableURLRequest *mutableRequest = [request mutableCopy];
mutableRequest.URL = [NSURL fileURLWithPath:[request.URL.path stringByAppendingPathExtension:@"png"]];
request = mutableRequest;
}
// Check for cached response before reloading
// TODO: move URL cache out of RCTImageLoader into its own module
NSCachedURLResponse *cachedResponse = [_URLCache cachedResponseForRequest:request];
while (cachedResponse) {
if ([cachedResponse.response isKindOfClass:[NSHTTPURLResponse class]]) {
NSHTTPURLResponse *httpResponse = (NSHTTPURLResponse *)cachedResponse.response;
if (httpResponse.statusCode == 301 || httpResponse.statusCode == 302) {
NSString *location = httpResponse.allHeaderFields[@"Location"];
if (location == nil) {
completionHandler(RCTErrorWithMessage(@"Image redirect without location"), nil);
return;
}
NSURL *redirectURL = [NSURL URLWithString: location];
request = [NSURLRequest requestWithURL: redirectURL];
cachedResponse = [_URLCache cachedResponseForRequest:request];
continue;
}
}
processResponse(cachedResponse.response, cachedResponse.data, nil);
return;
}
// Download image
RCTNetworkTask *task = [_bridge.networking networkTaskWithRequest:request completionBlock:^(NSURLResponse *response, NSData *data, NSError *error) {
if (error) {
completionHandler(error, nil);
return;
}
dispatch_async(_URLCacheQueue, ^{
// Cache the response
// TODO: move URL cache out of RCTImageLoader into its own module
BOOL isHTTPRequest = [request.URL.scheme hasPrefix:@"http"];
[strongSelf->_URLCache storeCachedResponse:
[[NSCachedURLResponse alloc] initWithResponse:response
data:data
userInfo:nil
storagePolicy:isHTTPRequest ? NSURLCacheStorageAllowed: NSURLCacheStorageAllowedInMemoryOnly]
forRequest:request];
// Process image data
processResponse(response, data, nil);
//clean up
[weakSelf dequeueTasks];
});
}];
task.downloadProgressBlock = progressHandler;
if (!_pendingTasks) {
_pendingTasks = [NSMutableArray new];
}
if (task) {
[_pendingTasks addObject:task];
if (MAX(_activeTasks, _scheduledDecodes) < _maxConcurrentLoadingTasks) {
[task start];
_activeTasks++;
}
}
cancelLoad = ^{
[task cancel];
[weakSelf dequeueTasks];
};
});
return ^{
if (cancelLoad) {
cancelLoad();
}
OSAtomicOr32Barrier(1, &cancelled);
};
}
- (RCTImageLoaderCancellationBlock)loadImageWithTag:(NSString *)imageTag
size:(CGSize)size
scale:(CGFloat)scale
resizeMode:(RCTResizeMode)resizeMode
progressBlock:(RCTImageLoaderProgressBlock)progressHandler
completionBlock:(RCTImageLoaderCompletionBlock)completionBlock
{
return [self loadImageWithoutClipping:imageTag
size:size
scale:scale
resizeMode:resizeMode
progressBlock:progressHandler
completionBlock:^(NSError *error, UIImage *image) {
completionBlock(error, RCTResizeImageIfNeeded(image, size, scale, resizeMode));
}];
}
- (RCTImageLoaderCancellationBlock)loadImageWithoutClipping:(NSString *)imageTag
size:(CGSize)size
scale:(CGFloat)scale
resizeMode:(RCTResizeMode)resizeMode
progressBlock:(RCTImageLoaderProgressBlock)progressHandler
completionBlock:(RCTImageLoaderCompletionBlock)completionBlock
{
__block volatile uint32_t cancelled = 0;
__block void(^cancelLoad)(void) = nil;
__weak RCTImageLoader *weakSelf = self;
// Check decoded image cache
NSString *cacheKey = RCTCacheKeyForImage(imageTag, size, scale, resizeMode);
{
UIImage *image = [_decodedImageCache objectForKey:cacheKey];
if (image) {
// 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), ^{
completionBlock(nil, image);
});
return ^{};
}
}
RCTImageLoaderCompletionBlock cacheResultHandler = ^(NSError *error, UIImage *image) {
if (image) {
CGFloat bytes = image.size.width * image.size.height * image.scale * image.scale * 4;
if (bytes <= RCTMaxCachableDecodedImageSizeInBytes) {
[_decodedImageCache setObject:image forKey:cacheKey cost:bytes];
}
}
completionBlock(error, image);
};
void (^completionHandler)(NSError *, id) = ^(NSError *error, id imageOrData) {
if (!cancelled) {
if (!imageOrData || [imageOrData isKindOfClass:[UIImage class]]) {
cacheResultHandler(error, imageOrData);
} else {
cancelLoad = [weakSelf decodeImageDataWithoutClipping:imageOrData
size:size
scale:scale
resizeMode:resizeMode
completionBlock:cacheResultHandler];
}
}
};
cancelLoad = [self loadImageOrDataWithTag:imageTag
size:size
scale:scale
resizeMode:resizeMode
progressBlock:progressHandler
completionBlock:completionHandler];
return ^{
if (cancelLoad) {
cancelLoad();
}
OSAtomicOr32Barrier(1, &cancelled);
};
}
- (RCTImageLoaderCancellationBlock)decodeImageData:(NSData *)data
size:(CGSize)size
scale:(CGFloat)scale
resizeMode:(RCTResizeMode)resizeMode
completionBlock:(RCTImageLoaderCompletionBlock)completionBlock
{
return [self decodeImageDataWithoutClipping:data
size:size
scale:scale
resizeMode:resizeMode
completionBlock:^(NSError *error, UIImage *image) {
completionBlock(error, RCTResizeImageIfNeeded(image, size, scale, resizeMode));
}];
}
- (RCTImageLoaderCancellationBlock)decodeImageDataWithoutClipping:(NSData *)data
size:(CGSize)size
scale:(CGFloat)scale
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 ([NSThread isMainThread]) {
// 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, image);
}
});
} else if (!cancelled) {
completionBlock(error, image);
}
};
id<RCTImageDataDecoder> imageDecoder = [self imageDataDecoderForData:data];
if (imageDecoder) {
return [imageDecoder decodeImageData:data
size:size
scale:scale
resizeMode:resizeMode
completionHandler:completionHandler] ?: ^{};
} else {
if (!_URLCacheQueue) {
[self setUp];
}
dispatch_async(_URLCacheQueue, ^{
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
_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(_URLCacheQueue, ^{
_scheduledDecodes--;
_activeBytes -= decodedImageBytes;
[self dequeueTasks];
});
});
};
// 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.
_scheduledDecodes++;
if (!_pendingDecodes) {
_pendingDecodes = [NSMutableArray new];
}
NSInteger activeDecodes = _scheduledDecodes - _pendingDecodes.count - 1;
if (activeDecodes == 0 || (_activeBytes <= _maxConcurrentDecodingBytes &&
activeDecodes <= _maxConcurrentDecodingTasks)) {
decodeBlock();
} else {
[_pendingDecodes addObject:decodeBlock];
}
});
return ^{
OSAtomicOr32Barrier(1, &cancelled);
};
}
}
- (RCTImageLoaderCancellationBlock)getImageSize:(NSString *)imageTag
block:(void(^)(NSError *error, CGSize size))completionBlock
{
return [self loadImageOrDataWithTag:imageTag
size:CGSizeZero
scale:1
resizeMode:RCTResizeModeStretch
progressBlock:nil
completionBlock:^(NSError *error, id imageOrData) {
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,
};
}
completionBlock(error, size);
}];
}
#pragma mark - Bridged methods
RCT_EXPORT_METHOD(prefetchImage:(NSString *)uri
resolve:(RCTPromiseResolveBlock)resolve
reject:(RCTPromiseRejectBlock)reject)
{
if (!uri.length) {
reject(RCTErrorInvalidURI, @"Cannot prefetch an image for an empty URI", nil);
return;
}
[_bridge.imageLoader loadImageWithTag:uri callback:^(NSError *error, UIImage *image) {
if (error) {
reject(RCTErrorPrefetchFailure, nil, error);
return;
}
resolve(@YES);
}];
}
#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 loadImageWithTag:request.URL.absoluteString 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