react-native/Libraries/Image/RCTImageLoader.m

727 lines
26 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";
@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;
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);
}
- (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];
if (cachedResponse) {
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];
}
[_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;
void (^completionHandler)(NSError *error, id imageOrData) = ^(NSError *error, id imageOrData) {
if (!cancelled) {
if (!imageOrData || [imageOrData isKindOfClass:[UIImage class]]) {
completionBlock(error, imageOrData);
} else {
cancelLoad = [weakSelf decodeImageDataWithoutClipping:imageOrData
size:size
scale:scale
resizeMode:resizeMode
completionBlock:completionBlock] ?: ^{};
}
}
};
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