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[ReactNative] Move image asset loading to a queue

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This commit is contained in:
Kevin Gozali
2015-04-14 18:02:42 -07:00
parent 758dd0d376
commit e362fb2095
1 changed files with 27 additions and 4 deletions
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31
Libraries/Image/RCTImageLoader.m
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@@ -19,6 +19,19 @@
#import "RCTImageDownloader.h"
#import "RCTLog.h"
static dispatch_queue_t RCTImageLoaderQueue(void)
{
static dispatch_queue_t queue = NULL;
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
queue = dispatch_queue_create("com.facebook.rctImageLoader", DISPATCH_QUEUE_SERIAL);
dispatch_set_target_queue(queue,
dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0));
});
return queue;
}
NSError *errorWithMessage(NSString *message)
{
NSDictionary *errorInfo = @{NSLocalizedDescriptionKey: message};
@@ -43,10 +56,20 @@ NSError *errorWithMessage(NSString *message)
if ([imageTag hasPrefix:@"assets-library"]) {
[[RCTImageLoader assetsLibrary] assetForURL:[NSURL URLWithString:imageTag] resultBlock:^(ALAsset *asset) {
if (asset) {
ALAssetRepresentation *representation = [asset defaultRepresentation];
ALAssetOrientation orientation = [representation orientation];
UIImage *image = [UIImage imageWithCGImage:[representation fullResolutionImage] scale:1.0f orientation:(UIImageOrientation)orientation];
callback(nil, image);
// ALAssetLibrary API is async and will be multi-threaded. Loading a few full
// resolution images at once will spike the memory up to store the image data,
// and might trigger memory warnings and/or OOM crashes.
// To improve this, process the loaded asset in a serial queue.
dispatch_async(RCTImageLoaderQueue(), ^{
// Also make sure the image is released immediately after it's used so it
// doesn't spike the memory up during the process.
@autoreleasepool {
ALAssetRepresentation *representation = [asset defaultRepresentation];
ALAssetOrientation orientation = [representation orientation];
UIImage *image = [UIImage imageWithCGImage:[representation fullResolutionImage] scale:1.0f orientation:(UIImageOrientation)orientation];
callback(nil, image);
}
});
} else {
NSString *errorText = [NSString stringWithFormat:@"Failed to load asset at URL %@ with no error message.", imageTag];
NSError *error = errorWithMessage(errorText);