GT2/Ejectable/node_modules/react-native/Libraries/Image/RCTImageCache.m

164 lines
5.6 KiB
Objective-C

/*
* Copyright (c) Facebook, Inc. and its affiliates.
*
* This source code is licensed under the MIT license found in the
* LICENSE file in the root directory of this source tree.
*/
#import <React/RCTImageCache.h>
#import <objc/runtime.h>
#import <ImageIO/ImageIO.h>
#import <React/RCTConvert.h>
#import <React/RCTNetworking.h>
#import <React/RCTUtils.h>
#import <React/RCTResizeMode.h>
#import <React/RCTImageUtils.h>
static const NSUInteger RCTMaxCachableDecodedImageSizeInBytes = 2097152; // 2 MB
static NSString *RCTCacheKeyForImage(NSString *imageTag, CGSize size, CGFloat scale,
RCTResizeMode resizeMode)
{
return [NSString stringWithFormat:@"%@|%g|%g|%g|%lld",
imageTag, size.width, size.height, scale, (long long)resizeMode];
}
@implementation RCTImageCache
{
NSOperationQueue *_imageDecodeQueue;
NSCache *_decodedImageCache;
NSMutableDictionary *_cacheStaleTimes;
}
- (instancetype)init
{
if (self = [super init]) {
_decodedImageCache = [NSCache new];
_decodedImageCache.totalCostLimit = 20 * 1024 * 1024; // 20 MB
_cacheStaleTimes = [[NSMutableDictionary alloc] init];
[[NSNotificationCenter defaultCenter] addObserver:self
selector:@selector(clearCache)
name:UIApplicationDidReceiveMemoryWarningNotification
object:nil];
[[NSNotificationCenter defaultCenter] addObserver:self
selector:@selector(clearCache)
name:UIApplicationWillResignActiveNotification
object:nil];
}
return self;
}
- (void)clearCache
{
[_decodedImageCache removeAllObjects];
@synchronized(_cacheStaleTimes) {
[_cacheStaleTimes removeAllObjects];
}
}
- (void)addImageToCache:(UIImage *)image
forKey:(NSString *)cacheKey
{
if (!image) {
return;
}
NSInteger bytes = image.reactDecodedImageBytes;
if (bytes <= RCTMaxCachableDecodedImageSizeInBytes) {
[self->_decodedImageCache setObject:image
forKey:cacheKey
cost:bytes];
}
}
- (UIImage *)imageForUrl:(NSString *)url
size:(CGSize)size
scale:(CGFloat)scale
resizeMode:(RCTResizeMode)resizeMode
{
NSString *cacheKey = RCTCacheKeyForImage(url, size, scale, resizeMode);
@synchronized(_cacheStaleTimes) {
id staleTime = _cacheStaleTimes[cacheKey];
if (staleTime) {
if ([[NSDate new] compare:(NSDate *)staleTime] == NSOrderedDescending) {
// cached image has expired, clear it out to make room for others
[_cacheStaleTimes removeObjectForKey:cacheKey];
[_decodedImageCache removeObjectForKey:cacheKey];
return nil;
}
}
}
return [_decodedImageCache objectForKey:cacheKey];
}
- (void)addImageToCache:(UIImage *)image
URL:(NSString *)url
size:(CGSize)size
scale:(CGFloat)scale
resizeMode:(RCTResizeMode)resizeMode
response:(NSURLResponse *)response
{
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 && 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];
}
}
}
- (NSDate *)dateWithHeaderString:(NSString *)headerDateString {
static NSDateFormatter *formatter;
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
formatter = [[NSDateFormatter alloc] init];
formatter.locale = [[NSLocale alloc] initWithLocaleIdentifier:@"en_US_POSIX"];
formatter.dateFormat = @"EEE',' dd MMM yyyy HH':'mm':'ss 'GMT'";
formatter.timeZone = [NSTimeZone timeZoneForSecondsFromGMT:0];
});
return [formatter dateFromString:headerDateString];
}
@end