iOS Video Caching - Manual cache deletion - ios

Question

I have a React Native application which uses React Native Video with iOS caching. I have been working on a method inside RCTVideoCache.m which would manually delete the data of a particular cache key. According to the documentation of SPTPersistentCache, which the video library uses for caching, data can be deleted either by locking/unlocking a file and invoking a wipe or after inspecting the source code of SPTPersistentCache.h with a method named removeDataForKeys.
I have tried both ways, however, unsuccessfully.
In my first try, I am using wipeLockedFiles. I have created a deleteFromCache() method inside RCTVideoCache.m. Since all my video files are unlocked by default, in this method I am trying to lock the file corresponding to my cacheKey and invoke a wipe on all locked files (which would consist of only my target cacheKey file) as it is demonstrated in the documentation. This method looks like:
- (void)deleteFromCache:(NSString *)cacheKey withCallback:(void(^)(BOOL))handler;
{
[self.videoCache lockDataForKeys:#[cacheKey] callback:nil queue:nil];
[self.videoCache wipeLockedFiles];
NSLog(#"Size = %#", #(self.videoCache.totalUsedSizeInBytes));
handler(YES);
}
The following results in two errors during compilation:
/Users/.../MyApp/node_modules/react-native-video/ios/VideoCaching/RCTVideoCache.m:79:20: error: no visible #interface for 'SPTPersistentCache' declares the selector 'lockDataForKeys:callback:queue:'
[self.videoCache lockDataForKeys:#[cacheKey] callback:nil queue:nil];
~~~~~~~~~~~~~~~ ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/Users/.../MyApp/node_modules/react-native-video/ios/VideoCaching/RCTVideoCache.m:80:20: error: no visible #interface for 'SPTPersistentCache' declares the selector 'wipeLockedFiles'
[self.videoCache wipeLockedFiles];
~~~~~~~~~~~~~~~ ^~~~~~~~~~~~~~~
I really have no idea why these selectors are not visible from SPTPersistentCache.
In my second try, I am using removeDataForKeys(). Again, I have created a deleteFromCache() method inside RCTVideoCache.m which looks like this:
- (void)deleteFromCache:(NSString *)cacheKey withCallback:(void(^)(BOOL))handler;
{
[self.videoCache removeDataForKeys:#[cacheKey] callback:^(SPTPersistentCacheResponse * _Nonnull response) {
NSLog(#"Result output: %#", response.output);
NSLog(#"Error output: %#", [response.error localizedDescription]);
} onQueue:dispatch_get_main_queue()];
NSLog(#"Size = %#", #(self.videoCache.totalUsedSizeInBytes));
handler(YES);
}
In this second way, there are no errors, however, the data of the key is never deleted. Also, both NSLogs for the response output null inside the terminal.
I am 100% sure that the cacheKey I am providing to my deleteFromCache() method is correct and data corresponding to it exists. However, in both methods NSLog(#"Size = %#", #(self.videoCache.totalUsedSizeInBytes)); does not change and I can also manually verify that the file has not been deleted.
I am really stuck and do not know what is wrong with the code I've written in both cases and why neither of them works. I would appreciate any help on this!

Answer 1

You can delete all sub-folder's files (tmp/rct.video.cache), iterating each one:
+ (void)deleteFromCache
{
NSArray* tmpDirectory = [[NSFileManager defaultManager] contentsOfDirectoryAtPath:self.temporaryCachePath error:NULL];
for (NSString *file in tmpDirectory) {
[[NSFileManager defaultManager] removeItemAtPath:[NSString stringWithFormat:#"%#%#", self.temporaryCachePath, file] error:NULL];
}
}

Answer 2

I ran your example and discovered that you are using incorrect method signatures. These methods simply don't exist in the caching library, their signatures are different.
Try something like this:
- (void)deleteFromCache:(NSString *)cacheKey withCallback:(void(^)(BOOL))handler;
{
NSLog(#"Size before = %#", #(self.videoCache.totalUsedSizeInBytes));
[self.videoCache lockDataForKeys:#[cacheKey] callback:nil onQueue:nil];
[self.videoCache wipeLockedFilesWithCallback:^(SPTPersistentCacheResponse * _Nonnull response) {
NSLog(#"Size after = %#, response = %#", #(self.videoCache.totalUsedSizeInBytes), response);
// Call handler after the files are wiped
handler(YES);
} onQueue:nil];
}
I have no idea why the second approach doesn't work, but NSLog(#"Size = %#", #(self.videoCache.totalUsedSizeInBytes)); is for sure called before the actual deletion happens. In the example I posted above, I have moved the logging statement into the callback closure, so that it reports the size before and after the deletion takes place.