Sending data from disk to server without loading into ram on iOS

Question

I am working on an application that sometimes requires sending large files (500MB) or more to our servers. Generally the files will already be stored on disk and I will have the local file URL, is there a way I can create an NSMutableRequest without having to first load all the data from disk into NSData?

It would be nice just to read a few MB at a time from the disk, send it off, and then repeat until its all gone. What is the best / most efficient way to go about this?

Edit

Basically if I had a 10GB video I wanted to upload, I would never be able to fit all of it into NSData before the system terminated my app due to memory constraints.

Unless the device has some dedicated hardware connected to both the "disk" and the radio, I don't think it is possible to send data out "without loading it into RAM". — Nicolas Miari, Aug 24 '17 at 00:54
Ya sorry should have specified without having to load it all in ram at once, just a couple MB at a time — Asleepace, Aug 24 '17 at 00:56
Basically if I had a 10GB video I wanted to upload, I would never be able to fit that into NSData before the system terminated my app due to memory constraints. — Asleepace, Aug 24 '17 at 00:58
Check this out: https://stackoverflow.com/questions/31965566/how-to-efficiently-write-large-files-to-disk-on-background-thread-swift — Nicolas Miari, Aug 24 '17 at 01:04
It seems to be about **writing** to disk, but the same or similar API should help — Nicolas Miari, Aug 24 '17 at 01:04
@NicolasMiari if you posted that as an answer I would accept it — Asleepace, Aug 24 '17 at 01:21

Nicolas Miari · Accepted Answer · 2017-08-24T01:45:31.580

Basically, you need to read your large, local file in bits and send it over the network. You can do that using the foundation class NSInputStream.

Sample code from Apple's documentation (Objective-C):

- (void)setUpStreamForFile:(NSString *)path {
    // iStream is NSInputStream instance variable
    iStream = [[NSInputStream alloc] initWithFileAtPath:path];
    [iStream setDelegate:self];
    [iStream scheduleInRunLoop:[NSRunLoop currentRunLoop]
                       forMode:NSDefaultRunLoopMode];
    [iStream open];
}

in Swift 3, that would be something like this:

func setUpStream(forFile path: String) -> InputStream? {
    guard let stream = InputStream(fileAtPath: path) else {
        return nil
    }
    stream.delegate = self
    stream.schedule(in: RunLoop.current, forMode: .defaultRunLoopMode)
    stream.open()

    return stream
}

(You will also need to adopt the protocol NSStreamDelegate, but this is enough to get oyu started I guess...)

Sending data from disk to server without loading into ram on iOS

1 Answers1