Asset Distribution Manager

A lightweight solution to manage OTA asset distribution to live iOS apps.

This project is currently in active development and should not be used in production

The problem

iOS apps must have an app size below 50MB to be downloaded OTA from a cellular network. This results in losing a lot of potential users by not being able to download the app if they're not connected to a WiFi network.

The solution

Do what it takes to ship the app with under 50MB of content (remove art, sound, etc.) and let ADM download those for you.

Goals

This project was built with specific goals in mind:

Very lightweight!
Zero dependencies!
NO singletons! Create as many ADMRepos as you like!
Delegate driven!
Excellent Documentation!
Unit Tested!

Documentation

View the documentation!

Example

- (void)viewDidLoad
{
    [super viewDidLoad];
    
    NSURL *url = [NSURL URLWithString:@"http://s3.amazonaws.com/my-bucket/"];
    
    self.repo = [[ADMRepo alloc] initWithSourceURL:url repoId:@"com.adm.level1"];
    self.repo.delegate = self;
    [self.repo update];
}

- (void)repo:(ADMRepo *)repo downloadProgress:(float)progress
{
    NSLog(@"%.2f%% downloaded", progress * 100);
}

- (void)didFinishUpdatingRepo:(ADMRepo *)repo
{
    NSBundle *dogsBundle = [ADMBundle bundleWithDescriptor:@"com.adm.level1.dogs"];
    NSBundle *catsBundle = [ADMBundle bundleWithDescriptor:@"com.adm.level1.cats"];
    
    NSString *dog = [dogsBundle pathForResource:@"dog1" ofType:@"png"];
    NSString *cat = [catsBundle pathForResource:@"cat1" ofType:@"png"];
    
    self.dogImageView.image = [UIImage imageWithContentsOfFile:dog];
    self.catImageView.image = [UIImage imageWithContentsOfFile:cat];
}

Server format

Repo

ADM treats server assets as repositories. A repository is a directory with a unique name that houses any number of bundles and an index.json file which lists the contents of the repo.

Bundle

A bundle is simply a tarball of a directory of assets that's named with a version identifier. For example, cats-1.tar.gz is a bundle that will become cats-2.tar.gz when new assets are added to that bundle.

index.json

The index.json file lists the contents of the bundles and their versions. It looks like this:

{
    "bundles": {
        "art": {
            "version": 4
        },
        "sound": {
            "version": 7
        }
    }
}

The bundles' dictionary keys correspond to each existing bundle name, and their version is listed as a dictionary of the bundle. This format is not subject to change. It looks more complex than necessary simply for future proofing. Currently there are no plans to create a tool to automatically build and eploy ADM repositories.

Acknowledgements

This project is heavily inspired by Zinc. If you need a more feature-complete solution, please check that out!
ADM's concurrent download operation is heavily influenced from AFNetworking's AFURLConnectionOperation.
In order to avoid dependencies, I borrowed and modified a large portion of Light-Untar-for-iOS.

TODO

Test every possible scenario
Write more tests
Write more documentation

marksands / AssetDistributionManager