ContentUpdate

class

csharp

public sealed class ContentUpdate

Step 2 of the boot sequence: find out whether the server has newer content.

No guide page documents this yet — the page shows what the code says about itself.

Remarks

Doc 08 lays out four steps — load the shipped catalog, check for a remote one and merge it over, resolve addresses through the result, fetch bundles on demand. This is the second, and it is the one that makes a content update possible without shipping a build.

The hash file is checked first because it is tiny. A catalog for a real game is hundreds of kilobytes and almost always unchanged; a 32-byte file next to it turns the common case — start the game, nothing is new — into one request the size of a packet. It also gives the downloaded catalog something to be checked against, which a catalog fetched on its own does not have.

Being offline is an outcome, not an error. A game whose CDN is unreachable has to start anyway, on the newest catalog it has: the previously downloaded one if there is one, and the shipped one if not. Throwing would turn a flaky connection into a game that will not launch. It is still reported, because the same silence means a misconfigured URL and nobody should have to guess which.

An update can replace an address but not remove one. That is MergedWith's rule and the reason is there: the shipped application still has the bundle on the device, and a runtime that forgot the address would refuse to load something it is sitting on.

Fields and properties (5)

public VirtualPath CacheRoot
Where the downloaded catalog and its hash are kept.
public string CatalogUrl
Where the catalog is served from, or empty if no remote content is configured.
public string HashUrl
Where the hash naming that catalog is served from.
public VirtualPath CachedCatalogPath
Where the downloaded catalog is cached.
public VirtualPath CachedHashPath
Where the hash of the downloaded catalog is cached.

Methods (3)

public ContentUpdate(VirtualFileSystem files, VirtualPath cacheRoot, IContentTransport transport, string catalogUrl)
Sets up the check.
public ObjectId? CachedVersion()
Which catalog is cached, if one is.
public Task<ContentUpdateResult> ApplyAsync(ContentCatalog local, CancellationToken cancellationToken = default(CancellationToken))
Checks for newer content and returns the catalog to resolve addresses through.

Used by (3)

ProgramAddressablesRemote
ContentUpdateTestsVixen.Assets.Tests
UpdateWorldVixen.Assets.Tests