1156405 - Cache and use expired Token Server tokens when querying info/collections

Status: RESOLVED FIXED

(Firefox for iOS :: Firefox Accounts, defect)

Description

[Nick Alexander :nalexander [he/him]]

Right now, Sync on Firefox iOS requests a fresh token server token every sync.  This is strictly not necessary: to reduce authentication requests, we can use a cached-but-expired token to make an info/collections request.  (Subsequent requests, if required, need a valid token.)

This ticket tracks caching and using an expired token as required.

Comment 1

[Nick Alexander :nalexander [he/him]]

rnewman: my plan for this is to surface the SyncAuthState directly to the Sync machine.  The Sync auth state will expose an expired token on request, and also a valid token.  The Account state machine will be advanced as necessary for both tokens.  This inversion of control should allow an efficient authentication flow.

Comment 2

[Richard Newman [:rnewman]]

I *think* the Sync side of this is done; it requests an expired or not token:

    public class func getInfoCollections(authState: SyncAuthState, prefs: Prefs) -> Deferred<Result<InfoCollections>> {
        log.debug("Fetching info/collections in state machine.")

        let token = authState.token(NSDate.now(), canBeExpired: true)

versus

    public class func toReady(authState: SyncAuthState, prefs: Prefs) -> ReadyDeferred {
        let token = authState.token(NSDate.now(), canBeExpired: false)



Indeed, we're already mostly ready to take a TokenSource when advancing, which is the next step when we think we do need to sync: see advanceWithToken in InitialWithExpiredTokenAndInfo.

Comment 3

[Nick Alexander :nalexander [he/him]]

Attachment: Link to Github pull-request: https://github.com/mozilla/firefox-ios/pull/359

rnewman: I see one comment, which I'm happy to address.  Add others as needed.

I expect to morph remoteTimestamp into a local clock skew to have (more) accurate expired testing in a follow-up commit.

Comment 4

[Nick Alexander :nalexander [he/him]]

https://github.com/mozilla/firefox-ios/commit/7a6b6d093dd20f275a5e81cc8824e9df8de09b7f