1583413 - SendTab device list will be empty is sync isn't configured

Status: RESOLVED FIXED

(Firefox :: Firefox Accounts, defect)

Description

[Mark Hammond [:markh] [:mhammond]]

Currently we populate the fxa device list via sync, but that's not going to work if sync isn't enabled - we will need to get it directly from fxa.

Comment 1

[Lina Butler (ex-Mozilla)]

I can take this one.

Comment 2

[Lina Butler (ex-Mozilla)]

Mark, while I'm here, should we drop support for old Send Tab clients (I guess just Fennec at this point?), or support both and combine the list we get from FxA with Sync?

Comment 3

[Mark Hammond [:markh] [:mhammond]]

(In reply to Lina Cambridge (she/her) [:lina] from comment #2)

Mark, while I'm here, should we drop support for old Send Tab clients (I guess just Fennec at this point?), or support both and combine the list we get from FxA with Sync?

Good question - in bug 1579445 I suggested to Ed that instead of doing a sync we just hit fxa, and he indicated that would cause issues. Ed, what was the reason we still went via sync in that bug?

Comment 4

[Lina Butler (ex-Mozilla)]

Calling getDeviceList() after every UIState.ON_UPDATE might hammer the server—but maybe we could do caching, like we do for profiles? IIUC, it would also mean we couldn't send tabs to Fennec, but maybe we're OK with dropping support at this point?

Comment 5

[Edouard Oger [:eoger]]

I'd like to see a FxAccountsDevice.js module that's sync aware but where the canonical source of truth is the FxA devices (and listens to sync events!). Bonus point would be to move the device registration logic in there also.
For caching I've proposed adding an eTag server-side but it never got traction: https://github.com/mozilla/fxa/issues/524, but I don't think it's entirely necessary anyway.

Comment 6

[Lina Butler (ex-Mozilla)]

Attachment: Bug 1583413 - Move device-related methods into `FxAccountsDevice.jsm`. r?markh!,eoger

This commit contains no functional changes, just moving code around to
make the next patch in this series easier to write.

Comment 7

[Lina Butler (ex-Mozilla)]

Attachment: Bug 1583413 - Fetch the Send Tab target list from FxA, not Sync. r?markh!,eoger

Instead of using the list of FxA devices from the Sync clients engine,
we now fetch the list of Send Tab devices from FxA. This works like
this:

• FxAccountsDevice caches the device list in memory, and limits
  requests to once every 10 minutes. (We don't serialize the requests,
  however, so FxA and Sync fetching the device list concurrently
  might still send multiple requests).
• FxAccountsDevice fires a new observer notification when the cached
  list is invalidated, after a device is connected or disconnected.
  This notifies Send Tab and FxA when to refresh their lists. Using the
  device connected and disconnected notifications might mean that the
  consumers will fetch a stale cached list, depending on if the
  FxAccountsDevice or the consumer observer fires first.
• The Send Tab UI refreshes FxA devices in the background. Matching
  FxA devices to Sync client records is best effort, and only impacts
  the fallback case if the target doesn't support FxA commands.

Depends on D47520

Comment 8

[Lina Butler (ex-Mozilla)]

I haven't fixed the tests yet, but does this look sensible?

Comment 9

[Lina Butler (ex-Mozilla)]

https://treeherder.mozilla.org/#/jobs?repo=try&revision=a5c0ecedd243b6a05b78738ce4474c65898b8039

Comment 10

[Lina Butler (ex-Mozilla)]

https://treeherder.mozilla.org/#/jobs?repo=try&revision=92c3096b234a8b6ec7dcfa5a5b2bc8be0d5a319b

Comment 11

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/8d090eb60c78
Move device-related methods into `FxAccountsDevice.jsm`. r=eoger
https://hg.mozilla.org/integration/autoland/rev/0e871ed50b6c
Fetch the Send Tab target list from FxA, not Sync. r=markh,eoger

Comment 12

[Noemi Erli[:noemi_erli]]

https://hg.mozilla.org/mozilla-central/rev/8d090eb60c78
https://hg.mozilla.org/mozilla-central/rev/0e871ed50b6c