1342479 - Get telemetry on webfont extensions

Status: RESOLVED INCOMPLETE

(Firefox for Android Graveyard :: Metrics, defect, P5)

Description

[Andrzej Hunt :ahunt]

For filename based webfont blocking, we need to know whether or not most sites actually use standard extensions for their webfonts (i.e. does the url end if woff/woff2/eot/ttf/otf/etc). I suspect that the answer is yes, but getting numbers on this means we can decide for certain whether this is viable for Focus.

Comment 1

[Andrzej Hunt :ahunt]

Attachment: Bug 1342479 - gather telemetry on webfont extension usage

Review commit: https://reviewboard.mozilla.org/r/115448/diff/#index_header
See other reviews: https://reviewboard.mozilla.org/r/115448/

Comment 2

[Andrzej Hunt :ahunt]

Comment on attachment 8841110 [details]
Bug 1342479 - gather telemetry on webfont extension usage

Review request updated; see interdiff: https://reviewboard.mozilla.org/r/115448/diff/1-2/

Comment 3

[Andrzej Hunt :ahunt]

Comment on attachment 8841110 [details]
Bug 1342479 - gather telemetry on webfont extension usage

I'd like to request data review for this probe.

This probe collects a boolean representing whether a given font load happened from a URL that contains an obvious file extension (.woff2/.woff/.ttf/.eot/.otf). It's needed to determine whether detecting file extensions is sufficient for blocking webfont usage on the basis of a resource URL (which we need to know to make decisions about supported features in Focus on Android). The probe will only be run in 55 (and possibly 54, depending on when it lands), and is only enabled on nightly/aurora.

Comment 4

[Andrzej Hunt :ahunt]

It turns out focus on iOS is actually only blocking woff/woff2/ttf, even for that it would be useful to know how (in?)effective such blocking is:
https://github.com/mozilla-mobile/focus/blob/master/Blockzilla/LocalContentBlocker.swift#L118

Comment 5

[Chenxia Liu [:liuche]]

Comment on attachment 8841110 [details]
Bug 1342479 - gather telemetry on webfont extension usage

https://reviewboard.mozilla.org/r/115448/#review124606

r+ data review - file extensions aren't personal data, short-lived probe, straightforward description.

::: toolkit/components/telemetry/Histograms.json:10314
(Diff revision 2)
>      "expires_in_version": "never",
>      "kind": "enumerated",
>      "n_values": 5,
>      "description": "Font src type loaded (1 = local, 2 = url, 3 = data)"
>    },
> +  "WEBFONT_STANDARD_EXTENSION": {

I'd rename this to something like IS_STANDARD_WEBFONT_EXTENSION to match the boolean state of the probe.

::: toolkit/components/telemetry/Histograms.json:10315
(Diff revision 2)
>      "kind": "enumerated",
>      "n_values": 5,
>      "description": "Font src type loaded (1 = local, 2 = url, 3 = data)"
>    },
> +  "WEBFONT_STANDARD_EXTENSION": {
> +    "expires_in_version": "56",

Sorry for taking so long on this review! You might want to bump this a version or two.

Comment 6

[Nevin Chen(Not active on Bugzilla)]

Hi Andrzej
Do you want to land this code or can I continue on this?

Comment 7

[Firefox Bug Husbandry Bot]

Re-triaging per https://bugzilla.mozilla.org/show_bug.cgi?id=1473195

Needinfo :susheel if you think this bug should be re-triaged.

Comment 8

[BMO Automation]

We have completed our launch of our new Firefox on Android. The development of the new versions use GitHub for issue tracking. If the bug report still reproduces in a current version of [Firefox on Android nightly](https://play.google.com/store/apps/details?id=org.mozilla.fenix) an issue can be reported at the [Fenix GitHub project](https://github.com/mozilla-mobile/fenix/). If you want to discuss your report please use [Mozilla's chat](https://wiki.mozilla.org/Matrix#Connect_to_Matrix) server https://chat.mozilla.org and join the [#fenix](https://chat.mozilla.org/#/room/#fenix:mozilla.org) channel.