This patch adds fetchpriority support for `<link rel=preload as=image>`
and equivalent HTTP Link header. The fetchpriority value is passed from
where the link is parsed down to `NewImageChannel` where the priority
is initially set. Currently, the default equals PRIORITY_LOW, but is
decreased a bit if LOAD_BACKGROUND flag is set (this is always the case
for link preload images, see `imgLoader::LoadImage`). Later, the
priority can be increased again depending on the category (see
`imgRequest::BoostPriority`).
In order to minimize the changes, the new calculation is to keep the
initial setting to PRIORITY_LOW, adjust it using a new
`network.fetchpriority.adjustments.*` preference depending on the
fetchpriority attributes, and then preserve further adjustments for
LOAD_BACKGROUND and `BoostPriority`.
For the default value `fetchpriority=auto`, there is no adjustment
i.e. we continue to start with PRIORITY_LOW. `fetchpriority=low/high`
are respectively mapped to PRIORITY_LOW/PRIORITY_HIGH which is simple
and consistent with the "Image" cases from Google's web.dev article
https://web.dev/articles/fetch-priority. These values could of course
be revised in the future after more experiments.
This change is covered by the following tests below. The expectations
is modified to match what is described above (i.e. map to PRIORITY_LOW
or PRIORITY_HIGH with adjustment due to LOAD_BACKGROUND):
- `link-initial-preload-image.h2.html`
- `link-dynamic-preload-image.h2.html`
- `kPipeHeaderPreloadImageLinks`
Based on a patch by Mirko Brodesser ([email protected])
Differential Revision: https://phabricator.services.mozilla.com/D197493
This patch adds fetchpriority support for `<link rel=preload as=image>`
and equivalent HTTP Link header. The fetchpriority value is passed from
where the link is parsed down to `NewImageChannel` where the priority
is initially set. Currently, the default equals PRIORITY_LOW, but is
decreased a bit if LOAD_BACKGROUND flag is set (this is always the case
for link preload images, see `imgLoader::LoadImage`). Later, the
priority can be increased again depending on the category (see
`imgRequest::BoostPriority`).
In order to minimize the changes, the new calculation is to keep the
initial setting to PRIORITY_LOW, adjust it using a new
`network.fetchpriority.adjustments.*` preference depending on the
fetchpriority attributes, and then preserve further adjustments for
LOAD_BACKGROUND and `BoostPriority`.
For the default value `fetchpriority=auto`, there is no adjustment
i.e. we continue to start with PRIORITY_LOW. `fetchpriority=low/high`
are respectively mapped to PRIORITY_LOW/PRIORITY_HIGH which is simple
and consistent with the "Image" cases from Google's web.dev article
https://web.dev/articles/fetch-priority. These values could of course
be revised in the future after more experiments.
This change is covered by the following tests below. The expectations
is modified to match what is described above (i.e. map to PRIORITY_LOW
or PRIORITY_HIGH with adjustment due to LOAD_BACKGROUND):
- `link-initial-preload-image.h2.html`
- `link-dynamic-preload-image.h2.html`
- `kPipeHeaderPreloadImageLinks`
Based on a patch by Mirko Brodesser ([email protected])
Differential Revision: https://phabricator.services.mozilla.com/D197493
Previously, for `rel=preload as=fetch`, the internal priority,
`nsISupportsPriority`, was not adjusted. Now, the adjustment happens in
`FetchPreloader::CreateChannel`.
For `rel=preload as=font`, previously, the internal priority was always
set to high in `FontLoaderUtils::BuildChannelSetup`. Now, the internal
priority is a parameter, whose value potentially depends on the
`fetchpriority` attribute.
Note the minor correction of calling `SetPriority` instead of
`AdjustPriority` in `FontLoaderUtils::BuildChannelSetup`.
Differential Revision: https://phabricator.services.mozilla.com/D194205
Sorry this is not a particularly easy patch to review. But it should be
mostly straight-forward.
I kept Document::Dispatch mostly for convenience, but could be
cleaned-up too / changed by SchedulerGroup::Dispatch. Similarly maybe
that can just be NS_DispatchToMainThread if we add an NS_IsMainThread
check there or something (to preserve shutdown semantics).
Differential Revision: https://phabricator.services.mozilla.com/D190450
We are working on an alternative approach to improving OnStart/OnStop request timing, and so will remove this probe because it's no longer as relevant and the implementation touchs many classes and methods.
Differential Revision: https://phabricator.services.mozilla.com/D187233
The request priority isn't propagated from `ScriptFetchOptions`, so
setting it has no effect for end-users. That will be implemented in a
following part.
Differential Revision: https://phabricator.services.mozilla.com/D183483
The request priority isn't propagated from `ScriptFetchOptions`, so
setting it has no effect for end-users. That will be implemented in a
following part.
Differential Revision: https://phabricator.services.mozilla.com/D183483
The request priority isn't propagated from `ScriptFetchOptions`, so
setting it has no effect for end-users. That will be implemented in a
following part.
Differential Revision: https://phabricator.services.mozilla.com/D183483
Note that modules can't be specified in Link preloads with `rel=preload`,
only in `rel=modulepreload`. We currently only support `rel=preload` in
early hints. See Bug 1798319 for updates on module preloads.
Differential Revision: https://phabricator.services.mozilla.com/D161175
Note that modules can't be specified in Link preloads with `rel=preload`,
only in `rel=modulepreload`. We currently only support `rel=preload` in
early hints. See Bug 1798319 for updates on module preloads.
Differential Revision: https://phabricator.services.mozilla.com/D161175
In particular, gather telemetry to evaluate the impact of unlabeled UTF-8
and how detector-triggered reloads would change if ASCII-only at initial
guess was treated as UTF-8.
Differential Revision: https://phabricator.services.mozilla.com/D140818
This removes the pref `security.csp.enable` and amends various callers
in dom/, which no longer have to take this pref into consideration.
Furthermore, we can remove the test in dom/base/test/browser_bug593387.js
The test used the pref to test that external content can be embedded into
about:plugins, which is historic baggage from a previous architecture of
said page that we no longer require. It's also an anti-pattern that we
do not want to support any longer. In fact, the test had to jump through
additional hoops to make that work at all.
Differential Revision: https://phabricator.services.mozilla.com/D138661
Florian Quèze