corysanin/tubestation
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Bug 1687358 - Implement telemetry probes to determine the best possible threshold for <lazyload> r=emilio

Browse Source 
This patch implements five telemetry probes to help us learn how
lazyload thresholds perform in the wild.

Differential Revision: https://phabricator.services.mozilla.com/D102845
This commit is contained in:
Sean Feng
2021-01-29 17:03:25 +00:00
parent ef6e37b2c0
commit 461677cdfb
10 changed files with 274 additions and 9 deletions
Download Patch File Download Diff File Expand all files Collapse all files

38
dom/html/HTMLImageElement.cpp
View File

@@ -352,7 +352,7 @@ nsresult HTMLImageElement::AfterSetAttr(int32_t aNameSpaceID, nsAtom* aName,
static_cast<HTMLImageElement::Loading>(
aOldValue->GetEnumValue()) == Loading::Lazy &&
!ImageState().HasState(NS_EVENT_STATE_LOADING)) {
StopLazyLoadingAndStartLoadIfNeeded();
StopLazyLoadingAndStartLoadIfNeeded(false);
}
} else if (aName == nsGkAtoms::src && !aValue) {
// NOTE: regular src value changes are handled in AfterMaybeChangeAttr, so
@@ -653,8 +653,18 @@ EventStates HTMLImageElement::IntrinsicState() const {
void HTMLImageElement::NodeInfoChanged(Document* aOldDoc) {
nsGenericHTMLElement::NodeInfoChanged(aOldDoc);
// Unlike the LazyLoadImageObserver, the intersection observer
// for the viewport could contain the element even if
// it's not lazy-loading. For instance, the element has
// started to load, but haven't reached to the viewport.
// So here we always try to unobserve it.
if (auto* observer = aOldDoc->GetLazyLoadImageObserverViewport()) {
observer->Unobserve(*this);
}
if (mLazyLoading) {
aOldDoc->GetLazyLoadImageObserver()->Unobserve(*this);
aOldDoc->DecLazyLoadImageCount();
mLazyLoading = false;
SetLazyLoading();
}
@@ -1256,10 +1266,9 @@ void HTMLImageElement::SetLazyLoading() {
return;
}
// There (maybe) is a race condition that we have no LazyLoadImageObserver
// when the root document has been removed from the docshell.
// In the case we don't need to worry about lazy-loading.
OwnerDoc()->EnsureLazyLoadImageObserver().Observe(*this);
doc->EnsureLazyLoadImageObserver().Observe(*this);
doc->EnsureLazyLoadImageObserverViewport().Observe(*this);
doc->IncLazyLoadImageCount();
mLazyLoading = true;
UpdateImageState(true);
}
@@ -1279,13 +1288,28 @@ void HTMLImageElement::StartLoadingIfNeeded() {
}
}
void HTMLImageElement::StopLazyLoadingAndStartLoadIfNeeded() {
void HTMLImageElement::StopLazyLoadingAndStartLoadIfNeeded(
bool aFromIntersectionObserver) {
if (!mLazyLoading) {
return;
}
mLazyLoading = false;
OwnerDoc()->GetLazyLoadImageObserver()->Unobserve(*this);
Document* doc = OwnerDoc();
doc->GetLazyLoadImageObserver()->Unobserve(*this);
StartLoadingIfNeeded();
if (aFromIntersectionObserver) {
doc->IncLazyLoadImageStarted();
} else {
doc->DecLazyLoadImageCount();
doc->GetLazyLoadImageObserverViewport()->Unobserve(*this);
}
}
void HTMLImageElement::LazyLoadImageReachedViewport() {
Document* doc = OwnerDoc();
doc->GetLazyLoadImageObserverViewport()->Unobserve(*this);
doc->IncLazyLoadImageReachViewport(!Complete());
}
} // namespace mozilla::dom