Bug 149069 – Should use CARenderServerRenderLayerWithTransform for snapshots on iOS

• Status: RESOLVED
• Resolution: FIXED
• Component: WebKit2

[Beth Dakin]

We should use CARenderServerRenderLayerWithTransform for snapshots on iOS. This will let us own the backing IOSurface, which will let us make them purgeable and share more code with Mac.

[Beth Dakin]

Created attachment 261010 [details]
Patch

[Tim Horton]

Comment on attachment 261010 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=261010&action=review

> Source/WebKit2/ChangeLog:11
> +        This will let us own the backing IOSurface, which will let us make them 
> +        purgeable and share more code with Mac.

Except we're not going to make them purgeable for now and it's not clear that that is actually the plan so maybe we shouldn't mention that part :D

> Source/WebKit2/UIProcess/API/Cocoa/WKWebView.mm:1110
> +    auto surface = WebCore::IOSurface::create(WebCore::expandedIntSize(snapshotSize), WebCore::ColorSpaceDeviceRGB);

We should do more perf testing here.

> Source/WebKit2/UIProcess/API/Cocoa/WKWebView.mm:1111
> +    CARenderServerRenderLayerWithTransform(MACH_PORT_NULL, self.layer.context.contextId, reinterpret_cast<uint64_t>(self.layer), surface->surface(), 0, 0, &transform);

I wonder if we have to use some other function on older OSes, like _snapshotWhatever does? Probably.

> Source/WebKit2/UIProcess/mac/ViewSnapshotStore.h:-44
> -#if PLATFORM(MAC)

YAYYYYY

[Tim Horton]

Also not sure I can really review this :D

[Beth Dakin]

(In reply to comment #2)
> Comment on attachment 261010 [details]
> Patch
> 
> View in context:
> https://bugs.webkit.org/attachment.cgi?id=261010&action=review
> 
> > Source/WebKit2/ChangeLog:11
> > +        This will let us own the backing IOSurface, which will let us make them 
> > +        purgeable and share more code with Mac.
> 
> Except we're not going to make them purgeable for now and it's not clear
> that that is actually the plan so maybe we shouldn't mention that part :D
> 

Fixed this!

> > Source/WebKit2/UIProcess/API/Cocoa/WKWebView.mm:1110
> > +    auto surface = WebCore::IOSurface::create(WebCore::expandedIntSize(snapshotSize), WebCore::ColorSpaceDeviceRGB);
> 
> We should do more perf testing here.
> 

Perf bot watcher has been alerted! 

> > Source/WebKit2/UIProcess/API/Cocoa/WKWebView.mm:1111
> > +    CARenderServerRenderLayerWithTransform(MACH_PORT_NULL, self.layer.context.contextId, reinterpret_cast<uint64_t>(self.layer), surface->surface(), 0, 0, &transform);
> 
> I wonder if we have to use some other function on older OSes, like
> _snapshotWhatever does? Probably.
> 

Tim and I considered this, and he changed his mind.

> > Source/WebKit2/UIProcess/mac/ViewSnapshotStore.h:-44
> > -#if PLATFORM(MAC)
> 
> YAYYYYY


YAY. Thanks Tim!

http://trac.webkit.org/changeset/189628

[Beth Dakin]

Build fix: http://trac.webkit.org/changeset/189630

[Beth Dakin]

Another build fix: http://trac.webkit.org/changeset/189635

[Beth Dakin]

More build fix: http://trac.webkit.org/changeset/189637