This removes paint threads, rust-layers dependency, and changes
optional webrender types to be required.
The use_webrender option has been removed, however I've left
the "-w" command line option in place so that wpt
runner can continue to pass that. Once it's removed from there
we can also remove the -w option.
Once this stage is complete, it should be fine to change the
display list building code to generate webrender display
lists directly and avoid the conversion step.
WebRender is an experimental GPU accelerated rendering backend for Servo.
The WebRender backend can be specified by running Servo with the -w option (otherwise the default rendering backend will be used).
WebRender has many bugs, and missing features - but it is usable to browse most websites - please report any WebRender specific rendering bugs you encounter!
On http://en.wikipedia.org/wiki/Spotted_hyena, I was seeing a 100% miss
rate in the first fast cache lookup and 45% of total layout time in this
function. After making this change, the first cache lookup almost always
succeeds, and the time spent in this function drops to 8%.
This will allow reporting of memory usage by FreeType instances, which
are measured in the MiBs for LayoutWorker threads.
This change also makes FreeType allocations happen with jemalloc instead
of the system malloc, which is a good thing.
Finally, the change documents some dubiousness involving
FontContextHandle.
The util component specified fnv and smallvec as dependencies and publicly
reexported both of them. Several other components utilized these reexports,
presumably because fnv and smallvec used to live in the tree so reexporting
made the transition easier.
These indirect dependencies through the util component are unnecessary.
This commit removes the fnv & smallvec crate reexports in the util component.
It exchange, it adds fnv & smallvec as dependencies to non-util components
wherever needed. Finally, it removes the fnv dependency from util as it is not
utilized anywhere in the util component.
`FontContext::get_layout_font_group_for_style()`.
There are several optimizations here:
* We make font families atoms, to allow for quicker comparisons.
* We precalculate an FNV hash of the relevant fields of the font style
structure.
* When obtaining a platform font group, we first check pointer equality
for the font style. If there's no match, we go to the FNV hash. Only
if both caches miss do we construct and cache a font group. Note that
individual fonts are *also* cached; thus there are two layers of
caching here.
15% improvement in total layout thread time for Facebook Timeline.
Thread font load errors from platform font loading code to
FontContext::get_layout_font_group_for_style, and cache the failure
result, instead of panicing the thread when a font fails to load.
Before this patch, a failed font load would panic a LayoutTask,
causing a cascade of panics, eventually aborting the whole engine
during a panic within panic.
