Having spent the last dev cycle looking at how we could specialize the
compositors for various backends, we once again look for the
commonalities in order to reduce the duplication. In part this is
motivated by the idea that spans is a good interface for both the
existent GL backend and pixman, and so they deserve a dedicated
compositor. xcb/xlib target an identical rendering system and so they
should be using the same compositor, and it should be possible to run
that same compositor locally against pixman to generate reference tests.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
P.S. This brings massive upheaval (read breakage) I've tried delaying in
order to fix as many things as possible but now this one patch does far,
far, far too much. Apologies in advance for breaking your favourite
backend, but trust me in that the end result will be much better. :)
Microsoft C Compiler complains about:
hash-table.c(44) : error C2466: cannot allocate an array of constant
size 0
Adding an unused element makes it happy.
A benchmark to test the speed of hash tables when inserting and
removing a huge number of elements.
Although originally hash tables were assumed not to get many
deletions, in practice they are now being used as caches in multiple
places. This means that they often have a fixed number of live
elements and an element is evicted whenever a new element is inserted
(this happens explicitly for cairo_cache_t objects, but also, for
example, in scaled_font_map + holdovers). This access pattern is very
inefficient with the current implementation.
