[E-devel] _edje_recalc() algorithm and optimizations

[Gustavo S. B. <bar...@gm...>]

Hi,

One guy here at the office was debugging his Smart_Object and noticed
that show() and move() were being called each time when something not
related to his object changed. We isolated the problem and the problem
is caused by how edje is marked dirty and then recalculated. Our test
case was an Edje with our smart object in the bottom and a text on the
top, they were not dependent (rel1 nor rel2), but when the text was
changed, the show/move calls were called on the smart object.

Today, if we have some change, the whole edje is marked as dirty and
then a loop marks both ep->calculated and ep->calculating with
FLAG_NONE, then  another look checks for ep->calculated != FLAG_XY and
then triggers recalculation of that part.

In an ideal world, the changed part should be flagged and recalc
should act on this part and those that depend on it.

My guess is that trade of common case impact versus difficulties to
implement don't worth it, maybe there is no dependency graph handy,
maybe something else.

I see that usually smart objects check for properties and return right
at the beginning if they're exactly the same. But in python bindings
this will result in extra C call, that will trigger python calls and
overhead is bigger there.

So, what's the reason for it being like that? Any ideas to improve? Is
that easy or will be a pain? How to get the dependency list?

Also, should us avoid calling move()/show() and possible others if
these properties are already the same? I mean this in Edje layer, not
Evas. This would avoid some overhead (although complexity is still
high).

-- 
Gustavo Sverzut Barbieri
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