#14214: Cythoned homsets
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Reporter: SimonKing | Owner: tbd
Type: enhancement | Status: needs_work
Priority: major | Milestone: sage-5.9
Component: performance | Resolution:
Keywords: Hom, cython, cached method | Work issues: Do not change
cmp too much
Report Upstream: N/A | Reviewers:
Authors: Simon King | Merged in:
Dependencies: #14159, #12951, #13184 | Stopgaps:
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Comment (by nbruin):
Replying to [comment:27 SimonKing]:
> I said that a `CachedMethodCallerNoArgs` ''is'' a property, since it has
a setter and a getter
It doesn't have a setter as far as I can see, so it's a "nondata
descriptor". Python treats those differently, e.g., they can be overridden
by an instance attribute (which is very important for your application!)
>with the only difference that for accessing it you need to do A.C() and
not just A.C.
which means extra overhead: After looking up `A.C`, executing `C.__get__`,
there is still a call to be processed on the returned object from that! A
"property" would already be done by then.
> If you would define it as a property, then you needed to implement
setter and getter by yourself. A cached method is more comfortable to use.
but with more overhead.
I suspect that (an optimized version of) `lazy_attribute` is potentially
better for argumentless "cached methods". Incidentally, looking at the
code there, it seems that `lazy_attribute` prefers to store the result in
`__cached_methods` rather than use `setattr` to override the descriptor.
Overriding the descriptor (i.e., storing the value in the instance
attribute dict if available) should be faster and preferable to looking up
in `__cached_methods`.
Shouldn't `lazy_attribute` be cythonized too?
--
Ticket URL: <http://trac.sagemath.org/sage_trac/ticket/14214#comment:29>
Sage <http://www.sagemath.org>
Sage: Creating a Viable Open Source Alternative to Magma, Maple, Mathematica,
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