On Aug 14, 2007, at 12:38 PM, svilen wrote:
>
>
> performance-wise - do u have any test/target for profiling? else i can
> repeat some tests i did somewhen in february (if i remember them..)
look in test/perf for some, just added a "mass-insert/mass-select" test.
also the current branch im doing today will chop out about 60% of
function call overhead from the abovementioned test.
> -------
> database/*
> get_col_spec(self) etc:
> these string-formats may be better without the artificial dict,
> eg. return self._extend("CHAR(%(length)s)" % {'length': self.length})
> -> return self._extend("CHAR(%s)" % self.length )
> or
> -> return self._extend("CHAR(%(length)s)" % self.__dict__ )
> no idea if get_col_spec() is used that much to have crucial impact on
> speed though, at least it looks simpler.
im fine with that (not crucial tho)
> -------
> orm.util.AliasedClauses._create_row_adapter()
> class AliasedRowAdapter( object):
> 1. can't this be made as standalone class, returning an instance,
> initialized with the map, which is then __call__()ed ?
is it faster to say "self.map" or to say "map" from locals() ? its
probably not very crucial either way.
> 2. this can be faster if:
> a) has_key = __contains__ #instead of yet another funccall
> b) __getitem__ uses try except instead of double lookup key in map
im not sure try/except is faster here - im pretty sure a missing key
is likely and exception throws are very expensive. would be worth a
try to see if the missing key exception actually occurs here.
>
> -------
> orm.mapper
> Mapper._instance():
> WTF is the **{'key':value, ... } ?
> eg. if extension.populate_instance(self, context, row, instance,
> **{'instancekey':identitykey, 'isnew':isnew}) ...
> same thing is done as separate variable a page later;
> btw there are several of these **{} in the file
i think thats a product of a refactoring where the ** was originally
not there.
>
> also, Mapper._options is redundant (leftover?) neverused
yeah gone along with the **{} in r3303
>
>
> -------
> orm.attribute
> AttributeManager.init_attr():
> the saving this one eventualy does is too small, compared to a
> property call of ._state.
i havent benched this in a while but my recollection is that the
AttributeError raise is *much* slower than pre-calling this method.
a single function call is always faster than an exception throw.
however, i see that the exception throw is being suppressed also with
a hasattr() being called every time....im not sure why thats that way
now so i might change it back to throwing AttributeError.
>
> AttributeManager.register_attribute():
> the def _get_state(self) that is made into as property _state can
> be made eventualy faster with try-except instead of 'if'.
exception throws are slower. but like above says, the throw here can
be prevented if init_attr() is called.
>
> btw: cant that ._state property be removed alltogether (i.e. made a
> plain attribute? then init_attr() MUST be there seting it up as plain
> dict.
it should be named something non-collisionworthy such as the current
_sa_attr_state.
>
> -------
> orm/unitofwork
> UOWTask._sort_circular_dependencies():
> def get_dependency_task(obj, depprocessor):
> try:
> dp = dependencies[obj]
> except KeyError:
> dp = dependencies.setdefault(obj, {})
> isnt just the setdefault() enough?
this should just say dependencies[obj] = dp = {}
>
> -------
> engine.url.
> def translate_connect_args(self, names):
> this assumes the order of passed names matches the order of
> attribute_names inside... very fragile. Why not use set of kwargs
> like (attr_name=replacement_name defaulting to None), then just use
> the non empty ones?
patches welcome
> def _parse_rfc1738_args():
> the 'opts' dict is redundant, would be cleaner if args are just
> passed to URL( name=value)
this is an old patch we got from someone, improvement patches welcome
>
> -------
> topological.py
> QueueDependencySorter.sort():
> 'cycles' is redundant neverused variable
would look good in the patch too
>
> -------
> util:
> ThreadLocal:
> - wouldnt be faster if the key in the _tdict is tuple(id,key) and
> not some formatted string off these? or the key is nonhashable?
good catch, should be patched
> - the engine/threadlocal.TLEngine._session() issues a hasattr() on
> such object. how does it actualy work? IMO it always fails
patch which includes a test case to add into test/engine/
transaction.py would be welcome
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