On Fri, Mar 20, 2009 at 6:27 PM, Brian Cole wrote:
> I'm trying to cache the construction and destruction of an expensive
> object coming out of a generator function. I can do the following to
> force a new object to be used if the object is being used somewhere
> else (based upon it's reference count). Here is the pseudo-code of
> what I am trying to accomplish.
>
> def GetExpensiveObjects():
> obj = ExpensiveObject()
> baserefs = sys.getrefcount(obj)
> while UpdateExpensiveObject(obj):
> yield obj
> if sys.getrefcount(obj) > baseline + 1:
> obj = ExpensiveObject()
Seems pretty evil to me! My approach would probably either be to have
two generators and allow the user to decide if they want the object to
be valid after a subsequent call to the iterator, or to use a wrapper
object like the following:
class ExpensiveProxy(object):
_cache = []
def __init__(self):
if self.cache:
self._object = self._cache.pop()
else:
self._object = ExpensiveObject()
UpdateExpensiveObject(self._object)
def __del__(self):
self._cache.append(self._object)
# Define your own methods to wrap those of the object,
# or maybe define __getattr__
-Miles
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