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()
Some users may use this generator by reading all objects into a list,
"objs = list(GetExpensiveObjects())". Others may use the generator and
just operate on each object totally independent of each other:
for obj in GetExpensiveObjects():
DoSomething(obj)
I would like to support both use cases. Unfortunately, the simple
approach of changing the following:
obj = ExpensiveObject()
while UpdateExpensiveObject(obj):
yield obj
To the following:
obj = ExpensiveObject()
while UpdateExpensiveObject(obj):
yield obj
obj = ExpensiveObject()
Is %30 - %50 more expensive. So is the getrefcount approach an
acceptable? I would prefer avoiding the proper object cache based on
weakref as it would be a lot more complexity.
Thanks
Brian
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