On Aug 25, 2010, at 10:47 AM, Michael Bayer wrote:
>
> On Aug 25, 2010, at 9:37 AM, Nikolaj wrote:
>
>> Hello,
>>
>> I'm struggling to use the Beaker caching example in my project.
>> Accessing any attribute on an instance from cache triggers a load from
>> database of the instance - even trying to read the primary key!
>
> that means the instances that you're putting in the cache are expired, or at
> least those attributes you are attempting to read. The beaker example
> takes the objects from a result and sends them straight to the cache, but
> does not detach them from the current session. Therefore, if your backend is
> the "memory" backend, the objects in the cache are the same as those in your
> current session and they'll get expired when the session is committed or
> rolled back.
>
> There's not a really spectacular way to get around that except to not use the
> "memory" backend, use one that pickles like memcached (well, pretty much
> memcached is the only backend I'd ever use, but the file/dbm file backends
> would work here too).
well, this probably would work, this diff is against tip:
diff -r 568ef214c1ac examples/beaker_caching/caching_query.py
--- a/examples/beaker_caching/caching_query.py Mon Aug 23 18:17:31 2010 -0400
+++ b/examples/beaker_caching/caching_query.py Wed Aug 25 10:55:53 2010 -0400
@@ -63,8 +63,15 @@
if particular attributes have been configured.
"""
+
+ def createfunc():
+ items = list(Query.__iter__(self))
+ for item in items:
+ self.session.expunge(item)
+ return items
+
if hasattr(self, '_cache_parameters'):
- return self.get_value(createfunc=lambda:
list(Query.__iter__(self)))
+ return self.get_value(createfunc=createfunc)
else:
return Query.__iter__(self)
I've added a comment in the example regarding this.
>
>
>
>
>>
>> The beaker_caching example runs just fine on my system and doesn't
>> exhibit the same problems, although that's on SQLite and without
>> Pylons. I traced through the calls to session._merge and prop.merge
>> without luck, it seems to run through the column properties and merge
>> as expected.
>>
>> How do I diagnose this, short of tearing my entire codebase apart? Are
>> there any instance state attributes I could inspect to see where the
>> merge is going wrong?
>>
>> N
>>
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>
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