EntityModeDictionary<TValue> sound good for me with a default capacity of 5
(in general is 3).

2009/2/6 Ayende Rahien <[email protected]>

> I would actually suggest EntityKeyDictionary<TValue>, instead
> Less chance of forgetting to do so
>
>
> On Fri, Feb 6, 2009 at 5:51 PM, Fabio Maulo <[email protected]> wrote:
>
>> Well... this is "our" work around; the real issue should be send to
>> Microsoft. I hope Microsoft solve it soon; the hope is the last to die ;)
>>
>> In NH we have few IDictionary<K,V> depending on enum and probably all are
>> using EntityMode as K so, probably, an implementation
>> of EntityModeEqualityComparer and a simple modification to the Dictionary
>> constructor call is enough.
>>
>>
>> 2009/2/6 Roger Kratz <[email protected]>
>>
>>>  It's been added to the JIRA.
>>>
>>>
>>>
>>> However – if you think this should be handled in more places in the code,
>>> I guess it could be more generic than this "isolated" patch.
>>>
>>>
>>>
>>> *From:* [email protected] [mailto:
>>> [email protected]] *On Behalf Of *Fabio Maulo
>>> *Sent:* den 6 februari 2009 16:34
>>>
>>> *To:* [email protected]
>>> *Subject:* [nhibernate-development] Re: IDictionary<entitymode, xxx>
>>>
>>>
>>>
>>> If the performance issue is caused by EqualityComparer I prefer the
>>> implementation of a specific EqualityComparer instead other solution.
>>>
>>> 2009/2/6 Roger Kratz <[email protected]>
>>>
>>> I can do a impl of the equalitycomparer and use that instead.
>>>
>>>
>>>
>>> Did a quick search in the source code and it seems to be other places
>>> where dics are keyed by entitymode. I'm not sure which of them are used
>>> heavily though, but I guess it wouldn't hurt to pass an IEqualityComparer to
>>> them all?
>>>
>>>
>>>
>>> Should I do this?
>>>
>>>
>>>
>>> *From:* [email protected] [mailto:
>>> [email protected]] *On Behalf Of *Ayende Rahien
>>> *Sent:* den 6 februari 2009 16:01
>>>
>>>
>>> *To:* [email protected]
>>> *Subject:* [nhibernate-development] Re: IDictionary<entitymode, xxx>
>>>
>>>
>>>
>>> Duh!
>>> The implementation makes it obvious what is actually going on.
>>> I think that a better alternative than int keys would be to use a
>>> IEqualityComparer<TEnum> instead, that would keep the clarity, reduce
>>> casting and prevent boxing.
>>>
>>> On Fri, Feb 6, 2009 at 4:53 PM, Roger Kratz <[email protected]>
>>> wrote:
>>>
>>> That you'll better ask the dictionary implementors at Redmond J. I was a
>>> bit surprised by this myself some time ago. Just create a little test
>>> yourself and probably you will be more than surprised by the result…
>>>
>>>
>>>
>>> There are some articles out there describing it better than I probably
>>> can…
>>>
>>> http://www.safnet.com/writing/tech/archives/2007/07/performance_3_c.html
>>>
>>>
>>> http://blogs.msdn.com/shawnhar/archive/2007/07/02/twin-paths-to-garbage-collector-nirvana.aspx
>>>
>>> http://beardseye.blogspot.com/2007/08/nuts-enum-conundrum.html
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>> *From:* [email protected] [mailto:
>>> [email protected]] *On Behalf Of *Ayende Rahien
>>> *Sent:* den 6 februari 2009 15:45
>>>
>>>
>>> *To:* [email protected]
>>> *Subject:* [nhibernate-development] Re: IDictionary<entitymode, xxx>
>>>
>>>
>>>
>>> Ha?
>>>
>>>
>>> Why would there be boxing involved at all?
>>>
>>> On Fri, Feb 6, 2009 at 3:46 PM, Roger <[email protected]> wrote:
>>>
>>>
>>> Hi
>>>
>>> EntityModeToTuplizerMapping holds a dic keyed by entitymode
>>> internally. From a perf perspective, it's a bad thing to do – enum as
>>> a key will cause a lot of boxing internally in dictionary operations.
>>> And in (large) resultsets these dictionary items in it will be
>>> retrieved _a lot_.
>>>
>>> I just made a quick test and changed this dictionary to be keyed by an
>>> int instead (casting the enum to int when added), some extreme queries
>>> (=fast query, big resultset) run approx 10% faster in total.
>>>
>>> I'll be glad to send this little patch. However, I would say a better
>>> solution would be to change this enum to a class instead (I don't
>>> really like enums at all :)). I can provide a patch for this as well,
>>> but this type has a lot of dependencies. In short words – before
>>> spending some hours doing this, I would like to see if you have any
>>> opinions on this?
>>>
>>> Whatever you think, I would strongly suggest that get rid of often
>>> used dictionaries keyed by enums.
>>>
>>> Keep up the great work!
>>>
>>> Regards
>>> Roger
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>> --
>>> Fabio Maulo
>>>
>>
>>
>>
>> --
>> Fabio Maulo
>>
>
>


-- 
Fabio Maulo

Reply via email to