Yes, it's put on the JIRA. There's a impl of IEqualityComparer<EntityMode> and "hard coded" in the constructor for the LinkedHashMap in EntityModeToTuplizerMapping. That's why a factory might be better (both used for dictionary and linkedhashmap and (?) some other IDictionary impl)?
From: [email protected] [mailto:[email protected]] On Behalf Of Fabio Maulo Sent: den 6 februari 2009 16:57 To: [email protected] Subject: [nhibernate-development] Re: IDictionary<entitymode, xxx> Roger, BTW the EntityModeEqualityComparer as separated class is need (when we must use some other implementation of IDictionary). 2009/2/6 Roger Kratz <[email protected]<mailto:[email protected]>> ...or... New EntityModeDic<tvalue>() ...or... EntityMode.CreateDic<tvalue() ...or... ?? From: [email protected]<mailto:[email protected]> [mailto:[email protected]<mailto:[email protected]>] On Behalf Of Fabio Maulo Sent: den 6 februari 2009 16:51 To: [email protected]<mailto:[email protected]> Subject: [nhibernate-development] Re: IDictionary<entitymode, xxx> 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]<mailto:[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]> [mailto:[email protected]<mailto:[email protected]>] On Behalf Of Fabio Maulo Sent: den 6 februari 2009 16:34 To: [email protected]<mailto:[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]<mailto:[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]> [mailto:[email protected]<mailto:[email protected]>] On Behalf Of Ayende Rahien Sent: den 6 februari 2009 16:01 To: [email protected]<mailto:[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]<mailto:[email protected]>> wrote: That you'll better ask the dictionary implementors at Redmond :). 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]> [mailto:[email protected]<mailto:[email protected]>] On Behalf Of Ayende Rahien Sent: den 6 februari 2009 15:45 To: [email protected]<mailto:[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]<mailto:[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
