Ayende @ Rahienhttp://ayende.comAyende @ RahienCopyright (C) Ayende Rahien 2004 - 2021 (c) 202660Ayende Rahien commented on The wages of sin: Inverse leaky abstractionsInfrastructure code is usually complex, especially when you are working at a low level. But if you want to talk about horrible code, take a look here: [github.com/.../Sender.cs](https://github.com/ayende/rhino-queues/blob/master/Rhino.Queues/Protocol/Sender.cs) [github.com/.../Receiver.cs](https://github.com/ayende/rhino-queues/blob/master/Rhino.Queues/Protocol/Receiver.cs) http://ayende.com/4789/the-wages-of-sin-inverse-leaky-abstractions#comment29http://ayende.com/4789/the-wages-of-sin-inverse-leaky-abstractions#comment29Sun, 27 Mar 2011 08:57:34 GMTRafiki commented on The wages of sin: Inverse leaky abstractions@Ayende. You know, MultiCriteriaImpl's code is HORRIBLE. All those array index manipulations make me cry every time I see them. How on Earth is it possible that you wrote this mess? http://ayende.com/4789/the-wages-of-sin-inverse-leaky-abstractions#comment28http://ayende.com/4789/the-wages-of-sin-inverse-leaky-abstractions#comment28Sat, 26 Mar 2011 21:29:00 GMTChris Marisic commented on The wages of sin: Inverse leaky abstractions@John Farrell You clearly didn't actually read my article then. Because by writing this code once I never need to implement a repository it's all handled through StructureMap and Inversion of Control By merely putting a dependency on IRepository <any into my constructors I immediately get access to Get/Save/Delete and to Query. I have to only create discrete queries ever and never waste time writing/copying boiler plate repository code that most people get into. >http://ayende.com/4789/the-wages-of-sin-inverse-leaky-abstractions#comment27http://ayende.com/4789/the-wages-of-sin-inverse-leaky-abstractions#comment27Fri, 25 Mar 2011 17:42:25 GMTShawn commented on The wages of sin: Inverse leaky abstractionsI think the point here is that you should challenge your assumptions about how you are designing your software. I don't need code to copy and paste so I can get the next set of received wisdom. I need to be reminded to challenge these assumptions so I can figure out what's right for the software I am designing. If you're taking this as toxic or whatever, I think you need to consider why you have such a deeply personal investment in this design pattern, or any design pattern, for that matter. This series has been really valuable, but I'm not even writing code that touches a database at the moment. http://ayende.com/4789/the-wages-of-sin-inverse-leaky-abstractions#comment26http://ayende.com/4789/the-wages-of-sin-inverse-leaky-abstractions#comment26Thu, 24 Mar 2011 18:24:38 GMTJames commented on The wages of sin: Inverse leaky abstractions@Paul Actually I have un subscribed. This is hardly constructive criticism. Just hateful crap. http://ayende.com/4789/the-wages-of-sin-inverse-leaky-abstractions#comment25http://ayende.com/4789/the-wages-of-sin-inverse-leaky-abstractions#comment25Thu, 24 Mar 2011 13:39:06 GMTJohn Chapman commented on The wages of sin: Inverse leaky abstractionsI'm sorry, but I fail to see the egregiousness of using futures in this scenario. I see that in this particular usage scenario, Future is providing no benefit, but it is it causing a problem? Does this scenario perform any worse than it would if we just called List() instead of returning the future? If not, returning the future seems like a good choice. If the consumer was in fact making multiple calls Future would provide a benefit, and in this case where they are not making additional calls it works the same as it would otherwise. I realize that it may be harder to see this due to the abstraction. And if they had multiple calls with .ToList() it would defeat the purpose. However, in most cases people don't actually need a List() and can bind the IEnumerable anyway. So I would guess that more often than not consumers with multiple queries would benefit here. While abstractions may provide simple implementations in certain cases, I do not believe that simple abstractions mean abstractions provide no value. I personally do not want to tightly couple my controllers to NHiberante sessions. I realize that removing all abstractions can result in an opportunity to achieve better performance as all of the tools of the underlying framework are available to you. However, that's a trade off I make for clear separation. C# is an abstraction, where I could potentially achieve better performance by properly tuning C++ for example, but I don't since that abstraction provides value to me and the performance penalty is deemed worth it. I think it's ok to make the same decision on separating persistence mechanisms from UI elements (such as controllers/presenters/viewmodels) http://ayende.com/4789/the-wages-of-sin-inverse-leaky-abstractions#comment24http://ayende.com/4789/the-wages-of-sin-inverse-leaky-abstractions#comment24Thu, 24 Mar 2011 13:18:53 GMTBelvasis commented on The wages of sin: Inverse leaky abstractions@Paul It does not matter if it bothers me or not. And I also don't want to blindly follow any pattern or practice. But after a lot of blogs about "How you should not do it" I simply think it is time for ONE "Here is how I would do it" blog, don't you think? http://ayende.com/4789/the-wages-of-sin-inverse-leaky-abstractions#comment23http://ayende.com/4789/the-wages-of-sin-inverse-leaky-abstractions#comment23Thu, 24 Mar 2011 12:53:11 GMTPaul commented on The wages of sin: Inverse leaky abstractionsSeriously people if it bothers you that much just unsubscribe. As far as I'm concerned these posts just show the dangers in blindly following a patterns and practices approach to development rather than concentrating on the problem in hand. There are plenty of other blogs out there that would have you event sourcing and DDDing your way to a death march on every project. I think Ayende's just trying to bring some balance to that. http://ayende.com/4789/the-wages-of-sin-inverse-leaky-abstractions#comment22http://ayende.com/4789/the-wages-of-sin-inverse-leaky-abstractions#comment22Thu, 24 Mar 2011 11:27:16 GMTSBG commented on The wages of sin: Inverse leaky abstractionsNo doubt. Go write something amazing and stop being a douche. http://ayende.com/4789/the-wages-of-sin-inverse-leaky-abstractions#comment21http://ayende.com/4789/the-wages-of-sin-inverse-leaky-abstractions#comment21Thu, 24 Mar 2011 04:33:25 GMTNC commented on The wages of sin: Inverse leaky abstractions@Belvasis - I agree, there's a massive archive of great posts. But over the last year the quality of posts on this blog has diminished. http://ayende.com/4789/the-wages-of-sin-inverse-leaky-abstractions#comment20http://ayende.com/4789/the-wages-of-sin-inverse-leaky-abstractions#comment20Thu, 24 Mar 2011 03:21:52 GMTBoB commented on The wages of sin: Inverse leaky abstractions@Joe It's always the same around here. You never get any answers as Ayende is just trolling to get you to one of the $3000 seminars held in London or Tokyo or some other joint that cost $6000 to get to. http://ayende.com/4789/the-wages-of-sin-inverse-leaky-abstractions#comment19http://ayende.com/4789/the-wages-of-sin-inverse-leaky-abstractions#comment19Thu, 24 Mar 2011 01:48:40 GMTBelvasis commented on The wages of sin: Inverse leaky abstractionsI agree with gunteman...I'm afraid the time of daily WOW's is long gone. In the past this was a blog where one could learn something and got some new ideas. But now...where are the clues, solutions, suggestions or brilliant ideas? :-( http://ayende.com/4789/the-wages-of-sin-inverse-leaky-abstractions#comment18http://ayende.com/4789/the-wages-of-sin-inverse-leaky-abstractions#comment18Thu, 24 Mar 2011 00:49:10 GMTJay Douglass commented on The wages of sin: Inverse leaky abstractionsKeep it coming Ayende. For too long the repository pattern has passed as conventional wisdom. http://ayende.com/4789/the-wages-of-sin-inverse-leaky-abstractions#comment17http://ayende.com/4789/the-wages-of-sin-inverse-leaky-abstractions#comment17Thu, 24 Mar 2011 00:45:38 GMTStanK commented on The wages of sin: Inverse leaky abstractionsEveryone keeps asking to see the 'correct' way to do things - I think that the point is that you don't need to abstract away NHibernate with a repository, just use the session directly in your controller (or whatever you are using). There's no 'correct' code to show - as presumably you already know how to use an NHibernate session! http://ayende.com/4789/the-wages-of-sin-inverse-leaky-abstractions#comment16http://ayende.com/4789/the-wages-of-sin-inverse-leaky-abstractions#comment16Thu, 24 Mar 2011 00:32:56 GMTAyende Rahien commented on The wages of sin: Inverse leaky abstractions@throwspoop, Ad revenue? Seriously? The blog isn't even paying for itself in ads http://ayende.com/4789/the-wages-of-sin-inverse-leaky-abstractions#comment15http://ayende.com/4789/the-wages-of-sin-inverse-leaky-abstractions#comment15Wed, 23 Mar 2011 23:18:52 GMTSteve Py commented on The wages of sin: Inverse leaky abstractionsIf anything, this should demonstrate that at least one of NHibernate's best practice paths is fraught with little land-mines. If people are stumbling on them and blowing off limbs then it's pretty clear that information about the best course using futures is missing or gotten foggy in the mist of time. Ayende's comments are rather toxic, most likely just a reflection of his mood at the time of writing; but it would be good to see links to the correct implementation and pitfalls to watch out for regarding the topic. Rather than just pointing out people's stupid little mistakes, please point everyone to information to make the correct assumptions. http://ayende.com/4789/the-wages-of-sin-inverse-leaky-abstractions#comment14http://ayende.com/4789/the-wages-of-sin-inverse-leaky-abstractions#comment14Wed, 23 Mar 2011 23:03:47 GMTAlex Simkin commented on The wages of sin: Inverse leaky abstractions@John Farrel - Yeah, that will teach him. http://ayende.com/4789/the-wages-of-sin-inverse-leaky-abstractions#comment13http://ayende.com/4789/the-wages-of-sin-inverse-leaky-abstractions#comment13Wed, 23 Mar 2011 21:23:19 GMTgunteman commented on The wages of sin: Inverse leaky abstractions@LukeB Repeated criticism and opinion, with no trace of humility or constructive suggestions, may not be bashing, but it's toxic and IMHO it constantly clouds Ayende's undisputable brilliance. More daily WOW than DailyWTF would be nice. Quite possibly also for Ayende's business... http://ayende.com/4789/the-wages-of-sin-inverse-leaky-abstractions#comment12http://ayende.com/4789/the-wages-of-sin-inverse-leaky-abstractions#comment12Wed, 23 Mar 2011 20:49:49 GMTJohn Farrell commented on The wages of sin: Inverse leaky abstractions@Chris Marisic - What abstraction? You may as well call that "NhibernateFacade" as its certainly not a repository. IMHO the code you've linked to is the perfect example of what Ayende has been talking about. Its 100% useless passthrough code that abstracts nothing. Whats the point of even writing that class? http://ayende.com/4789/the-wages-of-sin-inverse-leaky-abstractions#comment11http://ayende.com/4789/the-wages-of-sin-inverse-leaky-abstractions#comment11Wed, 23 Mar 2011 20:48:53 GMTthrowspoop commented on The wages of sin: Inverse leaky abstractionsThe point of these posts is to create controversy (interest, etc) so that his site gets more traffic and earns more ad revenue, and most importantly, sells more licenses. Duh...seriously, who gives a flying F if this app is written poorly or not? http://ayende.com/4789/the-wages-of-sin-inverse-leaky-abstractions#comment10http://ayende.com/4789/the-wages-of-sin-inverse-leaky-abstractions#comment10Wed, 23 Mar 2011 20:12:23 GMTChris Marisic commented on The wages of sin: Inverse leaky abstractionsI completely agree that inverse of leaky abstractions is more nefarious than leaky abstractions themselves. This has lead me to view all people who implement the repository pattern using a base class to have fallen victim to it already. To have a repository be a dependency through inheritance is the ultimate of giving up since you completely through all aggregation out of the window. You can't write a CarInsuranceRepository, you need to write a CarRepository, an InsuranceRepostiroy, a StateRepository and god knows how many other concrete class implementations before you can do even the most basic business functionality. My post is now a year old on this topic but I think it's as relevant as ever for any DAL. [dotnetchris.wordpress.com/.../creating-a-common...](http://dotnetchris.wordpress.com/2010/03/15/creating-a-common-generic-and-extensible-nhiberate-repository-version-2/) as the post says you can mostly ignore the Conversation objects they're wrappers for the session that i use to complete the sessions in an AOP manner. Do you agree with me that my solution is a very proper use of abstraction? My pattern doesn't "lose features" the way many abstraction layers do, or that you end up with abstractions that completely obfuscate things you're trying to do like the exact point of this post that the future usage was completely lost due to the Controller's usage of the repository layers. With my code you could create a discrete repository that aggregates all of the calls you need to satisfy a demand and keep all of the future aspects behind the repository. http://ayende.com/4789/the-wages-of-sin-inverse-leaky-abstractions#comment9http://ayende.com/4789/the-wages-of-sin-inverse-leaky-abstractions#comment9Wed, 23 Mar 2011 18:31:36 GMTDmitry commented on The wages of sin: Inverse leaky abstractions@stu, Let's say you have another method, GetEnabledDiscounts() that returns a future collection. If you do var a = ...GetEnabledCurrencies().ToList(); var b = ...GetEnabledDiscounts().ToList(); there will be 2 separate db calls. The right way to do this is: var a = ... GetEnabledCurrencies(); var b = ....GetEnabledDiscounts(); var aa = a.ToList(); var bb = b.ToList(); This way the 2 queries will be batched. However, there is no intuitive way to realize this with the encapsulated service objects. http://ayende.com/4789/the-wages-of-sin-inverse-leaky-abstractions#comment8http://ayende.com/4789/the-wages-of-sin-inverse-leaky-abstractions#comment8Wed, 23 Mar 2011 17:44:06 GMTLukeB commented on The wages of sin: Inverse leaky abstractions"Please explain how the ToList() breaks Future()." ToList() immediately executes a linq statement. http://ayende.com/4789/the-wages-of-sin-inverse-leaky-abstractions#comment7http://ayende.com/4789/the-wages-of-sin-inverse-leaky-abstractions#comment7Wed, 23 Mar 2011 17:42:47 GMTJoe commented on The wages of sin: Inverse leaky abstractionsI agree with Frank though, if you engage in criticism its helpful to those reading the blog and who are learning to know what the recommended solution is. Unless of course you have no interest in pointing those who are learning to some helpful reading. http://ayende.com/4789/the-wages-of-sin-inverse-leaky-abstractions#comment6http://ayende.com/4789/the-wages-of-sin-inverse-leaky-abstractions#comment6Wed, 23 Mar 2011 16:40:18 GMTstu commented on The wages of sin: Inverse leaky abstractionsPlease explain how the ToList() breaks Future <t(). This should be the point of your post. Write to be understood. >http://ayende.com/4789/the-wages-of-sin-inverse-leaky-abstractions#comment5http://ayende.com/4789/the-wages-of-sin-inverse-leaky-abstractions#comment5Wed, 23 Mar 2011 16:38:40 GMTLukeB commented on The wages of sin: Inverse leaky abstractionsI'm always amazed at the thin skin of software developers. Criticism and opinion are not "bashing" and are not being "toxic". http://ayende.com/4789/the-wages-of-sin-inverse-leaky-abstractions#comment4http://ayende.com/4789/the-wages-of-sin-inverse-leaky-abstractions#comment4Wed, 23 Mar 2011 15:49:15 GMTJason Meckley commented on The wages of sin: Inverse leaky abstractionsI understand batched reads. I understand over-architecture. But with this snippet of code I fail to see the problem with the use of Future.ToList(). if this is the only db call then it makes sense to call ToList() at this point. If the remaining block of code had additional Future.ToList() calls, then yes, the benefit of batching is lost. http://ayende.com/4789/the-wages-of-sin-inverse-leaky-abstractions#comment3http://ayende.com/4789/the-wages-of-sin-inverse-leaky-abstractions#comment3Wed, 23 Mar 2011 14:23:43 GMTR commented on The wages of sin: Inverse leaky abstractionsSend them a patch and stop being toxic http://ayende.com/4789/the-wages-of-sin-inverse-leaky-abstractions#comment2http://ayende.com/4789/the-wages-of-sin-inverse-leaky-abstractions#comment2Wed, 23 Mar 2011 14:09:09 GMTFrank Quednau commented on The wages of sin: Inverse leaky abstractionsAs with every feature of moderate complexity, guidance as to how it is used is needed, fortunately you already wrote about it: [www.google.ch/search](http://www.google.ch/search?q=nhibernate+future+site%3Aayende.com)http://ayende.com/4789/the-wages-of-sin-inverse-leaky-abstractions#comment1http://ayende.com/4789/the-wages-of-sin-inverse-leaky-abstractions#comment1Wed, 23 Mar 2011 13:41:52 GMT