Ayende @ Rahien

Ryan Roberts commented on Rhino DivanDB – A full coding sample – Embedded

Fri, 12 Mar 2010 16:16:21 GMT

Wasn't there talk on the remotion / relinq project of using javascript as an intermediate format for sending linq expressions over the wire? Can't see anything in the codebase though and the oloh page has changed since I last remember it. It's a shame as I would kill puppies for a linq expression to js translator.

Ayende Rahien commented on Rhino DivanDB – A full coding sample – Embedded

Wed, 03 Mar 2010 13:28:18 GMT

I am aware of that,and the name was changed

Khalid Abuhakmeh commented on Rhino DivanDB – A full coding sample – Embedded

Wed, 03 Mar 2010 13:12:00 GMT

I was actually curious as to why you called it DivanDB and then I did a google search on Divan. That's pretty funny, it's a play off of CouchDB. There is a library that allows you to do linq queries over WCF [http://interlinq.codeplex.com/](http://interlinq.codeplex.com/) check it out it might give you some ideas.

o_o commented on Rhino DivanDB – A full coding sample – Embedded

Wed, 03 Mar 2010 11:55:31 GMT

Expression Tree Serialization: [http://code.msdn.microsoft.com/exprserialization](http://code.msdn.microsoft.com/exprserialization)

Ayende Rahien commented on Rhino DivanDB – A full coding sample – Embedded

Tue, 02 Mar 2010 18:42:53 GMT

Rafal, It is compiled and run on the server. The results are JSON docs

Rafal commented on Rhino DivanDB – A full coding sample – Embedded

Tue, 02 Mar 2010 18:30:40 GMT

But why use LINQ syntax if you put it in a string anyway? Is it C# that is compiled and executed server side, or some expression language that only mimics C#? And what happens to projection objects produced by the query - are they persisted somehow, or just used to stuff Lucene Document with data fields? One more question: what are the results returned by query? Full documents or just the 'title' column? How are they returned - as strings?

Ayende Rahien commented on Rhino DivanDB – A full coding sample – Embedded

Tue, 02 Mar 2010 18:11:55 GMT

Not in a way that allow you to recompile it, though

Dan Finch commented on Rhino DivanDB – A full coding sample – Embedded

Tue, 02 Mar 2010 17:48:46 GMT

Expression.ToString() returns the actual expression (sort of), that may be helpful.

Jeff Handley commented on Rhino DivanDB – A full coding sample – Embedded

Tue, 02 Mar 2010 16:23:20 GMT

Ayende, You might want to look at DynamicQueryable. Scott Hanselman and Marcin Dobosz have blogged about it recently. I have used a flavor of DynamicQuerable to serialize and deserialize LINQ expressions very well. Here's Hanselman's recent post: [www.hanselman.com/.../...INQExpressionsEasier.aspx](http://www.hanselman.com/blog/TheWeeklySourceCode48DynamicQueryableMakesCustomLINQExpressionsEasier.aspx) And Marcin's: [blogs.msdn.com/.../...-DynamicQueryable_2E00_.aspx](http://blogs.msdn.com/marcinon/archive/2010/01/14/Building-custom-LINQ-expressions-made-easy-with-DynamicQueryable_2E00_.aspx) And ScottGu's post from long ago: [weblogs.asp.net/.../...-dynamic-query-library.aspx](http://weblogs.asp.net/scottgu/archive/2008/01/07/dynamic-linq-part-1-using-the-linq-dynamic-query-library.aspx) At the very least, DynamicQueryable could give you a good starting point for the (de)serialization of the expression - that's what it did for me. -Jeff

Chris commented on Rhino DivanDB – A full coding sample – Embedded

Tue, 02 Mar 2010 16:05:52 GMT

Looks good - can't wait to play with it. Now I see the programming interface, I can almost see how it works. Regarding all the moaning about stale results and blocking; It is NICE that consistency is OPTIONALLY enforceable (by waiting). For the stuff I do, it is useful to make that distinction.

Roy commented on Rhino DivanDB – A full coding sample – Embedded

Tue, 02 Mar 2010 15:23:50 GMT

True, and I guess introducing refactorability using expressions is nice, but not if it comes at the cost of adding a lot of complexity.

Ayende Rahien commented on Rhino DivanDB – A full coding sample – Embedded

Tue, 02 Mar 2010 15:18:58 GMT

Roy, This isn't a query, this is building an index. Those are different things

Roy commented on Rhino DivanDB – A full coding sample – Embedded

Tue, 02 Mar 2010 14:38:58 GMT

Oh, some tags got clipped, but AddView should be a generic of type "Doc". But that's assuming you even want to have domain objects defined in that way. Meh, that seems like a fiddly solution anyway.

Roy commented on Rhino DivanDB – A full coding sample – Embedded

Tue, 02 Mar 2010 14:29:06 GMT

Maybe then the parameters could be passed in as lambdas? So, something like: db.AddView doc.Title); >

Ayende Rahien commented on Rhino DivanDB – A full coding sample – Embedded

Tue, 02 Mar 2010 14:10:02 GMT

Roy, That is likely to be _very_ hard.

Andrew Stewart commented on Rhino DivanDB – A full coding sample – Embedded

Tue, 02 Mar 2010 13:47:23 GMT

@Roy, I'm hoping we can do this, I'm going to be working on something like that shortly.

Roy commented on Rhino DivanDB – A full coding sample – Embedded

Tue, 02 Mar 2010 13:31:17 GMT

But wouldn't it still be possible to create the expression on the client side, and before it goes on the wire have it converted to something serializable? That way, the client code still has the benefit of compile-time checking.

Ayende Rahien commented on Rhino DivanDB – A full coding sample – Embedded

Tue, 02 Mar 2010 13:09:54 GMT

Darius, You shouldn't, this is a client/server thing, you can't pass live isntances along the wire.

Darius Damalakas commented on Rhino DivanDB – A full coding sample – Embedded

Tue, 02 Mar 2010 12:48:22 GMT

I am really supprised to see that a call to db.AddView accepts some kind of string, which is not validated at compile time.

Ayende Rahien commented on Rhino DivanDB – A full coding sample – Embedded

Tue, 02 Mar 2010 12:42:19 GMT

Configurator, This is a unit test, and I know that I'll wait for ~ms or so, because I know the entire context. As for waiting with scaling, you put waits, or if you accept potentially stale results

configurator commented on Rhino DivanDB – A full coding sample – Embedded

Tue, 02 Mar 2010 12:35:05 GMT

So why did you busy wait here, on your first full example? Do you have an idea how to actually wait for queries to be not-stale without busy waiting?

Ayende Rahien commented on Rhino DivanDB – A full coding sample – Embedded

Tue, 02 Mar 2010 10:59:43 GMT

Bruce, Try passing expression tree on the wire, and making sense of them on the other side. And Query doesn't know how long to wait. Busy waiting is NOT something that I want to do, talk about DoS yourself

Bruce Boughton commented on Rhino DivanDB – A full coding sample – Embedded

Tue, 02 Mar 2010 10:52:28 GMT

Out of interest: why do you pass the views as strings instead of expression trees? Also, why not provide an overload to Query that does the do... while for you to ensure non stale results? Is this just an early preview of the API?

Ayende Rahien commented on Rhino DivanDB – A full coding sample – Embedded

Tue, 02 Mar 2010 10:33:35 GMT

addys, I am doing some funky things there.

addys commented on Rhino DivanDB – A full coding sample – Embedded

Tue, 02 Mar 2010 10:32:23 GMT

curious: are you using a library for parsing the linq string into an expression tree, or did you cook up your own parser?