Async Wrappers

The implementation is once again making more and more sense - proof of my own self-delusional state or perhaps proof that the project and the design are going in the right direction! Now fleshing out the data device initialisation/mounting code and that is proving not too strenuous. Need to get the root page and distribution page init code sorted - then I'll be able to see the log-writer do its work - I can't wait!

I was under the mistaken impression that these updates to promote asynchronous behaviour and removing swaths of class hierarchy were going to make the app a dash simpler but as I found out the stack trace during writes is actually longer than before - lots and lots of async wrapper objects the root of the issue - I may need to assign these wrappers from a pool of the things to keep the C# memory manager happy but then again this is what .NET is all about so I'll just flag it for now!

Taken a brief look at the index manager implementation - which still looks rather slick with it's generics all over the place and crossed another TODO off the list... I created an initial implementation of B-Trees operating over pages ages ago but the code was totally synchronous. I realised it needed some careful rework in order to get it to work efficiently with the BeginLoadPage/EndLoadPage APIs that have cropped up following the async conversions and today I can happily say I have solved it with some of the scariest code I've ever written!! Not scary for it's complexity - it is some of the most elegant encapsulated OO code you'll ever meet - no, what scared me was the fact that when I started I didn't actually think the task at hand was entirely possible - writing the B-Tree handler in the first place was nothing short of pain and misery...

Worse yet I still need to provide the B-tree implementation for the table index manager - similar but with the added complication of defining a class hierarchy for dealing with the different data-types I plan to support and the obvious headaches involved in doing string comparisons... I have never understood the various collations - ever...

Anyways I'm happy - my writing of asynchronous code has come of age - almost to the point where I am considering writing an article on just that! Watch this space for a URL...

Need to revisit the locking implementation as it currently needs too much information some of which is not present until the page is loaded - a situation I am keen to avoid...