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Project Model Improvements Re: [cdt-dev] CDT Summit Report

Hi Doug,

> Not yet. We didn't get very much time on build as we did on the other
> topics. I think the summary of it is to redo the Project model to simplify
> it and to break the dependency on managed build that was introduced with it
> in 4.0.

Is there any indication on what's planned, who might be doing this
work, and in what time frame?

Time's come full circle again for me and I'm once again focusing on my
users with larger projects.  The problem with the current
implementation is twofold:
1) For an XML file >3M CDT exceeds a 512M HEAP and performance is
really bad (BUG238421)
2) The current XML model is not threadsafe (get the indexer going,
open settings page and hit apply rapidly... BUG239627).

I think this all boils down to choice of XML as the data structure.
It's verbose, inherently not threadsafe and, for all its verbosity,
it's still not human readable. The tree duplication is expensive in
terms of time and memory, and the end result is that changes made to
the project description from different threads can easily be lost
(BUG248962).
And all this before we consider what happens if a powercut or crash
happens during serialization.

It's my feeling that for something as important as the project model
we actually need a data store with ACID properties with reasonable
performance -- a very lightweight db would seem to be an ideal
solution.

I've got some time in my schedule to start work on this, but am keen
not to tread on anyone else's toes if they're intending on working on
the project model.  My first aim would be to port the existing project
model to use sqllite as its db backend, and any changes to the actual
structure of the model could be made in parallel or after.

If this all sounds like a really bad idea then someone please say!
Otherwise it's the only solution I can see that would ensure we have a
scalable project description with ACID properties.

Cheers,

James


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