[mapguide-internals] Exception Handling for Memory limitations + Patch for #480 & #520

[Jason Birch]

This is from a non-technical perspective, but I would _much_ rather have a missing tile than a corrupt tile.  IMO, if an exception is thrown and it's not possible to determine that the file was written without errors, delete it.  I haven't tried this with a recent release, but I think that earlier versions were writing white tiles when exceptions were encountered. Differentiating between these failed tiles and tiles were not corrupt but had minimal information on them was difficult.

It would be useful if the logged error included information on which file was being written as well as the reason for the exception.  I've run into a few cases where bad geometry causes rendering exceptions, and tracking these down can be a royal pain.

Jason

________________________________________
From: Walt Welton-Lair [walt.welton-lair at autodesk.com]
Sent: Thursday, April 02, 2009 8:40 PM
To: MapGuide Internals Mail List
Subject: RE: [mapguide-internals] Exception Handling for Memory limitations     +       Patch for #480 & #520

Also, in my change I delete the file if any exception is encountered - in your case you delete it only if it's empty.  Both seem like reasonable choices.  When an exception occurs it's possible the file got written out completely and is valid, but it's also possible it was only partially written and therefore not valid.  Any more thoughts on that?