[GD-General] Multifile atomic updates

[Brian H. <bri...@py...>]

Say you have a patch installer that needs to update the following 
files:

GAME.EXE
GAME.DLL
NETAPI.DLL

The typical way would be to download the patch, apply it to temporary 
files, then copy over the files upon completion.

PATCH GAME.EXE NEWGAME.EXE
PATCH GAME.DLL NEWGAME.DLL
PATCH NETAPI.DLL NEWNETAPI.DLL

//Assume UPDATE renames existing to .EXT.OLD
//and copies NEW*.EXT to *.EXT
UPDATE GAME.EXE
UPDATE GAME.DLL
UPDATE NETAPI.DLL

Obviously nothing destructive happens until after the patches are 
applied and you can verify that everything is okay.  But what do you 
do if something bad happens during the destructive update portion, 
e.g. lost connection to remote disk or power outage or system crash, 
etc. during the update?

The brute force mechanism seems a little, well, brute force, I was 
wondering if there's something more elegant I could do.

Brian