Re: [Gnumeric] Re: [PATCH] first draft of new auto-save functionality.

[Jody Goldberg <jody gnome org>]

On Sat, Feb 23, 2002 at 02:36:18AM -0500, C. Scott Ananian wrote:
> Yes, I got that impression from your last message, but I think the
> simplicity of the current code has much to recommend it.  The auto-save
> should be bullet-proof.  A journalled backup, although theoretically nice,
> is going to absorb a lot of coding time and will never be tested enough
> (because how often does anyone use the recovery code?  hopefully not
> often!) to guarantee that it won't fail at the worst possible time.
> Also, with any journalled system you have to worry about consistency in
> the face of crashes mid-update & etc...
The current autosave approach of saving the entire file is not
feasible when working with large files.  It is simply too expensive.
A journal is not as hard as you might think.  I'm fairly sure that
some read/write xml operators as part undo/redo mechanism
will get us where we want to go.  Dumping a small xml blurb per
command seems easy.

> The *current* auto-save code, modelled on XL, is next to useless.
> You have to explicitly enable it?  For every workbook?  And it will
> sometimes silently overwrite your existing file with changes you really
> didn't mean to commit?  That might be all right for Microsoft, but we know
> how to do things better.
Any mechanism that saves the entire file must be disableable.  I'd
accept a patch to do the saving to an emacs #foo# style file name,
but the current timers and layout are sufficient.  Nor does it seem
necessary to add the 'save to fd'.  We overwrite the file if it
exists. It seems more fruitful to add the journaling.