Re: Use of versioning in archiving.

[Richard Frith-Macdonald]

On Tuesday, December 4, 2001, at 06:13 AM, Gerrit Van Dyk wrote:

> Hi all,
>
> I logged a bug yesterday in connection with the unarchiving of NSValue.
> Thanks Richard for responding so quickly. I was just wondering now, I 
> saw
> that the encoding of NSValue also changed without using versioning. Is 
> this
> a common practice within GNUstep to change some of the encoding methods
> without checking for versioning?

No.
In fact, the 'final' version of my changes included versioning,
moderate optimisation, and a few other fixes and tidyups.

> Our system makes use of Blob's in the
> database, these blobs are created using archiving and then unarchived 
> when
> their details are needed. If GNUstep does not check for versioning then 
> our
> blobs will become unusable the moment the archiving methods change. 
> Should I
> start using different ways of archiving our objects into blobs, just to 
> make
> sure that our system will not become unstable with a new release of 
> GNUstep.
> I can also see a potential problem over DO if the versions of GNUstep on
> either side of the connection is not 100% the same.

Well ... it shouldn't happen.  As of GNUstep-base 1.0, newer releases of 
the
code should remain capable of decoding archives produced by older 
releases
(at least within a major release version).

However, mistakes/bugs will obviously creep in on occasions ... 
fortunately,
with GNUstep you are better off than with a proprietory system ... if an
incompatible coding change gets in to a release, you can get quicker help
and/or fix the problem yourself and contribute the fix back.