Re: [PATCH] make the pack index version configurable

On Fri, 2 Nov 2007, David Symonds wrote:

On 11/2/07, Nicolas Pitre [off-list ref] wrote:

quoted

+pack.indexVersion::
+       Specify the default pack index version.  Valid values are 1 for
+       legacy pack index used by Git versions prior to 1.5.2, and 2 for
+       the new pack index with capabilities for packs larger than 4 GB
+       as well as proper protection against the repacking of corrupted
+       packs.  Version 2 is selected and this config option ignored
+       whenever the corresponding pack is larger than 2 GB.  Otherwise
+       the default is 1.

If you're trying to force a previous pack version for some reason
(backward compatibility, or whatever), this "feature" of automatic
forcing version 2 for 2 GB packs might come as a nasty suprise.
Wouldn't it be better to fail with an error?

No.  The fact is that you don't know in advance what the pack size will 
be, and reaching that limit might take a long while already if 
repacking, or even more so if the pack is fetched over a network 
connection.  That would be wasteful to simply throw away all the whole 
repack/download with an error which would be an even nastier surprise at 
that point just because you specified index v1.

And such a pack would be impossible to work with using an old Git 
version anyway, so the old Git version will happily give you the error, 
suggesting that you upgrade to a later version.

And this has been the implemented behavior for the last 7 months 
already.

And the idea is to switch the default to version 2 eventually.

Etc.


Nicolas