Re: pack v4 status

On Tue, 27 Feb 2007, Johannes Schindelin wrote:

Hi,

On Tue, 27 Feb 2007, Linus Torvalds wrote:

quoted

On Tue, 27 Feb 2007, Shawn O. Pearce wrote:

quoted

We have thus far reformatted OBJ_TREEs with a new dictionary based
compression scheme.  In this scheme we pool the filenames and modes
that appear within trees into a single table within the packfile.
All trees are then converted to use a 22 byte record format:

  - 2 byte network byte order index into the string pool
  - 20 byte SHA-1

Umm. Am I missing something, or is this totally braindamaged?

Are you really expecting there to never be more than 64k basenames? 
Trust me, that's a totally broken assumption. Anything that tracks 
generated stuff will _easily_ have several tens of thousands of random 
filenames even in a single tree, much less over the whole history of the 
repository.

The sane thing, of course, is to use some sort of prefix coding, together 
with an escape code.

No.  There is a fundamental reason for having a fixed size tree record.


Nicolas