Re: Request for detailed documentation of git pack protocol

[Junio C Hamano <gitster@pobox.com>]

"Shawn O. Pearce" <spearce@spearce.org> writes:

> I think there's something like that in DIRC too, but that change
> (to introduce the current DIRC format) may predate my involvement
> with Git, so my memory isn't very good there.

The index_extension part where the cache-tree is stored is another
example.  The length of the index is known from the mmap, the file
checksum is defined to appear at the end of the file, and the number of
entries are recorded in the file header, so there was a hole after that
many index entries I could add new section.

>> P.S. By the way, is pkt-line format original invention, or was it 
>> 'borrowed' from some other standard or protocol?
>
> No clue.  I find it f'king odd that the length is in hex.  There
> isn't much value to the protocol being human readable.  The PACK
> part of the stream sure as hell ain't.  You aren't going to type
> out a sequence of "have" lines against the remote, like you could
> with say an HTTP GET.  *shrug*

The text-ness made it easier to debug while I was developing the sideband
support.  I literally typed the pkt-line from the terminal ;-).