Re: Print Precedes/Follows in git log

["Marco Costalba" <mcostalba@gmail.com>]

On Jan 15, 2008 12:34 AM, Jan Engelhardt <jengelh@computergmbh.de> wrote:
>
> And it would be really nice if `git log` would also show the
> Precedes/Follows lines so one can identify much more easily in
> big logs like those of the Linux kernel what the next release to
> have a given patch is.
>
>

You need two complete revisions walk for this, one from the newest to
oldset to compute the 'precedes' and one from the oldest to newest to
compute the 'follows', so I would say it's more suitable used together
with --topo-order option of git log that already does a walk, at least
the slowdown is hidden in this case.

Anyhow being able to compute precedes/following info in timely fashion
and with low memory consumption is quite not trivial code, I have
implemented for qgit long time ago and I remember gave a kook at the
gitk code for reference also if at the end my implementation it's a
bit different (less memory used but slightly more complicated).

Just to give an idea of timing, on my new and awesome ;-) laptop
loading full Linux tree it takes 3316ms, then calculating
precedes/follows info (indexing the tree) it takes 233ms.

Perhaps the slowest part is to load refs info, you need this to know
what sha a tag/branch has and is a prerequisite to indexing, also if
refs are compacted it takes almost 1 second on my PC because there is
heavy disk activity in any case.

Marco