visionmedia/git-extras — pull request #152 by themalkolm (2012-11-17 00:42:16+00:00)
Title: Update bin/git-count

Use git-rev-list and builtin --count option

$ time git log --oneline | wc -l
30613
real	0m0.858s
user	0m0.684s
sys	0m0.239s

$ time git rev-list --count HEAD
30613
real	0m0.416s
user	0m0.396s
sys	0m0.018s