From 750bd6ac350079cf1f76c24acb7686ad89a95102 Mon Sep 17 00:00:00 2001 From: Nicolas Pitre Date: Thu, 12 Jul 2007 03:40:18 -0400 Subject: [PATCH] script to display a distribution of longest common hash prefixes This script was originally posted on the git mailing list by Randal L. Schwartz . Signed-off-by: Nicolas Pitre Signed-off-by: Junio C Hamano --- contrib/stats/git-common-hash | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+) create mode 100755 contrib/stats/git-common-hash diff --git a/contrib/stats/git-common-hash b/contrib/stats/git-common-hash new file mode 100755 index 000000000..e27fd088b --- /dev/null +++ b/contrib/stats/git-common-hash @@ -0,0 +1,26 @@ +#!/bin/sh + +# This script displays the distribution of longest common hash prefixes. +# This can be used to determine the minimum prefix length to use +# for object names to be unique. + +git rev-list --objects --all | sort | perl -lne ' + substr($_, 40) = ""; + # uncomment next line for a distribution of bits instead of hex chars + # $_ = unpack("B*",pack("H*",$_)); + if (defined $p) { + ($p ^ $_) =~ /^(\0*)/; + $common = length $1; + if (defined $pcommon) { + $count[$pcommon > $common ? $pcommon : $common]++; + } else { + $count[$common]++; # first item + } + } + $p = $_; + $pcommon = $common; + END { + $count[$common]++; # last item + print "$_: $count[$_]" for 0..$#count; + } +' -- 2.30.2