From ba087e328525f49c44c594669657cdedc67ab3c3 Mon Sep 17 00:00:00 2001
From: "Bradley M. Kuhn" <bkuhn@ebb.org>
Date: Thu, 15 Aug 2013 20:48:16 -0400
Subject: [PATCH] First draft of new diffstat-total-compare.plx script.

---
 diffstat-total-compare.plx | 73 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 73 insertions(+)
 create mode 100755 diffstat-total-compare.plx

diff --git a/diffstat-total-compare.plx b/diffstat-total-compare.plx
new file mode 100755
index 0000000..f768491
--- /dev/null
+++ b/diffstat-total-compare.plx
@@ -0,0 +1,73 @@
+#!/usr/bin/perl -w
+# diffstat-total-compare.plx                                         -*- Perl -*-
+
+# Copyright (C) 2013 Bradley M. Kuhn <bkuhn@ebb.org>
+#
+# This software's license gives you freedom; you can copy, convey,
+# propogate, redistribute and/or modify this program under the terms of
+# the GNU  General Public License (GPL) as published by the Free
+# Software Foundation (FSF), either version 3 of the License, or (at your
+# option) any later version of the GPL published by the FSF.
+#
+# This program is distributed in the hope that it will be useful, but
+# WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program in a file in the toplevel directory called
+# "GPLv3".  If not, see <http://www.gnu.org/licenses/>.
+
+# The problem this script is trying to solve:
+
+#   You have a source release separated from the a git repository.
+#   Non-hypothetical example: a CCS release from a GPL compliance source dump
+#   from a cmopany.
+#   You want to know the git revision it's closest to.
+#   Well, the only way I've found to solve this problem is this way:
+
+#   build a list of commit ids that are the candidates for the base revision
+#   for this sort release, and put them in commit-list, one per line, and run:
+
+#   for i in `cat commit-list `; do
+#       echo Doing $i
+#       git checkout -q $i; diff -wB -N -x .git -ru . /path/to/source/release > /path/to/diffs/${i}.log
+#       cat /path/to/diffs/${i}.log |diffstat > /path/to/diffs//${i}.diffstat
+#       rm /path/to/diffs/${i}.log
+#       echo Done $i
+#    done
+
+# Then, this script is run across that directory.
+
+my %commitTotals;
+for my $file (<*.diffstat>) {
+  my $commitID = $file;
+  $commitID =~ s/\.diffstat$// or die "$file isn't ending in .diffstat, huh?";
+  my %commit;
+  open(DIFFSTAT, "<", $file) or die "unable to open $file for reading: $!";
+  while (my $line = <DIFFSTAT>) {
+    if ($line =~ /^\s*(\d+)files\s+changed\s*,\s+(\d+)insertions[^\d]+\s+(\d+) deletions.*$/) {
+      ($commit{files}, $commit{insertions}, $commit{deletions}) = ($1, $2, $3);
+      last;
+    }
+    die "unable to find diffstat summary line in $file"
+      unless defined $commit{files} and defined $commit{insertions} 
+        and defined $commit{deletions};
+  }
+  close DIFFSTAT;    die "error reading $file: $!" unless ($? == 0);
+  $commitTotals{$commitID} = \%commit;
+}
+
+foreach my $type (qw/files insertions deletions/) {
+  print "Sorted by $type:\n";
+  foreach my $commitID (
+        sort { $commitTotals{$a}{$type} <=> $commitTotals{$b}{$type} }
+                        keys %commitTotals) {
+    print "     $commitID $commitTotals{$commitID}{$type}\n";
+  }
+}
+
+#
+# Local variables:
+# compile-command: "perl -c diffstat-total-compare.plx"
+# End: