Meta/amlook: wip gc

diff --git a/amlook b/amlook
new file mode 100755 (executable)
index 0000000..5c270d6
--- /dev/null
+++ b/amlook
@@ -0,0 +1,116 @@
+#!/bin/sh
+# Usage:
+# Meta/amlook <mbox (for single message from MUA) or
+# Meta/amlook id1 id2... (from the command line)
+# Meta/amlook --gc
+
+find_commit () {
+       in=
+       # I know I know there should be "notes grep" command...
+       commits=$(
+               git grep -l -e "$1" notes/amlog |
+               sed -e 's|^notes/amlog:||' -e 's|/||g'
+       )
+       if test -z "$commits"
+       then
+               echo "Never applied"
+               return
+       fi
+       found=$(
+               echo "$commits" |
+               while read commit
+               do
+                       git branch --with $commit
+               done | sed -e 's|^..||' |
+               sort -u |
+               tr '\012' ' '
+       )
+       if test -z "$found"
+       then
+               echo "Not merged ($commits)"
+               return
+       fi
+       case " $found " in
+       *' maint '*) in=maint ;;
+       *' master '*) in=master ;;
+       *' next '*) in=next ;;
+       esac
+       if test -n "$in"
+       then
+               echo "Found in $in"
+       else
+               echo "Found in $found"
+       fi
+}
+
+garbage_collect () {
+       cutoff_days=${1-"180"} &&
+       git notes --ref amlog list |
+       sed -e 's/.* //' |
+       xargs -n 1 git show -s --format="%ci %H" 2>/dev/null |
+       perl -e '
+               my @time = localtime(time() - $ARGV[0] * 24 * 3600);
+               my $cutoff = sprintf("%04d-%02d-%02d 00:00:00",
+                               $time[5]+1900, $time[4]+1, $time[3]);
+               while (<STDIN>) {
+                       if ($_ le $cutoff) {
+                               s/.* //;
+                               print;
+                       }
+               }
+       ' "$cutoff_days" >..gcinput
+
+: <<\INVALID
+       : (
+               GIT_INDEX_FILE=/tmp/amlook.$$.tmp &&
+               export GIT_INDEX_FILE &&
+               rm -f "$GIT_INDEX_FILE" &&
+               git read-tree refs/notes/amlog &&
+               xargs git rm -f &&
+               T=$(git write-tree) &&
+               C=$(echo Prune amlog | git commit-tree $T -p refs/notes/amlog) &&
+               git update-ref -m "Prune amlog" refs/notes/amlog $C
+       )
+INVALID
+}
+
+if test $# = 0
+then
+       msg=$(sed -ne '
+               /^[     ]/{
+                       # Append continuation line
+                       H
+                       x
+                       s/\n//
+                       x
+                       n
+               }
+               # Hold this new line, and look at what is in the hold space
+               x
+               # Is it the Message-ID line?  If so, spit out and finish.
+               /^[Mm][Ee][Ss][Ss][Aa][Gg][Ee]-[Ii][Dd]:[       ]*/{
+                       s///p
+                       q
+               }
+               # Otherwise, check if this new line is empty
+               x
+               # Is it?  Then we are done with the header
+               /^$/b end
+               # Otherwise we need to hold onto this header line
+               x
+               # And start the next cycle
+               b
+       : end
+               q
+       ') &&
+       find_commit "$msg"
+elif test "$1" = "--gc"
+then
+       shift
+       garbage_collect "$@"
+else
+       for msg
+       do
+               find_commit "$msg"
+       done
+fi