scripts/gc-tattoo

   1 #!/bin/sh
   2
   3 #
   4 # Some docs
   5 #
   6 # A --- B --- C    stable
   7 # |\         /
   8 # | D ----- E      topic1
   9 #  \       /
  10 #   F --- G        topic2
  11 #
  12 # topic1 stable result
  13 #  D      A      contains, merge base=A
  14 #  D      C      contains, merge base=A
  15 #  E      A      contains, merge base=E
  16 #  E      C      contains, merge base=A
  17
  18 #
  19 # * --- * --------- *   stable
  20 # |\     \
  21 # | A --- B ---- C      topic1
  22 # \             /
  23 #  D --- E --- F        topic2
  24 #
  25 # F: contains=topic1,topic2
  26 # C: contains=topic1
  27
  28 head=$(git rev-parse HEAD)
  29
  30 # Watch out for the very first commit in the repo because we use head^
  31 # Hopefully we can optimize this away later.
  32 git rev-parse --verify --quiet "$head^" >/dev/null
  33 if [ $? -ne 0 ] ; then
  34         echo "0"
  35         exit 0
  36 fi
  37
  38 contains=($(git branch -r --contains $head))
  39 if [ ${#contains[@]} -eq 0 ] ; then
  40         echo "$head has not been pushed"
  41         exit 1
  42 fi
  43
  44 potential=" "
  45 for branch in ${contains[@]} ; do
  46         branch=${branch##origin/}
  47         #echo "branch=$branch"
  48
  49         # Walk back until we hit a baserev that is not the branch_tip itself (because it was merged)
  50         branch_tip=$(git rev-parse origin/$branch)
  51         stable_rev=$(git rev-parse origin/stable)
  52         stable_base=$(git merge-base "$branch_tip" "$stable_rev")
  53
  54         # echo "stable_base=$stable_base"
  55         while [ "$stable_base" == "$branch_tip" ] ; do
  56                 stable_rev=$(git rev-parse "${stable_rev}^")
  57                 stable_base=$(git merge-base "$branch_tip" "$stable_rev")
  58         done
  59         # echo "stable_base=$stable_base"
  60
  61         git rev-list --first-parent $stable_base..$branch_tip | grep --quiet "$head"
  62         if [ $? -eq 0 ] ; then
  63                 if [ "$branch" == "stable" ] ; then
  64                         describe=$(git describe $head 2>/dev/null)
  65                         if [ $? -eq 0 ] ; then
  66                                 potential="$potential $describe"
  67                         else
  68                                 potential="$potential stable-$head"
  69                         fi
  70                 else
  71                         number=$(git rev-list --first-parent "$stable_base..$head" | wc -l)
  72                         potential="$potential $branch-$number"
  73                 fi
  74         fi
  75 done
  76
  77 potential=($potential)
  78 if [ ${#potential[@]} -eq 1 ] ; then
  79         echo "${potential[0]}"
  80 else
  81         echo "unknown"
  82 fi
  83