tg-migrate-bases.sh

   1 #!/bin/sh
   2
   3 # tg--migrate-bases -- migrate from old top-bases to new {top-bases}
   4 # Copyright (C) 2017 Kyle J. McKay
   5 # All rights reserved.
   6 # License GPLv2+
   7
   8 USAGE="\
   9 Usage: ${tgname:-tg} [...] migrate-bases (--dry-run | --force) [--no-remotes | --remotes-only]"
  10
  11 usage()
  12 {
  13         if [ "${1:-0}" != 0 ]; then
  14                 printf '%s\n' "$USAGE" >&2
  15         else
  16                 printf '%s\n' "$USAGE"
  17         fi
  18         exit ${1:-0}
  19 }
  20
  21 ## Parse options
  22
  23 dryrun=
  24 force=
  25 noremotes=
  26 remotesonly=
  27 reverse=
  28 orphans=1
  29
  30 while [ $# -gt 0 ]; do case "$1" in
  31         -h|--help)
  32                 usage
  33                 ;;
  34         -n|--dry-run|--dryrun)
  35                 dryrun=1
  36                 ;;
  37         -f|--force)
  38                 force=1
  39                 ;;
  40         --no-remotes)
  41                 noremotes=1
  42                 ;;
  43         --remotes-only)
  44                 remotesonly=1
  45                 ;;
  46         --reverse)
  47                 reverse=1
  48                 ;;
  49         --orphans|--orphan)
  50                 orphans=1
  51                 ;;
  52         --no-orphans|--no-orphan)
  53                 orphans=
  54                 ;;
  55         -?*)
  56                 echo "Unknown option: $1" >&2
  57                 usage 1
  58                 ;;
  59 esac; shift; done
  60
  61 [ "$dryrun$force" = "1" ] || usage 1
  62 [ "$noremotes$remotesonly" != "11" ] || usage 1
  63 [ $# -eq 0 ] || usage 1
  64
  65 remotes=
  66 [ -n "$noremotes" ] || remotes="$(git remote)" || :
  67
  68 if [ -z "$reverse" ]; then
  69         oldbases="top-bases"
  70         oldbasesrx="top-bases"
  71         newbases="heads/{top-bases}"
  72         newbasesrx="heads/[{]top-bases[}]"
  73 else
  74         oldbases="heads/{top-bases}"
  75         oldbasesrx="heads/[{]top-bases[}]"
  76         newbases="top-bases"
  77         newbasesrx="top-bases"
  78 fi
  79
  80 refpats=
  81 [ -n "$remotesonly" ] || refpats="refs/$oldbases"
  82 [ -z "$remotes" ] || refpats="$refpats$(printf " refs/remotes/%s/${oldbases#heads/}" $remotes)"
  83 [ -n "$refpats" ] || exit 0
  84
  85 topbraces="{top-bases}"
  86 not_orphan_base() {
  87         _check=
  88         case "$1" in
  89                 "refs/top-bases"/[!/]*)
  90                         _check="refs/heads/${1#refs/top-bases/}"
  91                         ;;
  92                 "refs/heads/{top-bases}"/[!/]*)
  93                         _check="refs/heads/${1#refs/heads/$topbraces/}"
  94                         ;;
  95                 "refs/remotes"/[!/]*)
  96                         _rb="${1#refs/remotes/}"
  97                         _rn="${_rb%%/*}"
  98                         _rr="${_rb#*/}"
  99                         case "$_rr" in
 100                                 "top-bases"/[!/]*)
 101                                         _check="refs/remotes/$_rn/${_rr#top-bases/}"
 102                                         ;;
 103                                 "{top-bases}"/[!/]*)
 104                                         _check="refs/remotes/$_rn/${_rr#$topbraces/}"
 105                                         ;;
 106                         esac
 107                         ;;
 108         esac
 109         [ -n "$_check" ] || return 1
 110         git rev-parse --verify --quiet "$_check" -- >/dev/null
 111 }
 112
 113 v_transform_base() {
 114         _newb=
 115         case "$2" in
 116                 "refs/top-bases"/[!/]*)
 117                         _newb="refs/heads/{top-bases}/${2#refs/top-bases/}"
 118                         ;;
 119                 "refs/heads/{top-bases}"/[!/]*)
 120                         _newb="refs/top-bases/${2#refs/heads/$topbraces/}"
 121                         ;;
 122                 "refs/remotes"/[!/]*)
 123                         _rb="${2#refs/remotes/}"
 124                         _rn="${_rb%%/*}"
 125                         _rr="${_rb#*/}"
 126                         case "$_rr" in
 127                                 "top-bases"/[!/]*)
 128                                         _newb="refs/remotes/$_rn/{top-bases}/${_rr#top-bases/}"
 129                                         ;;
 130                                 "{top-bases}"/[!/]*)
 131                                         _newb="refs/remotes/$_rn/top-bases/${_rr#$topbraces/}"
 132                                         ;;
 133                         esac
 134                         ;;
 135         esac
 136         if [ -n "$_newb" ] && [ -n "$1" ]; then
 137                 eval "$1="'"$_newb"'
 138                 return 0
 139         fi
 140         [ -z "$1" ] || eval "$1="
 141         return 1
 142 }
 143
 144 for r in $remotes; do
 145         nv="+refs/$newbases/*:refs/remotes/$r/${newbases#heads/}/*"
 146         if rf="$(git config --get-all "remote.$r.fetch" \
 147                 "\\+?refs/(top-bases|heads/[{]top-bases[}])/\\*:refs/remotes/$r/(top-bases|[{]top-bases[}])/\\*")" &&
 148                 [ "$rf" != "$nv" ]; then
 149                 echo "remote.$r.fetch:"
 150                 printf '    %s\n' $rf
 151                 printf ' -> %s\n' "$nv"
 152                 if [ -n "$force" ]; then
 153                         git config --replace-all "remote.$r.fetch" "$nv" \
 154                                 "\\+?refs/(top-bases|heads/[{]top-bases[}])/\\*:refs/remotes/$r/(top-bases|[{]top-bases[}])/\\*"
 155                 fi
 156         elif [ "$rf" != "$nv" ] && rf="$(git config --get-all "remote.$r.fetch" "\\+?refs/(top-bases|heads/[{]top-bases[}])/.*")"; then
 157                 echo "remote.$r.fetch may need manual updates of:"
 158                 printf '    %s\n' $rf
 159         fi
 160 done
 161
 162 git for-each-ref --format='%(refname) %(objecttype) %(objectname)' $refpats |
 163 while read -r rn rt rh; do
 164         if [ -z "$orphans" ] && ! not_orphan_base "$rn"; then
 165                 echo "skipping orphan base (use --orphans): $rn" >&2
 166                 continue
 167         fi
 168         if [ "$rt" = "tree" ] || [ "$rt" = "blob" ]; then
 169                 echo "ignoring base with type $rt: $rn" >&2
 170                 continue
 171         fi
 172         if [ "$rt" = "tag" ]; then
 173                 rnc="$(git rev-parse --verify --quiet "$rh^0" -- 2>/dev/null)" || :
 174                 if [ -z "$rnc" ]; then
 175                         echo "ignoring base with type tag of non-commit: $rn" >&2
 176                         continue
 177                 fi
 178                 echo "warning: resolving base with type tag to commit: $rn" >&2
 179                 rh="$rnc"
 180         fi
 181         v_transform_base newb "$rn" || die "unexpected non-bases ref: $rn"
 182         newbrev="$(git rev-parse --verify --quiet "$newb" --)" || :
 183         newbtype=
 184         [ -z "$newbrev" ] || newbtype="$(git cat-file -t "$newbrev")"
 185         if [ "$newbtype" = "tree" ] || [ "$newbtype" = "blob" ]; then
 186                 echo "warning: $rn" >&2
 187                 echo "    refusing to update existing ref:" >&2
 188                 echo "    $newb" >&2
 189                 echo "    of type $newbtype" >&2
 190                 continue
 191         fi
 192         if [ "$newbtype" = "tag" ]; then
 193                 newbrev="$(git rev-parse --verify --quiet "$newbrev^0" -- 2>/dev/null)" || :
 194                 if [ -z "$newbrev" ]; then
 195                         echo "warning: $rn" >&2
 196                         echo "    refusing to update existing ref:" >&2
 197                         echo "    $newb" >&2
 198                         echo "    of type tag of non-commit" >&2
 199                         continue
 200                 fi
 201                 echo "warning: $rn" >&2
 202                 echo "    treating existing ref:" >&2
 203                 echo "    $newb" >&2
 204                 echo "    of type tag as the tagged commit" >&2
 205         fi
 206         if [ -n "$newbrev" ] && [ "$newbrev" != "rh" ]; then
 207                 mb="$(git merge-base "$newbrev" "$rh" 2>/dev/null)" || :
 208                 if [ "$mb" = "$newbrev" ]; then
 209                         echo "warning: $rn" >&2
 210                         echo "    ignoring existing ref:" >&2
 211                         echo "    $newb" >&2
 212                         echo "    since it's contained in $rn" >&2
 213                 elif [ "$mb" = "$rh" ]; then
 214                         echo "warning: $rn" >&2
 215                         echo "    using existing value of ref:" >&2
 216                         echo "    $newb" >&2
 217                         echo "    since it contains $rn" >&2
 218                         rh="$newbrev"
 219                 else
 220                         rd="$(git --no-pager log -n 1 --format='format:%ct' "$rh" --)"
 221                         newbdt="$(git --no-pager log -n 1 --format='format:%ct' "$newbrev" --)"
 222                         if [ "$rd" -ge "$newbdt" ]; then
 223                                 echo "warning: $rn" >&2
 224                                 echo "    ignoring existing diverged ref:" >&2
 225                                 echo "    $newb" >&2
 226                                 echo "    since it's got an older committer timestamp" >&2
 227                         else
 228                                 echo "warning: $rn" >&2
 229                                 echo "    using existing value of diverged ref:" >&2
 230                                 echo "    $newb" >&2
 231                                 echo "    since it's got a newer committer timestamp" >&2
 232                                 rh="$newbrev"
 233                         fi
 234                 fi
 235         fi
 236         printf 'update: %s\n -> %s\n' "$rn" "$newb"
 237         if [ -n "$force" ]; then
 238                 git update-ref "$newb" "$rh"
 239                 if [ "$(git rev-parse --quiet --verify "$newb" --)" = "$rh" ] && [ "$newb" != "$rn" ]; then
 240                         git update-ref -d "$rn"
 241                 fi
 242         fi
 243 done
 244 [ $? -eq 0 ] || exit 1