tg-export.sh

   1 #!/bin/sh
   2 # TopGit - A different patch queue manager
   3 # (c) Petr Baudis <pasky@suse.cz>  2008
   4 # GPLv2
   5
   6 name=
   7 branches=
   8 output=
   9 driver=collapse
  10
  11
  12 ## Parse options
  13
  14 while [ -n "$1" ]; do
  15         arg="$1"; shift
  16         case "$arg" in
  17         -b)
  18                 branches="$1"; shift;;
  19         --quilt)
  20                 driver=quilt;;
  21         --collapse)
  22                 driver=collapse;;
  23         -*)
  24                 echo "Usage: tg [...] export [-b BRANCH1,BRANCH2...] ([--collapse] NEWBRANCH | --quilt DIRECTORY)" >&2
  25                 exit 1;;
  26         *)
  27                 [ -z "$output" ] || die "output already specified ($output)"
  28                 output="$arg";;
  29         esac
  30 done
  31
  32
  33 name="$(git symbolic-ref HEAD | sed 's#^refs/heads/##')"
  34 base_rev="$(git rev-parse --short --verify "refs/top-bases/$name" 2>/dev/null)" ||
  35         die "not on a TopGit-controlled branch"
  36
  37 [ -z "$branches" -o "$driver" = "quilt" ] ||
  38         die "-b works only with the quilt driver"
  39
  40
  41 playground="$(mktemp -d -t tg-export.XXXXXX)"
  42 trap 'rm -rf "$playground"' EXIT
  43
  44
  45 ## Collapse driver
  46
  47 # pretty_tree NAME
  48 # Output tree ID of a cleaned-up tree without tg's artifacts.
  49 pretty_tree()
  50 {
  51         (export GIT_INDEX_FILE="$playground/^index"
  52          git read-tree "$1"
  53          git update-index --force-remove ".topmsg" ".topdeps"
  54          git write-tree)
  55 }
  56
  57 # collapsed_commit NAME
  58 # Produce a collapsed commit of branch NAME.
  59 collapsed_commit()
  60 {
  61         name="$1"
  62
  63         rm -f "$playground/^pre" "$playground/^post"
  64         >"$playground/^body"
  65
  66         # Get commit message and authorship information
  67         git cat-file blob "$name:.topmsg" | git mailinfo "$playground/^msg" /dev/null > "$playground/^info"
  68
  69         GIT_AUTHOR_NAME="$(sed -n '/^Author/ s/Author: //p' "$playground/^info")"
  70         GIT_AUTHOR_EMAIL="$(sed -n '/^Email/ s/Email: //p' "$playground/^info")"
  71         GIT_AUTHOR_DATE="$(sed -n '/^Date/ s/Date: //p' "$playground/^info")"
  72         SUBJECT="$(sed -n '/^Subject/ s/Subject: //p' "$playground/^info")"
  73
  74         test -n "$GIT_AUTHOR_NAME" && export GIT_AUTHOR_NAME
  75         test -n "$GIT_AUTHOR_EMAIL" && export GIT_AUTHOR_EMAIL
  76         test -n "$GIT_AUTHOR_DATE" && export GIT_AUTHOR_DATE
  77
  78         # Determine parent
  79         parent="$(cut -f 1 "$playground/$name^parents")"
  80         if [ "$(cat "$playground/$name^parents" | wc -l)" -gt 1 ]; then
  81                 # Produce a merge commit first
  82                 parent="$({
  83                         echo "TopGit-driven merge of branches:"
  84                         echo
  85                         cut -f 2 "$playground/$name^parents"
  86                 } | git commit-tree "$(pretty_tree "refs/top-bases/$name")" \
  87                         $(for p in $parent; do echo -p $p; done))"
  88         fi
  89
  90         (printf '%s\n\n' "$SUBJECT"; cat "$playground/^msg") |
  91         git stripspace |
  92         git commit-tree "$(pretty_tree "$name")" -p "$parent"
  93
  94         echo "$name" >>"$playground/^ticker"
  95 }
  96
  97 # collapse
  98 # This will collapse a single branch, using information about
  99 # previously collapsed branches stored in $playground.
 100 collapse()
 101 {
 102         if [ -s "$playground/$_dep" ]; then
 103                 # We've already seen this dep
 104                 commit="$(cat "$playground/$_dep")"
 105
 106         elif [ -z "$_dep_is_tgish" ]; then
 107                 # This dep is not for rewrite
 108                 commit="$(git rev-parse --verify "$_dep")"
 109
 110         else
 111                 # First time hitting this dep; the common case
 112                 echo "Collapsing $_dep"
 113                 commit="$(collapsed_commit "$_dep")"
 114                 mkdir -p "$playground/$(dirname "$_dep")"
 115                 echo "$commit" >"$playground/$_dep"
 116         fi
 117
 118         # Propagate our work through the dependency chain
 119         mkdir -p "$playground/$(dirname "$_name")"
 120         echo "$commit   $_dep" >>"$playground/$_name^parents"
 121 }
 122
 123
 124 ## Quilt driver
 125
 126 quilt()
 127 {
 128         if [ -z "$_dep_is_tgish" ]; then
 129                 # This dep is not for rewrite
 130                 return
 131         fi
 132
 133         filename="$output/$_dep.diff"
 134         if [ -e "$filename" ]; then
 135                 # We've already seen this dep
 136                 return
 137         fi
 138
 139         echo "Exporting $_dep"
 140         mkdir -p "$(dirname "$filename")"
 141         $tg patch "$_dep" >"$filename"
 142         echo "$_dep.diff -p1" >>"$output/series"
 143 }
 144
 145
 146 ## Machinery
 147
 148 if [ "$driver" = "collapse" ]; then
 149         [ -n "$output" ] ||
 150                 die "no target branch specified"
 151         ! ref_exists "$output"  ||
 152                 die "target branch '$output' already exists; first run: git branch -D $output"
 153
 154 elif [ "$driver" = "quilt" ]; then
 155         [ -n "$output" ] ||
 156                 die "no target directory specified"
 157         [ ! -e "$output" ] ||
 158                 die "target directory already exists: $output"
 159
 160         mkdir -p "$output"
 161 fi
 162
 163
 164 driver()
 165 {
 166         case $_dep in refs/remotes/*) return;; esac
 167         branch_needs_update >/dev/null
 168         [ "$_ret" -eq 0 ] ||
 169                 die "cancelling export of $_dep (-> $_name): branch not up-to-date"
 170
 171         $driver
 172 }
 173
 174 # Call driver on all the branches - this will happen
 175 # in topological order.
 176 if [ -z "$branches" ]; then
 177         recurse_deps driver "$name"
 178         (_ret=0; _dep="$name"; _name=""; _dep_is_tgish=1; driver)
 179 else
 180         echo "$branches" | tr ',' '\n' | while read _dep; do
 181                 _dep_is_tgish=1
 182                 $driver
 183         done
 184         name="$(echo "$branches" | sed 's/.*,//')"
 185 fi
 186
 187
 188 if [ "$driver" = "collapse" ]; then
 189         git update-ref "refs/heads/$output" "$(cat "$playground/$name")" ""
 190
 191         depcount="$(cat "$playground/^ticker" | wc -l)"
 192         echo "Exported topic branch $name (total $depcount topics) to branch $output"
 193
 194 elif [ "$driver" = "quilt" ]; then
 195         depcount="$(cat "$output/series" | wc -l)"
 196         echo "Exported topic branch $name (total $depcount topics) to directory $output"
 197 fi