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