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