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