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