git-deltafy-script

   1 #!/bin/bash
   2
   3 # Script to deltafy an entire GIT repository based on the commit list.
   4 # The most recent version of a file is the reference and previous versions
   5 # are made delta against the best earlier version available. And so on for
   6 # successive versions going back in time.  This way the delta overhead is
   7 # pushed towards older version of any given file.
   8 #
   9 # NOTE: the "best earlier version" is not implemented in mkdelta yet
  10 #       and therefore only the next eariler version is used at this time.
  11 #
  12 # TODO: deltafy tree objects as well.
  13 #
  14 # The -d argument allows to provide a limit on the delta chain depth.
  15 # If 0 is passed then everything is undeltafied.
  16
  17 set -e
  18
  19 depth=
  20 [ "$1" == "-d" ] && depth="--max-depth=$2" && shift 2
  21
  22 curr_file=""
  23
  24 git-rev-list HEAD |
  25 git-diff-tree -r --stdin |
  26 awk '/^:/ { if ($5 == "M" || $5 == "N") print $4, $6 }' |
  27 LC_ALL=C sort -s -k 2 | uniq |
  28 while read sha1 file; do
  29         if [ "$file" == "$curr_file" ]; then
  30                 list="$list $sha1"
  31         else
  32                 if [ "$list" ]; then
  33                         echo "Processing $curr_file"
  34                         echo "$head $list" | xargs git-mkdelta $depth -v
  35                 fi
  36                 curr_file="$file"
  37                 list=""
  38                 head="$sha1"
  39         fi
  40 done