ga-rdiff

   1 #!/bin/sh
   2
   3 #==============================================================================
   4 # ga-rdiff
   5 # File ID: 6317a006-78d9-11ea-8dd3-4f45262dc9b5
   6 #
   7 # Author: Øyvind A. Holm <sunny@sunbase.org>
   8 # License: GNU General Public License version 2 or later.
   9 #==============================================================================
  10
  11 progname=ga-rdiff
  12 VERSION=0.3.1
  13
  14 std_block_size=2048
  15
  16 opt_block_size=$std_block_size
  17 opt_help=0
  18 opt_old_file=''
  19 opt_quiet=0
  20 opt_verbose=0
  21 opt_whole=0
  22 while test -n "$1"; do
  23         case "$1" in
  24         -b|--block-size) opt_block_size="$2"; shift 2 ;;
  25         -h|--help) opt_help=1; shift ;;
  26         -o|--old-file) opt_old_file="$2"; shift 2 ;;
  27         -q|--quiet) opt_quiet=$(($opt_quiet + 1)); shift ;;
  28         -v|--verbose) opt_verbose=$(($opt_verbose + 1)); shift ;;
  29         -w|--whole) opt_whole=1; shift ;;
  30         --version) echo $progname $VERSION; exit 0 ;;
  31         --) shift; break ;;
  32         *)
  33                 if printf '%s\n' "$1" | grep -q ^-; then
  34                         echo "$progname: $1: Unknown option" >&2
  35                         exit 1
  36                 else
  37                         break
  38                 fi
  39         break ;;
  40         esac
  41 done
  42 opt_verbose=$(($opt_verbose - $opt_quiet))
  43
  44 if test "$opt_help" = "1"; then
  45         test $opt_verbose -gt 0 && { echo; echo $progname $VERSION; }
  46         cat <<END
  47
  48 Create a rdiff(1) file with differences between the previous and
  49 current version of a file stored in git-annex.
  50
  51 Usage: $progname [options] ANNEX_FILE RDIFF_FILE
  52
  53 Options:
  54
  55   -b SIZE, --block-size SIZE
  56     Use SIZE as block size with "rdiff signature". Smaller size may
  57     create a smaller rdiff file, but takes longer time.
  58     Default value: $std_block_size
  59   -h, --help
  60     Show this help.
  61   -o FILE, --old-file FILE
  62     Use FILE instead of previous version as base for the patch.
  63   -q, --quiet
  64     Be more quiet. Can be repeated to increase silence.
  65   -v, --verbose
  66     Increase level of verbosity. Can be repeated.
  67   -w, --whole
  68     Create rdiff patch for the whole file against /dev/null if no
  69     previous version of the file was found.
  70   --version
  71     Print version information.
  72
  73 For example, to create rdiff files for all files in the current
  74 directory tree:
  75
  76   \$ git annex find | while read f; do ga-rdiff "\$f" "\$f.rdiff"; done
  77
  78 Does not work with files renamed or moved in the newest revision.
  79
  80 END
  81         exit 0
  82 fi
  83
  84 create_rdiff() {
  85         local src="$1" dest="$2"
  86
  87         repotop="$(git rev-parse --show-toplevel)"
  88         if [ -z "$repotop" ]; then
  89                 echo "$progname: Could not find top of Git repo" >&2
  90                 return 1
  91         fi
  92
  93         local currfile="$(realpath -e "$src")"
  94         if [ -z "$currfile" ]; then
  95                 echo -n "$progname: $src: " >&2
  96                 echo "Could not find annex data for current revision" >&2
  97                 return 1
  98         fi
  99
 100         local prevfile="$opt_old_file"
 101         if [ -z "$opt_old_file" ]; then
 102                 prevfile="$(git log -1 -p --color=never "$src" \
 103                 | grep ^- \
 104                 | grep -F .git/annex/objects/ \
 105                 | sed 's/^.*\.git/.git/')"
 106                 prevfile="$(cd "$repotop" && test -e "$prevfile" \
 107                            && realpath -e "$prevfile")"
 108                 if [ -z "$prevfile" ]; then
 109                         if [ "$opt_whole" = "1" ]; then
 110                                 prevfile=/dev/null
 111                         else
 112                                 echo -n "$progname: $src: Could not find " >&2
 113                                 echo "annex data for previous revision" >&2
 114                                 return 1
 115                         fi
 116                 fi
 117         fi
 118
 119         rdiff -b $opt_block_size signature "$prevfile" \
 120         | rdiff delta - "$currfile" "$dest"
 121 }
 122
 123 if [ -z "$2" ]; then
 124         echo "$progname: Need src and dest command line arguments" >&2
 125         exit 1
 126 fi
 127
 128 create_rdiff "$1" "$2"
 129
 130 # vim: set ts=8 sw=8 sts=8 noet fo+=w tw=79 fenc=UTF-8 :