git.scottworley.com Git - annex-ec/blob - annex-ec-recover

   1 #!/usr/bin/env bash
   2
   3 # annex-ec: Use erasure codes for more efficient storage use in git-annex
   4 # Copyright (C) 2026  Scott Worley
   5
   6 # This program is free software: you can redistribute it and/or modify
   7 # it under the terms of the GNU Affero General Public License as
   8 # published by the Free Software Foundation, either version 3 of the
   9 # License, or (at your option) any later version.
  10
  11 set -euo pipefail
  12
  13 die() {
  14   echo "$*" >&2
  15   exit 1
  16 }
  17
  18 find_recovery_set_files() {
  19   local found
  20   found=false
  21   recovery_set_files=()
  22   while IFS= read -r line;do
  23     if [[ "$line" == ' '* ]];then
  24       recovery_set_files+=( "${line# }" )
  25       if [[ "${line# }" == "$1" ]];then
  26         found=true
  27       fi
  28     else
  29       if $found;then
  30         break
  31       fi
  32       recovery_set_name=$line
  33       recovery_set_files=()
  34     fi
  35   done < ec/.meta
  36   if ! $found;then
  37     die "Could not find a recovery set containing file $1"
  38   fi
  39 }
  40
  41 while [[ "$1" == -- ]];do shift; done
  42
  43 for target;do
  44   if [[ -e "$target" ]];then continue; fi
  45   set +e
  46   git annex get "$target"
  47   set -e
  48   if [[ -e "$target" ]];then continue; fi
  49
  50   find_recovery_set_files "$target"
  51
  52   set +e
  53   git annex get "${recovery_set_files[@]}" ec/"$recovery_set_name"*
  54   set -e
  55
  56   # par2 doesn't like directory structure, so we work from a temp dir where we can flatten everything
  57   srcdir=$PWD
  58   flat="$(mktemp -d)"
  59   pushd "$flat"
  60
  61     for f in "${recovery_set_files[@]}";do
  62       ln -s "$srcdir"/"$f" .
  63     done
  64     ln -s "$srcdir"/ec/"$recovery_set_name"* .
  65
  66     # We have to remove the broken symlinks or par2 gets confused trying to write to them
  67     find -L . -type l -exec rm -v {} +
  68
  69     par2 r -- *.par2
  70
  71   popd
  72   for f in "${recovery_set_files[@]}";do
  73     git annex reinject "$flat"/"$(basename "$f")" "$f"
  74   done
  75 done