btr-backup-clean

#!/usr/bin/ruby
#
# btr-backup-clean: cleanup old backup directory for btr-backup
#
# Usage:
#   btr-backup-clean <backup directories...>
#
# This script was forked from hlbackup-clean;
# http://hlbackup.sourceforge.jp/
#
# Copyright(C) 2003 Taku YASUI <tach@debian.or.jp>,
# Copyright(C) 2010 Tatsuki Sugiura <sugi@nemui.org>, All rights reserved.
# This is free software with ABSOLUTELY NO WARRANTY.
#
# You can redistribute it and/or modify it under the terms of 
# the GNU General Public License version 2.
#
# 2010-09-20:
# Modified for btr-backup by Tatsuki Sugiura <sugi@nemui.org>
#

require 'getoptlong'
require 'date'

NAME = 'btr-backup-clean'
VERS = '0.0.1'
DEFAULT = { 'year' => 2,
	    'month' => 6,
	    'week' => 6,
	    'day' => 7 }

def parse_options
  options = Hash.new
  parser = GetoptLong.new
  parser.set_options(['--help',          '-h', GetoptLong::NO_ARGUMENT],
		     ['--no-act',	 '-n', GetoptLong::NO_ARGUMENT],
		     ['--verbose',	 '-v', GetoptLong::NO_ARGUMENT],
		     ['--version',	 '-V', GetoptLong::NO_ARGUMENT],
		     ['--keep',		 '-k', GetoptLong::REQUIRED_ARGUMENT])
  parser.each_option {|name, arg|
    options[name.sub(/^--/, "")] = arg
  }
  show_version if options['version']
  show_usage if options['help'] or ARGV[0].nil?
  return options
end

def parse_keep(keep)
  ch_tables = { 'year' => /(\d+)Y/,
  		'month' => /(\d+)M/,
		'week' => /(\d+)W/,
		'day' => /(\d+)D/ }
  ret = {}
  ch_tables.each do |key, regex|
    ret[key] = DEFAULT[key]
    ret[key] = $1.to_i if ( regex.match(keep) )
    ret[key] -= 1
  end
  return ret
end

def create_keepdirs(keep)
  nowdate = Date.new(Time.now.year, Time.now.month, Time.now.day)
  ret = {}
  # year
  keep['year'].downto(0) do |i|
    (ret["#{Time.now.year-i}-01-01"] ||= []) << :Yearly
  end
  # month  
  keep['month'].downto(0) do |i|
    date = nowdate << i
    (ret["#{date.year}-#{sprintf("%02d", date.month)}-01"] ||= []) << :Monthly
  end
  # week
  keep['week'].downto(0) do |i|
  date = nowdate - nowdate.cwday - 7 * i
    (ret["#{date.year}-#{sprintf("%02d", date.month)}-#{sprintf("%02d", date.day)}"] ||= []) << :Weekly
  end
  # day
  keep['day'].downto(0) do |i|
    date = nowdate - i
    (ret[("#{date.year}-#{sprintf("%02d", date.month)}-#{sprintf("%02d", date.day)}")] ||= []) << :Daily
  end
  ret
end 

def show_usage
  print <<_EOT
Usage: #{NAME} [OPTIONS] directories...
OPTIONS:
  --help,              -h: show this help
  --keep KEEPARGS,     -k: use KEEPARGS to decide delete directories
  --no-act,            -n: run command but don't do it
  --verbose,           -v: verbose output
  --version,           -V: show software version

KEEPARGS: [digitY][digitM][digitW][digitD]
  e.g. --keep 2Y6M6W7D (2years, 6months, 6weeks, 7days, default)
_EOT
  exit
end

def show_version
  print <<_EOT
#{NAME} version #{VERS}
Copyright (C) 2003 Taku YASUI <tach@debian.or.jp>
Copyright (C) 2010 Tatsuki Sugiura <sugi@nemui.org>

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or (at
your option) any later version.
_EOT
  exit
end

def main

  opts = parse_options
  keepdirs = create_keepdirs(parse_keep(opts['keep']))

  # lower priority
  Process.setpriority(Process::PRIO_PROCESS, $$, 19)
  begin
    system('ionice', '-c3', "-p#{$$}")
  rescue
    # ignore
  end

  ARGV.each do |basedir|
    keeped = []
    Dir.glob("#{basedir}/[0-9][0-9][0-9][0-9]-[01][0-9]-[0-3][0-9]T[0-2][0-9]:[0-5][0-9]:[0-5][0-9]").sort.each do |dir|
      next if ( ! File.directory?(dir) )
      if File.stat(dir).ino != 256
	$stderr.puts "Skip: '#{dir}' seems not snapshot."
	next
      end
      daykey = dir[(basedir.length+1)..(basedir.length+10)]
      if keepdirs.has_key? daykey
        keeped.push [dir, keepdirs[daykey]]
        next
      end
      puts "Deleting #{dir}" if opts['verbose'] && opts['no-act']
      args = ['btrfs', 'subvolume', 'delete', "'"+dir.gsub(/'/, %q{\'})+"'"]
      args << "> /dev/null" unless opts['verbose']
      begin
	system(args.join(' ')) unless opts['no-act']
      rescue => e
	$stderr.puts "btrfs command execution failed: #{e.inspect}"
	next
      end
      if !opts['no-act'] && ($? >> 8) != 0
	$stderr.puts "btrfs has been exited with error=#{$?>>8} on #{dir}"
      end
    end
    if opts['verbose']
      puts "Keep dirs on #{basedir}:"
      keeped.each do |dir|
        puts "#{dir[0]} (#{dir[1].join(', ').to_s})"
      end
    end
  end

end

main if __FILE__ == $0