Class: Bup::Tar

Inherits:
Object
  • Object
show all
Defined in:
lib/bup/tar.rb

Instance Method Summary collapse

Constructor Details

#initialize(config) ⇒ Tar

Returns a new instance of Tar.



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# File 'lib/bup/tar.rb', line 9

def initialize(config)
  @config = config
end

Instance Method Details

#build_exclude_file(patterns) ⇒ Object 



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# File 'lib/bup/tar.rb', line 23

def build_exclude_file(patterns)
  tf = Tempfile.new("bup")
  patterns.each do |p|
    p = expand_string(p)
    tf.write(p)
    tf.write("\n")
  end
  tf.close
  tf
end

#call(profile_name = nil) ⇒ Object

Run tar.



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# File 'lib/bup/tar.rb', line 90

def call(profile_name = nil)
  profile_name ||= @config.runtime["profile"]
  profile = @config.config["profiles"][profile_name]

  raise "Missing profile #{profile_name}." unless profile

  args = profile["tarcmd"].dup || ["tar", "cJvf", "${BUP_FILENAME}.tar.xz"]

  prepare_destination(profile_name, profile)

  if @config.runtime["type"] == "incremental"
    lastrun = @config.lastrun(profile_name)
    args += ["--newer", lastrun.strftime("%Y-%m-%d %H:%M:%S %z")] if lastrun
  end

  run_pre_cmds profile

  @config.update_lastrun(profile_name)

  tf = build_exclude_file(profile["exclude"] || [])

  # Build and run tar command.
  begin
    args += ["--exclude-from", tf.path]
    args += (profile["include"] || ["."])
    args = args.map do |str|
      expand_string(str)
    end

    # Run tar.
    run_cmd(*args)
  ensure
    tf.unlink
  end

  run_post_cmds profile
end

#clear_history(profile_name, destination) ⇒ Object 



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# File 'lib/bup/tar.rb', line 61

def clear_history(profile_name, destination)
  Dir["#{destination}/#{profile_name}*"].each do |backup|
    File.delete(backup)
  end
end

#expand_string(str) ⇒ Object 



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# File 'lib/bup/tar.rb', line 13

def expand_string(str)
  while str =~ /\${?([a-zA-Z0-9_]+)}?/
    all = $~[0]
    nm = $~[1]
    str = str.sub(all, ENV[nm] || "")
  end

  str
end

#prepare_destination(profile_name, profile) ⇒ Object

Prepare the destination directory.



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# File 'lib/bup/tar.rb', line 35

def prepare_destination(profile_name, profile)
  destination = expand_string(profile["destination"] || ".")

  type = @config.runtime["type"] || "full"

  FileUtils.mkdir_p(destination) unless File.exist?(destination)

  filename_base = "#{profile_name}-#{type}"
  filename = File.join(destination,
                       "#{filename_base}-#{DateTime.now.new_offset(0).strftime("%Y%m%d%H%M%S")}")

  history = @config.profile(profile_name)["history"] || 0

  if type == "full" 
    if history.positive?
      prune_history(profile_name, destination, filename_base, history)
    elsif history == 0
      clear_history(profile_name, destination)
    end
  end

  ENV["BUP_DESTINATION"] = destination
  ENV["BUP_FILENAME"] = filename
  filename
end

#prune_history(profile_name, destination, filename_base, history) ⇒ Object 



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# File 'lib/bup/tar.rb', line 67

def prune_history(profile_name, destination, filename_base, history)
  oldest_kept_file = nil

  # Keep some full backups and remove the others.
  # We capture the oldest full backup and get rid of preceeding incrementals.
  Dir["#{destination}/#{filename_base}*"].sort.reverse.each_with_index do |fullbackup, idx|
    if idx < history
      oldest_kept_file = fullbackup
    else
      File.delete(fullbackup)
    end
  end

  # Remove all incremental files that are older than the oldest kept full backup.
  if oldest_kept_file
    remove_before = File.stat(oldest_kept_file).ctime
    Dir["#{destination}/#{profile_name}*"].each do |backupfile|
      File.delete(backupfile) if File.stat(backupfile).ctime < remove_before
    end
  end
end

#run_cmd(*args) ⇒ Object

Exec and run a command in a standard way.



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# File 'lib/bup/tar.rb', line 142

def run_cmd(*args)
  Open3.popen3(*args) do |stdin, stdout, stderr, wait_thr|
    stdin.close
    x = nil
    while wait_thr.status
      r, _w, _e = IO.select([stdout, stderr])
      r.each do |stream|
        print x if (x = stream.read_nonblock(1024, exception: false))
      end
    end

    wait_thr.join
    print x if (x = stdout.read_nonblock(1024, exception: false))

    print x if (x = stderr.read_nonblock(1024, exception: false))

    $stdout.flush
  end
end

#run_post_cmds(profile) ⇒ Object 



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# File 'lib/bup/tar.rb', line 135

def run_post_cmds(profile)
  (profile["post_cmds"] || []).each do |args|
    run_cmd(*args.map { |c| expand_string(c) })
  end
end

#run_pre_cmds(profile) ⇒ Object 



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# File 'lib/bup/tar.rb', line 128

def run_pre_cmds(profile)
  # Before we update the last_run, execute any pre_cmds.
  (profile["pre_cmds"] || []).each do |args|
    run_cmd(*args.map { |c| expand_string(c) })
  end
end