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| | # Copyright (C) 2013-2016 all contributors <dtas-all@nongnu.org>
# License: GPL-3.0+ (https://www.gnu.org/licenses/gpl-3.0.txt)
# frozen_string_literal: true
require 'yaml'
require 'tempfile'
# state file preserves state across restarts of dtas-player
class DTAS::StateFile # :nodoc:
attr_reader :path
def initialize(path, do_fsync = false)
@path = path
@do_fsync = do_fsync
end
def tryload
YAML.load(IO.binread(@path)) if File.readable?(@path)
end
def dump(obj, force_fsync = false)
yaml = obj.to_hsh.to_yaml.b
# do not replace existing state file if there are no changes
# this will be racy if we ever do async dumps or shared state
# files, but we don't do that...
return if File.readable?(@path) && IO.binread(@path) == yaml
dir = File.dirname(@path)
Tempfile.open(%w(player.state .tmp), dir) do |tmp|
tmp.binmode
tmp.write(yaml)
tmp.flush
tmp.fsync if @do_fsync || force_fsync
File.rename(tmp.path, @path)
end
end
end
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