class WEBrick::HTTPAuth::Htgroup

def add(group, members)
  @group[group] = members(group) | members
end

def flush(output=nil)
  output ||= @path
  tmp = Tempfile.create("htgroup", File::dirname(output))
  begin
    @group.keys.sort.each{|group|
      tmp.puts(format("%s: %s", group, self.members(group).join(" ")))
    }
  ensure
    tmp.close
    if $!
      File.unlink(tmp.path)
    else
      return File.rename(tmp.path, output)
    end
  end
end

def initialize(path)
  @path = path
  @mtime = Time.at(0)
  @group = Hash.new
  File.open(@path,"a").close unless File.exist?(@path)
  reload
end

def members(group)
  reload
  @group[group] || []
end

def reload
  if (mtime = File::mtime(@path)) > @mtime
    @group.clear
    File.open(@path){|io|
      while line = io.gets
        line.chomp!
        group, members = line.split(/:\s*/, 2)
        @group[group] = members.split(/\s+/)
      end
    }
    @mtime = mtime
  end
end