# File lib/innodb/log_block.rb, line 45
  def header
    @header ||= cursor(HEADER_OFFSET).name("header") do |c|
      {
        :flush => c.name("flush") {
          c.peek { (c.get_uint32 & HEADER_FLUSH_BIT_MASK) > 0 }
        },
        :block_number => c.name("block_number") {
          c.get_uint32 & ~HEADER_FLUSH_BIT_MASK
        },
        :data_length      => c.name("data_length")     { c.get_uint16 },
        :first_rec_group  => c.name("first_rec_group") { c.get_uint16 },
        :checkpoint_no    => c.name("checkpoint_no")   { c.get_uint32 },
      }
    end
  end