crc32.rb

CRC校验采用多项式编码方法。多项式乘除法运算过程与普通代数多项式的乘除法相同。多项式的加减法运算以2为模

if defined?(NO_CRC32_IN_C) || defined?(NO_C)
  require 'digest/crc32_in_ruby'
  module Digest
    class CRC32 < CRC32InRuby
    end
  end
else
  begin
    require 'digest/crc32_in_c'
    module Digest
      class CRC32 < CRC32InC
      end
    end
  rescue
    require 'digest/crc32_in_ruby'
    module Digest
      class CRC32 < CRC32InRuby
      end
    end
  end
end