Class: CRC

Inherits:
Object
  • Object
show all
Extended by:
Utils
Defined in:
lib/crc/_byruby.rb,
lib/crc/acrc.rb,
lib/crc/finder.rb,
lib/crc/codegen.rb,
lib/crc/version.rb,
lib/crc/_combine.rb,
lib/crc/_modules.rb,
lib/crc.rb

Overview

This is a general CRC generator.

When you want to use CRC-32 module, there are following ways:

  1. Generate CRC-32’d value at direct:

    CRC.crc32("123456789") # => 3421780262

  2. Generate CRC-32’d hex-digest at direct:

    CRC::CRC32.hexdigest("123456789") # => "CBF43926"

  3. Streaming process:

    crc32 = CRC::CRC32.new  # => #<CRC::CRC32:00000000>
IO.foreach("/boot/kernel/kernel", nil, 262144, mode: "rb") do |s|
  crc32 << s
end
p crc32           # => #<CRC::CRC32:6A632AA5>
p crc32.crc       # => 1784883877
p crc32.digest    # => "jc*\xA5"
p crc32.hexdigest # => "6A632AA5"

Defined Under Namespace

Modules: Aux, ModuleClass, Utils

Constant Summary collapse

ALGORITHM_BITBYBIT = 
-2
ALGORITHM_BITBYBIT_FAST = 
-1
ALGORITHM_HALFBYTE_TABLE = 
0
ALGORITHM_STANDARD_TABLE = 
1
ALGORITHM_SLICING_BY_4 = 
4
ALGORITHM_SLICING_BY_8 = 
8
ALGORITHM_SLICING_BY_16 = 
16
VERSION = 
"0.3.1.1"
LIST = 
[
  #
  # bit size,  polynomial,              initial crc,
  #                reflect input,                xor output,
  #                      reflect output,                       crc("123456789"), names...
  #
  [ 1,               0x01,  true,  true,          0,     ~0,               0x01, "CRC-1"],
  [ 3,               0x03,  true,  true,         ~0,      0,               0x06, "CRC-3-ROHC", "CRC-3-RFC 3095"],
  [ 4,               0x03, false, false,          0,     ~0,               0x0b, "CRC-4-INTERLAKEN"],
  [ 4,               0x03,  true,  true,          0,      0,               0x07, "CRC-4-ITU"],
  [ 5,               0x09, false, false,       0x09,      0,               0x00, "CRC-5-EPC"],
  [ 5,               0x15,  true,  true,          0,      0,               0x07, "CRC-5-ITU"],
  [ 5,               0x05,  true,  true,          0,     ~0,               0x19, "CRC-5-USB"],
  [ 6,               0x27, false, false,         ~0,      0,               0x0D, "CRC-6-CDMA2000-A"],
  [ 6,               0x07, false, false,         ~0,      0,               0x3B, "CRC-6-CDMA2000-B"],
  [ 6,               0x19,  true,  true,          0,      0,               0x26, "CRC-6-DARC"],
  [ 6,               0x03,  true,  true,          0,      0,               0x06, "CRC-6-ITU"],
  [ 7,               0x09, false, false,          0,      0,               0x75, "CRC-7", "CRC-7-JESD84-A441"],
  #[ 7,               0x65, false, false,          0,      0,                nil, "CRC-7-MVB"],
  [ 7,               0x4F,  true,  true,         ~0,      0,               0x53, "CRC-7-ROHC", "CRC-7-RFC 3095"],
  [ 7,               0x45, false, false,          0,      0,               0x61, "CRC-7-UMTS"],
  #[ 8,               0xD5, false, false,          0,      0,                nil, "CRC-8"],
  [ 8,               0x07, false, false,          0,      0,               0xF4, "CRC-8-CCITT", "CRC-8-SMBus"],
  [ 8,               0x31,  true,  true,          0,      0,               0xA1, "CRC-8-MAXIM", "CRC-8-Dallas/Maxim", "DOW-CRC"],
  [ 8,               0x39,  true,  true,          0,      0,               0x15, "CRC-8-DARC"],
  [ 8,               0x1D, false, false,          0,     ~0,               0x4B, "CRC-8-SAE", "CRC-8-SAE-J1850"],
  [ 8,               0x9B,  true,  true,          0,      0,               0x25, "CRC-8-WCDMA"],
  [ 8,               0x9B, false, false,         ~0,      0,               0xDA, "CRC-8-CDMA2000"],
  [ 8,               0xD5, false, false,          0,      0,               0xBC, "CRC-8-DVB-S2"],
  [ 8,               0x1D,  true,  true,         ~0,      0,               0x97, "CRC-8-EBU", "CRC-8-AES"],
  [ 8,               0x1D, false, false,       0xFD,      0,               0x7E, "CRC-8-I-CODE"],
  [ 8,               0x07, false, false,       0x55,   0x55,               0xA1, "CRC-8-ITU"],
  [ 8,               0x9B, false, false,          0,      0,               0xEA, "CRC-8-LTE"],
  [ 8,               0x07,  true,  true,         ~0,      0,               0xD0, "CRC-8-ROHC", "CRC-8-RFC 3095"],
  [10,             0x0233, false, false,          0,      0,             0x0199, "CRC-10"],
  [10,             0x03D9, false, false,         ~0,      0,             0x0233, "CRC-10-CDMA2000"],
  [11,             0x0385, false, false,     0x001A,      0,             0x05A3, "CRC-11"],
  [11,             0x0307, false, false,          0,      0,             0x0061, "CRC-11-UMTS"],
  [12,             0x0F13, false, false,         ~0,      0,             0x0D4D, "CRC-12-CDMA2000"],
  [12,             0x080F, false, false,          0,      0,             0x0F5B, "CRC-12-DECT", "X-CRC-12"],
  [12,             0x080F, false,  true,          0,      0,             0x0DAF, "CRC-12-UMTS", "CRC-12-3GPP"],
  [13,             0x1CF5, false, false,          0,      0,             0x04FA, "CRC-13-BBC"],
  [14,             0x0805,  true,  true,          0,      0,             0x082D, "CRC-14-DARC"],
  [15,             0x4599, false, false,          0,      0,             0x059E, "CRC-15", "CRC-15-CAN"],
  [15,             0x6815, false, false,          1,      1,             0x2566, "CRC-15-MPT1327"],
  #[16,             0x2F15, false, false,          0,      0,                nil, "Chakravarty"],
  [16,             0x8005,  true,  true,          0,      0,             0xBB3D, "CRC-16", "ARC", "CRC-IBM", "CRC-16-ARC", "CRC-16-LHA"],
  #[16,             0xA02B, false, false,          0,      0,                nil, "CRC-16-ARINC"],
  [16,             0x1021, false, false,     0x1D0F,      0,             0xE5CC, "CRC-16-AUG-CCITT", "CRC-16-SPI-FUJITSU"],
  [16,             0xC867, false, false,         ~0,      0,             0x4C06, "CRC-16-CDMA2000"],
  [16,             0x0589, false, false,          1,      1,             0x007E, "CRC-16-DECT-R", "R-CRC-16"],
  [16,             0x0589, false, false,          0,      0,             0x007F, "CRC-16-DECT-X", "X-CRC-16"],
  [16,             0x8BB7, false, false,          0,      0,             0xD0DB, "CRC-16-T10-DIF"],
  [16,             0x3D65,  true,  true,         ~0,     ~0,             0xEA82, "CRC-16-DNP"],
  [16,             0x8005, false, false,          0,      0,             0xFEE8, "CRC-16-BUYPASS", "CRC-16-VERIFONE", "CRC-16-UMTS"],
  [16,             0x1021, false, false,         ~0,      0,             0x29B1, "CRC-16-CCITT-FALSE"],
  [16,             0x8005, false, false,     0x800D,      0,             0x9ECF, "CRC-16-DDS-110"],
  [16,             0x3D65, false, false,         ~0,     ~0,             0xC2B7, "CRC-16-EN-13757"],
  [16,             0x1021, false, false,          0,     ~0,             0xD64E, "CRC-16-GENIBUS", "CRC-16-EPC", "CRC-16-I-CODE", "CRC-16-DARC"],
  [16,             0x6F63, false, false,          0,      0,             0xBDF4, "CRC-16-LJ1200"],
  [16,             0x8005,  true,  true,         ~0,     ~0,             0x44C2, "CRC-16-MAXIM"],
  [16,             0x1021,  true,  true,         ~0,      0,             0x6F91, "CRC-16-MCRF4XX"],
  [16,             0x1021,  true,  true,     0xB2AA,      0,             0x63D0, "CRC-16-RIELLO"],
  [16,             0xA097, false, false,          0,      0,             0x0FB3, "CRC-16-TELEDISK"],
  [16,             0x1021,  true,  true,     0x89EC,      0,             0x26B1, "CRC-16-TMS37157"],
  [16,             0x8005,  true,  true,          0,     ~0,             0xB4C8, "CRC-16-USB"],
  [16,             0x1021,  true,  true,     0xC6C6,      0,             0xBF05, "CRC-16-A", "CRC-A", "CRC-16-ISO/IEC FCD 14443-3"],
  [16,             0x1021,  true,  true,          0,      0,             0x2189, "CRC-16-KERMIT", "KERMIT", "CRC-16-CCITT", "CRC-16-CCITT-TRUE", "CRC-CCITT"],
  [16,             0x8005,  true,  true,         ~0,      0,             0x4B37, "CRC-16-MODBUS", "MODBUS"],
  [16,             0x1021,  true,  true,          0,     ~0,             0x906E, "CRC-16-X-25", "X-25", "CRC-16-IBM-SDLC", "CRC-16-ISO-HDLC", "CRC-16-CRC-B", "CRC-B"],
  [16,             0x1021, false, false,          0,      0,             0x31C3, "CRC-16-XMODEM", "XMODEM", "CRC-16-ZMODEM", "ZMODEM", "CRC-16-ACORN", "CRC-16-LTE"],
  #[17,         0x0001685B, false, false,          0,      0,                nil, "CRC-17-CAN"],
  #[21,         0x00102899, false, false,          0,      0,                nil, "CRC-21-CAN"],
  #[24,         0x005D6DCB, false, false,          0,      0,                nil, "CRC-24"],
  [24,         0x00864CFB, false, false,          0,      0,         0x00CDE703, "CRC-24-Radix-64"],
  [24,         0x00864CFB, false, false, 0x00B704CE,      0,         0x0021CF02, "CRC-24-OPENPGP"],
  [24,         0x0000065B,  true,  true, 0x00555555,      0,         0x00C25A56, "CRC-24-BLE"],
  [24,         0x005D6DCB, false, false, 0x00FEDCBA,      0,         0x007979BD, "CRC-24-FLEXRAY-A"],
  [24,         0x005D6DCB, false, false, 0x00ABCDEF,      0,         0x001F23B8, "CRC-24-FLEXRAY-B"],
  [24,         0x00328B63, false, false,          0,     ~0,         0x00B4F3E6, "CRC-24-INTERLAKEN"],
  [24,         0x00864CFB, false, false,          0,      0,         0x00CDE703, "CRC-24-LTE-A"],
  [24,         0x00800063, false, false,          0,      0,         0x0023EF52, "CRC-24-LTE-B"],
  #[30,         0x2030B9C7, false, false,          0,      0,                nil, "CRC-30"],
  [30,         0x2030B9C7, false, false,          0,     ~0,         0x04C34ABF, "CRC-30-CDMA"],
  [31,         0x04C11DB7, false, false,          0,     ~0,         0x0CE9E46C, "CRC-31-PHILIPS"],
  [32,         0x04C11DB7,  true,  true,          0,     ~0,         0xCBF43926, "CRC-32", "CRC-32-ADCCP", "CRC-32-PKZIP", "PKZIP"],
  [32,         0x04C11DB7, false, false,          0,     ~0,         0xFC891918, "CRC-32-BZIP2", "CRC-32-AAL5", "CRC-32-DECT-B", "B-CRC-32"],
  [32,         0x1EDC6F41,  true,  true,          0,     ~0,         0xE3069283, "CRC-32C", "CRC-32-ISCSI", "CRC-32-CASTAGNOLI", "CRC-32-INTERLAKEN"],
  [32,         0xa833982b,  true,  true,          0,     ~0,         0x87315576, "CRC-32D"],
  [32,         0x04C11DB7, false, false,         ~0,      0,         0x0376E6E7, "CRC-32-MPEG-2"],
  [32,         0x04C11DB7, false, false,         ~0,     ~0,         0x765E7680, "CRC-32-POSIX", "CKSUM"],
  #[32,         0x741B8CD7,  true,  true,          0,     ~0,                nil, "CRC-32K"],
  #[32,         0x32583499,  true,  true,          0,     ~0,                nil, "CRC-32K2"],
  [32,         0x814141AB, false, false,          0,      0,         0x3010BF7F, "CRC-32Q"],
  [32,         0x04C11DB7,  true,  true,         ~0,      0,         0x340BC6D9, "CRC-32-JAMCRC", "JAMCRC"],
  [32,         0x000000AF, false, false,          0,      0,         0xBD0BE338, "CRC-32-XFER", "XFER"],
  [40,       0x0004820009, false, false,         ~0,     ~0,       0xD4164FC646, "CRC-40-GSM"],
  [64, 0x42F0E1EBA9EA3693,  true,  true,          0,     ~0, 0x995DC9BBDF1939FA, "CRC-64-XZ", "CRC-64"],
  [64, 0xAD93D23594C935A9,  true,  true,         ~0,      0, 0xCAA717168609F281, "CRC-64-JONES"],
  [64, 0x42F0E1EBA9EA3693, false, false,          0,      0, 0x6C40DF5F0B497347, "CRC-64-ECMA", "CRC-64-ECMA-182"],
  [64, 0x42F0E1EBA9EA3693, false, false,          0,     ~0, 0x62EC59E3F1A4F00A, "CRC-64-WE"],
  [64, 0x000000000000001B,  true,  true,          0,      0, 0x46A5A9388A5BEFFE, "CRC-64-ISO", "CRC-64-ISO-3309"],
  # [82, 0x308C0111011401440411,  true,  true,          0,      0, 0x9EA83F625023801FD612, "CRC-82/DARC"],
]
IMPLEMENT = 
:ruby
CRC = 
self

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Methods included from Utils

bitreflect, bitreflect128, bitreflect16, bitreflect32, bitreflect64, bitreflect8, bitreflect_reference, build_reflect_table, build_table, export_table

Constructor Details

#initialize(*args) ⇒ CRC

call-seq:

initialize(initial_crc = nil, size = 0)
initialize(seq, initial_crc = nil, size = 0)



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# File 'lib/crc.rb', line 314

def initialize(*args)
  initialize_args(args) do |seq, initial_crc, size|
    m = self.class
    @state = m.setup((initial_crc || m.initial_crc).to_i)
    @size = size.to_i
    update(seq) if seq
  end
end

Instance Attribute Details

#size ⇒ Object

Returns the value of attribute size.



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# File 'lib/crc.rb', line 307

def size
  @size
end

#state ⇒ Object

Returns the value of attribute state.



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# File 'lib/crc.rb', line 307

def state
  @state
end

Class Method Details

.crc(modulename, seq, crc = nil) ⇒ Object 



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# File 'lib/crc.rb', line 451

def crc(modulename, seq, crc = nil)
  lookup(modulename).crc(seq, crc)
end

.digest(modulename, seq, crc = nil) ⇒ Object 



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# File 'lib/crc.rb', line 455

def digest(modulename, seq, crc = nil)
  lookup(modulename).digest(seq, crc)
end

.dump_to_c(func_name = nil, header_name = nil, source_name = nil, indent: 4, visible: true, algorithm: ALGORITHM_SLICING_BY_16) ⇒ Object 



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# File 'lib/crc/codegen.rb', line 14

def self.dump_to_c(func_name = nil, header_name = nil, source_name = nil, indent: 4, visible: true, algorithm: ALGORITHM_SLICING_BY_16)
  func_name ||= self.to_s.slice(/\w+$/).downcase
  #func_name ||= self.name.gsub(/[\W]+/, "_").gsub(/_{2,}/, "_").gsub(/^_|_$/, "").downcase
  header_name ||= "#{func_name}.h"
  source_name ||= "#{func_name}.c"
  indentunit = " " * Integer(indent.to_i)
  indent = ->(level) { indentunit * level }
  visibility = visible ? "" : "static "

  case
  when bitsize <= 8
    type = "uint8_t"
    sizeof = 1
    suffix = "u"
  when bitsize <= 16
    type = "uint16_t"
    sizeof = 2
    suffix = "u"
  when bitsize <= 32
    type = "uint32_t"
    sizeof = 4
    suffix = "ul"
  else
    type = "uint64_t"
    sizeof = 8
    suffix = "ull"
  end

  typesize = sizeof * 8
  alignedbytes = (bitsize + 7) / 8
  alignedbits = (bitsize + 7) & ~0x07 # 8 bit alignmented bitsize
  bitreflect = func_name + "_bitreflect"
  hexnum = ->(n) { "0x%0#{sizeof * 2}X%s" % [n, suffix] }
  hexbyte = ->(n) { "0x%02Xu" % n }

  if reflect_input?
    getleadbyte = ->(expr, off = 0) { "(uint8_t)(#{expr} >> %2d)" % (off * 8) }
    getheadbit_from_byte = ->(expr, off = 0) { "((#{expr} >> #{off}) & 1)" }
    getleadbit = ->(expr, off = 0, width = 1) { "((%s >> %2d) & 0x%02X)" % [expr, off, ~(~0 << width)] }
    slideinput = ->(expr) { "#{expr}" }
    slidestate1 = ->(expr) { "(#{expr} >> 1)" }
    slidestate4 = ->(expr) { "(#{expr} >> 4)" }
    slidestate8 = ->(expr) { "(#{expr} >> 8)" }
    slideslicing = ->(expr) { "(#{expr} >> #{algorithm * 8})" }
    padding = depadding = nil
    workpoly = hexnum[Utils.bitreflect(polynomial, bitsize)]
    if algorithm >= 0
      table = Utils.build_reflect_table(bitsize, polynomial, true, slice: (algorithm < 1 ? 1 : algorithm))
    end
  else
    getleadbyte = ->(expr, off = 0) { "(uint8_t)(#{expr} >> %2d)" % (alignedbits - (off + 1) * 8) }
    getheadbit_from_byte = ->(expr, off = 0) { "((#{expr} >> #{8 - (off + 1)}) & 1)" }
    getleadbit = ->(expr, off = 0, width = 1) { "((%s >> %2d) & 0x%02X)" % [expr, (alignedbits - (off + 1) - (width - 1)), ~(~0 << width)] }
    slideinput = ->(expr) { "((#{type})#{expr} << #{alignedbits - 8})" }
    slidestate1 = ->(expr) { "(#{expr} << 1)" }
    slidestate4 = ->(expr) { "(#{expr} << 4)" }
    slidestate8 = ->(expr) { "(#{expr} << 8)" }
    slideslicing = ->(expr) { "(#{expr} << #{algorithm * 8})" }
    if (pad = (alignedbits - bitsize)) > 0
      padding = " << #{pad}"
      depadding = " >> #{pad}"
      workpoly = "#{func_name.upcase}_POLYNOMIAL << #{pad}"
    else
      padding = depadding = nil
      workpoly = "#{func_name.upcase}_POLYNOMIAL"
    end
    if algorithm >= 0
      table = Utils.build_table(bitsize, polynomial, true, slice: (algorithm < 1 ? 1 : algorithm))
    end
  end

  case algorithm
  when ALGORITHM_BITBYBIT
    comment = " /* bit reflected */" if reflect_input?
    prepare = <<-PREPARE_BITBYBIT
  static const #{type} workpoly = #{workpoly};#{comment}
    PREPARE_BITBYBIT
    update = <<-UPDATE_BITBYBIT
  for (; p < pp; p ++) {
      int i;
      s ^= #{slideinput["*p"]};
      for (i = 0; i < 8; i ++) {
          s = #{slidestate1["s"]} ^ (workpoly & -(#{type})#{getleadbit["s"]});
      }
  }
    UPDATE_BITBYBIT
  when ALGORITHM_BITBYBIT_FAST
    comment = " /* bit reflected */" if reflect_input?
    tspc = " " * type.size
    prepare = <<-PREPARE_BITBYBIT_FAST
  static const #{type} workpoly = #{workpoly};#{comment}
  static const #{type} g0 = workpoly,
               #{tspc} g1 = #{slidestate1["g0"]} ^ (workpoly & -(#{type})#{getleadbit["g0"]}),
               #{tspc} g2 = #{slidestate1["g1"]} ^ (workpoly & -(#{type})#{getleadbit["g1"]}),
               #{tspc} g3 = #{slidestate1["g2"]} ^ (workpoly & -(#{type})#{getleadbit["g2"]}),
               #{tspc} g4 = #{slidestate1["g3"]} ^ (workpoly & -(#{type})#{getleadbit["g3"]}),
               #{tspc} g5 = #{slidestate1["g4"]} ^ (workpoly & -(#{type})#{getleadbit["g4"]}),
               #{tspc} g6 = #{slidestate1["g5"]} ^ (workpoly & -(#{type})#{getleadbit["g5"]}),
               #{tspc} g7 = #{slidestate1["g6"]} ^ (workpoly & -(#{type})#{getleadbit["g6"]});
    PREPARE_BITBYBIT_FAST
    update = <<-UPDATE_BITBYBIT_FAST
  for (; p < pp; p ++) {
      const uint8_t s1 = #{getleadbit["s", 0, 8]} ^ *p;
      s = #{slidestate8["s"]} ^
          (g7 & -(#{type})#{getheadbit_from_byte["s1", 0]}) ^
          (g6 & -(#{type})#{getheadbit_from_byte["s1", 1]}) ^
          (g5 & -(#{type})#{getheadbit_from_byte["s1", 2]}) ^
          (g4 & -(#{type})#{getheadbit_from_byte["s1", 3]}) ^
          (g3 & -(#{type})#{getheadbit_from_byte["s1", 4]}) ^
          (g2 & -(#{type})#{getheadbit_from_byte["s1", 5]}) ^
          (g1 & -(#{type})#{getheadbit_from_byte["s1", 6]}) ^
          (g0 & -(#{type})#{getheadbit_from_byte["s1", 7]});
  }
    UPDATE_BITBYBIT_FAST
  when ALGORITHM_HALFBYTE_TABLE
    table = table[0]
    if reflect_input?
      table = 16.times.map { |i| table[i * 16] }
    else
      table = 16.times.map { |i| table[i] }
    end
    prepare = <<-PREPARE_HALFBYTE_TABLE
  static const #{type} table[16] = {
#{Aux.export_slicing_table(table, "    ", 4, nil, nil, nil, nil, sizeof > 2 ? 4 : 8, &hexnum)}
  };
    PREPARE_HALFBYTE_TABLE
    update = <<-UPDATE_HALFBYTE_TABLE
  for (; p < pp; p ++) {
      s ^= #{slideinput["(#{type})*p"]};
      s = table[#{getleadbit["s", 0, 4]}] ^ #{slidestate4["s"]};
      s = table[#{getleadbit["s", 0, 4]}] ^ #{slidestate4["s"]};
  }
    UPDATE_HALFBYTE_TABLE
  when ALGORITHM_STANDARD_TABLE
    prepare = <<-PREPARE_STANDARD_TABLE
  static const #{type} table[256] = {
#{Aux.export_slicing_table(table[0], "    ", 4, nil, nil, nil, nil, sizeof > 2 ? 4 : 8, &hexnum)}
  };
    PREPARE_STANDARD_TABLE
    update = <<-UPDATE_STANDARD_TABLE
  for (; p < pp; p ++) {
      s ^= #{slideinput["(#{type})*p"]};
      s = table[(uint8_t)#{getleadbit["s", 0, 8]}] ^ #{slidestate8["s"]};
  }
    UPDATE_STANDARD_TABLE
  when ALGORITHM_SLICING_BY_4,
       ALGORITHM_SLICING_BY_8,
       ALGORITHM_SLICING_BY_16
    slicing = algorithm.times.map { |off|
      ioff = (algorithm - 1) - off
      "table[%2d][p[%2d] %20s]" % [
        off, ioff,
        ioff >= alignedbytes ? nil : "^ #{getleadbyte["s", ioff]}"]
    }
    if algorithm < alignedbytes
      slicing.insert 0, slideslicing["s"]
    end
    slicing = slicing.join(" ^\n            ")

    prepare = <<-PREPARE_SLICING_TABLE
  static const #{type} table[#{algorithm}][256] = {
#{Aux.export_slicing_table(table, "    ", 4, nil, nil, "{", "}", sizeof > 2 ? 4 : 8, &hexnum)}
  };
    PREPARE_SLICING_TABLE
    update = <<-UPDATE_SLICING_TABLE
  const uint8_t *ppby = p + (len / #{algorithm} * #{algorithm});
  for (; p < ppby; p += #{algorithm}) {
      s = #{slicing};
  }

  for (; p < pp; p ++) {
      s = table[0][*p ^ #{getleadbyte["s"]}] ^ #{slidestate8["s"]};
  }
    UPDATE_SLICING_TABLE
  else
    raise ArgumentError, "wrong algorithm code - #{algorithm}"
  end

  if reflect_output? ^ reflect_input?
    slideleft = (typesize == bitsize) ? nil : "\n" << <<-SLIDELEFT.chomp!
  n <<= #{typesize - bitsize};
    SLIDELEFT
    swapby32 = (sizeof < 8) ? nil : "\n" << <<-SWAPBY32.chomp!
  n = ((n & 0X00000000FFFFFFFF#{suffix}) << 32) |  (n >> 32);
    SWAPBY32
    swapby16 = (sizeof < 4) ? nil : "\n" << <<-SWAPBY16.chomp!
  n = ((n & 0x#{"0000FFFF" * (sizeof / 4)}#{suffix}) << 16) | ((n >> 16) & 0x#{"0000FFFF" * (sizeof / 4)}#{suffix});
    SWAPBY16
    swapby8 = (sizeof < 2) ? nil : "\n" << <<-SWAPBY8.chomp!
  n = ((n & 0x#{"00FF" * (sizeof / 2)}#{suffix}) <<  8) | ((n >>  8) & 0x#{"00FF" * (sizeof / 2)}#{suffix});
    SWAPBY8

    func_bitreflect = "\n" << <<-BITREFLECT
static #{type}
#{bitreflect}(#{type} n)
{#{slideleft}#{swapby32}#{swapby16}#{swapby8}
  n = ((n & 0x#{"0F" * sizeof}#{suffix}) <<  4) | ((n >>  4) & 0x#{"0F" * sizeof}#{suffix});
  n = ((n & 0x#{"33" * sizeof}#{suffix}) <<  2) | ((n >>  2) & 0x#{"33" * sizeof}#{suffix});
  n = ((n & 0x#{"55" * sizeof}#{suffix}) <<  1) | ((n >>  1) & 0x#{"55" * sizeof}#{suffix});
  return n;
}
    BITREFLECT
  else
    bitreflect = nil
  end

  { header: <<-CHEADER, source: <<-CSOURCE }
/*
#{Aux.dump_banner(" *", "#{self.name}{#{to_str}}", algorithm)}
 */

#include "#{header_name}"
#{func_bitreflect}
#{visibility}#{type}
#{func_name}(const void *ptr, size_t len, #{type} crc)
{
#{prepare}
  #{type} s = ((#{bitreflect}(crc) & #{func_name.upcase}_BITMASK) ^ #{func_name.upcase}_XOR_OUTPUT)#{padding};
  const uint8_t *p = (const uint8_t *)ptr;
  const uint8_t *pp = p + len;

#{update}
  return #{bitreflect}((s#{depadding}) & #{func_name.upcase}_BITMASK) ^ #{func_name.upcase}_XOR_OUTPUT;
}
  CSOURCE
end

.dump_to_javascript(class_name = nil) ⇒ Object 



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# File 'lib/crc/codegen.rb', line 549

def self.dump_to_javascript(class_name = nil)
  class_name ||= self.to_s.slice(/\w+$/).downcase
  name = class_name.split("::")
  name.map! { |nm| nm.gsub!(/[\W]+/m, "_"); nm.sub!(/^_+/, ""); nm }
  case
  when bitsize <= 8
    sizeof = 1
  when bitsize <= 16
    sizeof = 2
  when bitsize <= 32
    sizeof = 4
  else
    sizeof = 8
  end

  pack = ""

  typebits = sizeof * 8
  hexnum = ->(n) { "0x%0*X" % [sizeof * 2, n] }
  if reflect_input?
    table1 = Utils.build_reflect_table(bitsize, polynomial, slice: 16)
    headstate = "(s & 0xFF)"
    slidestate = "(s >>> 8)"
    slicing = ->(off) {
      t = "t%X" % (15 - off)
      getbyte = off > 0 ? "+ %2d" % off : ""
      shiftstate = off < sizeof ? "^ (s %6s) & 0xFF" % (off > 0 ? ">>> %2d" % (off * 8) : "") : ""
      "%s[(0xFF & seq.charCodeAt(i %4s)) %19s]" % [t, getbyte, shiftstate]
    }
  else
    table1 = Utils.build_table(bitsize, polynomial, true, slice: 16)
    bitpad = typebits - bitsize
    #table1.each { |t| t.map! { |tt| tt << bitpad } }
    headstate = "((s >>> #{typebits - 8}) & 0xFF)"
    slidestate = "((s & #{hexnum[~(~0 << typebits) >> 8]}) << 8)"
    slicing = ->(off) {
      t = "t%X" % (15 - off)
      getbyte = off > 0 ? "+ %2d" % off : ""
      shiftstate = off < sizeof ? "^ (s %6s) & 0xFF" % (off + 1 < sizeof ? ">>> %2d" % ((sizeof - off) * 8 - 8) : "") : ""
      "%s[(0xFF & seq.charCodeAt(i %4s)) %19s]" % [t, getbyte, shiftstate]
    }
  end

  typename = name.join(".")

  code = <<-EOS
/*
#{Aux.dump_banner(" *", "#{self.name}{#{to_str}}", ALGORITHM_SLICING_BY_16)}
 * * Required ECMASCript version: 6th edition
 *
 * *** IMPORTANT BUG! ***
 *
 * This can not be calculated correctly,
 * if string included with 0x100+ codepointed character.
 */

"use strict";

/*
 * #{typename}(prevcrc = null)
 * #{typename}(seq, prevcrc = null)
 * new #{typename}(prevcrc = null)
 * new #{typename}(seq, prevcrc = null)
 */
(function(root, undefined) {
if (typeof(module) != "undefined") {
  // case node-js
  root = global;
}

var BITSIZE         = #{bitsize};
var BITMASK         = #{hexnum[bitmask]} >>> 0;
var POLYNOMIAL      = #{hexnum[polynomial]} >>> 0;
var INITIAL_CRC     = #{hexnum[initial_crc]} >>> 0;
var REFLECT_INPUT   = #{reflect_input?.inspect};
var REFLECT_OUTPUT  = #{reflect_output?.inspect};
var XOR_OUTPUT      = #{hexnum[xor_output]} >>> 0;

var #{typename} = function() {
  if(!(this instanceof #{typename})) {
      return new #{typename}(...arguments).crc;
  }

  var seq, prevcrc;

  switch (arguments.length) {
  case 0:
    seq = null;
    prevcrc = null;
    break;
  case 1:
    if (typeof(arguments[0]) == "string") {
      seq = arguments[0];
    } else {
      prevcrc = arguments[0];
    }
    break;
  case 2:
    seq = arguments[0];
    prevcrc = arguments[1];
    break;
  default:
    throw `wrong number of argument (given ${arguments.size}, expect 0..2)`;
  }

  this.reset(prevcrc);
  if (seq) { this.update(seq); }
};

var proto = #{typename}.prototype;

proto.reset = function(prevcrc = null) {
  this.state = #{typename}.setup(prevcrc || INITIAL_CRC);
  return this;
};

proto.update = function(seq) {
  this.state = #{typename}.update(seq, this.state);
  return this;
};

// proto.operator << = proto.update;

proto.finish = function() {
  return #{typename}.finish(this.state);
};

Object.defineProperty(proto, "crc", {
  get: proto.finish
});

Object.defineProperty(proto, "hexdigest", {
  get: function() {
    var s = this.crc.toString(16);
    for (var i = s.length; i < #{sizeof * 2}; i ++) {
      s = "0" + s;
    }
    return s;
  }
});

proto.toString = function() {
  return `#<#{typename}:${this.hexdigest}>`;
};

#{typename}.setup = function(crc = INITIAL_CRC) {
  return #{
    s = "(BITMASK & crc ^ XOR_OUTPUT)"

    if reflect_output? ^ reflect_input?
      s = "bitreflect#{s}"
    end

    if !reflect_input? && typebits > bitsize
      s << " << #{typebits - bitsize}"
    end

    s
  };
};

#{typename}.init = #{typename}.setup;

#{typename}.finish = function(state) {
  return (#{
    if !reflect_input? && typebits > bitsize
      state = "(state >>> #{typebits - bitsize})"
    else
      state = "state"
    end

    if reflect_output? ^ reflect_input?
      "bitreflect(BITMASK & #{state} ^ XOR_OUTPUT)"
    else
      "BITMASK & #{state} ^ XOR_OUTPUT"
    end
  }) >>> 0;
};

/*
 * update(seq, state) -> state
 */
#{typename}.update = function(seq, s) {
  var i = 0;
  var ii = seq.length;
  var ii16 = ii & ~15;
  var t0 = TABLE[ 0], t1 = TABLE[ 1], t2 = TABLE[ 2], t3 = TABLE[ 3],
      t4 = TABLE[ 4], t5 = TABLE[ 5], t6 = TABLE[ 6], t7 = TABLE[ 7],
      t8 = TABLE[ 8], t9 = TABLE[ 9], tA = TABLE[10], tB = TABLE[11],
      tC = TABLE[12], tD = TABLE[13], tE = TABLE[14], tF = TABLE[15];
  for (; i < ii16; i += 16) {
    s = #{slicing[ 0]} ^
        #{slicing[ 1]} ^
        #{slicing[ 2]} ^
        #{slicing[ 3]} ^
        #{slicing[ 4]} ^
        #{slicing[ 5]} ^
        #{slicing[ 6]} ^
        #{slicing[ 7]} ^
        #{slicing[ 8]} ^
        #{slicing[ 9]} ^
        #{slicing[10]} ^
        #{slicing[11]} ^
        #{slicing[12]} ^
        #{slicing[13]} ^
        #{slicing[14]} ^
        #{slicing[15]};
  }

  for (; i < ii; i ++) {
    s = t0[(0xFF & seq.charCodeAt(i)) ^ #{headstate}] ^ #{slidestate}
  }

  return s;
}

#{typename}.crc = function(seq, initcrc = INITIAL_CRC) {
  return #{typename}.finish(#{typename}.update(seq, #{typename}.setup(initcrc)));
};

#{typename}.hexdigest = function(seq, initcrc = INITIAL_CRC) {
  var s = #{typename}.crc(seq, initcrc).toString(16);
  for (var i = s.length; i < #{sizeof * 2}; i ++) {
    s = "0" + s;
  }
  return s;
};
  EOS

  if reflect_output? ^ reflect_input?
    code << <<-EOS

#{typename}.bitreflect = function(n) {
    EOS

    if typebits > bitsize
      code << <<-EOS
  n <<= #{typebits - bitsize}
      EOS
    end

    if typebits > 32
      code << <<-EOS
  n = ((n >>> 32) & 0x00000000ffffffff) | ((n & 0x00000000ffffffff) << 32)
      EOS
    end

    if typebits > 16
      code << <<-EOS
  n = ((n >>> 16) & 0x#{"0000ffff" * (sizeof / 4)}) | ((n & 0x#{"0000ffff" * (sizeof / 4)}) << 16)
      EOS
    end

    if typebits > 8
      code << <<-EOS
  n = ((n >>>  8) & 0x#{"00ff" * (sizeof / 2)}) | ((n & 0x#{"00ff" * (sizeof / 2)}) <<  8)
      EOS
    end

    code << <<-EOS
  n = ((n >>>  4) & 0x#{"0f" * sizeof}) | ((n & 0x#{"0f" * sizeof}) <<  4)
  n = ((n >>>  2) & 0x#{"33" * sizeof}) | ((n & 0x#{"33" * sizeof}) <<  2)
  n = ((n >>>  1) & 0x#{"55" * sizeof}) | ((n & 0x#{"55" * sizeof}) <<  1)
  return n;
}
    EOS
  end

  code << <<-EOS

var TABLE = [
#{Aux.export_slicing_table(table1, "  ", 2, nil, nil, "[", "]", sizeof > 2 ? 4 : 8, &hexnum)}
];

root.#{typename} = #{typename};

Object.defineProperty(#{typename}, "BITSIZE", { get: function() { return BITSIZE } });
Object.defineProperty(#{typename}, "BITMASK", { get: function() { return BITMASK } });
Object.defineProperty(#{typename}, "POLYNOMIAL", { get: function() { return POLYNOMIAL } });
Object.defineProperty(#{typename}, "INITIAL_CRC", { get: function() { return INITIAL_CRC } });
Object.defineProperty(#{typename}, "REFLECT_INPUT", { get: function() { return REFLECT_INPUT } });
Object.defineProperty(#{typename}, "REFLECT_OUTPUT", { get: function() { return REFLECT_OUTPUT } });
Object.defineProperty(#{typename}, "XOR_OUTPUT", { get: function() { return XOR_OUTPUT } });

return #{typename};
})(this);
  EOS

  ({ source: code })
end

.dump_to_ruby(class_name = nil) ⇒ Object 



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# File 'lib/crc/codegen.rb', line 269

def self.dump_to_ruby(class_name = nil)
  class_name ||= self.to_s.slice(/\w+$/)
  name = class_name.split("::")
  name.map! { |nm| nm.gsub!(/[\W]+/m, "_"); nm.sub!(/^_+/, ""); nm.sub!(/^[a-z]/) { |m| m.upcase! }; nm }
  case
  when bitsize <= 8
    sizeof = 1
    pack = "C"
  when bitsize <= 16
    sizeof = 2
    pack = "n"
  when bitsize <= 32
    sizeof = 4
    pack = "N"
  else
    sizeof = 8
    pack = "Q>"
  end

  typebits = sizeof * 8
  hexnum = ->(n) { "0x%0*X" % [sizeof * 2, n] }
  if reflect_input?
    table1 = Utils.build_reflect_table(bitsize, polynomial, slice: 16)
    headstate = "(s & 0xFF)"
    slidestate = "(s >> 8)"
    slicing = ->(off) {
      t = "t%X" % (15 - off)
      getbyte = off > 0 ? "+ %2d" % off : ""
      shiftstate = off < sizeof ? "^ (s %5s) & 0xFF" % (off > 0 ? ">> %2d" % (off * 8) : "") : ""
      "%s[seq.getbyte(i %4s) %18s]" % [t, getbyte, shiftstate]
    }
  else
    table1 = Utils.build_table(bitsize, polynomial, true, slice: 16)
    bitpad = typebits - bitsize
    headstate = "((s >> #{typebits - 8}) & 0xFF)"
    slidestate = "((s & #{hexnum[~(~0 << typebits) >> 8]}) << 8)"
    slicing = ->(off) {
      t = "t%X" % (15 - off)
      getbyte = off > 0 ? "+ %2d" % off : ""
      shiftstate = off < sizeof ? "^ (s %5s) & 0xFF" % (off + 1 < sizeof ? ">> %2d" % ((sizeof - off) * 8 - 8) : "") : ""
      "%s[seq.getbyte(i %4s) %18s]" % [t, getbyte, shiftstate]
    }
  end

  code = <<-EOS
#!ruby

#
#{Aux.dump_banner("#", "#{self.name}{#{to_str}}", ALGORITHM_SLICING_BY_16)}
#

# for ruby-1.8
unless "".respond_to?(:getbyte)
class String
  alias getbyte []
end
end

# for mruby
unless [].respond_to?(:freeze)
class Array
  def freeze
    self
  end
end
end

class #{name.join("::")}
BITSIZE         = #{bitsize}
BITMASK         = #{hexnum[bitmask]}
POLYNOMIAL      = #{hexnum[polynomial]}
INITIAL_CRC     = #{hexnum[initial_crc]}
REFLECT_INPUT   = #{reflect_input?.inspect}
REFLECT_OUTPUT  = #{reflect_output?.inspect}
XOR_OUTPUT      = #{hexnum[xor_output]}

attr_accessor :state

#
# call-seq:
#   initialize(prevcrc = nil)
#   initialize(seq, prevcrc = nil)
#
def initialize(*args)
  case args.size
  when 0
    seq = nil
    prevcrc = nil
  when 1
    if args[0].kind_of?(String)
      seq = args[0]
    else
      prevcrc = args[0]
    end
  when 2
    (seq, prevcrc) = args
  else
    raise ArgumentError, "wrong number of argument (given \#{args.size}, expect 0..2)"
  end

  reset(prevcrc)
  update(seq) if seq
end

def reset(prevcrc = nil)
  @state = self.class.setup(prevcrc || INITIAL_CRC)
  self
end

def update(seq)
  @state = self.class.update(seq, state)
  self
end

alias << update

def crc
  self.class.finish(state)
end

alias finish crc

def digest
  [crc].pack(#{pack.inspect})
end

def hexdigest
  "%0#{sizeof * 2}X" % crc
end

def inspect
  "#<\#{self.class}:\#{hexdigest}>"
end

def pretty_print(q)
  q.text inspect
end

class << self
  def [](seq, prevcrc = nil)
    new(seq, prevcrc)
  end

  def setup(crc = INITIAL_CRC)
    #{
      s = "(BITMASK & crc ^ XOR_OUTPUT)"

      if reflect_output? ^ reflect_input?
        s = "bitreflect#{s}"
      end

      if !reflect_input? && typebits > bitsize
        s << " << #{typebits - bitsize}"
      end

      s
    }
  end

  alias init setup

  def finish(state)
    #{
      if !reflect_input? && typebits > bitsize
        state = "(state >> #{typebits - bitsize})"
      else
        state = "state"
      end

      if reflect_output? ^ reflect_input?
        "bitreflect(BITMASK & #{state} ^ XOR_OUTPUT)"
      else
        "BITMASK & #{state} ^ XOR_OUTPUT"
      end
    }
  end

  #
  # call-seq:
  #   update(seq, state) -> state
  #
  def update(seq, s)
    i = 0
    ii = seq.bytesize
    ii16 = ii & ~15
    t0 = TABLE[ 0]; t1 = TABLE[ 1]; t2 = TABLE[ 2]; t3 = TABLE[ 3]
    t4 = TABLE[ 4]; t5 = TABLE[ 5]; t6 = TABLE[ 6]; t7 = TABLE[ 7]
    t8 = TABLE[ 8]; t9 = TABLE[ 9]; tA = TABLE[10]; tB = TABLE[11]
    tC = TABLE[12]; tD = TABLE[13]; tE = TABLE[14]; tF = TABLE[15]
    while i < ii16
      s = #{slicing[ 0]} ^
          #{slicing[ 1]} ^
          #{slicing[ 2]} ^
          #{slicing[ 3]} ^
          #{slicing[ 4]} ^
          #{slicing[ 5]} ^
          #{slicing[ 6]} ^
          #{slicing[ 7]} ^
          #{slicing[ 8]} ^
          #{slicing[ 9]} ^
          #{slicing[10]} ^
          #{slicing[11]} ^
          #{slicing[12]} ^
          #{slicing[13]} ^
          #{slicing[14]} ^
          #{slicing[15]}
      i += 16
    end

    while i < ii
      s = t0[seq.getbyte(i) ^ #{headstate}] ^ #{slidestate}
      i += 1
    end

    s
  end

  def crc(seq, initcrc = INITIAL_CRC)
    finish(update(seq, setup(initcrc)))
  end

  def digest(seq, initcrc = INITIAL_CRC)
    [crc(seq, initcrc)].pack(#{pack.inspect})
  end

  def hexdigest(seq, initcrc = INITIAL_CRC)
    "%0#{sizeof * 2}X" % crc(seq, initcrc)
  end
    EOS

    if reflect_output? ^ reflect_input?
    code << <<-EOS

  def bitreflect(n)
    EOS

    if typebits > bitsize
      code << <<-EOS
    n <<= #{typebits - bitsize}
      EOS
    end

    if typebits > 32
      code << <<-EOS
    n = ((n >> 32) & 0x00000000ffffffff) | ((n & 0x00000000ffffffff) << 32)
      EOS
    end

    if typebits > 16
      code << <<-EOS
    n = ((n >> 16) & 0x#{"0000ffff" * (sizeof / 4)}) | ((n & 0x#{"0000ffff" * (sizeof / 4)}) << 16)
      EOS
    end

    if typebits > 8
      code << <<-EOS
    n = ((n >>  8) & 0x#{"00ff" * (sizeof / 2)}) | ((n & 0x#{"00ff" * (sizeof / 2)}) <<  8)
      EOS
    end

    code << <<-EOS
    n = ((n >>  4) & 0x#{"0f" * sizeof}) | ((n & 0x#{"0f" * sizeof}) <<  4)
    n = ((n >>  2) & 0x#{"33" * sizeof}) | ((n & 0x#{"33" * sizeof}) <<  2)
    n = ((n >>  1) & 0x#{"55" * sizeof}) | ((n & 0x#{"55" * sizeof}) <<  1)
  end
    EOS
  end

  code << <<-EOS
end

TABLE = [
#{Aux.export_slicing_table(table1, "  ", 2, nil, nil, "[", "].freeze", sizeof > 2 ? 4 : 8, &hexnum)}
].freeze
end
  EOS

  ({ source: code })
end

.find(crc, seq, bitsize, polynomial, initstate = [0, ~0, 1], xor = [0, ~0, 1]) ⇒ Object 



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# File 'lib/crc/finder.rb', line 6

def self.find(crc, seq, bitsize, polynomial, initstate = [0, ~0, 1], xor = [0, ~0, 1])
  bitsize0 = bitsize.to_i
  if bitsize0 < 1 || bitsize0 > 128
    raise ArgumentError, "wrong bitsize (expect 1..128, but given #{bitsize})"
  end
  bitmask = ~(~0 << bitsize0)
  crc &= bitmask
  results = []
  poly = Array(polynomial)
  poly.each do |poly|
    poly &= bitmask
    [false, true].each do |refin|
      [false, true].each do |refout|
        Array(xor).each do |xormask|
          xormask &= bitmask
          Array(initstate).each do |init|
            init &= bitmask
            mod = CRC.new(bitsize0, poly, init, refin, refout, xormask)
            results << mod if mod.crc(seq) == crc
          end
        end
      end
    end
  end

  results
end

.hexdigest(modulename, seq, crc = nil) ⇒ Object 



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# File 'lib/crc.rb', line 459

def hexdigest(modulename, seq, crc = nil)
  lookup(modulename).hexdigest(seq, crc)
end

.lookup(modulename) ⇒ Object Also known as: [] 



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# File 'lib/crc.rb', line 443

def lookup(modulename)
  modulename1 = modulename.to_s.gsub(/[\W_]+/, "")
  modulename1.downcase!
  MODULE_TABLE[modulename1] or raise NameError, "modulename is not matched (for #{modulename})"
end

.new(bitsize, polynomial, initial_crc = 0, reflect_input = true, reflect_output = true, xor_output = ~0,, name = nil) ⇒ Object

call-seq:

new(bitsize, polynomial, initial_crc = 0, reflect_input = true, reflect_output = true, xor_output = ~0, name = nil) -> new crc module class (CRC based class)
new(initial_crc = nil, size = 0) -> new crc generator (CRC instance)
new(seq, initial_crc = nil, size = 0) -> new crc generator (CRC instance)



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# File 'lib/crc/_byruby.rb', line 34

def new(bitsize, polynomial, initial_crc = 0, reflect_input = true, reflect_output = true, xor_output = ~0, name = nil)
  bitsize = bitsize.to_i
  if bitsize < 1 || bitsize > 64
    raise ArgumentError, "wrong bitsize (except 1..64, but given #{bitsize})"
  end

  bitmask = ~(~0 << bitsize)
  polynomial = bitmask & polynomial
  initial_crc = bitmask & initial_crc
  xor_output = bitmask & xor_output
  name = (name.nil? || ((name = String(name)).empty?)) ? nil : name

  ::Class.new(self) do
    @bitsize = bitsize
    @bitmask = bitmask
    @polynomial = polynomial
    @initial_crc = initial_crc
    @table = nil
    @reflect_input = !!reflect_input
    @reflect_output = !!reflect_output
    @xor_output = xor_output
    @name = name

    # CRC クラスを普通に派生させた場合でも、CRC.new の基底メソッドが呼ばれるための細工
    define_singleton_method(:new, &Class.instance_method(:new).bind(self))

    singleton_class.class_eval do
      alias_method :[], :new
    end

    extend CRC::ModuleClass
  end
end

.table ⇒ Object 



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# File 'lib/crc/_byruby.rb', line 233

def table
  if SLICING_SIZE
    if reflect_input
      @table = CRC.build_reflect_table(bitsize, polynomial, slice: SLICING_SIZE)
    else
      @table = CRC.build_table(bitsize, polynomial, slice: SLICING_SIZE)
    end
  else
    @table = nil
  end

  singleton_class.class_eval "attr_reader :table"

  @table
end

.update_with_lookup_table(seq, state) ⇒ Object 



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# File 'lib/crc/_byruby.rb', line 92

def update_with_lookup_table(seq, state)
  t = table[0]

  if reflect_input
    String(seq).each_byte do |ch|
      state = t[state & 0xff ^ ch] ^ (state >> 8)
    end
    state
  else
    Aux.slide_to_head(bitsize, state, polynomial, bitmask) do |s, poly, csh, head, carries|
      carries8 = carries >> 7
      String(seq).each_byte do |ch|
        s = t[(s >> csh) ^ ch] ^ ((carries8 & s) << 8)
      end
      s
    end
  end
end

.update_with_reference(seq, state) ⇒ Object 



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# File 'lib/crc/_byruby.rb', line 68

def update_with_reference(seq, state)
  if reflect_input
    poly = CRC.bitreflect(polynomial, bitsize)
    seq.each_byte do |ch|
      state ^= ch
      8.times { state = (state[0] == 0) ? (state >> 1) : ((state >> 1) ^ poly) }

      # 8.times { state = (state >> 1) ^ (poly & -state[0]) }
      # NOTE: ruby だと、分岐したほうが2割くらい高速
    end

    state
  else
    Aux.slide_to_head(bitsize, state, polynomial, bitmask) do |s, poly, csh, head, carries|
      seq.each_byte do |ch|
        s ^= ch << csh
        8.times { s = (s[head] == 0) ? (s << 1) : (((carries & s) << 1) ^ poly) }
      end

      s
    end
  end
end

.update_with_slice_by_16(seq, s) ⇒ Object 



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# File 'lib/crc/_byruby.rb', line 111

def update_with_slice_by_16(seq, s)
  tX = table
  t0 = tX[ 0]; t1 = tX[ 1]; t2 = tX[ 2]; t3 = tX[ 3]
  t4 = tX[ 4]; t5 = tX[ 5]; t6 = tX[ 6]; t7 = tX[ 7]
  t8 = tX[ 8]; t9 = tX[ 9]; tA = tX[10]; tB = tX[11]
  tC = tX[12]; tD = tX[13]; tE = tX[14]; tF = tX[15]

  i = 0
  ii = seq.bytesize
  ii16 = ii & ~15

  if reflect_input
    case
    when bitsize > 32
      i = 0
      while i < ii16
        s = tF[seq.getbyte(i     ) ^ (s      ) & 0xff] ^ tE[seq.getbyte(i +  1) ^ (s >>  8) & 0xff] ^
            tD[seq.getbyte(i +  2) ^ (s >> 16) & 0xff] ^ tC[seq.getbyte(i +  3) ^ (s >> 24) & 0xff] ^
            tB[seq.getbyte(i +  4) ^ (s >> 32) & 0xff] ^ tA[seq.getbyte(i +  5) ^ (s >> 40) & 0xff] ^
            t9[seq.getbyte(i +  6) ^ (s >> 48) & 0xff] ^ t8[seq.getbyte(i +  7) ^ (s >> 56)       ] ^
            t7[seq.getbyte(i +  8)                   ] ^ t6[seq.getbyte(i +  9)                   ] ^
            t5[seq.getbyte(i + 10)                   ] ^ t4[seq.getbyte(i + 11)                   ] ^
            t3[seq.getbyte(i + 12)                   ] ^ t2[seq.getbyte(i + 13)                   ] ^
            t1[seq.getbyte(i + 14)                   ] ^ t0[seq.getbyte(i + 15)                   ]
        i += 16
      end
    when bitsize > 16
      # speed improvement for 32-bits CRC
      i = 0
      while i < ii16
        s = tF[seq.getbyte(i     ) ^ (s      ) & 0xff] ^ tE[seq.getbyte(i +  1) ^ (s >>  8) & 0xff] ^
            tD[seq.getbyte(i +  2) ^ (s >> 16) & 0xff] ^ tC[seq.getbyte(i +  3) ^ (s >> 24)       ] ^
            tB[seq.getbyte(i +  4)                   ] ^ tA[seq.getbyte(i +  5)                   ] ^
            t9[seq.getbyte(i +  6)                   ] ^ t8[seq.getbyte(i +  7)                   ] ^
            t7[seq.getbyte(i +  8)                   ] ^ t6[seq.getbyte(i +  9)                   ] ^
            t5[seq.getbyte(i + 10)                   ] ^ t4[seq.getbyte(i + 11)                   ] ^
            t3[seq.getbyte(i + 12)                   ] ^ t2[seq.getbyte(i + 13)                   ] ^
            t1[seq.getbyte(i + 14)                   ] ^ t0[seq.getbyte(i + 15)                   ]
        i += 16
      end
    else # when bitsize <= 16
      # speed improvement for 16-bits CRC
      i = 0
      while i < ii16
        s = tF[seq.getbyte(i     ) ^ (s      ) & 0xff] ^ tE[seq.getbyte(i +  1) ^ (s >>  8)       ] ^
            tD[seq.getbyte(i +  2)                   ] ^ tC[seq.getbyte(i +  3)                   ] ^
            tB[seq.getbyte(i +  4)                   ] ^ tA[seq.getbyte(i +  5)                   ] ^
            t9[seq.getbyte(i +  6)                   ] ^ t8[seq.getbyte(i +  7)                   ] ^
            t7[seq.getbyte(i +  8)                   ] ^ t6[seq.getbyte(i +  9)                   ] ^
            t5[seq.getbyte(i + 10)                   ] ^ t4[seq.getbyte(i + 11)                   ] ^
            t3[seq.getbyte(i + 12)                   ] ^ t2[seq.getbyte(i + 13)                   ] ^
            t1[seq.getbyte(i + 14)                   ] ^ t0[seq.getbyte(i + 15)                   ]
        i += 16
      end
    end

    (i...ii).each do |n|
      s = t0[seq.getbyte(n) ^ s & 0xff] ^ (s >> 8)
    end

    s
  else
    Aux.slide_to_head(bitsize, s, polynomial, bitmask) do |s, poly, csh, head, carries|
      case
      when bitsize > 32
        sh = 64 - (head + 1)

        while i < ii16
          s <<= sh
          s = tF[seq.getbyte(i     ) ^ (s >> 56)       ] ^ tE[seq.getbyte(i +  1) ^ (s >> 48) & 0xff] ^
              tD[seq.getbyte(i +  2) ^ (s >> 40) & 0xff] ^ tC[seq.getbyte(i +  3) ^ (s >> 32) & 0xff] ^
              tB[seq.getbyte(i +  4) ^ (s >> 24) & 0xff] ^ tA[seq.getbyte(i +  5) ^ (s >> 16) & 0xff] ^
              t9[seq.getbyte(i +  6) ^ (s >>  8) & 0xff] ^ t8[seq.getbyte(i +  7) ^ (s      ) & 0xff] ^
              t7[seq.getbyte(i +  8)                   ] ^ t6[seq.getbyte(i +  9)                   ] ^
              t5[seq.getbyte(i + 10)                   ] ^ t4[seq.getbyte(i + 11)                   ] ^
              t3[seq.getbyte(i + 12)                   ] ^ t2[seq.getbyte(i + 13)                   ] ^
              t1[seq.getbyte(i + 14)                   ] ^ t0[seq.getbyte(i + 15)                   ]
          i += 16
        end
      when bitsize > 16
        # speed improvement for 32-bits CRC
        sh = 32 - (head + 1)

        while i < ii16
          s <<= sh
          s = tF[seq.getbyte(i     ) ^ (s >> 24)       ] ^ tE[seq.getbyte(i +  1) ^ (s >> 16) & 0xff] ^
              tD[seq.getbyte(i +  2) ^ (s >>  8) & 0xff] ^ tC[seq.getbyte(i +  3) ^ (s      ) & 0xff] ^
              tB[seq.getbyte(i +  4)                   ] ^ tA[seq.getbyte(i +  5)                   ] ^
              t9[seq.getbyte(i +  6)                   ] ^ t8[seq.getbyte(i +  7)                   ] ^
              t7[seq.getbyte(i +  8)                   ] ^ t6[seq.getbyte(i +  9)                   ] ^
              t5[seq.getbyte(i + 10)                   ] ^ t4[seq.getbyte(i + 11)                   ] ^
              t3[seq.getbyte(i + 12)                   ] ^ t2[seq.getbyte(i + 13)                   ] ^
              t1[seq.getbyte(i + 14)                   ] ^ t0[seq.getbyte(i + 15)                   ]
          i += 16
        end
      else # when bitsize <= 16
        # speed improvement for 16-bits CRC
        sh = 16 - (head + 1)

        while i < ii16
          s <<= sh
          s = tF[seq.getbyte(i     ) ^ (s >>  8)       ] ^ tE[seq.getbyte(i +  1) ^ (s      ) & 0xff] ^
              tD[seq.getbyte(i +  2)                   ] ^ tC[seq.getbyte(i +  3)                   ] ^
              tB[seq.getbyte(i +  4)                   ] ^ tA[seq.getbyte(i +  5)                   ] ^
              t9[seq.getbyte(i +  6)                   ] ^ t8[seq.getbyte(i +  7)                   ] ^
              t7[seq.getbyte(i +  8)                   ] ^ t6[seq.getbyte(i +  9)                   ] ^
              t5[seq.getbyte(i + 10)                   ] ^ t4[seq.getbyte(i + 11)                   ] ^
              t3[seq.getbyte(i + 12)                   ] ^ t2[seq.getbyte(i + 13)                   ] ^
              t1[seq.getbyte(i + 14)                   ] ^ t0[seq.getbyte(i + 15)                   ]
          i += 16
        end
      end

      carries8 = carries >> 7
      (i...ii).each do |n|
        s = t0[(s >> csh) ^ seq.getbyte(n)] ^ ((carries8 & s) << 8)
      end
      s
    end
  end
end

Instance Method Details

#+(crc2) ⇒ Object

Raises:

  • (ArgumentError) 


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# File 'lib/crc.rb', line 342

def +(crc2)
  raise ArgumentError, "not a CRC instance (#{crc2.inspect})" unless crc2.kind_of?(CRC)
  m1 = self.class
  m2 = crc2.class
  unless m1.bitsize == m2.bitsize &&
         m1.polynomial == m2.polynomial &&
         m1.reflect_input? == m2.reflect_input? &&
         m1.reflect_output? == m2.reflect_output? &&
         # m1.initial_crc == m2.initial_crc &&
         m1.xor_output == m2.xor_output
    raise ArgumentError, "different CRC module (#{m1.inspect} and #{m2.inspect})"
  end
  m1.new(m1.combine(crc, crc2.crc, crc2.size), size + crc2.size)
end

#==(a) ⇒ Object 



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# File 'lib/crc.rb', line 357

def ==(a)
  case a
  when CRC
    m1 = self.class
    m2 = a.class
    if m1.bitsize == m2.bitsize &&
       m1.polynomial == m2.polynomial &&
       m1.reflect_input? == m2.reflect_input? &&
       m1.reflect_output? == m2.reflect_output? &&
       # m1.initial_crc == m2.initial_crc &&
       m1.xor_output == m2.xor_output &&
       state == a.state
      true
    else
      false
    end
  when Integer
    crc == a
  else
    super
  end
end

#crc ⇒ Object 



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# File 'lib/crc.rb', line 338

def crc
  self.class.finish(state)
end

#digest ⇒ Object 



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# File 'lib/crc.rb', line 387

def digest
  Aux.digest(crc, self.class.bitsize)
end

#digest! ⇒ Object

return digest as internal state



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# File 'lib/crc.rb', line 392

def digest!
  Aux.digest(state, self.class.bitsize)
end

#hexdigest ⇒ Object 



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# File 'lib/crc.rb', line 396

def hexdigest
  Aux.hexdigest(crc, self.class.bitsize)
end

#hexdigest! ⇒ Object

return hex-digest as internal state



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# File 'lib/crc.rb', line 401

def hexdigest!
  Aux.hexdigest(state, self.class.bitsize)
end

#inspect ⇒ Object 



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# File 'lib/crc.rb', line 408

def inspect
  "\#<#{self.class}:#{hexdigest}>"
end

#pretty_inspect(q) ⇒ Object 



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# File 'lib/crc.rb', line 412

def pretty_inspect(q)
  q.text inspect
end

#reset(initial_crc = nil, size = 0) ⇒ Object 



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# File 'lib/crc.rb', line 323

def reset(initial_crc = nil, size = 0)
  m = self.class
  @state = m.setup((initial_crc || m.initial_crc).to_i)
  @size = size.to_i
  self
end

#to_a ⇒ Object 



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# File 'lib/crc.rb', line 383

def to_a
  [crc]
end

#to_i ⇒ Object 



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# File 'lib/crc.rb', line 380

def crc
  self.class.finish(state)
end

#to_int ⇒ Object 



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# File 'lib/crc.rb', line 381

def crc
  self.class.finish(state)
end

#to_s ⇒ Object 



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# File 'lib/crc.rb', line 406

def hexdigest
  Aux.hexdigest(crc, self.class.bitsize)
end

#to_str ⇒ Object 



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# File 'lib/crc.rb', line 405

def hexdigest
  Aux.hexdigest(crc, self.class.bitsize)
end

#update(seq) ⇒ Object Also known as: << 



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# File 'lib/crc.rb', line 330

def update(seq)
  @state = self.class.update(seq, state)
  @size += seq.bytesize
  self
end