Class: Mysql::Charset

Inherits:
Object
  • Object
show all
Defined in:
lib/mysql/charset.rb

Instance Attribute Summary collapse

Instance Attribute Details

#csnameString (readonly)

Returns collation name.

Returns:

  • (String)

    collation name


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# File 'lib/mysql/charset.rb', line 13

class Charset
  # @private
  # @param [Integer] number
  # @param [String] name
  # @param [String] csname
  def initialize(number, name, csname)
    @number, @name, @csname = number, name, csname
    @unsafe = false
  end

  attr_reader :number, :name, :csname

  # @private
  attr_accessor :unsafe

  # [[charset_number, charset_name, collation_name, default], ...]
  # @private
  CHARSETS = [
    [  1, "big5",     "big5_chinese_ci",       true ],
    [  2, "latin2",   "latin2_czech_cs",       false],
    [  3, "dec8",     "dec8_swedish_ci",       true ],
    [  4, "cp850",    "cp850_general_ci",      true ],
    [  5, "latin1",   "latin1_german1_ci",     false],
    [  6, "hp8",      "hp8_english_ci",        true ],
    [  7, "koi8r",    "koi8r_general_ci",      true ],
    [  8, "latin1",   "latin1_swedish_ci",     true ],
    [  9, "latin2",   "latin2_general_ci",     true ],
    [ 10, "swe7",     "swe7_swedish_ci",       true ],
    [ 11, "ascii",    "ascii_general_ci",      true ],
    [ 12, "ujis",     "ujis_japanese_ci",      true ],
    [ 13, "sjis",     "sjis_japanese_ci",      true ],
    [ 14, "cp1251",   "cp1251_bulgarian_ci",   false],
    [ 15, "latin1",   "latin1_danish_ci",      false],
    [ 16, "hebrew",   "hebrew_general_ci",     true ],
    [ 17, "filename", "filename",              true ],
    [ 18, "tis620",   "tis620_thai_ci",        true ],
    [ 19, "euckr",    "euckr_korean_ci",       true ],
    [ 20, "latin7",   "latin7_estonian_cs",    false],
    [ 21, "latin2",   "latin2_hungarian_ci",   false],
    [ 22, "koi8u",    "koi8u_general_ci",      true ],
    [ 23, "cp1251",   "cp1251_ukrainian_ci",   false],
    [ 24, "gb2312",   "gb2312_chinese_ci",     true ],
    [ 25, "greek",    "greek_general_ci",      true ],
    [ 26, "cp1250",   "cp1250_general_ci",     true ],
    [ 27, "latin2",   "latin2_croatian_ci",    false],
    [ 28, "gbk",      "gbk_chinese_ci",        true ],
    [ 29, "cp1257",   "cp1257_lithuanian_ci",  false],
    [ 30, "latin5",   "latin5_turkish_ci",     true ],
    [ 31, "latin1",   "latin1_german2_ci",     false],
    [ 32, "armscii8", "armscii8_general_ci",   true ],
    [ 33, "utf8",     "utf8_general_ci",       true ],
    [ 34, "cp1250",   "cp1250_czech_cs",       false],
    [ 35, "ucs2",     "ucs2_general_ci",       true ],
    [ 36, "cp866",    "cp866_general_ci",      true ],
    [ 37, "keybcs2",  "keybcs2_general_ci",    true ],
    [ 38, "macce",    "macce_general_ci",      true ],
    [ 39, "macroman", "macroman_general_ci",   true ],
    [ 40, "cp852",    "cp852_general_ci",      true ],
    [ 41, "latin7",   "latin7_general_ci",     true ],
    [ 42, "latin7",   "latin7_general_cs",     false],
    [ 43, "macce",    "macce_bin",             false],
    [ 44, "cp1250",   "cp1250_croatian_ci",    false],
    [ 45, "utf8mb4",  "utf8mb4_general_ci",    true ],
    [ 46, "utf8mb4",  "utf8mb4_bin",           false],
    [ 47, "latin1",   "latin1_bin",            false],
    [ 48, "latin1",   "latin1_general_ci",     false],
    [ 49, "latin1",   "latin1_general_cs",     false],
    [ 50, "cp1251",   "cp1251_bin",            false],
    [ 51, "cp1251",   "cp1251_general_ci",     true ],
    [ 52, "cp1251",   "cp1251_general_cs",     false],
    [ 53, "macroman", "macroman_bin",          false],
    [ 57, "cp1256",   "cp1256_general_ci",     true ],
    [ 58, "cp1257",   "cp1257_bin",            false],
    [ 59, "cp1257",   "cp1257_general_ci",     true ],
    [ 63, "binary",   "binary",                true ],
    [ 64, "armscii8", "armscii8_bin",          false],
    [ 65, "ascii",    "ascii_bin",             false],
    [ 66, "cp1250",   "cp1250_bin",            false],
    [ 67, "cp1256",   "cp1256_bin",            false],
    [ 68, "cp866",    "cp866_bin",             false],
    [ 69, "dec8",     "dec8_bin",              false],
    [ 70, "greek",    "greek_bin",             false],
    [ 71, "hebrew",   "hebrew_bin",            false],
    [ 72, "hp8",      "hp8_bin",               false],
    [ 73, "keybcs2",  "keybcs2_bin",           false],
    [ 74, "koi8r",    "koi8r_bin",             false],
    [ 75, "koi8u",    "koi8u_bin",             false],
    [ 77, "latin2",   "latin2_bin",            false],
    [ 78, "latin5",   "latin5_bin",            false],
    [ 79, "latin7",   "latin7_bin",            false],
    [ 80, "cp850",    "cp850_bin",             false],
    [ 81, "cp852",    "cp852_bin",             false],
    [ 82, "swe7",     "swe7_bin",              false],
    [ 83, "utf8",     "utf8_bin",              false],
    [ 84, "big5",     "big5_bin",              false],
    [ 85, "euckr",    "euckr_bin",             false],
    [ 86, "gb2312",   "gb2312_bin",            false],
    [ 87, "gbk",      "gbk_bin",               false],
    [ 88, "sjis",     "sjis_bin",              false],
    [ 89, "tis620",   "tis620_bin",            false],
    [ 90, "ucs2",     "ucs2_bin",              false],
    [ 91, "ujis",     "ujis_bin",              false],
    [ 92, "geostd8",  "geostd8_general_ci",    true ],
    [ 93, "geostd8",  "geostd8_bin",           false],
    [ 94, "latin1",   "latin1_spanish_ci",     false],
    [ 95, "cp932",    "cp932_japanese_ci",     true ],
    [ 96, "cp932",    "cp932_bin",             false],
    [ 97, "eucjpms",  "eucjpms_japanese_ci",   true ],
    [ 98, "eucjpms",  "eucjpms_bin",           false],
    [ 99, "cp1250",   "cp1250_polish_ci",      false],
    [128, "ucs2",     "ucs2_unicode_ci",       false],
    [129, "ucs2",     "ucs2_icelandic_ci",     false],
    [130, "ucs2",     "ucs2_latvian_ci",       false],
    [131, "ucs2",     "ucs2_romanian_ci",      false],
    [132, "ucs2",     "ucs2_slovenian_ci",     false],
    [133, "ucs2",     "ucs2_polish_ci",        false],
    [134, "ucs2",     "ucs2_estonian_ci",      false],
    [135, "ucs2",     "ucs2_spanish_ci",       false],
    [136, "ucs2",     "ucs2_swedish_ci",       false],
    [137, "ucs2",     "ucs2_turkish_ci",       false],
    [138, "ucs2",     "ucs2_czech_ci",         false],
    [139, "ucs2",     "ucs2_danish_ci",        false],
    [140, "ucs2",     "ucs2_lithuanian_ci",    false],
    [141, "ucs2",     "ucs2_slovak_ci",        false],
    [142, "ucs2",     "ucs2_spanish2_ci",      false],
    [143, "ucs2",     "ucs2_roman_ci",         false],
    [144, "ucs2",     "ucs2_persian_ci",       false],
    [145, "ucs2",     "ucs2_esperanto_ci",     false],
    [146, "ucs2",     "ucs2_hungarian_ci",     false],
    [192, "utf8",     "utf8_unicode_ci",       false],
    [193, "utf8",     "utf8_icelandic_ci",     false],
    [194, "utf8",     "utf8_latvian_ci",       false],
    [195, "utf8",     "utf8_romanian_ci",      false],
    [196, "utf8",     "utf8_slovenian_ci",     false],
    [197, "utf8",     "utf8_polish_ci",        false],
    [198, "utf8",     "utf8_estonian_ci",      false],
    [199, "utf8",     "utf8_spanish_ci",       false],
    [200, "utf8",     "utf8_swedish_ci",       false],
    [201, "utf8",     "utf8_turkish_ci",       false],
    [202, "utf8",     "utf8_czech_ci",         false],
    [203, "utf8",     "utf8_danish_ci",        false],
    [204, "utf8",     "utf8_lithuanian_ci",    false],
    [205, "utf8",     "utf8_slovak_ci",        false],
    [206, "utf8",     "utf8_spanish2_ci",      false],
    [207, "utf8",     "utf8_roman_ci",         false],
    [208, "utf8",     "utf8_persian_ci",       false],
    [209, "utf8",     "utf8_esperanto_ci",     false],
    [210, "utf8",     "utf8_hungarian_ci",     false],
    [211, "utf8",     "utf8_sinhala_ci",       false],
    [224, "utf8mb4",  "utf8mb4_unicode_ci",    false],
    [225, "utf8mb4",  "utf8mb4_icelandic_ci",  false],
    [226, "utf8mb4",  "utf8mb4_latvian_ci",    false],
    [227, "utf8mb4",  "utf8mb4_romanian_ci",   false],
    [228, "utf8mb4",  "utf8mb4_slovenian_ci",  false],
    [229, "utf8mb4",  "utf8mb4_polish_ci",     false],
    [230, "utf8mb4",  "utf8mb4_estonian_ci",   false],
    [231, "utf8mb4",  "utf8mb4_spanish_ci",    false],
    [232, "utf8mb4",  "utf8mb4_swedish_ci",    false],
    [233, "utf8mb4",  "utf8mb4_turkish_ci",    false],
    [234, "utf8mb4",  "utf8mb4_czech_ci",      false],
    [235, "utf8mb4",  "utf8mb4_danish_ci",     false],
    [236, "utf8mb4",  "utf8mb4_lithuanian_ci", false],
    [237, "utf8mb4",  "utf8mb4_slovak_ci",     false],
    [238, "utf8mb4",  "utf8mb4_spanish2_ci",   false],
    [239, "utf8mb4",  "utf8mb4_roman_ci",      false],
    [240, "utf8mb4",  "utf8mb4_persian_ci",    false],
    [241, "utf8mb4",  "utf8mb4_esperanto_ci",  false],
    [242, "utf8mb4",  "utf8mb4_hungarian_ci",  false],
    [243, "utf8mb4",  "utf8mb4_sinhala_ci",    false],
    [254, "utf8",     "utf8_general_cs",       false],
  ]

  # @private
  UNSAFE_CHARSET = [
    "big5", "sjis", "filename", "gbk", "ucs2", "cp932",
  ]

  # @private
  NUMBER_TO_CHARSET = {}
  # @private
  COLLATION_TO_CHARSET = {}
  # @private
  CHARSET_DEFAULT = {}
  CHARSETS.each do |number, csname, clname, default|
    cs = Charset.new number, csname, clname
    cs.unsafe = true if UNSAFE_CHARSET.include? csname
    NUMBER_TO_CHARSET[number] = cs
    COLLATION_TO_CHARSET[clname] = cs
    CHARSET_DEFAULT[csname] = cs if default
  end

  # @private
  BINARY_CHARSET_NUMBER = CHARSET_DEFAULT['binary'].number

  # @private
  # @param [Integer] n
  # @return [Mysql::Charset]
  def self.by_number(n)
    raise ClientError, "unknown charset number: #{n}" unless NUMBER_TO_CHARSET.key? n
    NUMBER_TO_CHARSET[n]
  end

  # @private
  # @param [String] str
  # @return [Mysql::Charset]
  def self.by_name(str)
    ret = COLLATION_TO_CHARSET[str] || CHARSET_DEFAULT[str]
    raise ClientError, "unknown charset: #{str}" unless ret
    ret
  end

  if defined? Encoding

    # @private
    # MySQL Charset -> Ruby's Encodeing
    CHARSET_ENCODING = {
      "armscii8" => nil,
      "ascii"    => Encoding::US_ASCII,
      "big5"     => Encoding::Big5,
      "binary"   => Encoding::ASCII_8BIT,
      "cp1250"   => Encoding::Windows_1250,
      "cp1251"   => Encoding::Windows_1251,
      "cp1256"   => Encoding::Windows_1256,
      "cp1257"   => Encoding::Windows_1257,
      "cp850"    => Encoding::CP850,
      "cp852"    => Encoding::CP852,
      "cp866"    => Encoding::IBM866,
      "cp932"    => Encoding::Windows_31J,
      "dec8"     => nil,
      "eucjpms"  => Encoding::EucJP_ms,
      "euckr"    => Encoding::EUC_KR,
      "gb2312"   => Encoding::EUC_CN,
      "gbk"      => Encoding::GBK,
      "geostd8"  => nil,
      "greek"    => Encoding::ISO_8859_7,
      "hebrew"   => Encoding::ISO_8859_8,
      "hp8"      => nil,
      "keybcs2"  => nil,
      "koi8r"    => Encoding::KOI8_R,
      "koi8u"    => Encoding::KOI8_U,
      "latin1"   => Encoding::ISO_8859_1,
      "latin2"   => Encoding::ISO_8859_2,
      "latin5"   => Encoding::ISO_8859_9,
      "latin7"   => Encoding::ISO_8859_13,
      "macce"    => Encoding::MacCentEuro,
      "macroman" => Encoding::MacRoman,
      "sjis"     => Encoding::SHIFT_JIS,
      "swe7"     => nil,
      "tis620"   => Encoding::TIS_620,
      "ucs2"     => Encoding::UTF_16BE,
      "ujis"     => Encoding::EucJP_ms,
      "utf8"     => Encoding::UTF_8,
      "utf8mb4"  => Encoding::UTF_8,
    }

    # @private
    # @param [String] value
    # @return [String]
    def self.to_binary(value)
      value.force_encoding Encoding::ASCII_8BIT
    end

    # @private
    # convert raw to encoding and convert to Encoding.default_internal
    # @param [String] raw
    # @param [Encoding] encoding
    # @return [String] result
    def self.convert_encoding(raw, encoding)
      raw.force_encoding(encoding).encode
    end

    # @private
    # retrun corresponding Ruby encoding
    # @return [Encoding] encoding
    def encoding
      enc = CHARSET_ENCODING[@name.downcase]
      raise Mysql::ClientError, "unsupported charset: #{@name}" unless enc
      enc
    end

    # @private
    # convert encoding to corrensponding to MySQL charset
    # @param [String] value
    # @return [String]
    def convert(value)
      if value.is_a? String and value.encoding != Encoding::ASCII_8BIT
        value = value.encode encoding
      end
      value
    end

  else
    # for Ruby 1.8

    def self.to_binary(value)
      value
    end

    def self.convert_encoding(raw, encoding)
      raw
    end

    def encoding
      nil
    end

    def convert(value)
      value
    end

  end
end

#nameString (readonly)

Returns charset name.

Returns:

  • (String)

    charset name


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# File 'lib/mysql/charset.rb', line 13

class Charset
  # @private
  # @param [Integer] number
  # @param [String] name
  # @param [String] csname
  def initialize(number, name, csname)
    @number, @name, @csname = number, name, csname
    @unsafe = false
  end

  attr_reader :number, :name, :csname

  # @private
  attr_accessor :unsafe

  # [[charset_number, charset_name, collation_name, default], ...]
  # @private
  CHARSETS = [
    [  1, "big5",     "big5_chinese_ci",       true ],
    [  2, "latin2",   "latin2_czech_cs",       false],
    [  3, "dec8",     "dec8_swedish_ci",       true ],
    [  4, "cp850",    "cp850_general_ci",      true ],
    [  5, "latin1",   "latin1_german1_ci",     false],
    [  6, "hp8",      "hp8_english_ci",        true ],
    [  7, "koi8r",    "koi8r_general_ci",      true ],
    [  8, "latin1",   "latin1_swedish_ci",     true ],
    [  9, "latin2",   "latin2_general_ci",     true ],
    [ 10, "swe7",     "swe7_swedish_ci",       true ],
    [ 11, "ascii",    "ascii_general_ci",      true ],
    [ 12, "ujis",     "ujis_japanese_ci",      true ],
    [ 13, "sjis",     "sjis_japanese_ci",      true ],
    [ 14, "cp1251",   "cp1251_bulgarian_ci",   false],
    [ 15, "latin1",   "latin1_danish_ci",      false],
    [ 16, "hebrew",   "hebrew_general_ci",     true ],
    [ 17, "filename", "filename",              true ],
    [ 18, "tis620",   "tis620_thai_ci",        true ],
    [ 19, "euckr",    "euckr_korean_ci",       true ],
    [ 20, "latin7",   "latin7_estonian_cs",    false],
    [ 21, "latin2",   "latin2_hungarian_ci",   false],
    [ 22, "koi8u",    "koi8u_general_ci",      true ],
    [ 23, "cp1251",   "cp1251_ukrainian_ci",   false],
    [ 24, "gb2312",   "gb2312_chinese_ci",     true ],
    [ 25, "greek",    "greek_general_ci",      true ],
    [ 26, "cp1250",   "cp1250_general_ci",     true ],
    [ 27, "latin2",   "latin2_croatian_ci",    false],
    [ 28, "gbk",      "gbk_chinese_ci",        true ],
    [ 29, "cp1257",   "cp1257_lithuanian_ci",  false],
    [ 30, "latin5",   "latin5_turkish_ci",     true ],
    [ 31, "latin1",   "latin1_german2_ci",     false],
    [ 32, "armscii8", "armscii8_general_ci",   true ],
    [ 33, "utf8",     "utf8_general_ci",       true ],
    [ 34, "cp1250",   "cp1250_czech_cs",       false],
    [ 35, "ucs2",     "ucs2_general_ci",       true ],
    [ 36, "cp866",    "cp866_general_ci",      true ],
    [ 37, "keybcs2",  "keybcs2_general_ci",    true ],
    [ 38, "macce",    "macce_general_ci",      true ],
    [ 39, "macroman", "macroman_general_ci",   true ],
    [ 40, "cp852",    "cp852_general_ci",      true ],
    [ 41, "latin7",   "latin7_general_ci",     true ],
    [ 42, "latin7",   "latin7_general_cs",     false],
    [ 43, "macce",    "macce_bin",             false],
    [ 44, "cp1250",   "cp1250_croatian_ci",    false],
    [ 45, "utf8mb4",  "utf8mb4_general_ci",    true ],
    [ 46, "utf8mb4",  "utf8mb4_bin",           false],
    [ 47, "latin1",   "latin1_bin",            false],
    [ 48, "latin1",   "latin1_general_ci",     false],
    [ 49, "latin1",   "latin1_general_cs",     false],
    [ 50, "cp1251",   "cp1251_bin",            false],
    [ 51, "cp1251",   "cp1251_general_ci",     true ],
    [ 52, "cp1251",   "cp1251_general_cs",     false],
    [ 53, "macroman", "macroman_bin",          false],
    [ 57, "cp1256",   "cp1256_general_ci",     true ],
    [ 58, "cp1257",   "cp1257_bin",            false],
    [ 59, "cp1257",   "cp1257_general_ci",     true ],
    [ 63, "binary",   "binary",                true ],
    [ 64, "armscii8", "armscii8_bin",          false],
    [ 65, "ascii",    "ascii_bin",             false],
    [ 66, "cp1250",   "cp1250_bin",            false],
    [ 67, "cp1256",   "cp1256_bin",            false],
    [ 68, "cp866",    "cp866_bin",             false],
    [ 69, "dec8",     "dec8_bin",              false],
    [ 70, "greek",    "greek_bin",             false],
    [ 71, "hebrew",   "hebrew_bin",            false],
    [ 72, "hp8",      "hp8_bin",               false],
    [ 73, "keybcs2",  "keybcs2_bin",           false],
    [ 74, "koi8r",    "koi8r_bin",             false],
    [ 75, "koi8u",    "koi8u_bin",             false],
    [ 77, "latin2",   "latin2_bin",            false],
    [ 78, "latin5",   "latin5_bin",            false],
    [ 79, "latin7",   "latin7_bin",            false],
    [ 80, "cp850",    "cp850_bin",             false],
    [ 81, "cp852",    "cp852_bin",             false],
    [ 82, "swe7",     "swe7_bin",              false],
    [ 83, "utf8",     "utf8_bin",              false],
    [ 84, "big5",     "big5_bin",              false],
    [ 85, "euckr",    "euckr_bin",             false],
    [ 86, "gb2312",   "gb2312_bin",            false],
    [ 87, "gbk",      "gbk_bin",               false],
    [ 88, "sjis",     "sjis_bin",              false],
    [ 89, "tis620",   "tis620_bin",            false],
    [ 90, "ucs2",     "ucs2_bin",              false],
    [ 91, "ujis",     "ujis_bin",              false],
    [ 92, "geostd8",  "geostd8_general_ci",    true ],
    [ 93, "geostd8",  "geostd8_bin",           false],
    [ 94, "latin1",   "latin1_spanish_ci",     false],
    [ 95, "cp932",    "cp932_japanese_ci",     true ],
    [ 96, "cp932",    "cp932_bin",             false],
    [ 97, "eucjpms",  "eucjpms_japanese_ci",   true ],
    [ 98, "eucjpms",  "eucjpms_bin",           false],
    [ 99, "cp1250",   "cp1250_polish_ci",      false],
    [128, "ucs2",     "ucs2_unicode_ci",       false],
    [129, "ucs2",     "ucs2_icelandic_ci",     false],
    [130, "ucs2",     "ucs2_latvian_ci",       false],
    [131, "ucs2",     "ucs2_romanian_ci",      false],
    [132, "ucs2",     "ucs2_slovenian_ci",     false],
    [133, "ucs2",     "ucs2_polish_ci",        false],
    [134, "ucs2",     "ucs2_estonian_ci",      false],
    [135, "ucs2",     "ucs2_spanish_ci",       false],
    [136, "ucs2",     "ucs2_swedish_ci",       false],
    [137, "ucs2",     "ucs2_turkish_ci",       false],
    [138, "ucs2",     "ucs2_czech_ci",         false],
    [139, "ucs2",     "ucs2_danish_ci",        false],
    [140, "ucs2",     "ucs2_lithuanian_ci",    false],
    [141, "ucs2",     "ucs2_slovak_ci",        false],
    [142, "ucs2",     "ucs2_spanish2_ci",      false],
    [143, "ucs2",     "ucs2_roman_ci",         false],
    [144, "ucs2",     "ucs2_persian_ci",       false],
    [145, "ucs2",     "ucs2_esperanto_ci",     false],
    [146, "ucs2",     "ucs2_hungarian_ci",     false],
    [192, "utf8",     "utf8_unicode_ci",       false],
    [193, "utf8",     "utf8_icelandic_ci",     false],
    [194, "utf8",     "utf8_latvian_ci",       false],
    [195, "utf8",     "utf8_romanian_ci",      false],
    [196, "utf8",     "utf8_slovenian_ci",     false],
    [197, "utf8",     "utf8_polish_ci",        false],
    [198, "utf8",     "utf8_estonian_ci",      false],
    [199, "utf8",     "utf8_spanish_ci",       false],
    [200, "utf8",     "utf8_swedish_ci",       false],
    [201, "utf8",     "utf8_turkish_ci",       false],
    [202, "utf8",     "utf8_czech_ci",         false],
    [203, "utf8",     "utf8_danish_ci",        false],
    [204, "utf8",     "utf8_lithuanian_ci",    false],
    [205, "utf8",     "utf8_slovak_ci",        false],
    [206, "utf8",     "utf8_spanish2_ci",      false],
    [207, "utf8",     "utf8_roman_ci",         false],
    [208, "utf8",     "utf8_persian_ci",       false],
    [209, "utf8",     "utf8_esperanto_ci",     false],
    [210, "utf8",     "utf8_hungarian_ci",     false],
    [211, "utf8",     "utf8_sinhala_ci",       false],
    [224, "utf8mb4",  "utf8mb4_unicode_ci",    false],
    [225, "utf8mb4",  "utf8mb4_icelandic_ci",  false],
    [226, "utf8mb4",  "utf8mb4_latvian_ci",    false],
    [227, "utf8mb4",  "utf8mb4_romanian_ci",   false],
    [228, "utf8mb4",  "utf8mb4_slovenian_ci",  false],
    [229, "utf8mb4",  "utf8mb4_polish_ci",     false],
    [230, "utf8mb4",  "utf8mb4_estonian_ci",   false],
    [231, "utf8mb4",  "utf8mb4_spanish_ci",    false],
    [232, "utf8mb4",  "utf8mb4_swedish_ci",    false],
    [233, "utf8mb4",  "utf8mb4_turkish_ci",    false],
    [234, "utf8mb4",  "utf8mb4_czech_ci",      false],
    [235, "utf8mb4",  "utf8mb4_danish_ci",     false],
    [236, "utf8mb4",  "utf8mb4_lithuanian_ci", false],
    [237, "utf8mb4",  "utf8mb4_slovak_ci",     false],
    [238, "utf8mb4",  "utf8mb4_spanish2_ci",   false],
    [239, "utf8mb4",  "utf8mb4_roman_ci",      false],
    [240, "utf8mb4",  "utf8mb4_persian_ci",    false],
    [241, "utf8mb4",  "utf8mb4_esperanto_ci",  false],
    [242, "utf8mb4",  "utf8mb4_hungarian_ci",  false],
    [243, "utf8mb4",  "utf8mb4_sinhala_ci",    false],
    [254, "utf8",     "utf8_general_cs",       false],
  ]

  # @private
  UNSAFE_CHARSET = [
    "big5", "sjis", "filename", "gbk", "ucs2", "cp932",
  ]

  # @private
  NUMBER_TO_CHARSET = {}
  # @private
  COLLATION_TO_CHARSET = {}
  # @private
  CHARSET_DEFAULT = {}
  CHARSETS.each do |number, csname, clname, default|
    cs = Charset.new number, csname, clname
    cs.unsafe = true if UNSAFE_CHARSET.include? csname
    NUMBER_TO_CHARSET[number] = cs
    COLLATION_TO_CHARSET[clname] = cs
    CHARSET_DEFAULT[csname] = cs if default
  end

  # @private
  BINARY_CHARSET_NUMBER = CHARSET_DEFAULT['binary'].number

  # @private
  # @param [Integer] n
  # @return [Mysql::Charset]
  def self.by_number(n)
    raise ClientError, "unknown charset number: #{n}" unless NUMBER_TO_CHARSET.key? n
    NUMBER_TO_CHARSET[n]
  end

  # @private
  # @param [String] str
  # @return [Mysql::Charset]
  def self.by_name(str)
    ret = COLLATION_TO_CHARSET[str] || CHARSET_DEFAULT[str]
    raise ClientError, "unknown charset: #{str}" unless ret
    ret
  end

  if defined? Encoding

    # @private
    # MySQL Charset -> Ruby's Encodeing
    CHARSET_ENCODING = {
      "armscii8" => nil,
      "ascii"    => Encoding::US_ASCII,
      "big5"     => Encoding::Big5,
      "binary"   => Encoding::ASCII_8BIT,
      "cp1250"   => Encoding::Windows_1250,
      "cp1251"   => Encoding::Windows_1251,
      "cp1256"   => Encoding::Windows_1256,
      "cp1257"   => Encoding::Windows_1257,
      "cp850"    => Encoding::CP850,
      "cp852"    => Encoding::CP852,
      "cp866"    => Encoding::IBM866,
      "cp932"    => Encoding::Windows_31J,
      "dec8"     => nil,
      "eucjpms"  => Encoding::EucJP_ms,
      "euckr"    => Encoding::EUC_KR,
      "gb2312"   => Encoding::EUC_CN,
      "gbk"      => Encoding::GBK,
      "geostd8"  => nil,
      "greek"    => Encoding::ISO_8859_7,
      "hebrew"   => Encoding::ISO_8859_8,
      "hp8"      => nil,
      "keybcs2"  => nil,
      "koi8r"    => Encoding::KOI8_R,
      "koi8u"    => Encoding::KOI8_U,
      "latin1"   => Encoding::ISO_8859_1,
      "latin2"   => Encoding::ISO_8859_2,
      "latin5"   => Encoding::ISO_8859_9,
      "latin7"   => Encoding::ISO_8859_13,
      "macce"    => Encoding::MacCentEuro,
      "macroman" => Encoding::MacRoman,
      "sjis"     => Encoding::SHIFT_JIS,
      "swe7"     => nil,
      "tis620"   => Encoding::TIS_620,
      "ucs2"     => Encoding::UTF_16BE,
      "ujis"     => Encoding::EucJP_ms,
      "utf8"     => Encoding::UTF_8,
      "utf8mb4"  => Encoding::UTF_8,
    }

    # @private
    # @param [String] value
    # @return [String]
    def self.to_binary(value)
      value.force_encoding Encoding::ASCII_8BIT
    end

    # @private
    # convert raw to encoding and convert to Encoding.default_internal
    # @param [String] raw
    # @param [Encoding] encoding
    # @return [String] result
    def self.convert_encoding(raw, encoding)
      raw.force_encoding(encoding).encode
    end

    # @private
    # retrun corresponding Ruby encoding
    # @return [Encoding] encoding
    def encoding
      enc = CHARSET_ENCODING[@name.downcase]
      raise Mysql::ClientError, "unsupported charset: #{@name}" unless enc
      enc
    end

    # @private
    # convert encoding to corrensponding to MySQL charset
    # @param [String] value
    # @return [String]
    def convert(value)
      if value.is_a? String and value.encoding != Encoding::ASCII_8BIT
        value = value.encode encoding
      end
      value
    end

  else
    # for Ruby 1.8

    def self.to_binary(value)
      value
    end

    def self.convert_encoding(raw, encoding)
      raw
    end

    def encoding
      nil
    end

    def convert(value)
      value
    end

  end
end