module Z85rb
Constants
- VERSION
Public Instance Methods
decode(string)
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Decode Z85 to binary string.
@param string [String] Z85 encoded @return [String] binary
@example HelloWorld
decode('HelloWorld') #=> "\x86\x4f\xd2\x6f\xb5\x59\xf7\x5b" decode('nm=QNzY&b1A+]nf') #=> 'Hello World!'
@example Not padded to a multiple of 5
assert_raise(ArgumentError) { decode('hello_world') } #=> true
@example longer data
decode('JTKVSB%%)wK0E.X)V>+}o?pNmC{O&4W4b!Ni{Lh6') #=> "\x8E\v\xDDiv(\xB9\x1D\x8F$U\x87\xEE\x95\xC5\xB0MH\x96?y%\x98w\xB4\x9C\xD9\x06:\xEA\xD3\xB7"
# File lib/z85rb.rb, line 64 def decode(string) if string.length % 5 != 0 raise ArgumentError, 'The input string frame should have a length that is divisible by 5 with no remainder.' end decoder = [ 0x00, 0x44, 0x00, 0x54, 0x53, 0x52, 0x48, 0x00, 0x4B, 0x4C, 0x46, 0x41, 0x00, 0x3F, 0x3E, 0x45, 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x40, 0x00, 0x49, 0x42, 0x4A, 0x47, 0x51, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2A, 0x2B, 0x2C, 0x2D, 0x2E, 0x2F, 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x3B, 0x3C, 0x3D, 0x4D, 0x00, 0x4E, 0x43, 0x00, 0x00, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F, 0x20, 0x21, 0x22, 0x23, 0x4F, 0x00, 0x50, 0x00, 0x00, ] dest = [] byte_nbr = 0 char_nbr = 0 string_len = string.length value = 0 while char_nbr < string_len idx = string[char_nbr].ord - 32 value = (value * 85) + decoder[idx] char_nbr += 1 if char_nbr % 5 == 0 divisor = 256 * 256 * 256 while divisor >= 1 dest[byte_nbr] = (value / divisor) % 256 byte_nbr += 1 divisor /= 256 end value = 0 end end # We think `C*` and `c*` is equivalent in this case. # We use `C*` merely because reference implement in C uses `unsigned char`. # https://github.com/zeromq/rfc/blob/master/src/spec_32.c# dest.pack 'C*' end
encode(data)
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Encode binary data into Z85.
@param data [String] binary @return [String] Z85 encoded
@example HelloWorld
# Encode to 'HelloWorld' is an example from Z85 RFC. encode("\x86\x4f\xd2\x6f\xb5\x59\xf7\x5b") #=> 'HelloWorld' encode('Hello World!') #=> 'nm=QNzY&b1A+]nf'
@example Not padded to a multiple of 4
assert_raise(ArgumentError) { encode('HelloWorld') } #=> true
@example longer data
# Borrowed from Z85 reference implementation in C. test_data_2 = "\x8E\v\xDDiv(\xB9\x1D\x8F$U\x87\xEE\x95\xC5\xB0MH\x96?y%\x98w\xB4\x9C\xD9\x06:\xEA\xD3\xB7" encode(test_data_2) #=> 'JTKVSB%%)wK0E.X)V>+}o?pNmC{O&4W4b!Ni{Lh6'
# File lib/z85rb.rb, line 23 def encode(data) if data.length % 4 != 0 raise ArgumentError, 'The input binary frame should have a length that is divisible by 4 with no remainder.' end encoder = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ.-:+=^!/*?&<>()[]{}@%$#' str = '' byte_nbr = 0 size = data.length value = 0 while byte_nbr < size value = (value * 256) + data[byte_nbr].ord byte_nbr += 1 if byte_nbr % 4 == 0 divisor = 85 * 85 * 85 * 85 while divisor >= 1 idx = (value / divisor).floor % 85 str += encoder[idx] divisor /= 85 end value = 0 end end str end