Module: ActiveRecord::ObscuredId::Base32

Defined in:
lib/activerecord-obscuredid/base32.rb

Overview

Implementation of Base32 encoding and decoding

Constant Summary collapse

BASE32_ALPHABET = 
'ABCDEFGHIJKLMNOPQRSTUVWXYZ234567'

Class Method Summary collapse

Class Method Details

.decode(base32_str) ⇒ Object 



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# File 'lib/activerecord-obscuredid/base32.rb', line 23

def decode(base32_str)
  # Convert Base32 string to binary representation
  binary_str = base32_str.chars.map do |char|
    # Convert each character to its 5-bit binary equivalent
    index = BASE32_ALPHABET.index(char.upcase)
    raise ArgumentError, "Invalid Base32 character: #{char}" if index.nil?

    index.to_s(2).rjust(5, '0')
  end.join

  # Convert binary string back to its original form, ignoring extra zeroes
  decoded_str = [binary_str].pack('B*')

  # Strip out any null characters (trailing zero bits that resulted from padding)
  decoded_str.delete("\x00")
end

.encode(input) ⇒ Object 



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# File 'lib/activerecord-obscuredid/base32.rb', line 11

def encode(input)
  # Convert input to a binary string
  binary = input.unpack1('B*')

  # Break the binary string into 5-bit chunks and map them to Base32 characters
  binary.scan(/.{1,5}/).map do |chunk|
    # Pad the chunk with zeroes to make it 5 bits long if needed
    chunk = chunk.ljust(5, '0')
    BASE32_ALPHABET[chunk.to_i(2)]
  end.join
end