Module: ShortUUID

Defined in:
lib/shortuuid.rb,
lib/shortuuid/version.rb

Constant Summary collapse

DEFAULT_BASE62 = 
%w[0 1 2 3 4 5 6 7 8 9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z a b c d e f g h i j k l m n o p q r s t u v w x y z].freeze
VERSION = 
'0.6.0'.freeze

Class Method Summary collapse

Class Method Details

.convert_alphabet_to_decimal(word, alphabet = DEFAULT_BASE62) ⇒ Object 



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# File 'lib/shortuuid.rb', line 28

def self.convert_alphabet_to_decimal(word, alphabet = DEFAULT_BASE62)
  num = 0
  radix = alphabet.length
  word.chars.to_a.reverse.each_with_index do |char, index|
    num += alphabet.index(char) * (radix**index)
  end
  num
end

.convert_decimal_to_alphabet(decimal, alphabet = DEFAULT_BASE62) ⇒ Object 



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# File 'lib/shortuuid.rb', line 14

def self.convert_decimal_to_alphabet(decimal, alphabet = DEFAULT_BASE62)
  alphabet = alphabet.to_a
  radix = alphabet.length
  i = decimal.to_i
  out = []
  return alphabet[0] if i.zero?
  loop do
    break if i.zero?
    out.unshift(alphabet[i % radix])
    i /= radix
  end
  out.join
end

.decode(word, alphabet = DEFAULT_BASE62) ⇒ Object 



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# File 'lib/shortuuid.rb', line 41

def self.decode(word, alphabet = DEFAULT_BASE62)
  convert_alphabet_to_decimal(word, alphabet)
end

.encode(number, alphabet = DEFAULT_BASE62) ⇒ Object 



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# File 'lib/shortuuid.rb', line 37

def self.encode(number, alphabet = DEFAULT_BASE62)
  convert_decimal_to_alphabet(number, alphabet)
end

.expand(short_uuid, alphabet = DEFAULT_BASE62) ⇒ Object 



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# File 'lib/shortuuid.rb', line 45

def self.expand(short_uuid, alphabet = DEFAULT_BASE62)
  return nil unless short_uuid && !short_uuid.empty?
  decimal_value = convert_alphabet_to_decimal(short_uuid, alphabet)
  uuid = decimal_value.to_s(16).rjust(32, '0')
  [
    uuid[0..7],
    uuid[8..11],
    uuid[12..15],
    uuid[16..19],
    uuid[20..31]
  ].join('-')
end

.shorten(uuid, alphabet = DEFAULT_BASE62) ⇒ Object 



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# File 'lib/shortuuid.rb', line 8

def self.shorten(uuid, alphabet = DEFAULT_BASE62)
  return nil unless uuid && !uuid.empty?
  decimal_value = uuid.split('-').join.to_i(16)
  convert_decimal_to_alphabet(decimal_value, alphabet)
end