Class: ActiveUxid::Hash

Inherits:
Base
  • Object
show all
Defined in:
lib/active_uxid/hash.rb

Constant Summary

Constants inherited from Base

Base::ENCODING_LENGTH

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(id) ⇒ Hash

Returns a new instance of Hash.



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# File 'lib/active_uxid/hash.rb', line 8

def initialize(id)
  @id = id
end

Class Method Details

.decode(id) ⇒ Object 



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# File 'lib/active_uxid/hash.rb', line 17

def self.decode(id)
  klass = new(id)
  klass.decode_uxid
end

.encode(id) ⇒ Object 



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# File 'lib/active_uxid/hash.rb', line 12

def self.encode(id)
  klass = new(id)
  klass.encode_uxid
end

Instance Method Details

#decode_uxid ⇒ Object 



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# File 'lib/active_uxid/hash.rb', line 26

def decode_uxid
  (uxid_decode_chars(@id) >> ENCODING_LENGTH) - ENCODING_SALT
end

#encode_uxid ⇒ Object 



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# File 'lib/active_uxid/hash.rb', line 22

def encode_uxid
  uxid_encode_chars((@id + ENCODING_SALT) << ENCODING_LENGTH)
end

#uxid_decode_chars(id) ⇒ Object 



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# File 'lib/active_uxid/hash.rb', line 44

def uxid_decode_chars(id)
  pos = 0
  num = 0
  len = id.length
  max = len - 1

  while pos < len
    pow = ENCODING_BASE**(max - pos)
    num += ENCODING_CHARS.index(id[pos]) * pow
    pos += 1
  end

  num
end

#uxid_encode_chars(id) ⇒ Object 



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# File 'lib/active_uxid/hash.rb', line 30

def uxid_encode_chars(id)
  return '0' if id.zero?
  return nil if id.negative?

  str = ''

  while id.positive?
    str = "#{ENCODING_CHARS[id % ENCODING_BASE]}#{str}"
    id /= ENCODING_BASE
  end

  str
end