Class: StringBase

Inherits:
Object show all
Defined in:
lib/common/string_base.rb

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(keys: nil, multiplier: 1) ⇒ StringBase

Returns a new instance of StringBase.



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# File 'lib/common/string_base.rb', line 39

def initialize keys: nil, multiplier: 1
  @keys = keys
  @multiplier = multiplier
end

Class Method Details

.decode(text) ⇒ Object 



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# File 'lib/common/string_base.rb', line 13

def decode text
  short.decode text
end

.encode(text) ⇒ Object 



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# File 'lib/common/string_base.rb', line 9

def encode text
  short.encode text
end

.long ⇒ Object 



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# File 'lib/common/string_base.rb', line 25

def long
  new(keys: LONG_KEYS)
end

.medium ⇒ Object 



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# File 'lib/common/string_base.rb', line 21

def medium
  new(keys: MDEIUM_KEYS)
end

.short ⇒ Object 



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# File 'lib/common/string_base.rb', line 17

def short
  new(keys: SHORT_KEYS, multiplier: 99)
end

.uid ⇒ Object 



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# File 'lib/common/string_base.rb', line 29

def uid
  [
    Time.now.to_f,
    rand.to_s.sub('0.',''),
  ].join('').to_s.sub('.','').to_i.to_s(36)[0, 16]
end

Instance Method Details

#decode(string) ⇒ Object 



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# File 'lib/common/string_base.rb', line 56

def decode string
  ring = Hash[@keys.chars.map.with_index.to_a]
  base = @keys.length
  ret = string.reverse.chars.map.with_index.inject(0) do |sum, (char, i)|
    sum + ring[char] * (base**i)
  end
  raise 'Invalid decode base' if ret % @multiplier > 0
  ret / @multiplier
end

#encode(value) ⇒ Object 



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# File 'lib/common/string_base.rb', line 44

def encode value
  value = value * @multiplier
  ring = Hash[@keys.chars.map.with_index.to_a.map(&:reverse)]
  base = @keys.length
  result = []
  until value == 0
    result << ring[ value % base ]
    value /= base
  end
  result.reverse.join
end

#extract(url_part) ⇒ Object

extract ID from url



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# File 'lib/common/string_base.rb', line 67

def extract url_part
  id_str = url_part.split('-').last
  return nil unless id_str
  StringBase.decode(id_str) rescue nil
end