Ruby on Rails - generating bit.ly style uuids

Question

I\'m trying to generate UUIDs with the same style as bit.ly urls like:

http://bit.ly/aUekJP

or cloudapp ones:

http://cl.ly/1hVU         


        

Answer 1

I found this to be short and reliable:

def create_uuid(prefix=nil)
  time   = (Time.now.to_f * 10_000_000).to_i
  jitter = rand(10_000_000) 
  key    = "#{jitter}#{time}".to_i.to_s(36)
  [prefix, key].compact.join('_')
end

This spits out unique keys that look like this: '3qaishe3gpp07w2m'
Reduce the 'jitter' size to reduce the key size.

Caveat: This is not guaranteed unique (use SecureRandom.uuid for that), but it is highly reliable:

10_000_000.times.map {create_uuid}.uniq.length == 10_000_000