benchmark.rb

require 'benchmark'
require 'yab62'

def generate_token(length)
  (1..length).collect { (i = Kernel.rand(62); i += ((i < 10) ? 48 : ((i < 36) ? 55 : 61 ))).chr }.join
end

def generate_mod_token(length)
  (rand(62**length)).encode62.rjust(length,rand(62).encode62)
end

Benchmark.bm do |b|
  b.report("#{10000.to_s.rjust(5, " ")} mod_records"){ 10000.times{ generate_mod_token(5) } }
  b.report("#{10000.to_s.rjust(5, " ")} records    "){ 10000.times{ generate_token(5) } }
end

output

       user     system      total        real
10000 mod_records  0.010000   0.000000   0.010000 (  0.015380)
10000 records      0.050000   0.000000   0.050000 (  0.055107)