Randomizing in Ruby with Redis/Cycle/Kernel.rand

randomizing.rb

require 'redis'
@emails = ['foo@bar.com', 'bar@bar.com', 'baz@bar.com','car@bar.com']
@cycle_usage = {}
@redis_usage = {}
@random_usage = {}

def reset
  @cycle_usage = {}
  @pos = 0
  @redis_usage = {}
  @random_usage = {}
end 

def cycle
  email = @emails[@pos % @emails.size]
  @pos+=1
  @cycle_usage[email] = @cycle_usage[email] ? @cycle_usage[email] + 1 : 1
end

def random
  email = @emails[Kernel.rand(@emails.size)]
  @random_usage[email] = @random_usage[email] ? @random_usage[email] + 1 : 1
end

@redis = Redis.new
@redis.del 'emails'
@emails.each do |e|
  @redis.sadd 'emails', e
end

def redis_random
  item = @redis.srandmember 'emails'
  @redis_usage[item] = @redis_usage[item] ? @redis_usage[item]+1 : 1
end

def percentages(hash, total)
  hash.collect do |k, v|
    [k, v.to_f/total.to_f]
  end
end


[10, 100, 200, 500, 1000, 2000, 5000, 10000, 20000, 50000, 100000].each do |i|
  puts '#################################################################'
  puts "At #{i} elements"
  puts "------------------Redis Random-----------------------"
  reset; i.times {redis_random}
  puts percentages( @redis_usage, i).inspect

  puts "------------------Cycle-----------------------"
  reset; i.times {cycle}
  puts percentages( @cycle_usage, i).inspect

  puts "------------------Randomm Ruby-----------------------"
  reset; i.times {random}
  puts percentages( @random_usage, i).inspect
end

Results Over various scenarios

althea/spaghetti/sf[cycling_email_addresses]% ruby script/random_test.rb
#################################################################
At 10 elements
------------------Redis Random-----------------------
[["foo@bar.com", 0.4], ["car@bar.com", 0.4], ["baz@bar.com", 0.1], ["bar@bar.com", 0.1]]
------------------Cycle-----------------------
[["foo@bar.com", 0.3], ["bar@bar.com", 0.3], ["baz@bar.com", 0.2], ["car@bar.com", 0.2]]
------------------Randomm Ruby-----------------------
[["bar@bar.com", 0.2], ["car@bar.com", 0.4], ["baz@bar.com", 0.3], ["foo@bar.com", 0.1]]
#################################################################
At 100 elements
------------------Redis Random-----------------------
[["bar@bar.com", 0.14], ["car@bar.com", 0.36], ["foo@bar.com", 0.35], ["baz@bar.com", 0.15]]
------------------Cycle-----------------------
[["foo@bar.com", 0.25], ["bar@bar.com", 0.25], ["baz@bar.com", 0.25], ["car@bar.com", 0.25]]
------------------Randomm Ruby-----------------------
[["bar@bar.com", 0.28], ["baz@bar.com", 0.26], ["car@bar.com", 0.21], ["foo@bar.com", 0.25]]
#################################################################
At 200 elements
------------------Redis Random-----------------------
[["foo@bar.com", 0.315], ["car@bar.com", 0.345], ["bar@bar.com", 0.225], ["baz@bar.com", 0.115]]
------------------Cycle-----------------------
[["foo@bar.com", 0.25], ["bar@bar.com", 0.25], ["baz@bar.com", 0.25], ["car@bar.com", 0.25]]
------------------Randomm Ruby-----------------------
[["foo@bar.com", 0.295], ["baz@bar.com", 0.245], ["car@bar.com", 0.22], ["bar@bar.com", 0.24]]
#################################################################
At 500 elements
------------------Redis Random-----------------------
[["foo@bar.com", 0.378], ["baz@bar.com", 0.158], ["car@bar.com", 0.304], ["bar@bar.com", 0.16]]
------------------Cycle-----------------------
[["foo@bar.com", 0.25], ["bar@bar.com", 0.25], ["baz@bar.com", 0.25], ["car@bar.com", 0.25]]
------------------Randomm Ruby-----------------------
[["bar@bar.com", 0.27], ["baz@bar.com", 0.21], ["foo@bar.com", 0.256], ["car@bar.com", 0.264]]
#################################################################
At 1000 elements
------------------Redis Random-----------------------
[["foo@bar.com", 0.317], ["car@bar.com", 0.343], ["baz@bar.com", 0.183], ["bar@bar.com", 0.157]]
------------------Cycle-----------------------
[["foo@bar.com", 0.25], ["bar@bar.com", 0.25], ["baz@bar.com", 0.25], ["car@bar.com", 0.25]]
------------------Randomm Ruby-----------------------
[["foo@bar.com", 0.233], ["baz@bar.com", 0.262], ["bar@bar.com", 0.251], ["car@bar.com", 0.254]]
#################################################################
At 2000 elements
------------------Redis Random-----------------------
[["foo@bar.com", 0.344], ["baz@bar.com", 0.1635], ["car@bar.com", 0.3265], ["bar@bar.com", 0.166]]
------------------Cycle-----------------------
[["foo@bar.com", 0.25], ["bar@bar.com", 0.25], ["baz@bar.com", 0.25], ["car@bar.com", 0.25]]
------------------Randomm Ruby-----------------------
[["foo@bar.com", 0.2435], ["bar@bar.com", 0.249], ["baz@bar.com", 0.271], ["car@bar.com", 0.2365]]
#################################################################
At 5000 elements
------------------Redis Random-----------------------
[["foo@bar.com", 0.3308], ["car@bar.com", 0.3352], ["baz@bar.com", 0.17], ["bar@bar.com", 0.164]]
------------------Cycle-----------------------
[["foo@bar.com", 0.25], ["bar@bar.com", 0.25], ["baz@bar.com", 0.25], ["car@bar.com", 0.25]]
------------------Randomm Ruby-----------------------
[["foo@bar.com", 0.2544], ["bar@bar.com", 0.2416], ["baz@bar.com", 0.256], ["car@bar.com", 0.248]]
#################################################################
At 10000 elements
------------------Redis Random-----------------------
[["baz@bar.com", 0.1677], ["foo@bar.com", 0.3329], ["car@bar.com", 0.3344], ["bar@bar.com", 0.165]]
------------------Cycle-----------------------
[["foo@bar.com", 0.25], ["bar@bar.com", 0.25], ["baz@bar.com", 0.25], ["car@bar.com", 0.25]]
------------------Randomm Ruby-----------------------
[["foo@bar.com", 0.2541], ["bar@bar.com", 0.2479], ["baz@bar.com", 0.2499], ["car@bar.com", 0.2481]]
#################################################################
At 20000 elements
------------------Redis Random-----------------------
[["foo@bar.com", 0.33245], ["bar@bar.com", 0.1707], ["car@bar.com", 0.3304], ["baz@bar.com", 0.16645]]
------------------Cycle-----------------------
[["foo@bar.com", 0.25], ["bar@bar.com", 0.25], ["baz@bar.com", 0.25], ["car@bar.com", 0.25]]
------------------Randomm Ruby-----------------------
[["foo@bar.com", 0.25315], ["car@bar.com", 0.24995], ["bar@bar.com", 0.2473], ["baz@bar.com", 0.2496]]
#################################################################
At 50000 elements
------------------Redis Random-----------------------
[["bar@bar.com", 0.1655], ["baz@bar.com", 0.16752], ["car@bar.com", 0.33672], ["foo@bar.com", 0.33026]]
------------------Cycle-----------------------
[["foo@bar.com", 0.25], ["bar@bar.com", 0.25], ["baz@bar.com", 0.25], ["car@bar.com", 0.25]]
------------------Randomm Ruby-----------------------
[["foo@bar.com", 0.24934], ["bar@bar.com", 0.25084], ["car@bar.com", 0.2496], ["baz@bar.com", 0.25022]]
#################################################################
At 100000 elements
------------------Redis Random-----------------------
[["car@bar.com", 0.33158], ["baz@bar.com", 0.16556], ["bar@bar.com", 0.16666], ["foo@bar.com", 0.3362]]
------------------Cycle-----------------------
[["foo@bar.com", 0.25], ["bar@bar.com", 0.25], ["baz@bar.com", 0.25], ["car@bar.com", 0.25]]
------------------Randomm Ruby-----------------------
[["baz@bar.com", 0.2522], ["bar@bar.com", 0.2504], ["car@bar.com", 0.24905], ["foo@bar.com", 0.24835]]
althea/spaghetti/sf[cycling_email_addresses]%