Example use case for redis scripting branch

gistfile1.rb

require 'rubygems'
require 'redis'
require 'benchmark'

r = Redis.new
saddkey = <<LUA
    redis('SADD', KEYS[1], KEYS[2])
    return redis('SET', KEYS[2], ARGV[1])
LUA

sdelkeys = <<LUA
    deleted = 0
    for i, v in ipairs(redis('SMEMBERS', KEYS[1])) do
      deleted = deleted + redis('DEL', v)
    end
    deleted = deleted + redis('DEL', KEYS[1])
    return deleted
LUA

n = 1000
Benchmark.bm do |x|
  x.report("without eval") do
    n.times do
      r.set(:k1, "hello")
      r.sadd(:keys, :k1)
      r.set(:k2, "world")
      r.sadd(:keys, :k2)

      keys = r.smembers(:keys)
      keys.each do |k|
        r.del(k)
      end
      r.del(:keys)
    end
  end
  x.report("with eval   ") do
    n.times do
      r.eval(saddkey, 2, :keys, :k1, "hello")
      r.eval(saddkey, 2, :keys, :k2, "world")

      r.eval(sdelkeys, 1, :keys)
    end
  end
end

__END__

Sample run on my macbook pro:

      user     system      total        real
without eval  0.310000   0.250000   0.560000 (  0.968522)
with eval     0.140000   0.100000   0.240000 (  0.480805)