Simple Ruby method to do a multi-set on a bunch of Redis keys together.

multiset.rb

require 'redis'

# Simple Lua script to set all the given keys to the given values.
# Note the magic of this is that it's done atomically. Yay atomicity!
MultiSetScript = <<EOF
  for i = 1, #KEYS do
    redis.call('SET', KEYS[i], ARGV[i])
  end
EOF

def multi_set(keys, vals)
  unless keys.is_a? Array and vals.is_a? Array
    raise ArgumentError, "keys and values must be arrays"
  end

  unless keys.length == vals.length
    raise ArgumentError, "number of keys must be same as number of values"
  end

  Redis.new.eval MultiSetScript, keys, vals
end