Pipeling Multiple REDIS Commands in Ruby

pipelined_example.rb

Pipeliner.pipeline redis do |pipe|
  objects.each do |object|
    pipe.enqueue redis.hgetall(object.key) do |result|
      object.values = result
    end
  end
end

pipeliner.rb

class Pipeliner
  def initialize(redis)
    @redis = redis
    @cmds = []
  end

  def enqueue(future, &proc)
    @cmds << { future: future, callback: proc }
  end

  def wait
    @cmds.each do |c|
      while c[:future].value.is_a?(Redis::FutureNotReady)
        sleep(1.0 / 100.0)
      end

      c[:callback].call c[:future].value
    end
  end

  def self.pipeline(redis, &proc)
    # Executes callbacks with each result. This blocks.
    pipeliner = Pipeliner.new redis
    redis.pipelined do
      proc.call pipeliner
    end

    pipeliner.wait
  end
end

source: http://mrdanadams.com/2012/pipeline-redis-commands-ruby/