colinsurprenant/redstorm

require 'red_storm'
require 'examples/native/word_count_bolt'
require 'redis'
require 'thread'

module RedStorm
  module Examples
    # RedisWordSpout reads the Redis queue "test" on localhost:6379
    # and emits each word items pop'ed from the queue.
    class RedisWordSpout
      def open(conf, context, collector)
        @collector = collector
        @q = Queue.new
        @redis_reader = detach_redis_reader
      end

      def next_tuple
        # per doc nextTuple should not block, and sleep a bit when there's no data to process.
        if @q.size > 0
          @collector.emit(Values.new(@q.pop))
        else
          sleep(0.1)
        end
      end

      def get_component_configuration
      end

      def declare_output_fields(declarer)
        declarer.declare(Fields.new("word"))
      end

      private

      def detach_redis_reader
        Thread.new do
          Thread.current.abort_on_exception = true

          redis = Redis.new(:host => "localhost", :port => 6379)
          loop do
            if data = redis.blpop("test", 0)
              @q << data[1]
            end
          end
        end
      end
    end

    class LocalRedisWordCountTopology
      RedStorm::Configuration.topology_class = self

      def start(base_class_path, env)
        builder = TopologyBuilder.new
        builder.setSpout('RedisWordSpout', JRubySpout.new(base_class_path, "RedStorm::Examples::RedisWordSpout", []), 1)
        builder.setBolt('WordCountBolt', JRubyBolt.new(base_class_path, "RedStorm::Examples::WordCountBolt", []), 3).fieldsGrouping('RedisWordSpout', Fields.new("word"))

        conf = Backtype::Config.new
        conf.setDebug(true)
        conf.setMaxTaskParallelism(3)

        cluster = LocalCluster.new
        cluster.submitTopology("redis_word_count", conf, builder.createTopology)
        sleep(600)
        cluster.shutdown
      end
    end
  end
end