mperham--sidekiq/lib/sidekiq/processor.rb

require 'sidekiq/util'
require 'sidekiq/actor'

require 'sidekiq/middleware/server/active_record'
require 'sidekiq/middleware/server/retry_jobs'
require 'sidekiq/middleware/server/logging'

module Sidekiq
  ##
  # The Processor receives a message from the Manager and actually
  # processes it.  It instantiates the worker, runs the middleware
  # chain and then calls Sidekiq::Worker#perform.
  class Processor
    STATS_TIMEOUT = 180 * 24 * 60 * 60

    include Util
    include Actor

    task_class TaskThread

    def self.default_middleware
      Middleware::Chain.new do |m|
        m.add Middleware::Server::Logging
        m.add Middleware::Server::RetryJobs
        m.add Middleware::Server::ActiveRecord
      end
    end

    # store the actual working thread so we
    # can later kill if it necessary during
    # hard shutdown.
    attr_accessor :actual_work_thread

    def initialize(boss)
      @boss = boss
    end

    def process(work)
      msgstr = work.message
      queue = work.queue_name

      @actual_work_thread = Thread.current
      begin
        msg = Sidekiq.load_json(msgstr)
        klass  = msg['class'].constantize
        worker = klass.new
        worker.jid = msg['jid']

        stats(worker, msg, queue) do
          Sidekiq.server_middleware.invoke(worker, msg, queue) do
            worker.perform(*cloned(msg['args']))
          end
        end
      rescue Sidekiq::Shutdown
        # Had to force kill this job because it didn't finish
        # within the timeout.
      rescue Exception => ex
        handle_exception(ex, msg || { :message => msgstr })
        raise
      ensure
        work.acknowledge
      end

      @boss.async.processor_done(current_actor)
    end

    # See http://github.com/tarcieri/celluloid/issues/22
    def inspect
      "#<Processor #{to_s}>"
    end

    private

    def identity
      @str ||= "#{hostname}:#{process_id}-#{Thread.current.object_id}:default"
    end

    def stats(worker, msg, queue)
      redis do |conn|
        conn.multi do
          conn.sadd('workers', identity)
          conn.setex("worker:#{identity}:started", EXPIRY, Time.now.to_s)
          hash = {:queue => queue, :payload => msg, :run_at => Time.now.to_i }
          conn.setex("worker:#{identity}", EXPIRY, Sidekiq.dump_json(hash))
        end
      end

      begin
        yield
      rescue Exception
        redis do |conn|
          failed = "stat:failed:#{Time.now.utc.to_date}"
          result = conn.multi do
            conn.incrby("stat:failed", 1)
            conn.incrby(failed, 1)
          end
          conn.expire(failed, STATS_TIMEOUT) if result.last == 1
        end
        raise
      ensure
        redis do |conn|
          processed = "stat:processed:#{Time.now.utc.to_date}"
          result = conn.multi do
            conn.srem("workers", identity)
            conn.del("worker:#{identity}")
            conn.del("worker:#{identity}:started")
            conn.incrby("stat:processed", 1)
            conn.incrby(processed, 1)
          end
          conn.expire(processed, STATS_TIMEOUT) if result.last == 1
        end
      end
    end

    # Singleton classes are not clonable.
    SINGLETON_CLASSES = [ NilClass, TrueClass, FalseClass, Symbol, Fixnum, Float, Bignum ].freeze

    # Clone the arguments passed to the worker so that if
    # the message fails, what is pushed back onto Redis hasn't
    # been mutated by the worker.
    def cloned(ary)
      ary.map do |val|
        SINGLETON_CLASSES.include?(val.class) ? val : val.clone
      end
    end
  end
end