resque/resque-loner

require 'resque-loner/legacy_helpers'

module Resque
  module Plugins
    module Loner
      class Helpers
        extend Resque::Plugins::Loner::LegacyHelpers

        def self.loner_queued?(queue, item)
          return false unless item_is_a_unique_job?(item)
          redis.get(unique_job_queue_key(queue, item)) == '1'
        end

        def self.mark_loner_as_queued(queue, item)
          return unless item_is_a_unique_job?(item)
          key = unique_job_queue_key(queue, item)
          redis.set(key, 1)
          unless (ttl = item_ttl(item)) == -1 # no need to incur overhead for default value
            redis.expire(key, ttl)
          end
        end

        def self.mark_loner_as_unqueued(queue, job)
          item = job.is_a?(Resque::Job) ? job.payload : job
          return unless item_is_a_unique_job?(item)
          unless (ttl = loner_lock_after_execution_period(item)) == 0
            redis.expire(unique_job_queue_key(queue, item), ttl)
          else
            redis.del(unique_job_queue_key(queue, item))
          end
        end

        def self.unique_job_queue_key(queue, item)
          job_key = constantize(item[:class] || item['class']).redis_key(item)
          "loners:queue:#{queue}:job:#{job_key}"
        end

        def self.item_is_a_unique_job?(item)
          begin
            klass = constantize(item[:class] || item['class'])
            klass.included_modules.include?(::Resque::Plugins::UniqueJob)
          rescue
            false # Resque testsuite also submits strings as job classes while Resque.enqueue'ing,
          end     # so resque-loner should not start throwing up when that happens.
        end

        def self.item_ttl(item)
          begin
            constantize(item[:class] || item['class']).loner_ttl
          rescue
            -1
          end
        end

        def self.loner_lock_after_execution_period(item)
          begin
            constantize(item[:class] || item['class']).loner_lock_after_execution_period
          rescue
            0
          end
        end

        def self.job_destroy(queue, klass, *args)
          klass = klass.to_s
          redis_queue = "queue:#{queue}"

          redis.lrange(redis_queue, 0, -1).each do |string|
            json   = decode(string)

            match  = json['class'] == klass
            match &= json['args'] == args unless args.empty?

            if match
              Resque::Plugins::Loner::Helpers.mark_loner_as_unqueued(queue, json)
            end
          end
        end

        def self.cleanup_loners(queue)
          keys = redis.keys("loners:queue:#{queue}:job:*")
          redis.del(*keys) unless keys.empty?
        end
      end
    end
  end
end