Class: Wakame::RuleEngine

Inherits:
Object
  • Object
show all
Defined in:
lib/wakame/rule_engine.rb

Constant Summary collapse

FORWARD_ATTRS = 
[:command_queue, :agent_monitor, :service_cluster, :master]

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(service_cluster, &blk) ⇒ RuleEngine

Returns a new instance of RuleEngine.



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# File 'lib/wakame/rule_engine.rb', line 31

def initialize(service_cluster, &blk)
  @service_cluster = service_cluster
  @triggers = []
  
  @active_jobs = {}
  @job_history = []
  @global_lock = nil
  instance_eval(&blk) if blk
end

Instance Attribute Details

#active_jobs ⇒ Object (readonly)

Returns the value of attribute active_jobs.



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# File 'lib/wakame/rule_engine.rb', line 13

def active_jobs
  @active_jobs
end

#triggers ⇒ Object (readonly)

Returns the value of attribute triggers.



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# File 'lib/wakame/rule_engine.rb', line 13

def triggers
  @triggers
end

Instance Method Details

#agent_monitor ⇒ Object 



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# File 'lib/wakame/rule_engine.rb', line 23

def agent_monitor
  master.agent_monitor
end

#cancel_action(job_id) ⇒ Object 



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# File 'lib/wakame/rule_engine.rb', line 62

def cancel_action(job_id)
  job_context = @active_jobs[job_id]
  if job_context.nil?
    Wakame.log.warn("JOB ID #{job_id} was not running.")
    return
  end
  
  return if job_context[:complete_at]

  root_act = job_context[:root_action]

  walk_subactions = proc { |a|
    if a.status == :running && (a.target_thread && a.target_thread.alive?) && a.target_thread != Thread.current
      Wakame.log.debug "Raising CancelBroadcast exception: #{a.class} #{a.target_thread}(#{a.target_thread.status}), current=#{Thread.current}"
      # Broadcast the special exception to all
      a.target_thread.raise(CancelBroadcast, "It's broadcasted from #{a.class}")
      # IMPORTANT: Ensure the worker thread to handle the exception.
      #Thread.pass
    end
    a.subactions.each { |n|
      walk_subactions.call(n)
    }
  }

  begin
    Thread.critical = true
    walk_subactions.call(root_act)
  ensure
    Thread.critical = false
    # IMPORTANT: Ensure the worker thread to handle the exception.
    Thread.pass
  end
end

#command_queue ⇒ Object 



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# File 'lib/wakame/rule_engine.rb', line 19

def command_queue
  master.command_queue
end

#create_job_context(trigger, root_action) ⇒ Object 



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# File 'lib/wakame/rule_engine.rb', line 48

def create_job_context(trigger, root_action)
  root_action.job_id = job_id = Wakame.gen_id

  @active_jobs[job_id] = {
    :job_id=>job_id,
    :src_trigger=>trigger,
    :create_at=>Time.now,
    :start_at=>nil, 
    :complete_at=>nil,
    :root_action=>root_action,
    :notes=>{}
  }
end

#master ⇒ Object 



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# File 'lib/wakame/rule_engine.rb', line 15

def master
  service_cluster.master
end

#register_trigger(trigger) ⇒ Object 



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# File 'lib/wakame/rule_engine.rb', line 41

def register_trigger(trigger)
  Wakame.log.debug("Registering trigger #{trigger.class}")
  trigger.bind_engine(self)
  trigger.register_hooks
  @triggers << trigger
end

#run_action(action) ⇒ Object 



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# File 'lib/wakame/rule_engine.rb', line 96

def run_action(action)
  job_context = @active_jobs[action.job_id]
  raise "The job session is killed.: job_id=#{action.job_id}" if job_context.nil?

  if action.acquire_lock
    if @global_lock.nil?
      @global_lock = action.job_id
    else
      unless @global_lock == action.job_id
        raise GlobalLockError, "Global Lock is already acquired by the JobID: #{@global_lock}"
      end
    end
  end

  EM.next_tick {

    begin
      
      if job_context[:start_at].nil?
        job_context[:start_at] = Time.new
        ED.fire_event(Event::JobStart.new(action.job_id))
      end

      EM.defer proc {
        res = nil
        begin
          action.bind_thread(Thread.current)
          action.status = :running
          Wakame.log.debug("Start action : #{action.class.to_s} triggered by [#{action.trigger.class}]")
          ED.fire_event(Event::ActionStart.new(action))
          begin
            action.run
            action.completion_status = :succeeded
            Wakame.log.debug("Complete action : #{action.class.to_s}")
            ED.fire_event(Event::ActionComplete.new(action))
          end
        rescue CancelBroadcast => e
          Wakame.log.info("Received cancel signal: #{e}")
          action.completion_status = :canceled
          begin
            action.on_canceled
          rescue => e
            Wakame.log.error(e)
          end
          ED.fire_event(Event::ActionFailed.new(action, e))
          res = e
        rescue => e
          Wakame.log.debug("Failed action : #{action.class.to_s} due to #{e}")
          Wakame.log.error(e)
          action.completion_status = :failed
          begin
            action.on_failed
          rescue => e
            Wakame.log.error(e)
          end
          ED.fire_event(Event::ActionFailed.new(action, e))
          # Escalate the cancelation event to parents.
          unless action.parent_action.nil?
            action.parent_action.notify(e)
          end
          # Force to cancel the current job when the root action ignored the elevated exception.
          if action === job_context[:root_action]
            Wakame.log.warn("The escalated exception (#{e.class}) has reached to the root action (#{action.class}). Forcing to cancel the current job #{job_context[:job_id]}")
            cancel_action(job_context[:job_id]) #rescue Wakame.log.error($!)
          end
          res = e
        ensure
          action.status = :complete
          action.bind_thread(nil)
        end

        res
      }, proc { |res|
        unless @active_jobs.has_key?(job_context[:job_id])
          next
        end
        
        jobary = []
        job_context[:root_action].walk_subactions {|a| jobary << a }
        Wakame.log.debug(jobary.collect{|a| {a.class.to_s=>a.status}}.inspect)

        if res.is_a?(Exception)
          job_context[:exception]=res
        end

        if jobary.all? { |act| act.status == :complete }

          if jobary.all? { |act| act.completion_status == :succeeded }
            ED.fire_event(Event::JobComplete.new(action.job_id))
          else
            ED.fire_event(Event::JobFailed.new(action.job_id, res))
          end

          job_context[:complete_at]=Time.now
          @job_history << job_context
          @active_jobs.delete(job_context[:job_id])
          @global_lock = nil
        end
      }
    rescue => e
      Wakame.log.error(e)
    end
  }
end

#service_cluster ⇒ Object 



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# File 'lib/wakame/rule_engine.rb', line 27

def service_cluster
  @service_cluster
end