Module: QueueProcessor::RootCalculation::StateMachines

Extended by:
ActiveSupport::Concern
Included in:
QueueProcessor::RootCalculation
Defined in:
lib/queue-processor/root_calculation/state_machines.rb

Instance Method Summary collapse

Instance Method Details

#check_and_start_dependencies ⇒ Object

After we finish our calculation (but not all the dependencies) look for dependent work to do and queue it. Set processing at to indicate that we have work in progress and later calculations should wait until the dependent calculations we created all finish.



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# File 'lib/queue-processor/root_calculation/state_machines.rb', line 87

def check_and_start_dependencies      
  if (has_dependent_calculations?)
    do_dependencies = self.with_lock do 
      if (self.processing_at.nil? && !calculation_stale?)
        update_attribute(:processing_at, delayed_job_queued_at)

        # this performs a callback, create_and_enqueue_dependent_calculations, to do queue up any calculations
        begin
          self.fire_events!(:start_dependent_calculations)    
        rescue StateMachine::Error => e
          Rails.logger.warn("#{self.describe}: invalid state transition for start_dependent_calculations: #{self.attributes}, changed: #{self.changed_attributes.map {|k,v| {k => {v => self.send(k) }}}}")
          raise e
        end
        
      else
        Rails.logger.warn("#{self.describe}: should have started dependencies, but something else set processing at ")
        false
      end        
    end
  end
end

#do_calculation ⇒ Object

Perform whatever calculation is associated with this class



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# File 'lib/queue-processor/root_calculation/state_machines.rb', line 33

def do_calculation
  Rails.logger.debug {"#{self.describe}: starting calculation"}

  # mark as waiting
  self.with_lock do
    
    begin
      self.fire_events!(:start_calculation) 
    rescue StateMachine::Error => e
      Rails.logger.warn("#{self.describe} invalid state transition starting calculation: #{self.attributes}, changed: #{self.changed_attributes.map {|k,v| {k => {v => self.send(k) }}}}")
      raise e
    end
  end    

  # callback to do the actual calculation
  perform_calculation

  # mark as calculated if we are still waiting (does this need to do a with_lock?)
  self.with_lock do
    self.fire_events(:finish_calculation) 
  end

  Rails.logger.debug {"#{self.describe}: finished calculation"}
end

#finish_work ⇒ Object

we’ve finished our calculation and all dependent calculations have finished



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# File 'lib/queue-processor/root_calculation/state_machines.rb', line 72

def finish_work
  Rails.logger.debug {"#{self.describe}: Cleaning up"}
  
  unless(processing_at.nil?)
    elapsed_time = (Time.now - self.processing_at)
    Rails.logger.info("#{self.describe}: finished after #{elapsed_time.round(2)} seconds")
    self.started_processing_at = self.processing_at # so observers can record how long it took to finish
    update_attribute(:processing_at, nil)
  end
  reload
end

#finished? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/queue-processor/root_calculation/state_machines.rb', line 15

def finished?
  processing_idle? && 
  calculation_available? && 
  dependent_calculations_idle? &&
  !something_queued?
end

#perform_work ⇒ Object

We’ve come off the queue and need to be calculated



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# File 'lib/queue-processor/root_calculation/state_machines.rb', line 24

def perform_work
  do_calculation
  check_and_start_dependencies 
  publish_calculation

  true
end

#publish_calculation ⇒ Object

Publish the calculation we just finished. The calculation is published before we’ve finished. We’re finished when we’ve queued any and all dependent calculations, but the number we just computed is available



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# File 'lib/queue-processor/root_calculation/state_machines.rb', line 61

def publish_calculation
  Rails.logger.debug {"#{self.describe}: publishing calculation"}
  
  # we can only transition from calulating => available.  If something else 
  # queued this calculation again, we'll keep the calculation unavailable
  self.with_lock do
    self.fire_events(:release_calculation)
  end
end

#reset_state_machines! ⇒ Object 



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# File 'lib/queue-processor/root_calculation/state_machines.rb', line 6

def reset_state_machines!
  reload
  update(:processing_at => nil,:calculation_state => 'available', :dependent_calculations_state => 'idle', :processing_state => 'idle')
end

#stuck? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/queue-processor/root_calculation/state_machines.rb', line 11

def stuck?
  (processing_waiting? || dependent_calculations_waiting?) && !dependencies_in_queue?
end