Class: Qtrix::Matrix::QueuePrioritizer

Inherits:
Object
  • Object
show all
Defined in:
lib/qtrix/matrix/queue_prioritizer.rb

Overview

Maintains current prioritization of queues based on the state of all rows in the matrix.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(desired_distribution, heads, all_entries) ⇒ QueuePrioritizer

Returns a new instance of QueuePrioritizer.



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# File 'lib/qtrix/matrix/queue_prioritizer.rb', line 13

def initialize(desired_distribution, heads, all_entries)
  @desired_distribution = desired_distribution
  @heads = heads
  @all_entries = all_entries
  @new_head_picked = false
end

Instance Attribute Details

#all_entries ⇒ Object (readonly)

Returns the value of attribute all_entries.



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# File 'lib/qtrix/matrix/queue_prioritizer.rb', line 11

def all_entries
  @all_entries
end

#desired_distribution ⇒ Object (readonly)

Returns the value of attribute desired_distribution.



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# File 'lib/qtrix/matrix/queue_prioritizer.rb', line 11

def desired_distribution
  @desired_distribution
end

#heads ⇒ Object (readonly)

Returns the value of attribute heads.



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# File 'lib/qtrix/matrix/queue_prioritizer.rb', line 11

def heads
  @heads
end

Instance Method Details

#by_priority_of_tuple(context = {}) ⇒ Object 



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# File 'lib/qtrix/matrix/queue_prioritizer.rb', line 32

def by_priority_of_tuple(context={})
  lambda {|i, j| j[1] <=> i[1]}
end

#current_priority_of(queue) ⇒ Object 



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# File 'lib/qtrix/matrix/queue_prioritizer.rb', line 40

def current_priority_of(queue)
  if has_appeared_at_head_of_row?(queue.name) || @new_head_picked
    normal_priority_for queue
  else
    @new_head_picked = true
    starting_priority_for queue
  end
end

#current_priority_queue ⇒ Object 



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# File 'lib/qtrix/matrix/queue_prioritizer.rb', line 20

def current_priority_queue
  # Not a true priority queue, since we are sorting after all elements
  # are inserted
  queue = queue_priority_tuples_from desired_distribution
  prioritized_queue = queue.sort &by_priority_of_tuple
  to_simple_queues_from prioritized_queue
end

#entries_for(queue) ⇒ Object 



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# File 'lib/qtrix/matrix/queue_prioritizer.rb', line 65

def entries_for(queue)
   all_entries.select{|entry| entry.queue == queue.name}
end

#has_appeared_at_head_of_row?(queue_name) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/qtrix/matrix/queue_prioritizer.rb', line 49

def has_appeared_at_head_of_row?(queue_name)
  heads.include?(queue_name)
end

#normal_priority_for(queue) ⇒ Object 



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# File 'lib/qtrix/matrix/queue_prioritizer.rb', line 53

def normal_priority_for(queue)
  queue.resource_percentage / (1 + sum_of(entries_for(queue)))
end

#queue_priority_tuples_from(dist) ⇒ Object 



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# File 'lib/qtrix/matrix/queue_prioritizer.rb', line 28

def queue_priority_tuples_from(dist)
  dist.map{|queue| [queue, current_priority_of(queue)]}
end

#starting_priority_for(queue) ⇒ Object 



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# File 'lib/qtrix/matrix/queue_prioritizer.rb', line 57

def starting_priority_for(queue)
  queue.resource_percentage * 1000
end

#sum_of(entries) ⇒ Object 



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# File 'lib/qtrix/matrix/queue_prioritizer.rb', line 61

def sum_of(entries)
  entries.inject(0) {|memo, e| memo += e.value}
end

#to_simple_queues_from(prioritized_queue) ⇒ Object 



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# File 'lib/qtrix/matrix/queue_prioritizer.rb', line 36

def to_simple_queues_from(prioritized_queue)
  prioritized_queue.map {|tuple| tuple[0]}
end