Class: QueueIt::Queue

Inherits:
ApplicationRecord show all
Defined in:
app/models/queue_it/queue.rb

Instance Method Summary collapse

Instance Method Details

#empty? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'app/models/queue_it/queue.rb', line 18

def empty?
  size.zero?
end

#get_next_in_queue_generic ⇒ Object 



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# File 'app/models/queue_it/queue.rb', line 43

def get_next_in_queue_generic
  next_node = ActiveRecord::Base.transaction do
    lock!
    old_head_node = head_node.lock!
    old_second_node = old_head_node.child_node.lock!
    old_tail_node = tail_node.lock!
    nodes.where.not(kind: :any).find_each { |node| node.update!(kind: :any) }
    old_head_node.update!(kind: :tail, parent_node: old_tail_node)
    old_second_node.update!(kind: :head, parent_node: nil)
    old_head_node
  end
  next_node
end

#get_next_in_queue_with_length_two ⇒ Object 



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# File 'app/models/queue_it/queue.rb', line 30

def get_next_in_queue_with_length_two
  next_node = ActiveRecord::Base.transaction do
    lock!
    old_head_node = head_node.lock!
    old_tail_node = tail_node.lock!
    nodes.where.not(kind: :any).each { |node| node.update!(kind: :any) }
    old_head_node.update!(kind: :tail, parent_node: old_tail_node)
    old_tail_node.update!(kind: :head, parent_node: nil)
    old_head_node
  end
  next_node
end

#head_node ⇒ Object 



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# File 'app/models/queue_it/queue.rb', line 6

def head_node
  nodes.find_by(kind: :head)
end

#one_node? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'app/models/queue_it/queue.rb', line 22

def one_node?
  size == 1
end

#push_in_head(nodable) ⇒ Object 



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# File 'app/models/queue_it/queue.rb', line 75

def push_in_head(nodable)
  ActiveRecord::Base.transaction do
    lock!
    old_head_node = head_node.lock!
    kind = one_node? ? :tail : :any
    old_head_node.update!(kind: kind)
    new_head_node = nodes.create!(nodable: nodable, kind: :head)
    old_head_node.update!(parent_node: new_head_node)
  end
end

#push_in_tail(nodable) ⇒ Object 



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# File 'app/models/queue_it/queue.rb', line 86

def push_in_tail(nodable)
  ActiveRecord::Base.transaction do
    lock!
    old_tail_node = tail_node.lock!
    old_tail_node.update!(kind: :any)
    nodes.create!(nodable: nodable, kind: :tail, parent_node: old_tail_node)
  end
end

#push_node_when_queue_length_is_one(nodable, in_head) ⇒ Object 



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# File 'app/models/queue_it/queue.rb', line 64

def push_node_when_queue_length_is_one(nodable, in_head)
  if in_head
    push_in_head(nodable)
  else
    ActiveRecord::Base.transaction do
      lock!
      nodes.create!(nodable: nodable, kind: :tail, parent_node: head_node)
    end
  end
end

#push_node_when_queue_length_is_zero(nodable) ⇒ Object 



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# File 'app/models/queue_it/queue.rb', line 57

def push_node_when_queue_length_is_zero(nodable)
  ActiveRecord::Base.transaction do
    lock!
    nodes.create!(nodable: nodable, kind: :head)
  end
end

#size ⇒ Object 



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# File 'app/models/queue_it/queue.rb', line 14

def size
  nodes.size
end

#tail_node ⇒ Object 



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# File 'app/models/queue_it/queue.rb', line 10

def tail_node
  nodes.find_by(kind: :tail)
end

#two_nodes? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'app/models/queue_it/queue.rb', line 26

def two_nodes?
  size == 2
end