Class: BubbleWrap::Reactor::Queue

Inherits:
Object
  • Object
show all
Defined in:
motion/reactor/queue.rb

Overview

A GCD scheduled, linear queue.

This class provides a simple “Queue” like abstraction on top of the GCD scheduler.

Useful as an API sugar for stateful protocols

q = BubbleWrap::Reactor::Queue.new
q.push('one', 'two', 'three')
3.times do
  q.pop{ |msg| puts(msg) }
end

Instance Method Summary collapse

Constructor Details

#initialize ⇒ Queue

Create a new queue



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# File 'motion/reactor/queue.rb', line 18

def initialize
  @items = []
end

Instance Method Details

#empty? ⇒ Boolean

Is the queue empty?

Returns:

  • (Boolean) 


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# File 'motion/reactor/queue.rb', line 23

def empty?
  @items.empty?
end

#pop(*args, &blk) ⇒ Object

Pop items off the queue, running the block on the work queue. The pop will not happen immediately, but at some point in the future, either in the next tick, if the queue has data, or when the queue is populated.



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# File 'motion/reactor/queue.rb', line 44

def pop(*args, &blk)
  cb = proc do
    blk.call(*args)
  end
  ::BubbleWrap::Reactor.schedule do
    if @items.empty?
      @popq << cb
    else
      cb.call @items.shift
    end
  end
  nil # Always returns nil
end

#push(*items) ⇒ Object

Push items onto the work queue. The items will not appear in the queue immediately, but will be scheduled for addition.



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# File 'motion/reactor/queue.rb', line 34

def push(*items)
  ::BubbleWrap::Reactor.schedule do
    @items.push(*items)
    @popq.shift.call @items.shift until @items.empty? || @popq.empty?
  end
end

#size ⇒ Object

The size of the queue



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# File 'motion/reactor/queue.rb', line 28

def size
  @items.size
end