Class: Raktr::Queue

Inherits:
Object
  • Object
show all
Defined in:
lib/raktr/queue.rb

Overview

Note:

Pretty much an ‘EventMachine::Queue` rip-off.

A cross thread, Raktr scheduled, linear queue.

This class provides a simple queue abstraction on top of the scheduler.

It services two primary purposes:

  • API sugar for stateful protocols.

  • Pushing processing onto the reactor thread.

Author:

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(reactor) ⇒ Queue

Returns a new instance of Queue.

Parameters:

  • reactor (Reactor) 


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# File 'lib/raktr/queue.rb', line 31

def initialize( reactor )
    @raktr = reactor
    @items   = []
    @waiting = []
end

Instance Attribute Details

#raktr ⇒ Raktr (readonly)

Returns:



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# File 'lib/raktr/queue.rb', line 28

def raktr
  @raktr
end

Instance Method Details

#empty? ⇒ Boolean

Note:

This is a peek, it’s not thread safe, and may only tend toward accuracy.

Returns:

  • (Boolean) 


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# File 'lib/raktr/queue.rb', line 67

def empty?
    @items.empty?
end

#num_waiting ⇒ Integer

Note:

Accuracy cannot be guaranteed.

Returns Number of jobs that are currently waiting on the Queue for items to appear.

Returns:

  • (Integer) —

    Number of jobs that are currently waiting on the Queue for items to appear.



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# File 'lib/raktr/queue.rb', line 83

def num_waiting
    @waiting.size
end

#pop(&block) ⇒ Object

Parameters:

  • block (Block) —

    Block to be scheduled by the Reactor and passed an item from the queue as soon as one becomes available.



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# File 'lib/raktr/queue.rb', line 40

def pop( &block )
    @raktr.schedule do
        if @items.empty?
            @waiting << block
        else
            block.call @items.shift
        end
    end

    nil
end

#push(item) ⇒ Object Also known as: <<

Parameters:

  • item (Object) —

    Schedules an item for addition to the queue.



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# File 'lib/raktr/queue.rb', line 54

def push( item )
    @raktr.schedule do
        @items.push( item )
        @waiting.shift.call @items.shift until @items.empty? || @waiting.empty?
    end

    nil
end

#size ⇒ Integer

Note:

This is a peek, it’s not thread safe, and may only tend toward accuracy.

Returns Queue size.

Returns:

  • (Integer) —

    Queue size.



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# File 'lib/raktr/queue.rb', line 75

def size
    @items.size
end