Class: Async::Container::Statistics::Rate

Inherits:
Object
  • Object
show all
Defined in:
lib/async/container/statistics.rb

Overview

Tracks rate information over a sliding time window using a circular buffer.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(window: 60) ⇒ Rate

Initialize the event rate counter.



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# File 'lib/async/container/statistics.rb', line 17

def initialize(window: 60)
	@window = window
	@samples = [0] * @window
	@last_update = Array.new(@window, 0)
end

Instance Attribute Details

#window ⇒ Object (readonly)

The time window in seconds for rate calculations.



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# File 'lib/async/container/statistics.rb', line 24

def window
  @window
end

Instance Method Details

#add(value = 1, time: self.now) ⇒ Object

Add a value to the current time slot.



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# File 'lib/async/container/statistics.rb', line 35

def add(value = 1, time: self.now)
	index = time % @samples.size
	
	# If this slot hasn't been updated in a full window cycle, reset it
	if (time - @last_update[index]) >= @window
		@samples[index] = 0
	end
	
	@samples[index] += value
	@last_update[index] = time
end

#now ⇒ Object

Get the current time in seconds.



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# File 'lib/async/container/statistics.rb', line 28

def now
	::Process.clock_gettime(::Process::CLOCK_MONOTONIC).to_i
end

#per_minute(time: self.now) ⇒ Object

Get the rate per minute over the window.



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# File 'lib/async/container/statistics.rb', line 71

def per_minute(time: self.now)
	per_second(time: time) * 60
end

#per_second(time: self.now) ⇒ Object

Get the rate per second over the window.



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# File 'lib/async/container/statistics.rb', line 64

def per_second(time: self.now)
	total(time: time).to_f / @window
end

#total(time: self.now) ⇒ Object

Get the total count in the current window.



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# File 'lib/async/container/statistics.rb', line 50

def total(time: self.now)
	@samples.each_with_index.sum do |value, index|
		# Only count samples that are within the window (inclusive of window boundary)
		if (time - @last_update[index]) <= @window
			value
		else
			0
		end
	end
end