Class: Spectator::DistributionSummary

Inherits:
Object
  • Object
show all
Defined in:
lib/spectator/distribution_summary.rb

Overview

Track the sample distribution of events. An example would be the response sizes for requests hitting an http server.

The class will report measurements for the total amount, the count, max, and the total of the square of the amounts recorded (useful for computing a standard deviation)

Instance Method Summary collapse

Constructor Details

#initialize(id) ⇒ DistributionSummary

Initialize a new DistributionSummary instance with a given id



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# File 'lib/spectator/distribution_summary.rb', line 12

def initialize(id)
  @id = id
  @count = AtomicNumber.new(0)
  @total_amount = AtomicNumber.new(0)
  @total_sq = AtomicNumber.new(0)
  @max = AtomicNumber.new(Float::NAN)
end

Instance Method Details

#count ⇒ Object

Get the current amount



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# File 'lib/spectator/distribution_summary.rb', line 30

def count
  @count.get
end

#measure ⇒ Object

Get a list of measurements, and reset the stats The stats returned are the current count, the total amount, the sum of the square of the amounts recorded, and the max value



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# File 'lib/spectator/distribution_summary.rb', line 42

def measure
  cnt = Measure.new(@id.with_stat('count'), @count.get_and_set(0))
  tot = Measure.new(@id.with_stat('totalAmount'),
                    @total_amount.get_and_set(0))
  tot_sq = Measure.new(@id.with_stat('totalOfSquares'),
                       @total_sq.get_and_set(0))
  mx = Measure.new(@id.with_stat('max'), @max.get_and_set(Float::NAN))

  [cnt, tot, tot_sq, mx]
end

#record(amount) ⇒ Object

Update the statistics kept by the summary with the specified amount.



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# File 'lib/spectator/distribution_summary.rb', line 21

def record(amount)
  return if amount < 0
  @count.add_and_get(1)
  @total_amount.add_and_get(amount)
  @total_sq.add_and_get(amount * amount)
  @max.max(amount)
end

#total_amount ⇒ Object

Return the total amount



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# File 'lib/spectator/distribution_summary.rb', line 35

def total_amount
  @total_amount.get
end