/usr/lib/ruby/vendor_ruby/metriks/ewma.rb is in ruby-metriks 0.9.9.6-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 | require 'atomic'
module Metriks
class EWMA
INTERVAL = 5.0
SECONDS_PER_MINUTE = 60.0
ONE_MINUTE = 1
FIVE_MINUTES = 5
FIFTEEN_MINUTES = 15
M1_ALPHA = 1 - Math.exp(-INTERVAL / SECONDS_PER_MINUTE / ONE_MINUTE)
M5_ALPHA = 1 - Math.exp(-INTERVAL / SECONDS_PER_MINUTE / FIVE_MINUTES)
M15_ALPHA = 1 - Math.exp(-INTERVAL / SECONDS_PER_MINUTE / FIFTEEN_MINUTES)
def self.new_m1
new(M1_ALPHA, INTERVAL)
end
def self.new_m5
new(M5_ALPHA, INTERVAL)
end
def self.new_m15
new(M15_ALPHA, INTERVAL)
end
def initialize(alpha, interval)
@alpha = alpha
@interval = interval
@initialized = false
@rate = Atomic.new(0.0)
@uncounted = Atomic.new(0)
end
def clear
@initialized = false
@rate.value = 0.0
@uncounted.value = 0
end
def update(value)
@uncounted.update { |v| v + value }
end
def tick
count = @uncounted.swap(0)
instant_rate = count / @interval.to_f
if @initialized
@rate.update { |v| v + @alpha * (instant_rate - v) }
else
@rate.value = instant_rate
@initialized = true
end
end
def rate
@rate.value
end
end
end
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