Class: Metriks::Histogram
- Inherits:
-
Object
- Object
- Metriks::Histogram
- Defined in:
- lib/metriks/histogram.rb
Constant Summary collapse
- DEFAULT_SAMPLE_SIZE =
1028
- DEFAULT_ALPHA =
0.015
Class Method Summary collapse
Instance Method Summary collapse
- #clear ⇒ Object
- #count ⇒ Object
-
#initialize(sample) ⇒ Histogram
constructor
A new instance of Histogram.
- #max ⇒ Object
- #max=(potential_max) ⇒ Object
- #mean ⇒ Object
- #min ⇒ Object
- #min=(potential_min) ⇒ Object
- #snapshot ⇒ Object
- #stddev ⇒ Object
- #sum ⇒ Object
- #update(value) ⇒ Object
- #update_variance(value) ⇒ Object
- #variance ⇒ Object
Constructor Details
#initialize(sample) ⇒ Histogram
Returns a new instance of Histogram.
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# File 'lib/metriks/histogram.rb', line 18 def initialize(sample) @sample = sample @count = Atomic.new(0) @min = Atomic.new(nil) @max = Atomic.new(nil) @sum = Atomic.new(0) @variance = Atomic.new([ -1, 0 ]) end |
Class Method Details
.new_exponentially_decaying ⇒ Object
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# File 'lib/metriks/histogram.rb', line 14 def self. new(Metriks::ExponentiallyDecayingSample.new(DEFAULT_SAMPLE_SIZE, DEFAULT_ALPHA)) end |
.new_uniform ⇒ Object
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# File 'lib/metriks/histogram.rb', line 10 def self.new_uniform new(Metriks::UniformSample.new(DEFAULT_SAMPLE_SIZE)) end |
Instance Method Details
#clear ⇒ Object
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# File 'lib/metriks/histogram.rb', line 27 def clear @sample.clear @count.value = 0 @min.value = nil @max.value = nil @sum.value = 0 @variance.value = [ -1, 0 ] end |
#count ⇒ Object
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# File 'lib/metriks/histogram.rb', line 49 def count @count.value end |
#max ⇒ Object
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# File 'lib/metriks/histogram.rb', line 57 def max count > 0 ? @max.value : 0.0 end |
#max=(potential_max) ⇒ Object
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# File 'lib/metriks/histogram.rb', line 77 def max=(potential_max) done = false while !done current_max = @max.value done = (!current_max.nil? && current_max >= potential_max) || @max.compare_and_swap(current_max, potential_max) end end |
#mean ⇒ Object
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# File 'lib/metriks/histogram.rb', line 65 def mean count > 0 ? @sum.value / count : 0.0 end |
#min ⇒ Object
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# File 'lib/metriks/histogram.rb', line 61 def min count > 0 ? @min.value : 0.0 end |
#min=(potential_min) ⇒ Object
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# File 'lib/metriks/histogram.rb', line 86 def min=(potential_min) done = false while !done current_min = @min.value done = (!current_min.nil? && current_min <= potential_min) || @min.compare_and_swap(current_min, potential_min) end end |
#snapshot ⇒ Object
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# File 'lib/metriks/histogram.rb', line 45 def snapshot @sample.snapshot end |
#stddev ⇒ Object
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# File 'lib/metriks/histogram.rb', line 69 def stddev count > 0 ? variance ** 0.5 : 0.0 end |
#sum ⇒ Object
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# File 'lib/metriks/histogram.rb', line 53 def sum @sum.value end |
#update(value) ⇒ Object
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# File 'lib/metriks/histogram.rb', line 36 def update(value) @count.update { |v| v + 1 } @sample.update(value) self.max = value self.min = value @sum.update { |v| v + value } update_variance(value) end |
#update_variance(value) ⇒ Object
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# File 'lib/metriks/histogram.rb', line 95 def update_variance(value) @variance.update do |old_values| new_values = Array.new(2) if old_values[0] == -1 new_values[0] = value new_values[1] = 0 else old_m = old_values[0] old_s = old_values[1] new_m = old_m + ((value - old_m) / count) new_s = old_s + ((value - old_m) * (value - new_m)) new_values[0] = new_m new_values[1] = new_s end new_values end end |
#variance ⇒ Object
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# File 'lib/metriks/histogram.rb', line 73 def variance count <= 1 ? 0.0 : @variance.value[1] / (count - 1) end |