diff options
Diffstat (limited to 'actionpack/lib/action_dispatch/vendor/rack-mount-0.6.6.pre/rack/mount/analysis/histogram.rb')
-rw-r--r-- | actionpack/lib/action_dispatch/vendor/rack-mount-0.6.6.pre/rack/mount/analysis/histogram.rb | 74 |
1 files changed, 74 insertions, 0 deletions
diff --git a/actionpack/lib/action_dispatch/vendor/rack-mount-0.6.6.pre/rack/mount/analysis/histogram.rb b/actionpack/lib/action_dispatch/vendor/rack-mount-0.6.6.pre/rack/mount/analysis/histogram.rb new file mode 100644 index 0000000000..20aaa132f9 --- /dev/null +++ b/actionpack/lib/action_dispatch/vendor/rack-mount-0.6.6.pre/rack/mount/analysis/histogram.rb @@ -0,0 +1,74 @@ +module Rack::Mount + module Analysis + class Histogram < Hash #:nodoc: + attr_reader :count + + def initialize + @count = 0 + super(0) + expire_caches! + end + + def <<(value) + @count += 1 + self[value] += 1 if value + expire_caches! + self + end + + def sorted_by_frequency + sort_by { |_, value| value }.reverse! + end + + def max + @max ||= values.max || 0 + end + + def min + @min ||= values.min || 0 + end + + def mean + @mean ||= calculate_mean + end + + def standard_deviation + @standard_deviation ||= calculate_standard_deviation + end + + def upper_quartile_limit + @upper_quartile_limit ||= calculate_upper_quartile_limit + end + + def keys_in_upper_quartile + @keys_in_upper_quartile ||= compute_keys_in_upper_quartile + end + + private + def calculate_mean + count / size + end + + def calculate_variance + values.inject(0) { |sum, e| sum + (e - mean) ** 2 } / count.to_f + end + + def calculate_standard_deviation + Math.sqrt(calculate_variance) + end + + def calculate_upper_quartile_limit + mean + standard_deviation + end + + def compute_keys_in_upper_quartile + sorted_by_frequency.select { |_, value| value >= upper_quartile_limit }.map! { |key, _| key } + end + + def expire_caches! + @max = @min = @mean = @standard_deviation = nil + @keys_in_upper_quartile = nil + end + end + end +end |