debian-mirror-gitlab/derailed-benchmarks/lib/derailed_benchmarks/stats_from_dir.rb
2020-04-08 18:37:08 +05:30

128 lines
3.6 KiB
Ruby

# frozen_string_literal: true
require 'bigdecimal'
require 'statistics'
module DerailedBenchmarks
# A class used to read several benchmark files
# it will parse each file, then sort by average
# time of benchmarks. It can be used to find
# the fastest and slowest examples and give information
# about them such as what the percent difference is
# and if the results are statistically significant
#
# Example:
#
# branch_info = {}
# branch_info["loser"] = { desc: "Old commit", time: Time.now, file: dir.join("loser.bench.txt"), name: "loser" }
# branch_info["winner"] = { desc: "I am the new commit", time: Time.now + 1, file: dir.join("winner.bench.txt"), name: "winner" }
# stats = DerailedBenchmarks::StatsFromDir.new(branch_info)
#
# stats.newest.average # => 10.5
# stats.oldest.average # => 11.0
# stats.significant? # => true
# stats.x_faster # => "1.0476"
class StatsFromDir
FORMAT = "%0.4f"
attr_reader :stats, :oldest, :newest
def initialize(hash)
@files = []
hash.each do |branch, info_hash|
file = info_hash.fetch(:file)
desc = info_hash.fetch(:desc)
time = info_hash.fetch(:time)
@files << StatsForFile.new(file: file, desc: desc, time: time, name: branch)
end
@files.sort_by! { |f| f.time }
@oldest = @files.first
@newest = @files.last
end
def call
@files.each(&:call)
stats_95 = statistical_test(confidence: 95)
# If default check is good, see if we also pass a more rigorous test
# if so, then use the more rigourous test
if stats_95[:alternative]
stats_99 = statistical_test(confidence: 99)
@stats = stats_99 if stats_99[:alternative]
end
@stats ||= stats_95
self
end
def statistical_test(series_1=oldest.values, series_2=newest.values, confidence: 95)
StatisticalTest::KSTest.two_samples(
group_one: series_1,
group_two: series_2,
alpha: (100 - confidence) / 100.0
)
end
def significant?
@stats[:alternative]
end
def d_max
@stats[:d_max].to_f
end
def d_critical
@stats[:d_critical].to_f
end
def x_faster
(oldest.median/newest.median).to_f
end
def faster?
newest.median < oldest.median
end
def percent_faster
(((oldest.median - newest.median) / oldest.median).to_f * 100)
end
def change_direction
if faster?
"FASTER 🚀🚀🚀"
else
"SLOWER 🐢🐢🐢"
end
end
def align
" " * (percent_faster.to_s.index(".") - x_faster.to_s.index("."))
end
def banner(io = Kernel)
io.puts
if significant?
io.puts "❤️ ❤️ ❤️ (Statistically Significant) ❤️ ❤️ ❤️"
else
io.puts "👎👎👎(NOT Statistically Significant) 👎👎👎"
end
io.puts
io.puts "[#{newest.name}] #{newest.desc.inspect} - (#{newest.median} seconds)"
io.puts " #{change_direction} by:"
io.puts " #{align}#{FORMAT % x_faster}x [older/newer]"
io.puts " #{FORMAT % percent_faster}\% [(older - newer) / older * 100]"
io.puts "[#{oldest.name}] #{oldest.desc.inspect} - (#{oldest.median} seconds)"
io.puts
io.puts "Iterations per sample: #{ENV["TEST_COUNT"]}"
io.puts "Samples: #{newest.values.length}"
io.puts
io.puts "Test type: Kolmogorov Smirnov"
io.puts "Confidence level: #{@stats[:confidence_level] * 100} %"
io.puts "Is significant? (max > critical): #{significant?}"
io.puts "D critical: #{d_critical}"
io.puts "D max: #{d_max}"
io.puts
end
end
end