debian-mirror-gitlab/derailed-benchmarks/lib/derailed_benchmarks/stats_from_dir.rb
2019-10-03 14:02:42 +05:30

99 lines
2.9 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 = students_t_test
self
end
def students_t_test(series_1=oldest.values, series_2=newest.values)
StatisticalTest::TTest.perform(
alpha = 0.05,
:two_tail,
series_1,
series_2
)
end
def significant?
@stats[:alternative]
end
def p_value
@stats[:p_value].to_f
end
def x_faster
FORMAT % (oldest.average/newest.average).to_f
end
def percent_faster
FORMAT % (((oldest.average - newest.average) / oldest.average).to_f * 100)
end
def change_direction
newest.average < oldest.average ? "FASTER" : "SLOWER"
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.average} seconds)"
io.puts " #{change_direction} by:"
io.puts " #{x_faster}x [older/newer]"
io.puts " #{percent_faster}\% [(older - newer) / older * 100]"
io.puts "[#{oldest.name}] #{oldest.desc.inspect} - (#{oldest.average} seconds)"
io.puts
io.puts "Iterations per sample: #{ENV["TEST_COUNT"]}"
io.puts "Samples: #{newest.values.length}"
io.puts "P-value: #{p_value}"
io.puts "Is significant? (P-value < 0.05): #{significant?}"
io.puts
end
end
end