compare.rb

# usage: ruby compare.rb first.json second.json
# gnuplot is required.
# produce output.json by running:
#   make clean
#   make bench
#   bin/ElonaFoobar --output json > output.json

require "json"

class Comparison
  attr_accessor :charts

  def initialize()
    @charts = {}
  end

  def add(filename)
    benchmarks = JSON.parse(File.read(filename))["benchmarks"]
    datum = {}

    benchmarks.each do |b|
      datum[b["name"]] = b
    end
    datum.each_pair do |name, data|
      charts[name] = Chart.new(name) unless charts[name]
      charts[name].add(filename, data)
    end
  end

  def output
    @charts.each_value do |c|
      puts c.output
      puts
      File.write("/tmp/plot.csv", c.output)
      plot = c.plot
      `echo '#{plot}' | gnuplot > result_#{c.name}.png`
    end
  end
end

class Chart
  attr_accessor :name, :results

  def initialize(name)
    @name = name
    @results = {}
  end

  def add(filename, data)
    results[filename] = Result.new(filename, data)
  end

  def run_count
    results.first[1].runs.size
  end

  def header
    "Filename,#{run_count.times.collect {|i| "Run#{i}" }.join(",")}"
  end

  def output
    "#{header}\n#{results.map {|n, r| r.output}.join("\n")}"
  end

  def plot
<<EOF
set term png size 800,600
set title "#{@name}"
set boxwidth 0.9 absolute
set style fill   solid 1.00 border lt -1
set key inside right top vertical Right noreverse noenhanced autotitles nobox
set style histogram clustered gap 1 title  offset character 0, 0, 0
set style data histograms
set xtics border in scale 0,0 nomirror rotate by -45  offset character 0, 0, 0 autojustify
set xtics  norangelimit font ",8"
set xtics   ()
set xlabel "Result file"
set ylabel "Iteration time (ms)"
i = 22
set yrange [0:.01 < * < 100]
set style line 1 lc rgb "blue";
set datafile separator ","
plot for [i=2:#{run_count+1}] "/tmp/plot.csv" using i:xtic(1) ti col ls 1
EOF
  end
end

class Result
  attr_accessor :filename, :runs

  def initialize(filename, table)
    @filename = filename
    parse table
  end

  def parse(table)
    @name = table["name"]
    @runs = table["runs"].map do |r|
      r["duration"]
    end
  end

  def output
    "#{filename},#{runs.join(",")}"
  end
end

comparison = Comparison.new()
comparison.add(ARGV[0])
comparison.add(ARGV[1])

comparison.output