#!/usr/bin/env ruby
# encoding: UTF-8
# frozen_string_literal: true

require 'rubygems'
require 'bundler/setup'

require 'git_dump'
require 'benchmark'
require 'tmpdir'

def measure(label, number = nil)
  label = "#{label} x#{number}" if number
  label = "#{label}:"

  result = nil
  print label.ljust(30)
  times = Benchmark.measure do
    (number || 1).times do |n|
      result = yield n
    end
  end
  puts " #{times}"
  result
end

puts "Using #{defined?(Rugged) ? 'libgit2' : 'git commands'}:"

urandom = File.open('/dev/urandom')

Dir.mktmpdir do |dir|
  dump = measure 'init' do
    GitDump.new(File.join(dir, 'bm.git'), :create => true)
  end

  builder = dump.new_version

  [
    ['1K', 1_000, 1024],
    ['10M', 10, 10 * 1024 * 1024],
  ].each do |label, times, size|
    datas = Array.new(times) do
      urandom.read(size)
    end.each
    measure "store #{label} strings", times do |n|
      path = format('data%s%08d', label, n).scan(/.{1,2}/).join('/')
      data = datas.next
      builder.store(path, data)
    end

    files = Array.new(times) do |i|
      path = File.join(dir, "file#{i}")
      File.open(path, 'w') do |f|
        f.write(urandom.read(size))
      end
      path
    end.each
    measure "store #{label} files", times do |n|
      path = format('file%s%08d', label, n).scan(/.{1,2}/).join('/')
      file = files.next
      builder.store_from(path, file)
    end
  end

  measure 'commit', 10 do
    builder.commit
  end

  measure 'read versions', 100 do
    dump.versions
  end

  entries = dump.versions.first.each_recursive.to_a

  measure 'read entries', entries.length do |n|
    entries[n].read
  end

  measure 'read entries to disk', entries.length do |n|
    entries[n].write_to(File.join(dir, 'out'))
  end
end