benchmarks/path_tree_benchmark.rb

require "spec_helper"

class CC::Workspace
  describe PathTree do
    include FileSystemHelpers

    MAX_FILTER_SECONDS = 10
    NUM_FILES = 50_000
    AVG_FILES_PER_DIR = 20
    REPO_DEPTH = 30
    NUM_EXCLUDES = 50

    it "performs acceptably" do
      within_temp_dir do
        make_files
        exclude_paths = make_exclude_paths

        elapsed = Benchmark.realtime do
          tree = PathTree.for_path(".")
          tree.exclude_paths(exclude_paths)
          tree.all_paths
        end
        puts "PathTree over #{`find . -type f -print | wc -l`.strip} files, with #{exclude_paths.count} excludes took: #{elapsed}s"

        expect(elapsed).to be_between(0, MAX_FILTER_SECONDS)
      end
    end

    def make_files
      NUM_FILES.times do
        dir = dir_names[rand(dir_names.count)]
        begin
          if dir.present?
            make_file File.join(dir, rand_file_name)
          else
            make_file rand_file_name
          end
        rescue Errno::EEXIST, Errno::EISDIR
          #noop
        end
      end
    end

    def dir_names
      # nil is for project root, plus a bunch of other random dirs
      @dir_names ||= [nil] + (NUM_FILES / AVG_FILES_PER_DIR).times.collect do
        File.join(rand(REPO_DEPTH).times.collect { rand_file_name })
      end
    end

    def rand_file_name
      SecureRandom.hex(rand(16) + 1)
    end

    def make_exclude_paths
      NUM_EXCLUDES.times.collect do
        base_dir = dir_names[rand(dir_names.count + 1)]
        next unless base_dir.present?
        case rand(3)
        when 0 # no change: exclude the dir
          base_dir
        when 1 # if dir is appropriate length, add /**/*, otherwise no change
          pieces = base_dir.split(File::SEPARATOR)
          if pieces.count > (REPO_DEPTH / 10) && pieces.count < REPO_DEPTH
            File.join(base_dir, "**", "*")
          else
            base_dir
          end
        when 2 # randomly replace bits of directories with * to force glob matching
          pieces = base_dir.split(File::SEPARATOR)
          if pieces.count > (REPO_DEPTH / 10) && pieces.count < REPO_DEPTH
            File.join(pieces.map do |piece|
              if rand(100) > 65
                piece[0..(1 + rand(piece[0].length))] + "*"
              else
                piece
              end
            end)
          else
            base_dir
          end
        end
      end.reject(&:nil?)
    end
  end
end