anonymize.rb

anonymize.rb

# anonymize a HTTP path, replacing numbers with :num and hexes with :hex
# for example,
# /shipments/12345/2a95f880b65f245b9158fd4240767d91 => /shipments/:num/:hex

event = {"path" => "/shipments/12345/2a95f880b65f245b9158fd4240767d91" }
expected = "/shipments/:num/:hex"
ONLY_NUM_REGEX = /^\d+$/
NUM = ':num'
HEX = ':hex'
NON_HEX_CHARS = %w[g h i j k l m n o p q r s t u v w x y z _]
PATH = 'path'
SLASH = '/'
TIMES = 10_000

REPLACE_NUM = lambda do |x|
  x.sub(ONLY_NUM_REGEX, NUM)
end

REPLACE_HEX = lambda do |x|
  if  (
        !x.empty? &&
         # String#chars is faster but in JRuby it returns an enumerator so we can't intersect it
        (x.each_char.to_a & NON_HEX_CHARS).empty?
      )
    HEX
  else
    x
  end
end

parsed = nil
GC.start
GC.disable

time_before = Time.now
obj_before = ObjectSpace.count_objects[:TOTAL]

# hot loop:
TIMES.times do
  parsed = event[PATH]
    .split(SLASH)
    .map(&REPLACE_NUM)
    .map(&REPLACE_HEX)
    .join(SLASH)
end

diff_obj = ObjectSpace.count_objects[:TOTAL] - obj_before
diff_time = ((Time.now - time_before) / TIMES) * 1_000_000
puts "per loop: #{diff_time} microseconds, objs: #{diff_obj / TIMES}"
raise "parsed wrong: #{parsed} != #{expected}" unless parsed == expected

# $ ruby anonymize.rb
# per loop: 48.993399999999994 microseconds, objs: 141