How to time an operation in milliseconds in Ruby?

Question

Hello, I'm wishing to figure out how many milliseconds a particular function uses. So I looked high and low, but could not find a way to get the time in Ruby with millisecond precision.

How do you do this? In most programming languages its just something like

start=now.milliseconds
myfunction()
end=now.milliseconds
time=end-start

Answer 1

Use Time.now.to_f

Answer 2

You should take a look at the benchmark module to perform benchmarks. However, as a quick and dirty timing method you can use something like this:

def time
  now = Time.now.to_f
  yield
  endd = Time.now.to_f
  endd - now
end

Note the use of Time.now.to_f, which unlike to_i, won't truncate to seconds.

Answer 3

You can use ruby's Time class. For example:

t1 = Time.now
# processing...
t2 = Time.now
delta = t2 - t1

Now, delta is a float object and you can get as fine grain a result as the class will provide.