Profile provides a way to Profile your Ruby application.

Profiling your program is a way of determining which methods are called and how long each method takes to complete. This way you can detect which methods are possible bottlenecks.

Profiling your program will slow down your execution time considerably, so activate it only when you need it. Don’t confuse benchmarking with profiling.

There are two ways to activate Profiling:

Command line

Run your Ruby script with -rprofile:

ruby -rprofile example.rb

If you’re profiling an executable in your $PATH you can use ruby -S:

ruby -rprofile -S some_executable

From code

Just require ‘profile’:

require 'profile'

def slow_method
  5000.times do
    9999999999999999*999999999
  end
end

def fast_method
  5000.times do
    9999999999999999+999999999
  end
end

slow_method
fast_method

The output in both cases is a report when the execution is over:

ruby -rprofile example.rb

  %   cumulative   self              self     total
 time   seconds   seconds    calls  ms/call  ms/call  name
 68.42     0.13      0.13        2    65.00    95.00  Integer#times
 15.79     0.16      0.03     5000     0.01     0.01  Fixnum#*
 15.79     0.19      0.03     5000     0.01     0.01  Fixnum#+
  0.00     0.19      0.00        2     0.00     0.00  IO#set_encoding
  0.00     0.19      0.00        1     0.00   100.00  Object#slow_method
  0.00     0.19      0.00        2     0.00     0.00  Module#method_added
  0.00     0.19      0.00        1     0.00    90.00  Object#fast_method
  0.00     0.19      0.00        1     0.00   190.00  #toplevel