Ruby Benchmarking & Big O Notation

Tue, 15 Nov 2016 00:00:00 +0000

The Ruby Benchmark library helps us to measure how long it takes for a block of code to run. Similar to when you subtract starting time and ending time in other languages such as Java.

I was doing some Big O Notation reviewing with Ruby the other day and did some common algorithm implementations for each of the most common Big O notations, just for fun.

Using Benchmark

To start benchmarking our code, we simply need to require benchmark and use the methods provided by the Benchmark module. For me, the most practical way is to use Benchmark#bm method, where we pass a block of code we want to measure:

require 'benchmark'

Benchmark.bm do |x|
  x.report do
    # our code here
  end

end

Inside the block we are using the report method of the block's variable, which will basically do a separate benchmark for each report.

However, we can improve this even more by adding a label to report and a label width to bm:

require 'benchmark'

Benchmark.bm(20) do |x|
  x.report("my_algorithm") do
    # our code here
  end
end

Let's see it in action with some common algorithms.

benchmarking on Andrés Álvarez

Ruby Benchmarking & Big O Notation

Using Benchmark