The Go Programming Language

11.4 Benchmark Functions

Benchmarking is the practice of measuring the performance of a program on a fixed workload. In Go, a benchmark function looks like a test function, but with the Benchmark prefix and a *testing.B parameter that provides most of the same methods as a *testing.T, plus a few extra related to performance measurement. It also exposes an integer field N, which specifies the number of times to perform the operation being measured.

Here’s a benchmark for IsPalindrome that calls it N times in a loop.

Click here to view code image

import "testing"

func BenchmarkIsPalindrome(b *testing.B) {
    for i := 0; i < b.N; i++ {
        IsPalindrome("A man, a plan, a canal: Panama")
    }
}

We run it with the command below. Unlike tests, by default ...