Module 2: Benchmarking (The Stopwatch)

📚 Module 2: Benchmarking

Course ID: GO-302
Subject: The Stopwatch

Go makes it incredibly easy to see exactly how fast your code is. We use Benchmarks to measure performance in nanoseconds.

🏗️ Step 1: The Race

🧩 The Analogy: The Olympics

You have two athletes (Two ways to solve a problem).
You want to know which one is faster.
You use a Stopwatch (Benchmark) to time them.
To be fair, you have them run the same race 1 million times and take the average.

🏗️ Step 2: In Code

func BenchmarkAdd(b *testing.B) {
    // b.N is automatically chosen by Go to be large enough
    for i := 0; i < b.N; i++ {
        Add(1, 2)
    }
}

🏗️ Step 3: Running the Test

Run: go test -bench=.

📊 The Result:

BenchmarkAdd-8 1000000000 1.05 ns/op

This means the code ran 1 billion times!
Every single “Add” took only 1.05 nanoseconds.

🥅 Module 2 Review

Benchmark: Measuring performance over many iterations.
testing.B: The object used for benchmarking.
ns/op: Nanoseconds per operation.

:::tip Senior Tip Go’s performance toolset is the best in the world. Use pprof (Advanced track) to see a 3D visualization of which function is stealing all your CPU time! ::: Riverside. Riverside.