Measure Node.js performance with perf_hooks Module!

Node.js perf_hooks is a built-in module that provides performance measurement and monitoring capabilities for Node.js applications. It allows you to analyze the performance of your code by measuring the execution time of specific sections or functions.

The perf_hooks module provides several classes and methods for performance measurement, including:

1. PerformanceObserver: This class is used to observe and collect performance entries generated by the perf_hooks module. You can create an instance of PerformanceObserver and subscribe to specific performance events.
2. PerformanceEntry: This class represents a single performance entry, which includes information such as the name of the entry, its duration, and the timestamp when it was recorded.
3. performance: This is a global object that provides methods for measuring the performance of your code. It includes functions like performance.now() to get the current timestamp with high-resolution, and performance.mark() to create custom marks in your code.

Here's an example that demonstrates the usage of perf_hooks to measure the execution time of a function:

const { performance, PerformanceObserver } = require('perf_hooks')


function fibonacci(n) {
  if (n <= 1) {
    return n;
  }
  return fibonacci(n - 1) + fibonacci(n - 2);
}


// Create a PerformanceObserver to collect performance entries
const observer = new PerformanceObserver((list) => {
  const entries = list.getEntries();
  entries.forEach((entry) => {
    console.log(entry);
  });
});
observer.observe({ entryTypes: ["measure"], buffer: true })


// Measure the performance of the fibonacci function
performance.mark('start');
fibonacci(40);
performance.mark('end');
performance.measure('fibonacci', 'start', 'end');        

In the example above, we first import the necessary classes and methods from the perf_hooks module. Then, we define a recursive fibonacci function to calculate the Fibonacci sequence. We create a PerformanceObserver instance and subscribe to the function entry type.

Next, we use performance.mark() to create marks before and after calling the fibonacci function. Finally, we use performance.measure() to measure the duration between the marks and collect the performance entry.

When you run this code, it will output the name and duration of the performance entry. In this case, it will display the duration of the fibonacci function execution.

PerformanceMeasure {
? name: 'fibonacci',
? entryType: 'measure',
? startTime: 60.554721999913454,
? duration: 2626.6919049993157,
? detail: null
}        

Go, Node! ????