An initial implementation of the Performance Timing API for Node.js.
This is the same Performance Timing API implemented by modern browsers
with a number of Node.js specific properties. The User Timing mark()
and measure() APIs are implemented, garbage collection timing, and
node startup milestone timing.
```js
const { performance } = require('perf_hooks');
performance.mark('A');
setTimeout(() => {
performance.mark('B');
performance.measure('A to B', 'A', 'B');
const entry = performance.getEntriesByName('A to B', 'measure')[0];
console.log(entry.duration);
}, 10000);
```
The implementation is at the native layer and makes use of uv_hrtime().
This should enable *eventual* integration with things like Tracing
and Inspection.
The implementation is extensible and should allow us to add new
performance entry types as we go (e.g. for measuring i/o perf,
etc).
Documentation and a test are provided.
PR-URL: https://github.com/nodejs/node/pull/14680
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
