perf_hooks: implementation of the perf timing API

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>

1 files changed, 93 insertions, 0 deletions

diff --git a/test/parallel/test-performance-function.js b/test/parallel/test-performance-function.js
new file mode 100644
index 0000000000..8dd4d3004b
--- /dev/null
+++ b/test/parallel/test-performance-function.js
@@ -0,0 +1,93 @@
+'use strict';
+
+const common = require('../common');
+const assert = require('assert');
+
+const {
+  performance,
+  PerformanceObserver
+} = require('perf_hooks');
+
+{
+  // Intentional non-op. Do not wrap in common.mustCall();
+  const n = performance.timerify(() => {});
+  n();
+  const entries = performance.getEntriesByType('function');
+  assert.strictEqual(entries.length, 0);
+
+  const obs = new PerformanceObserver(common.mustCall((list) => {
+    const entries = list.getEntries();
+    const entry = entries[0];
+    assert(entry);
+    assert.strictEqual(entry.name, 'performance.timerify');
+    assert.strictEqual(entry.entryType, 'function');
+    assert.strictEqual(typeof entry.duration, 'number');
+    assert.strictEqual(typeof entry.startTime, 'number');
+    obs.disconnect();
+    performance.clearFunctions();
+  }));
+  obs.observe({ entryTypes: ['function'] });
+  n();
+}
+
+{
+  // If the error throws, the error should just be bubbled up and the
+  // performance timeline entry will not be reported.
+  const obs = new PerformanceObserver(common.mustNotCall());
+  obs.observe({ entryTypes: ['function'] });
+  const n = performance.timerify(() => {
+    throw new Error('test');
+  });
+  assert.throws(() => n(), /^Error: test$/);
+  const entries = performance.getEntriesByType('function');
+  assert.strictEqual(entries.length, 0);
+  obs.disconnect();
+}
+
+{
+  class N {}
+  const n = performance.timerify(N);
+  new n();
+  const entries = performance.getEntriesByType('function');
+  assert.strictEqual(entries.length, 0);
+
+  const obs = new PerformanceObserver(common.mustCall((list) => {
+    const entries = list.getEntries();
+    const entry = entries[0];
+    assert.strictEqual(entry[0], 1);
+    assert.strictEqual(entry[1], 'abc');
+    assert(entry);
+    assert.strictEqual(entry.name, 'N');
+    assert.strictEqual(entry.entryType, 'function');
+    assert.strictEqual(typeof entry.duration, 'number');
+    assert.strictEqual(typeof entry.startTime, 'number');
+    obs.disconnect();
+    performance.clearFunctions();
+  }));
+  obs.observe({ entryTypes: ['function'] });
+
+  new n(1, 'abc');
+}
+
+{
+  [1, {}, [], null, undefined, Infinity].forEach((i) => {
+    assert.throws(() => performance.timerify(i),
+                  common.expectsError({
+                    code: 'ERR_INVALID_ARG_TYPE',
+                    type: TypeError,
+                    message: 'The "fn" argument must be of type Function'
+                  }));
+  });
+}
+
+// Function can only be wrapped once, also check length and name
+{
+  const m = (a, b = 1) => {};
+  const n = performance.timerify(m);
+  const o = performance.timerify(m);
+  const p = performance.timerify(n);
+  assert.strictEqual(n, o);
+  assert.strictEqual(n, p);
+  assert.strictEqual(n.length, m.length);
+  assert.strictEqual(n.name, 'timerified m');
+}