updoot

tgui/packages/common/perf.js

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+/**
+ * Ghetto performance measurement tools.
+ *
+ * Uses NODE_ENV to redact itself from production bundles.
+ *
+ * @file
+ * @copyright 2020 Aleksej Komarov
+ * @license MIT
+ */
+
+let markersByLabel = {};
+
+/**
+ * Marks a certain spot in the code for later measurements.
+ */
+const mark = (label, timestamp) => {
+  if (process.env.NODE_ENV !== 'production') {
+    markersByLabel[label] = timestamp || Date.now();
+  }
+};
+
+/**
+ * Calculates and returns the difference between two markers as a string.
+ *
+ * Use logger.log() to print the measurement.
+ */
+const measure = (markerA, markerB) => {
+  if (process.env.NODE_ENV !== 'production') {
+    return timeDiff(
+      markersByLabel[markerA],
+      markersByLabel[markerB]);
+  }
+};
+
+const timeDiff = (startedAt, finishedAt) => {
+  const diff = Math.abs(finishedAt - startedAt);
+  const diffFrames = (diff / 16.6667).toFixed(2);
+  return `${diff}ms (${diffFrames} frames)`;
+};
+
+export const perf = {
+  mark,
+  measure,
+};