1 files changed, 83 insertions, 0 deletions
diff --git a/packages/astro-parser/src/Stats.ts b/packages/astro-parser/src/Stats.ts
new file mode 100644
index 000000000..5f7f991f8
--- /dev/null
+++ b/packages/astro-parser/src/Stats.ts
@@ -0,0 +1,83 @@
+// @ts-nocheck
+
+const now =
+  typeof process !== 'undefined' && process.hrtime
+    ? () => {
+        const t = process.hrtime();
+        return t[0] * 1e3 + t[1] / 1e6;
+      }
+    : () => self.performance.now();
+
+interface Timing {
+  label: string;
+  start: number;
+  end: number;
+  children: Timing[];
+}
+
+/** Format benchmarks */
+function collapse_timings(timings) {
+  const result = {};
+  timings.forEach((timing) => {
+    result[timing.label] = Object.assign(
+      {
+        total: timing.end - timing.start,
+      },
+      timing.children && collapse_timings(timing.children)
+    );
+  });
+  return result;
+}
+
+export default class Stats {
+  start_time: number;
+  current_timing: Timing;
+  current_children: Timing[];
+  timings: Timing[];
+  stack: Timing[];
+
+  constructor() {
+    this.start_time = now();
+    this.stack = [];
+    this.current_children = this.timings = [];
+  }
+
+  start(label) {
+    const timing = {
+      label,
+      start: now(),
+      end: null,
+      children: [],
+    };
+
+    this.current_children.push(timing);
+    this.stack.push(timing);
+
+    this.current_timing = timing;
+    this.current_children = timing.children;
+  }
+
+  stop(label) {
+    if (label !== this.current_timing.label) {
+      throw new Error(`Mismatched timing labels (expected ${this.current_timing.label}, got ${label})`);
+    }
+
+    this.current_timing.end = now();
+    this.stack.pop();
+    this.current_timing = this.stack[this.stack.length - 1];
+    this.current_children = this.current_timing ? this.current_timing.children : this.timings;
+  }
+
+  render() {
+    const timings = Object.assign(
+      {
+        total: now() - this.start_time,
+      },
+      collapse_timings(this.timings)
+    );
+
+    return {
+      timings,
+    };
+  }
+}