feat: implement performance view

app/src/lib/performance/store.ts

@@ -0,0 +1,67 @@
+import { readable, type Readable } from "svelte/store";
+
+export type PerformanceData = {
+  total: Record<string, number>;
+  runs: Record<string, number[]>[];
+}
+
+export interface PerformanceStore extends Readable<PerformanceData> {
+  startRun(): void;
+  stopRun(): void;
+  addPoint(name: string, value?: number): void;
+  get: () => PerformanceData;
+}
+
+export function createPerformanceStore(): PerformanceStore {
+
+  let data: PerformanceData = { total: {}, runs: [] };
+
+  let currentRun: Record<string, number[]> | undefined;
+
+  let set: (v: PerformanceData) => void;
+
+  const { subscribe } = readable<PerformanceData>({ total: {}, runs: [] }, (_set) => {
+    set = _set;
+  });
+
+  function startRun() {
+    currentRun = {};
+  }
+
+  function stopRun() {
+    if (currentRun) {
+      // Calculate total
+      Object.keys(currentRun).forEach((name) => {
+        if (!currentRun?.[name]?.length) return;
+        let runTotal = currentRun[name].reduce((a, b) => a + b, 0) / currentRun[name].length;
+        if (!data.total[name]) {
+          data.total[name] = runTotal;
+        } else {
+          data.total[name] = (data.total[name] + runTotal) / 2;
+        }
+      });
+
+      data.runs.push(currentRun);
+      currentRun = undefined;
+      if (set) set(data);
+    }
+  }
+
+  function addPoint(name: string, value: number) {
+    if (!currentRun) return;
+    currentRun[name] = currentRun[name] || [];
+    currentRun[name].push(value);
+  }
+
+  function get() {
+    return data;
+  }
+
+  return {
+    subscribe,
+    startRun,
+    stopRun,
+    addPoint,
+    get
+  }
+}