feat(oceanbase-oracle): split execution time from client wait

apps/desktop/src/composables/useResultViewUpdateTiming.ts

@@ -0,0 +1,59 @@
+import { computed, nextTick, onActivated, onDeactivated, onUnmounted, ref, shallowRef, watch } from "vue";
+
+type ViewMode = "dom" | "canvas";
+
+/** Times the grid's DOM update or synchronous Canvas draw, excluding screen paint. */
+export function useResultViewUpdateTiming<T extends object>(result: () => T, enabled: () => boolean, mode: () => ViewMode) {
+  const lastMeasurement = shallowRef<{ result: T; mode: ViewMode; elapsedMs: number } | null>(null);
+  const active = ref(true);
+  let generation = 0;
+  let pending: { result: T; mode: ViewMode; startedAt: number; generation: number } | null = null;
+
+  function finish(current: T, currentMode: ViewMode, expectedGeneration: number) {
+    if (!active.value || !enabled() || result() !== current || mode() !== currentMode) return;
+    if (!pending || pending.result !== current || pending.mode !== currentMode || pending.generation !== expectedGeneration) return;
+    lastMeasurement.value = { result: current, mode: currentMode, elapsedMs: Math.max(0, Math.round(performance.now() - pending.startedAt)) };
+    pending = null;
+  }
+
+  function start(current: T, currentMode: ViewMode, isEnabled: boolean) {
+    const currentGeneration = ++generation;
+    lastMeasurement.value = null;
+    pending = active.value && isEnabled ? { result: current, mode: currentMode, startedAt: performance.now(), generation: currentGeneration } : null;
+    if (pending && currentMode === "dom") void nextTick(() => finish(current, "dom", currentGeneration));
+  }
+
+  watch(
+    () => [result(), mode(), enabled()] as const,
+    ([current, currentMode, isEnabled]) => start(current, currentMode, isEnabled),
+    { immediate: true },
+  );
+
+  onDeactivated(() => {
+    active.value = false;
+    generation++;
+    pending = null;
+    lastMeasurement.value = null;
+  });
+  onActivated(() => {
+    if (!active.value) {
+      active.value = true;
+      start(result(), mode(), enabled());
+    }
+  });
+  onUnmounted(() => {
+    active.value = false;
+    generation++;
+    pending = null;
+  });
+
+  return {
+    elapsedMs: computed(() => {
+      const measured = lastMeasurement.value;
+      return active.value && enabled() && measured?.result === result() && measured.mode === mode() ? measured.elapsedMs : undefined;
+    }),
+    canvasDrawCompleted: (drawnResult: T) => {
+      if (pending?.mode === "canvas") finish(drawnResult, "canvas", pending.generation);
+    },
+  };
+}