feat(native-export): scaffold local Expo module + native decode/encode bench probe (P0)

Local Kotlin module modules/recipescam-export (autolinked via expo ./modules) exposes decodeEncodeAsync — BitmapFactory decode -> JPEG q95 encode -> file, all on Dispatchers.IO off the JS/main threads. EXPO_PUBLIC_BENCH=1 builds run src/dev/nativeBenchProbe.ts: 3 timed decode+encode passes on the bundled wallframe artwork plus a JS-timer gap check proving the JS thread never blocks during native rendering. Legacy Skia engine untouched (reference).
2026-09-09 12:39:35 +07:00
parent f588849ac5
commit a8932f52ed
8 changed files with 157 additions and 0 deletions
@@ -0,0 +1,57 @@
+import { Asset } from 'expo-asset';
+import * as FileSystem from 'expo-file-system/legacy';
+import RecipescamExport from '../../modules/recipescam-export';
+
+const RUNS = 3;
+
+/**
+ * P0 spike harness (temporary — removed at P7). Runs native decode+encode on
+ * the bundled wallframe artwork (3117x4000, representative of a 12MP export)
+ * and logs per-stage ms plus a JS-timer gap check proving the JS thread is
+ * not blocked while native work runs. Gated by EXPO_PUBLIC_BENCH=1.
+ */
+export async function nativeBenchProbe(): Promise<void> {
+  console.log('[BENCH] start');
+  try {
+    const asset = Asset.fromModule(require('../../wallframe.png'));
+    await asset.downloadAsync();
+    if (!asset.localUri) {
+      console.error('[BENCH] wallframe asset has no localUri');
+      return;
+    }
+    const src = asset.localUri.replace(/^file:\/\//, '');
+    console.log('[BENCH] src=' + src);
+
+    for (let i = 0; i < RUNS; i++) {
+      const dst = `${FileSystem.cacheDirectory}bench-dst-${Date.now()}-${i}.jpg`;
+      const gaps: number[] = [];
+      let last = Date.now();
+      // 5ms JS timer while native work runs: a blocked JS thread would stretch gaps.
+      const iv = setInterval(() => {
+        const now = Date.now();
+        gaps.push(now - last);
+        last = now;
+      }, 5);
+
+      const t0 = Date.now();
+      const timings = await RecipescamExport.decodeEncodeAsync(src, dst, 95);
+      const jsElapsed = Date.now() - t0;
+      clearInterval(iv);
+
+      const sorted = [...gaps].sort((a, b) => b - a);
+      console.log(
+        '[BENCH] run=' + i +
+        ' jsElapsed=' + jsElapsed + 'ms' +
+        ' decodeMs=' + timings.decodeMs +
+        ' encodeWriteMs=' + timings.encodeWriteMs +
+        ' totalMs=' + timings.totalMs +
+        ' jsGapMax=' + (sorted[0] ?? 0) + 'ms' +
+        ' jsGapP95=' + (sorted[Math.floor(sorted.length * 0.05)] ?? 0) + 'ms' +
+        ' dst=' + dst
+      );
+    }
+    console.log('[BENCH] done');
+  } catch (e) {
+    console.error('[BENCH] failed', e);
+  }
+}