fix: first binary on y-indexeddb (#1972)

packages/y-indexeddb/src/utils.ts

@@ -0,0 +1,22 @@
+import { openDB } from 'idb';
+import { mergeUpdates } from 'yjs';
+
+import type { BlockSuiteBinaryDB, UpdateMessage } from './shared';
+import { dbVersion, DEFAULT_DB_NAME, upgradeDB } from './shared';
+
+export async function downloadBinary(
+  id: string,
+  dbName = DEFAULT_DB_NAME
+): Promise<UpdateMessage['update']> {
+  const dbPromise = openDB<BlockSuiteBinaryDB>(dbName, dbVersion, {
+    upgrade: upgradeDB,
+  });
+  const db = await dbPromise;
+  const t = db.transaction('workspace', 'readonly').objectStore('workspace');
+  const doc = await t.get(id);
+  if (!doc) {
+    return new Uint8Array(0);
+  } else {
+    return mergeUpdates(doc.updates.map(({ update }) => update));
+  }
+}