feat(nbstore): new doc sync engine (#8918)

packages/common/nbstore/src/sync/doc/index.ts

@@ -0,0 +1,18 @@
+import type { DocStorage, SyncStorage } from '../../storage';
+import { DocSyncPeer } from './peer';
+
+export class DocSyncEngine {
+  constructor(
+    readonly local: DocStorage,
+    readonly sync: SyncStorage,
+    readonly peers: DocStorage[]
+  ) {}
+
+  async run(signal?: AbortSignal) {
+    await Promise.all(
+      this.peers.map(peer =>
+        new DocSyncPeer(this.local, this.sync, peer).mainLoop(signal)
+      )
+    );
+  }
+}