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

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

@@ -0,0 +1,23 @@
+import type { DocStorage, SpaceStorage } from '../storage';
+import { DocSyncEngine } from './doc';
+
+export class SyncEngine {
+  constructor(
+    readonly local: SpaceStorage,
+    readonly peers: SpaceStorage[]
+  ) {}
+
+  async run(signal?: AbortSignal) {
+    const doc = this.local.tryGet('doc');
+    const sync = this.local.tryGet('sync');
+
+    if (doc && sync) {
+      const peerDocs = this.peers
+        .map(peer => peer.tryGet('doc'))
+        .filter((v): v is DocStorage => !!v);
+
+      const engine = new DocSyncEngine(doc, sync, peerDocs);
+      await engine.run(signal);
+    }
+  }
+}