interface: Remove const from BatchCallback

This enables the clients to filter out the
responses with errors without making a copy
of the returned responses.

Bug: NA
Change-Id: I8bcdd2b2321c440d26415fc1baf9df5548ec9ded
GitOrigin-RevId: 948beb69435932e512258f83dcd2e37c83e1f829

src/roma/interface/roma.h

@@ -134,9 +134,9 @@ struct ResponseObject {
 using Callback = absl::AnyInvocable<void(absl::StatusOr<ResponseObject>)>;
 
 // Batch API
-// void Callback(const vector<ResponseObject>&);
-using BatchCallback = absl::AnyInvocable<void(
-    const std::vector<absl::StatusOr<ResponseObject>>&)>;
+// void Callback(vector<ResponseObject>);
+using BatchCallback =
+    absl::AnyInvocable<void(std::vector<absl::StatusOr<ResponseObject>>)>;
 }  // namespace google::scp::roma
 
 #endif  // ROMA_INTERFACE_ROMA_H_

src/roma/roma_service/roma_service.h

@@ -384,9 +384,8 @@ class RomaService {
     auto batch_callback_ptr = std::make_shared<BatchCallback>(
         [&, uuids = std::move(uuids),
          batch_callback = std::move(batch_callback)](
-            const std::vector<absl::StatusOr<ResponseObject>>&
-                batch_resp) mutable {
-          std::move(batch_callback)(batch_resp);
+            std::vector<absl::StatusOr<ResponseObject>> batch_resp) mutable {
+          std::move(batch_callback)(std::move(batch_resp));
           for (const auto& uuid : uuids) {
             DeleteMetadata(uuid);
           }
@@ -402,7 +401,7 @@ class RomaService {
         (*batch_response)[index] = std::move(obj_response);
         auto finished_value = finished_counter->fetch_add(1);
         if (finished_value + 1 == batch_response->size()) {
-          (*batch_callback_ptr)(*batch_response);
+          (*batch_callback_ptr)(std::move(*batch_response));
         }
       };
       absl::Status result;