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use entry and extend

Co-authored-by: John Argérus <[email protected]>

kuksa_databroker/databroker/src/grpc/kuksa_val_v1/val.rs

@@ -414,17 +414,12 @@ impl proto::val_server::Val for broker::DataBroker {
                     .for_each_entry(|entry| {
                         let entry_path = &entry.metadata().path;
                         if regex.is_match(entry_path) {
-                            let id = &entry.metadata().id;
-                            match entries.get(id) {
-                                Some(fields) => {
-                                    let joined_set: HashSet<_> =
-                                        fields.union(&fields_set).cloned().collect();
-                                    entries.insert(*id, joined_set);
-                                }
-                                None => {
-                                    entries.insert(*id, fields_set.clone());
-                                }
-                            }
+                            entries
+                                .entry(entry.metadata().id)
+                                .and_modify(|existing_fields| {
+                                    existing_fields.extend(fields.clone());
+                                })
+                                .or_insert(fields.clone());
                         }
                     })
                     .await;