LibWeb/IDB: Implement retrieve_a_value_from_an_object_store

Author: https://github.com/stelar7
Commit: 18a008d073
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/4505
Reviewed-by: https://github.com/AtkinsSJ
Reviewed-by: https://github.com/gmta ✅

Libraries/LibWeb/IndexedDB/Internal/Algorithms.cpp

@@ -1458,4 +1458,21 @@ JS::Value count_the_records_in_a_range(GC::Ref<ObjectStore> source, GC::Ref<IDBK
     return JS::Value(count);
 }
 
+// https://w3c.github.io/IndexedDB/#retrieve-a-value-from-an-object-store
+WebIDL::ExceptionOr<JS::Value> retrieve_a_value_from_an_object_store(JS::Realm& realm, GC::Ref<ObjectStore> store, GC::Ref<IDBKeyRange> range)
+{
+    // 1. Let record be the first record in store’s list of records whose key is in range, if any.
+    auto record = store->first_in_range(range);
+
+    // 2. If record was not found, return undefined.
+    if (!record.has_value())
+        return JS::js_undefined();
+
+    // 3. Let serialized be record’s value. If an error occurs while reading the value from the underlying storage, return a newly created "NotReadableError" DOMException.
+    auto serialized = record->value;
+
+    // 4. Return ! StructuredDeserialize(serialized, targetRealm).
+    return MUST(HTML::structured_deserialize(realm.vm(), serialized, realm));
+}
+
 }

Libraries/LibWeb/IndexedDB/Internal/Algorithms.h

@@ -43,5 +43,6 @@ void delete_records_from_an_object_store(GC::Ref<ObjectStore>, GC::Ref<IDBKeyRan
 WebIDL::ExceptionOr<GC::Ptr<Key>> store_a_record_into_an_object_store(JS::Realm&, GC::Ref<ObjectStore>, JS::Value, GC::Ptr<Key>, bool);
 WebIDL::ExceptionOr<GC::Ref<IDBKeyRange>> convert_a_value_to_a_key_range(JS::Realm&, Optional<JS::Value>, bool = false);
 JS::Value count_the_records_in_a_range(GC::Ref<ObjectStore>, GC::Ref<IDBKeyRange>);
+WebIDL::ExceptionOr<JS::Value> retrieve_a_value_from_an_object_store(JS::Realm&, GC::Ref<ObjectStore>, GC::Ref<IDBKeyRange>);
 
 }

Libraries/LibWeb/IndexedDB/Internal/ObjectStore.cpp

@@ -77,4 +77,11 @@ u64 ObjectStore::count_records_in_range(GC::Ref<IDBKeyRange> range)
     return count;
 }
 
+Optional<Record&> ObjectStore::first_in_range(GC::Ref<IDBKeyRange> range)
+{
+    return m_records.first_matching([&](auto const& record) {
+        return range->is_in_range(record.key);
+    });
+}
+
 }

Libraries/LibWeb/IndexedDB/Internal/ObjectStore.h

@@ -53,6 +53,7 @@ public:
     bool has_record_with_key(GC::Ref<Key> key);
     void store_a_record(Record const& record);
     u64 count_records_in_range(GC::Ref<IDBKeyRange> range);
+    Optional<Record&> first_in_range(GC::Ref<IDBKeyRange> range);
 
 protected:
     virtual void visit_edges(Visitor&) override;