LibWeb/IDB: Implement IDBIndex::count

Author: https://github.com/stelar7
Commit: 852323009f
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/4727
Reviewed-by: https://github.com/gmta ✅
Reviewed-by: https://github.com/shannonbooth

Libraries/LibWeb/IndexedDB/IDBIndex.cpp

@@ -265,4 +265,35 @@ WebIDL::ExceptionOr<GC::Ref<IDBRequest>> IDBIndex::get_all_keys(Optional<JS::Val
     return result;
 }
 
+// https://w3c.github.io/IndexedDB/#dom-idbindex-count
+WebIDL::ExceptionOr<GC::Ref<IDBRequest>> IDBIndex::count(JS::Value query)
+{
+    auto& realm = this->realm();
+
+    // 1. Let transaction be this’s transaction.
+    auto transaction = this->transaction();
+
+    // 2. Let index be this’s index.
+    auto index = this->index();
+
+    // FIXME: 3. If index or index’s object store has been deleted, throw an "InvalidStateError" DOMException.
+
+    // 4. If transaction’s state is not active, then throw a "TransactionInactiveError" DOMException.
+    if (transaction->state() != IDBTransaction::TransactionState::Active)
+        return WebIDL::TransactionInactiveError::create(realm, "Transaction is not active while counting"_string);
+
+    // 5. Let range be the result of converting a value to a key range with query. Rethrow any exceptions.
+    auto range = TRY(convert_a_value_to_a_key_range(realm, query));
+
+    // 6. Let operation be an algorithm to run count the records in a range with index and range.
+    auto operation = GC::Function<WebIDL::ExceptionOr<JS::Value>()>::create(realm.heap(), [index, range] -> WebIDL::ExceptionOr<JS::Value> {
+        return count_the_records_in_a_range(index, range);
+    });
+
+    // 7. Return the result (an IDBRequest) of running asynchronously execute a request with this and operation.
+    auto result = asynchronously_execute_a_request(realm, GC::Ref(*this), operation);
+    dbgln_if(IDB_DEBUG, "Executing request for count with uuid {}", result->uuid());
+    return result;
+}
+
 }

Libraries/LibWeb/IndexedDB/IDBIndex.h

@@ -33,6 +33,7 @@ public:
     [[nodiscard]] WebIDL::ExceptionOr<GC::Ref<IDBRequest>> get_key(JS::Value);
     [[nodiscard]] WebIDL::ExceptionOr<GC::Ref<IDBRequest>> get_all(Optional<JS::Value>, Optional<WebIDL::UnsignedLong>);
     [[nodiscard]] WebIDL::ExceptionOr<GC::Ref<IDBRequest>> get_all_keys(Optional<JS::Value>, Optional<WebIDL::UnsignedLong>);
+    [[nodiscard]] WebIDL::ExceptionOr<GC::Ref<IDBRequest>> count(JS::Value);
     [[nodiscard]] WebIDL::ExceptionOr<GC::Ref<IDBRequest>> open_cursor(JS::Value, Bindings::IDBCursorDirection = Bindings::IDBCursorDirection::Next);
 
     // The transaction of an index handle is the transaction of its associated object store handle.

Libraries/LibWeb/IndexedDB/IDBIndex.idl

@@ -11,7 +11,7 @@ interface IDBIndex {
     [NewObject] IDBRequest getKey(any query);
     [NewObject] IDBRequest getAll(optional any query, optional [EnforceRange] unsigned long count);
     [NewObject] IDBRequest getAllKeys(optional any query, optional [EnforceRange] unsigned long count);
-    [FIXME, NewObject] IDBRequest count(optional any query);
+    [NewObject] IDBRequest count(optional any query);
     [NewObject] IDBRequest openCursor(optional any query, optional IDBCursorDirection direction = "next");
     [FIXME, NewObject] IDBRequest openKeyCursor(optional any query, optional IDBCursorDirection direction = "next");
 };

Libraries/LibWeb/IndexedDB/Internal/Algorithms.cpp

@@ -1453,10 +1453,16 @@ WebIDL::ExceptionOr<GC::Ref<IDBKeyRange>> convert_a_value_to_a_key_range(JS::Rea
 }
 
 // https://w3c.github.io/IndexedDB/#count-the-records-in-a-range
-JS::Value count_the_records_in_a_range(GC::Ref<ObjectStore> source, GC::Ref<IDBKeyRange> range)
+JS::Value count_the_records_in_a_range(RecordSource source, GC::Ref<IDBKeyRange> range)
 {
     // 1. Let count be the number of records, if any, in source’s list of records with key in range.
-    auto count = source->count_records_in_range(range);
+    auto count = source.visit(
+        [range](GC::Ref<ObjectStore> object_store) {
+            return object_store->count_records_in_range(range);
+        },
+        [range](GC::Ref<Index> index) {
+            return index->count_records_in_range(range);
+        });
 
     // 2. Return count.
     return JS::Value(count);

Libraries/LibWeb/IndexedDB/Internal/Algorithms.h

@@ -18,6 +18,7 @@
 namespace Web::IndexedDB {
 
 using KeyPath = Variant<String, Vector<String>>;
+using RecordSource = Variant<GC::Ref<ObjectStore>, GC::Ref<Index>>;
 
 WebIDL::ExceptionOr<GC::Ref<IDBDatabase>> open_a_database_connection(JS::Realm&, StorageAPI::StorageKey, String, Optional<u64>, GC::Ref<IDBRequest>);
 bool fire_a_version_change_event(JS::Realm&, FlyString const&, GC::Ref<DOM::EventTarget>, u64, Optional<u64>);
@@ -44,7 +45,7 @@ void inject_a_key_into_a_value_using_a_key_path(JS::Realm&, JS::Value, GC::Ref<K
 JS::Value delete_records_from_an_object_store(GC::Ref<ObjectStore>, GC::Ref<IDBKeyRange>);
 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>);
+JS::Value count_the_records_in_a_range(RecordSource, GC::Ref<IDBKeyRange>);
 WebIDL::ExceptionOr<JS::Value> retrieve_a_value_from_an_object_store(JS::Realm&, GC::Ref<ObjectStore>, GC::Ref<IDBKeyRange>);
 GC::Ptr<IDBCursor> iterate_a_cursor(JS::Realm&, GC::Ref<IDBCursor>, GC::Ptr<Key> = nullptr, GC::Ptr<Key> = nullptr, u64 = 1);
 JS::Value clear_an_object_store(GC::Ref<ObjectStore>);

Libraries/LibWeb/IndexedDB/Internal/Index.cpp

@@ -97,4 +97,14 @@ GC::ConservativeVector<IndexRecord> Index::first_n_in_range(GC::Ref<IDBKeyRange>
     return records;
 }
 
+u64 Index::count_records_in_range(GC::Ref<IDBKeyRange> range)
+{
+    u64 count = 0;
+    for (auto const& record : m_records) {
+        if (range->is_in_range(record.key))
+            ++count;
+    }
+    return count;
+}
+
 }

Libraries/LibWeb/IndexedDB/Internal/Index.h

@@ -43,6 +43,7 @@ public:
     void clear_records();
     Optional<IndexRecord&> first_in_range(GC::Ref<IDBKeyRange> range);
     GC::ConservativeVector<IndexRecord> first_n_in_range(GC::Ref<IDBKeyRange> range, Optional<WebIDL::UnsignedLong> count);
+    u64 count_records_in_range(GC::Ref<IDBKeyRange> range);
 
     HTML::SerializationRecord referenced_value(IndexRecord const& index_record) const;