LibWeb/IDB: Implement IDBIndex::get

Author: https://github.com/stelar7
Commit: e74e571b56
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

@@ -141,4 +141,35 @@ WebIDL::ExceptionOr<GC::Ref<IDBRequest>> IDBIndex::open_cursor(JS::Value query,
     return request;
 }
 
+// https://w3c.github.io/IndexedDB/#dom-idbindex-get
+WebIDL::ExceptionOr<GC::Ref<IDBRequest>> IDBIndex::get(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 getting"_string);
+
+    // 5. Let range be the result of converting a value to a key range with query and true. Rethrow any exceptions.
+    auto range = TRY(convert_a_value_to_a_key_range(realm, query, true));
+
+    // 6. Let operation be an algorithm to run retrieve a referenced value from an index with the current Realm record, index, and range.
+    auto operation = GC::Function<WebIDL::ExceptionOr<JS::Value>()>::create(realm.heap(), [&realm, index, range] -> WebIDL::ExceptionOr<JS::Value> {
+        return retrieve_a_referenced_value_from_an_index(realm, 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 get with uuid {}", result->uuid());
+    return result;
+}
+
 }

Libraries/LibWeb/IndexedDB/IDBIndex.h

@@ -29,12 +29,13 @@ public:
     bool multi_entry() const { return m_index->multi_entry(); }
     bool unique() const { return m_index->unique(); }
 
+    [[nodiscard]] WebIDL::ExceptionOr<GC::Ref<IDBRequest>> get(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.
     GC::Ref<IDBTransaction> transaction() { return m_object_store_handle->transaction(); }
     GC::Ref<Index> index() { return m_index; }
 
-    [[nodiscard]] WebIDL::ExceptionOr<GC::Ref<IDBRequest>> open_cursor(JS::Value, Bindings::IDBCursorDirection = Bindings::IDBCursorDirection::Next);
-
 protected:
     explicit IDBIndex(JS::Realm&, GC::Ref<Index>, GC::Ref<IDBObjectStore>);
     virtual void initialize(JS::Realm&) override;

Libraries/LibWeb/IndexedDB/IDBIndex.idl

@@ -7,7 +7,7 @@ interface IDBIndex {
     readonly attribute any keyPath;
     readonly attribute boolean multiEntry;
     readonly attribute boolean unique;
-    [FIXME, NewObject] IDBRequest get(any query);
+    [NewObject] IDBRequest get(any query);
     [FIXME, NewObject] IDBRequest getKey(any query);
     [FIXME, NewObject] IDBRequest getAll(optional any query, optional [EnforceRange] unsigned long count);
     [FIXME, NewObject] IDBRequest getAllKeys(optional any query, optional [EnforceRange] unsigned long count);

Libraries/LibWeb/IndexedDB/Internal/Algorithms.cpp

@@ -1929,4 +1929,21 @@ GC::Ref<JS::Array> retrieve_multiple_keys_from_an_object_store(JS::Realm& realm,
     return list;
 }
 
+// https://w3c.github.io/IndexedDB/#retrieve-a-referenced-value-from-an-index
+JS::Value retrieve_a_referenced_value_from_an_index(JS::Realm& realm, GC::Ref<Index> index, GC::Ref<IDBKeyRange> range)
+{
+    // 1. Let record be the first record in index’s list of records whose key is in range, if any.
+    auto record = index->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 referenced value.
+    auto serialized = index->referenced_value(*record);
+
+    // 4. Return ! StructuredDeserialize(serialized, targetRealm).
+    return MUST(HTML::structured_deserialize(realm.vm(), serialized, realm));
+}
+
 }

Libraries/LibWeb/IndexedDB/Internal/Algorithms.h

@@ -9,6 +9,7 @@
 #include <AK/Variant.h>
 #include <LibJS/Runtime/Realm.h>
 #include <LibWeb/HTML/DOMStringList.h>
+#include <LibWeb/IndexedDB/IDBKeyRange.h>
 #include <LibWeb/IndexedDB/IDBRequest.h>
 #include <LibWeb/IndexedDB/Internal/Key.h>
 #include <LibWeb/StorageAPI/StorageKey.h>
@@ -50,5 +51,6 @@ JS::Value clear_an_object_store(GC::Ref<ObjectStore>);
 JS::Value retrieve_a_key_from_an_object_store(JS::Realm&, GC::Ref<ObjectStore>, GC::Ref<IDBKeyRange>);
 GC::Ref<JS::Array> retrieve_multiple_values_from_an_object_store(JS::Realm&, GC::Ref<ObjectStore>, GC::Ref<IDBKeyRange>, Optional<WebIDL::UnsignedLong>);
 GC::Ref<JS::Array> retrieve_multiple_keys_from_an_object_store(JS::Realm&, GC::Ref<ObjectStore>, GC::Ref<IDBKeyRange>, Optional<WebIDL::UnsignedLong>);
+JS::Value retrieve_a_referenced_value_from_an_index(JS::Realm&, GC::Ref<Index>, GC::Ref<IDBKeyRange>);
 
 }

Libraries/LibWeb/IndexedDB/Internal/Index.cpp

@@ -76,4 +76,11 @@ void Index::clear_records()
     m_records.clear();
 }
 
+Optional<IndexRecord&> Index::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/Index.h

@@ -41,6 +41,7 @@ public:
 
     [[nodiscard]] bool has_record_with_key(GC::Ref<Key> key);
     void clear_records();
+    Optional<IndexRecord&> first_in_range(GC::Ref<IDBKeyRange> range);
 
     HTML::SerializationRecord referenced_value(IndexRecord const& index_record) const;