LibSQL: Database layer

This patch implements the beginnings of a database API allowing for the
creation of tables, inserting rows in those tables, and retrieving those
rows.

Userland/Libraries/LibSQL/Row.cpp

@@ -0,0 +1,52 @@
+/*
+ * Copyright (c) 2021, Jan de Visser <jan@de-visser.net>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <LibSQL/Meta.h>
+#include <LibSQL/Row.h>
+#include <LibSQL/Serialize.h>
+#include <LibSQL/Tuple.h>
+
+namespace SQL {
+
+Row::Row()
+    : Tuple()
+{
+}
+
+Row::Row(TupleDescriptor const& descriptor)
+    : Tuple(descriptor)
+{
+}
+
+Row::Row(RefPtr<TableDef> table)
+    : Tuple(table->to_tuple_descriptor())
+    , m_table(table)
+{
+}
+
+Row::Row(RefPtr<TableDef> table, u32 pointer, ByteBuffer& buffer)
+    : Tuple(table->to_tuple_descriptor())
+{
+    // FIXME Sanitize constructor situation in Tuple so this can be better
+    size_t offset = 0;
+    deserialize(buffer, offset);
+    deserialize_from<u32>(buffer, offset, m_next_pointer);
+    set_pointer(pointer);
+}
+
+void Row::serialize(ByteBuffer& buffer) const
+{
+    Tuple::serialize(buffer);
+    serialize_to<u32>(buffer, next_pointer());
+}
+
+void Row::copy_from(Row const& other)
+{
+    Tuple::copy_from(other);
+    m_next_pointer = other.next_pointer();
+}
+
+}