should be it

external/duckdb/extension/jemalloc/include/jemalloc_extension.hpp

@@ -0,0 +1,32 @@
+//===----------------------------------------------------------------------===//
+//                         DuckDB
+//
+// jemalloc_extension.hpp
+//
+//
+//===----------------------------------------------------------------------===//
+
+#pragma once
+
+#include "duckdb.hpp"
+
+namespace duckdb {
+
+class JemallocExtension : public Extension {
+public:
+	void Load(ExtensionLoader &loader) override;
+	std::string Name() override;
+	std::string Version() const override;
+
+	static data_ptr_t Allocate(PrivateAllocatorData *private_data, idx_t size);
+	static void Free(PrivateAllocatorData *private_data, data_ptr_t pointer, idx_t size);
+	static data_ptr_t Reallocate(PrivateAllocatorData *private_data, data_ptr_t pointer, idx_t old_size, idx_t size);
+
+	static int64_t DecayDelay();
+	static void ThreadFlush(idx_t threshold);
+	static void ThreadIdle();
+	static void FlushAll();
+	static void SetBackgroundThreads(bool enable);
+};
+
+} // namespace duckdb