rename fs atomic impl and add simple testcase

pre refactor

test/CMakeLists.txt

@@ -12,3 +12,14 @@ target_link_libraries(solanaceae_file2_zstd_test PUBLIC
 
 add_test(NAME solanaceae_file2_zstd_test COMMAND solanaceae_file2_zstd_test)
 
+########################################
+
+add_executable(solanaceae_backend_fs_atomic_test
+	./test_backend_fs_atomic.cpp
+)
+
+target_link_libraries(solanaceae_backend_fs_atomic_test PUBLIC
+	solanaceae_object_store_backend_filesystem
+)
+
+add_test(NAME solanaceae_backend_fs_atomic_test COMMAND solanaceae_backend_fs_atomic_test)

test/test_backend_fs_atomic.cpp

@@ -0,0 +1,76 @@
+#include <solanaceae/object_store/object_store.hpp>
+#include <solanaceae/object_store/backends/filesystem_storage_atomic.hpp>
+
+#include <solanaceae/object_store/meta_components.hpp>
+#include <solanaceae/object_store/meta_components_file.hpp>
+
+#include <filesystem>
+
+#include <cassert>
+#include <vector>
+
+int main(void) {
+	const auto temp_dir_str = (std::filesystem::temp_directory_path() / "test_obj_store_tests").u8string();
+
+	assert(!std::filesystem::exists(temp_dir_str));
+
+	// test1, create store with 2 objects
+	{
+		ObjectStore2 os;
+		Backends::FilesystemStorageAtomic fsa{os, temp_dir_str};
+
+		// empty, does nothing
+		fsa.scanAsync();
+		assert(!std::filesystem::exists(temp_dir_str));
+
+		{ // o1
+			// id1
+			std::vector<uint8_t> id{0x00, 0x13, 0x37, 0x01};
+			auto o = fsa.newObject(ByteSpan{id});
+			std::vector<uint8_t> data{0x01, 0x01, 0x11, 0xf1, 0xae, 0x0b, 0x33};
+			static_cast<StorageBackendIAtomic&>(fsa).write(o, ByteSpan{data});
+		}
+
+		{ // o2
+			// id2
+			std::vector<uint8_t> id{0x00, 0x13, 0x37, 0x02};
+			auto o = fsa.newObject(ByteSpan{id});
+			std::vector<uint8_t> data{0x11, 0x11, 0x11, 0xff, 0xff, 0xee, 0xee};
+			static_cast<StorageBackendIAtomic&>(fsa).write(o, ByteSpan{data});
+		}
+	}
+
+	assert(std::filesystem::exists(temp_dir_str));
+
+	// test2, load store created in test1
+	{
+		ObjectStore2 os;
+
+		Backends::FilesystemStorageAtomic fsa{os, temp_dir_str};
+
+		fsa.scanAsync();
+
+		assert(os.registry().storage<Object>().size() == 2);
+
+		{ // o1
+			std::vector<uint8_t> id{0x00, 0x13, 0x37, 0x01};
+			auto o = os.getOneObjectByID(ByteSpan{id});
+			assert(static_cast<bool>(o));
+
+			std::vector<uint8_t> orig_data{0x01, 0x01, 0x11, 0xf1, 0xae, 0x0b, 0x33};
+			// TODO: read and test content
+
+			//static_cast<StorageBackendIAtomic&>(fsa).write(o, ByteSpan{data});
+		}
+
+		{ // o2
+			std::vector<uint8_t> id{0x00, 0x13, 0x37, 0x02};
+			auto o = os.getOneObjectByID(ByteSpan{id});
+			assert(static_cast<bool>(o));
+		}
+	}
+
+	std::filesystem::remove_all(temp_dir_str);
+
+	return 0;
+}