ABI fixes: libNet, libSaveData (rewrite the legacy Kyty implementation)

src/libs/saveDataMountSlots.h

@@ -0,0 +1,67 @@
+#ifndef EMULATOR_INCLUDE_EMULATOR_LIBS_SAVEDATAMOUNTSLOTS_H_
+#define EMULATOR_INCLUDE_EMULATOR_LIBS_SAVEDATAMOUNTSLOTS_H_
+
+#include <array>
+#include <optional>
+#include <string>
+#include <string_view>
+
+namespace Libs::SaveData {
+
+class SaveDataMountSlots {
+public:
+	static constexpr int    BUSY  = -2;
+	static constexpr int    FULL  = -1;
+	static constexpr size_t COUNT = 16;
+
+	[[nodiscard]] int FindAvailable(std::string_view directory) const {
+		int available = FULL;
+		for (size_t index = 0; index < m_directories.size(); index++) {
+			const auto& mounted = m_directories[index];
+			if (mounted == directory) {
+				return BUSY;
+			}
+			if (!mounted.has_value() && available == FULL) {
+				available = static_cast<int>(index);
+			}
+		}
+		return available;
+	}
+
+	void Mount(size_t slot, std::string_view directory) { m_directories[slot] = directory; }
+
+	void Release(size_t slot) {
+		if (slot < m_directories.size()) {
+			m_directories[slot].reset();
+		}
+	}
+
+	[[nodiscard]] int Find(std::string_view mount_point) const {
+		for (size_t index = 0; index < m_directories.size(); index++) {
+			if (m_directories[index].has_value() && MountPoint(index) == mount_point) {
+				return static_cast<int>(index);
+			}
+		}
+		return FULL;
+	}
+
+	[[nodiscard]] static std::string MountPoint(size_t slot) {
+		return "/savedata" + std::to_string(slot);
+	}
+
+	[[nodiscard]] bool Empty() const {
+		for (const auto& directory: m_directories) {
+			if (directory.has_value()) {
+				return false;
+			}
+		}
+		return true;
+	}
+
+private:
+	std::array<std::optional<std::string>, COUNT> m_directories;
+};
+
+} // namespace Libs::SaveData
+
+#endif /* EMULATOR_INCLUDE_EMULATOR_LIBS_SAVEDATAMOUNTSLOTS_H_ */