appFs - introduce telemetry::appFs library for managing FUSE filesyst…

…em with telemetry librabry integration

This commit introduces the telemetry::appFs library, which seamlessly integrates with the telemetry library to simplify the management of FUSE (Filesystem in Userspace) filesystems.

include/appFs.hpp

@@ -0,0 +1,71 @@
+/**
+ * @file
+ * @brief Definition of the AppFsFuse class for managing FUSE filesystem
+ * @author Pavel Siska <siska@cesnet.cz>
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#pragma once
+
+#include <fuse3/fuse.h>
+#include <memory>
+#include <string>
+#include <telemetry.hpp>
+#include <thread>
+
+namespace telemetry::appFs {
+
+/**
+ * @brief The AppFsFuse class for managing FUSE filesystem.
+ */
+class AppFsFuse {
+public:
+	/**
+	 * @brief Constructor for AppFsFuse.
+	 *
+	 * @param rootDirectory A shared pointer to the telemetry root directory.
+	 *
+	 * @throws std::runtime_error if rootDirectory is nullptr.
+	 */
+	AppFsFuse(std::shared_ptr<Directory> rootDirectory);
+
+	/**
+	 * @brief Sets up and mounts the FUSE filesystem.
+	 *
+	 * This method sets up the FUSE filesystem with the provided mount point directory path.
+	 * It creates a new thread to run the FUSE event loop.
+	 *
+	 * @param mountPoint The mount point directory path.
+	 * @param tryToUnmountOnStart Whether to attempt unmounting the mount point if it's already
+	 * mounted.
+	 *
+	 * @throws std::runtime_error if setup and mount process fails.
+	 */
+	void setupAndMount(const std::string& mountPoint, bool tryToUnmountOnStart = true);
+
+	/**
+	 * @brief Unmounts the FUSE filesystem.
+	 *
+	 * This method unmounts the FUSE filesystem. It interrupts the FUSE event loop.
+	 *
+	 * @note This method is also called automatically when the AppFsFuse instance is destroyed.
+	 */
+	void unmount();
+
+	/**
+	 * @brief Destructor for AppFsFuse.
+	 *
+	 * Terminates the thread running the loop.
+	 *
+	 * @note This method unmounts the FUSE filesystem.
+	 */
+	~AppFsFuse();
+
+private:
+	std::unique_ptr<struct fuse, decltype(&fuse_destroy)> m_fuse {nullptr, &fuse_destroy};
+	std::shared_ptr<Directory> m_rootDirectory;
+	std::thread m_fuseThread;
+};
+
+} // namespace telemetry::appFs

pkg/rpm/telemetry.spec.in

@@ -33,5 +33,7 @@ telemetry data in your program.
 %{_libdir}/libtelemetry.so
 %{_includedir}/telemetry.hpp
 %{_includedir}/telemetry/*.hpp
+%{_libdir}/libappFs.so
+%{_includedir}/appFs.hpp
 
 %changelog

src/CMakeLists.txt

@@ -1 +1,2 @@
 add_subdirectory(telemetry)
+add_subdirectory(appFs)

src/appFs/CMakeLists.txt

@@ -0,0 +1,20 @@
+list(APPEND APPFS_SOURCE_FILES
+	appFs.cpp
+)
+
+if (TELEMETRY_BUILD_SHARED)
+	add_library(appFs SHARED ${APPFS_SOURCE_FILES})
+else()
+	add_library(appFs STATIC ${APPFS_SOURCE_FILES})
+endif()
+
+add_library(telemetry::appFs ALIAS appFs)
+
+target_compile_definitions(appFs PUBLIC FUSE_USE_VERSION=30 _FILE_OFFSET_BITS=64)
+target_link_libraries(appFs PUBLIC telemetry PkgConfig::fuse)
+target_include_directories(appFs PUBLIC ${CMAKE_SOURCE_DIR}/include)
+
+if (TELEMETRY_INSTALL_TARGETS)
+	install(TARGETS appFs LIBRARY DESTINATION ${INSTALL_DIR_LIB})
+	install(DIRECTORY ${CMAKE_SOURCE_DIR}/include/ DESTINATION ${INSTALL_DIR_INCLUDE})
+endif()