lovefs_clean

fs.lua

-- by megagrump@pm.me
-- contains some code by Caldas Lopes: https://github.com/linux-man/lovefs
-- License: MIT
local ffi = require("ffi")
local bit = require("bit")

local fs

if ffi.os == "Windows" then
	local lib = ffi.C

	ffi.cdef[[
		#pragma pack(push)
		#pragma pack(1)
			struct WIN32_FIND_DATAW {
				uint32_t dwFileWttributes;
				uint64_t ftCreationTime;
				uint64_t ftLastAccessTime;
				uint64_t ftLastWriteTime;
				uint32_t dwReserved[4];
				char cFileName[520];
				char cAlternateFileName[28];
			};
		#pragma(pop)

		int MultiByteToWideChar(unsigned int CodePage, uint32_t dwFlags, const char* lpMultiByteStr, int cbMultiByte, const char* lpWideCharStr, int cchWideChar);
		int WideCharToMultiByte(unsigned int CodePage, uint32_t dwFlags, const char* lpWideCharStr, int cchWideChar, const char* lpMultiByteStr, int cchMultiByte, const char* default, int* used);

		int _wchdir(const char* path);
		char* _wgetcwd(char* buffer, int maxlen);

		void* FindFirstFileW(const char* pattern, struct WIN32_FIND_DATAW* fd);
		bool FindNextFileW(void* ff, struct WIN32_FIND_DATAW* fd);
		bool FindClose(void* ff);

		void* CreateFileW(const char* lpFileName, unsigned long dwDesiredAccess, unsigned long dwShareMode, void* lpSecurityAttributes, unsigned long dwCreationDisposition, unsigned long dwFlagsAndAttributes, void* hTemplateFile);
		long WriteFile(void* hFile, void* lpBuffer, unsigned long nNumberOfBytesToWrite, unsigned long* lpNumberOfBytesWritten, void* lpOverlapped);
		long ReadFile(void* hFile, void* lpBuffer, unsigned long nNumberOfBytesToRead, unsigned long* lpNumberOfBytesRead, void* lpOverlapped);
		long GetFileSize(void* hFile, void* lpFileSizeHigh);

		void CloseHandle(void* hHandle);

		int GetLogicalDrives(void);
	]]

	local GENERIC_READ  = 0x80000000
	local GENERIC_WRITE = 0x40000000
	local WIN32_FIND_DATA = ffi.typeof('struct WIN32_FIND_DATAW')
	local INVALID_HANDLE = ffi.cast('void*', -1)
	local MAX_PATH = 260
	local _cwdBuffer = ffi.new("char[?]", MAX_PATH * 2 + 2)

	local function u2w(str, code)
		local size = lib.MultiByteToWideChar(code or 65001, 0, str, #str, nil, 0)
		local buf = ffi.new("char[?]", size * 2 + 2)
		lib.MultiByteToWideChar(code or 65001, 0, str, #str, buf, size * 2)
		return buf
	end

	local function w2u(wstr, code)
		local size = lib.WideCharToMultiByte(code or 65001, 0, wstr, -1, nil, 0, nil, nil)
		local buf = ffi.new("char[?]", size + 1)
		size = lib.WideCharToMultiByte(code or 65001, 0, wstr, -1, buf, size, nil, nil)
		return ffi.string(buf)
	end

	local function getWorkingDirectory()
		return ffi.string(w2u(lib._wgetcwd(_cwdBuffer, MAX_PATH)))
	end

	local function getFileList(dir)
		dir = dir or getWorkingDirectory()
		local fd = ffi.new(WIN32_FIND_DATA)
		local hFile = lib.FindFirstFileW(u2w(dir..'\\*'), fd)
		ffi.gc(hFile, lib.FindClose)
		local files = {}
		if hFile ~= INVALID_HANDLE then
			repeat
				local fn = w2u(fd.cFileName)
				if bit.band(fd.dwFileWttributes, 2) == 0 then
					table.insert(files, {
						name = fn,
						type = bit.band(fd.dwFileWttributes, 16) == 16 and "directory" or "file"
					})
				end
			until not lib.FindNextFileW(hFile, fd)
		end
		lib.FindClose(ffi.gc(hFile, nil))

		return files
	end

	local function changeDirectory(dir)
		return lib._wchdir(u2w(dir)) == 0
	end

	local function getDriveList(dir)
		local drives = {}
		local bits = lib.GetLogicalDrives()
		for i = 0, 25 do
			if bit.band(bits, 2 ^ i) > 0 then
				table.insert(drives, string.char(65 + i))
			end
		end

		return drives
	end

	local function readFile(path)
		local handle = lib.CreateFileW(u2w(path), GENERIC_READ, 1, nil, 3, 128, nil)
		if handle == INVALID_HANDLE then error("Could not open file") end
		local size = lib.GetFileSize(handle, nil)
		local buffer = ffi.new("char[?]", size)
		local nread = ffi.new('unsigned long[?]', 1)
		local result = lib.ReadFile(handle, buffer, size, nread, nil) ~= 0
		lib.CloseHandle(handle)
		if not result then
			error("Could not read file")
		end
		return ffi.string(buffer, size)
	end

	local function writeFile(path, data)
		local handle = lib.CreateFileW(u2w(path), GENERIC_WRITE, 0, nil, 2, 128, nil)
		if handle == INVALID_HANDLE then error("Could not create file") end
		local nwritten = ffi.new('unsigned long[?]', 1)
		local result = lib.WriteFile(handle, ffi.cast("void*", data), #data, nwritten, nil) ~= 0
		lib.CloseHandle(handle)
		if not result then
			error("Could not write file")
		end
		return result
	end

	local function writeTextFile(path, text)
		local rn = text:gsub("([^\r\n]*)\r?\n", "%1\r\n")
		return writeFile(path, rn)
	end

	fs = {
		fileList         = getFileList,
		driveList        = getDriveList,
		currentDirectory = getWorkingDirectory,
		changeDirectory  = changeDirectory,
		readFile         = readFile,
		writeFile        = writeFile,
		writeTextFile    = writeTextFile,
		pathSeparator    = "\\",
		maxPath          = MAX_PATH,
	}
else
	ffi.cdef[[
		struct dirent {
			unsigned long  d_ino;       /* inode number */
			unsigned long  d_off;       /* not an offset */
			unsigned short d_reclen;    /* length of this record */
			unsigned char  d_type;      /* type of file; not supported by all filesystem types */
			char           d_name[256]; /* filename */
		};

		char* getcwd(char *buffer, int maxlen);
		int chdir(const char* path);
		struct DIR *opendir(const char *name);
		struct dirent *readdir(struct DIR *dirstream);
		int closedir(struct DIR *dirstream);
		char *realpath(const char *name, char *resolved);
	]]

	local MAX_PATH = 4096
	local _pathBuffer = ffi.new("char[?]", MAX_PATH)

	local function getWorkingDirectory()
		return ffi.string(ffi.C.getcwd(_pathBuffer, MAX_PATH))
	end

	local function getFileList(dir)
		dir = dir or getWorkingDirectory()

		local files = {}
		local hDir = ffi.C.opendir(dir)
		ffi.gc(hDir, ffi.C.closedir)
		local hasDotDot = false
		if hDir ~= nil then
			local dirent = ffi.C.readdir(hDir)
			while dirent ~= nil do
				if dirent.d_type == 10 then
					local realpath = ffi.C.realpath(dirent.d_name, _pathBuffer)
					if realpath ~= nil then
						realpath = ffi.string(realpath)
						local isdir = ffi.C.opendir(realpath)
						if isdir ~= nil then
							dirent.d_type = 4
							ffi.C.closedir(isdir)
						else
							dirent.d_type = 8
						end
					end
				end
				if dirent.d_type == 4 or dirent.d_type == 8 then
					local file = {
						name = ffi.string(dirent.d_name),
						type = dirent.d_type == 4 and "directory" or "file"
					}
					table.insert(files, file)
					hasDotDot = hasDotDot or file.name == ".."
				end
				dirent = ffi.C.readdir(hDir)
			end
		end
		ffi.C.closedir(ffi.gc(hDir, nil))

		if not hasDotDot then
			table.insert(files, { name = "..", type = "directory" })
		end
		return files
	end

	function changeDirectory(dir)
		return ffi.C.chdir(dir) == 0
	end

	function getDriveList()
		return {}
	end

	function readFile(path, mode)
		local file, err = io.open(path, "rb")
		if not file then error(err) end

		local data = file:read("*all")
		file:close()

		return data
	end

	function writeFile(path, data)
		local file, err = io.open(path, "wb")
		if not file then error(err) end
		local okay = file:write(data)
		file:close()
		return okay
	end

	fs = {
		fileList         = getFileList,
		driveList        = getDriveList,
		currentDirectory = getWorkingDirectory,
		changeDirectory  = changeDirectory,
		readFile         = readFile,
		writeFile        = writeFile,
		writeTextFile    = writeFile,
		pathSeparator    = "/",
		maxPath          = MAX_PATH,
	}
end

function fs.splitPath(filepath)
	local dir, name, ext

	dir = filepath:match("(.*[\\/]).*$")
	filepath = dir and filepath:sub(#dir + 1) or filepath
	name = filepath:match("(.*)$")

	if name then
		local splitname
		splitname, ext = name:match("(.*)%.(.*)$")
		if splitname then name = splitname end
	end

	if ext and name == "" then
		name, ext = "." .. ext, nil
	end

	if name == "" then name = nil end
	if ext == "" then ext = nil end
	return dir, name, ext
end

function fs.makePath(dir, name, ext)
	local format = ""
	if dir then
		if dir:match("[/\\]$") then
			format = format .. "%{dir}"
		else
			format = format .. "%{dir}%{sep}"
		end
	end
	if name then format = format .. "%{name}" end
	if ext and ext ~= "" then format = format .. ".%{ext}" end

	return malib.utils.interpolate(format, {
		dir = dir,
		name = name,
		ext = ext,
		sep = fs.pathSeparator
	})
end

return fs