libobs/util: Add function to get free disk space

libobs/util/platform-nix.c

@@ -679,3 +679,12 @@ int os_get_logical_cores(void)
 	return logical_cores;
 }
 #endif
+
+uint64_t os_get_free_disk_space(const char *dir)
+{
+	struct statvfs info;
+	if (statvfs(dir, &info) != 0)
+		return 0;
+
+	return (uint64_t)info.f_frsize * (uint64_t)info.f_bavail;
+}

libobs/util/platform-windows.c

@@ -946,3 +946,16 @@ int os_get_logical_cores(void)
 		os_get_cores_internal();
 	return logical_cores;
 }
+
+uint64_t os_get_free_disk_space(const char *dir)
+{
+	wchar_t *wdir = NULL;
+	if (!os_utf8_to_wcs_ptr(dir, 0, &wdir))
+		return 0;
+
+	ULARGE_INTEGER free;
+	bool success = !!GetDiskFreeSpaceExW(wdir, &free, NULL, NULL);
+	bfree(wdir);
+
+	return success ? free.QuadPart : 0;
+}

libobs/util/platform.h

@@ -153,6 +153,8 @@ EXPORT int os_rmdir(const char *path);
 EXPORT char *os_getcwd(char *path, size_t size);
 EXPORT int os_chdir(const char *path);
 
+EXPORT uint64_t os_get_free_disk_space(const char *dir);
+
 #define MKDIR_EXISTS   1
 #define MKDIR_SUCCESS  0
 #define MKDIR_ERROR   -1