initial commit

overlay-common.hh

@@ -0,0 +1,43 @@
+/* SPDX-License-Identifier: Apache-2.0
+ * (c) 2025, Konstantin Demin
+ */
+
+#ifndef INCLUDE_OVERLAY_COMMON_HH
+#define INCLUDE_OVERLAY_COMMON_HH 1
+
+#include <vector>
+
+extern "C" {
+	#include <dirent.h>
+}
+
+constexpr unsigned int ovl_name_max = sizeof(dirent::d_name);
+constexpr unsigned int ovl_path_max = (PATH_MAX);
+/*
+constexpr unsigned int ovl_path_max =
+#ifdef PATH_MAX
+  #if (PATH_MAX > 0) && (PATH_MAX <= 8192)
+    (PATH_MAX);
+  #else
+    8192;
+  #endif
+#else
+    4096;
+#endif
+*/
+
+constexpr unsigned int ovl_path_name_ratio = ovl_path_max / ovl_name_max;
+constexpr unsigned int ovl_depth_max = ovl_path_name_ratio - 1;
+
+struct ovl_name_t {
+	size_t  len;
+	char    str[ovl_name_max];
+};
+
+struct ovl_path_t {
+	size_t  len;
+	char    str[ovl_path_max];
+};
+typedef std::vector<ovl_path_t>  ovl_path_vec;
+
+#endif /* INCLUDE_OVERLAY_COMMON_HH */