- added integrity checks on .moo files

[helm.git] / helm / matita / matitaMoo.ml

diff --git a/helm/matita/matitaMoo.ml b/helm/matita/matitaMoo.ml
new file mode 100644 (file)
index 0000000..ea5c748
--- /dev/null
+++ b/helm/matita/matitaMoo.ml
@@ -0,0 +1,67 @@
+(* Copyright (C) 2005, HELM Team.
+ * 
+ * This file is part of HELM, an Hypertextual, Electronic
+ * Library of Mathematics, developed at the Computer Science
+ * Department, University of Bologna, Italy.
+ * 
+ * HELM is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ * 
+ * HELM is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with HELM; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+ * MA  02111-1307, USA.
+ * 
+ * For details, see the HELM World-Wide-Web page,
+ * http://helm.cs.unibo.it/
+ *)
+
+exception Checksum_failure of string
+exception Corrupt_moo of string
+exception Version_mismatch of string
+
+let marshal_flags = []
+
+(** .moo file format
+ * - an integer -- magic number -- denoting the version of the dumped data
+ *   structure. Different magic numbers stand for incompatible data structures
+ * - an integer -- checksum -- denoting the hash value (computed with
+ *   Hashtbl.hash) of the string representation of the dumped data structur
+ * - marshalled list of GrafiteAst.command
+ *)
+
+let save_moo ~fname moo =
+ let oc = open_out fname in
+ let marshalled_moo = Marshal.to_string (List.rev moo) marshal_flags in
+ let checksum = Hashtbl.hash marshalled_moo in
+ output_binary_int oc GrafiteAst.magic;
+ output_binary_int oc checksum;
+ output_string oc marshalled_moo;
+ close_out oc
+
+let load_moo ~fname =
+  let ic = open_in fname in
+  HExtlib.finally
+    (fun () -> close_in ic)
+    (fun () ->
+      try
+        let moo_magic = input_binary_int ic in
+        if moo_magic <> GrafiteAst.magic then raise (Version_mismatch fname);
+        let moo_checksum = input_binary_int ic in
+        let marshalled_moo = HExtlib.input_all ic in
+        let checksum = Hashtbl.hash marshalled_moo in
+        if checksum <> moo_checksum then raise (Checksum_failure fname);
+        let (moo: MatitaTypes.ast_command list) =
+          Marshal.from_string marshalled_moo 0
+        in
+        moo
+      with End_of_file -> raise (Corrupt_moo fname))
+    ()
+