1 (* Copyright (C) 2005, HELM Team.
3 * This file is part of HELM, an Hypertextual, Electronic
4 * Library of Mathematics, developed at the Computer Science
5 * Department, University of Bologna, Italy.
7 * HELM is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version 2
10 * of the License, or (at your option) any later version.
12 * HELM is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
17 * You should have received a copy of the GNU General Public License
18 * along with HELM; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place - Suite 330, Boston,
22 * For details, see the HELM World-Wide-Web page,
23 * http://helm.cs.unibo.it/
28 exception Checksum_failure of string
29 exception Corrupt_metadata of string
30 exception Version_mismatch of string
35 | Dependency of string (* baseuri without trailing slash *)
38 let eq_metadata (m1:metadata) (m2:metadata) = m1 = m2
40 let marshal_flags = []
42 (** .metadata file format
43 * - an integer -- magic number -- denoting the version of the dumped data
44 * structure. Different magic numbers stand for incompatible data structures
45 * - an integer -- checksum -- denoting the hash value (computed with
46 * Hashtbl.hash) of the string representation of the dumped data structur
47 * - marshalled data: list of metadata
50 let save_metadata ~fname metadata =
51 let oc = open_out fname in
52 let marshalled = Marshal.to_string metadata marshal_flags in
53 let checksum = Hashtbl.hash marshalled in
54 output_binary_int oc magic;
55 output_binary_int oc checksum;
56 output_string oc marshalled;
59 let load_metadata ~fname =
60 let ic = open_in fname in
62 (fun () -> close_in ic)
65 let file_magic = input_binary_int ic in
66 if file_magic <> magic then raise (Version_mismatch fname);
67 let file_checksum = input_binary_int ic in
68 let marshalled = HExtlib.input_all ic in
69 let checksum = Hashtbl.hash marshalled in
70 if checksum <> file_checksum then raise (Checksum_failure fname);
71 let (metadata:metadata list) = Marshal.from_string marshalled 0 in
73 with End_of_file -> raise (Corrupt_metadata fname))