Mercurial > embed
comparison libzip/lib/zip_source_seek.c @ 20:3b18afe43c9d
libzip: reimport version 1.1.3
author | David Demelier <markand@malikania.fr> |
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date | Wed, 29 Jun 2016 09:24:55 +0200 |
parents | 2306f4b04790 |
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19:07f2cdc6e430 | 20:3b18afe43c9d |
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1 /* | |
2 zip_source_seek.c -- seek to offset | |
3 Copyright (C) 2014 Dieter Baron and Thomas Klausner | |
4 | |
5 This file is part of libzip, a library to manipulate ZIP archives. | |
6 The authors can be contacted at <libzip@nih.at> | |
7 | |
8 Redistribution and use in source and binary forms, with or without | |
9 modification, are permitted provided that the following conditions | |
10 are met: | |
11 1. Redistributions of source code must retain the above copyright | |
12 notice, this list of conditions and the following disclaimer. | |
13 2. Redistributions in binary form must reproduce the above copyright | |
14 notice, this list of conditions and the following disclaimer in | |
15 the documentation and/or other materials provided with the | |
16 distribution. | |
17 3. The names of the authors may not be used to endorse or promote | |
18 products derived from this software without specific prior | |
19 written permission. | |
20 | |
21 THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS | |
22 OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED | |
23 WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |
24 ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY | |
25 DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | |
26 DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE | |
27 GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS | |
28 INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER | |
29 IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR | |
30 OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN | |
31 IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | |
32 */ | |
33 | |
34 | |
35 #include "zipint.h" | |
36 | |
37 | |
38 ZIP_EXTERN int | |
39 zip_source_seek(zip_source_t *src, zip_int64_t offset, int whence) | |
40 { | |
41 zip_source_args_seek_t args; | |
42 | |
43 if (src->source_closed) { | |
44 return -1; | |
45 } | |
46 if (!ZIP_SOURCE_IS_OPEN_READING(src) || (whence != SEEK_SET && whence != SEEK_CUR && whence != SEEK_END)) { | |
47 zip_error_set(&src->error, ZIP_ER_INVAL, 0); | |
48 return -1; | |
49 } | |
50 | |
51 args.offset = offset; | |
52 args.whence = whence; | |
53 | |
54 return (_zip_source_call(src, &args, sizeof(args), ZIP_SOURCE_SEEK) < 0 ? -1 : 0); | |
55 } | |
56 | |
57 | |
58 zip_int64_t | |
59 zip_source_seek_compute_offset(zip_uint64_t offset, zip_uint64_t length, void *data, zip_uint64_t data_length, zip_error_t *error) | |
60 { | |
61 zip_int64_t new_offset; | |
62 zip_source_args_seek_t *args = ZIP_SOURCE_GET_ARGS(zip_source_args_seek_t, data, data_length, error); | |
63 | |
64 if (args == NULL) { | |
65 return -1; | |
66 } | |
67 | |
68 switch (args->whence) { | |
69 case SEEK_CUR: | |
70 new_offset = (zip_int64_t)offset + args->offset; | |
71 break; | |
72 | |
73 case SEEK_END: | |
74 new_offset = (zip_int64_t)length + args->offset; | |
75 break; | |
76 | |
77 case SEEK_SET: | |
78 new_offset = args->offset; | |
79 break; | |
80 | |
81 default: | |
82 zip_error_set(error, ZIP_ER_INVAL, 0); | |
83 return -1; | |
84 } | |
85 | |
86 if (new_offset < 0 || (zip_uint64_t)new_offset > length) { | |
87 zip_error_set(error, ZIP_ER_INVAL, 0); | |
88 return -1; | |
89 } | |
90 | |
91 return new_offset; | |
92 } |