archiver_hog.c
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
/*
* HOG support routines for PhysicsFS.
*
* This driver handles Descent I/II HOG archives.
*
* The format is very simple:
*
* The file always starts with the 3-byte signature "DHF" (Descent
* HOG file). After that the files of a HOG are just attached after
* another, divided by a 17 bytes header, which specifies the name
* and length (in bytes) of the forthcoming file! So you just read
* the header with its information of how big the following file is,
* and then skip exact that number of bytes to get to the next file
* in that HOG.
*
* char sig[3] = {'D', 'H', 'F'}; // "DHF"=Descent HOG File
*
* struct {
* char file_name[13]; // Filename, padded to 13 bytes with 0s
* int file_size; // filesize in bytes
* char data[file_size]; // The file data
* } FILE_STRUCT; // Repeated until the end of the file.
*
* (That info is from http://www.descent2.com/ddn/specs/hog/)
*
26
* Please see the file LICENSE.txt in the source's root directory.
27
28
29
30
31
32
33
34
*
* This file written by Bradley Bell.
* Based on grp.c by Ryan C. Gordon.
*/
#define __PHYSICSFS_INTERNAL__
#include "physfs_internal.h"
35
36
#if PHYSFS_SUPPORTS_HOG
37
static UNPKentry *hogLoadEntries(PHYSFS_Io *io, PHYSFS_uint32 *_entCount)
39
40
41
const PHYSFS_uint64 iolen = io->length(io);
PHYSFS_uint32 entCount = 0;
void *ptr = NULL;
42
43
UNPKentry *entries = NULL;
UNPKentry *entry = NULL;
44
45
46
47
PHYSFS_uint32 size = 0;
PHYSFS_uint32 pos = 3;
while (pos < iolen)
49
entCount++;
50
ptr = allocator.Realloc(ptr, sizeof (UNPKentry) * entCount);
51
GOTO_IF_MACRO(ptr == NULL, PHYSFS_ERR_OUT_OF_MEMORY, failed);
52
53
entries = (UNPKentry *) ptr;
entry = &entries[entCount-1];
55
GOTO_IF_MACRO(!__PHYSFS_readAll(io, &entry->name, 13), ERRPASS, failed);
56
pos += 13;
57
GOTO_IF_MACRO(!__PHYSFS_readAll(io, &size, 4), ERRPASS, failed);
58
59
60
61
62
63
pos += 4;
entry->size = PHYSFS_swapULE32(size);
entry->startPos = pos;
pos += size;
64
/* skip over entry */
65
GOTO_IF_MACRO(!io->seek(io, pos), ERRPASS, failed);
68
69
*_entCount = entCount;
return entries;
72
73
74
allocator.Free(entries);
return NULL;
} /* hogLoadEntries */
77
static void *HOG_openArchive(PHYSFS_Io *io, const char *name, int forWriting)
79
PHYSFS_uint8 buf[3];
80
PHYSFS_uint32 count = 0;
81
UNPKentry *entries = NULL;
83
assert(io != NULL); /* shouldn't ever happen. */
84
85
86
BAIL_IF_MACRO(forWriting, PHYSFS_ERR_READ_ONLY, NULL);
BAIL_IF_MACRO(!__PHYSFS_readAll(io, buf, 3), ERRPASS, NULL);
BAIL_IF_MACRO(memcmp(buf, "DHF", 3) != 0, PHYSFS_ERR_UNSUPPORTED, NULL);
88
entries = hogLoadEntries(io, &count);
89
BAIL_IF_MACRO(!entries, ERRPASS, NULL);
90
return UNPK_openArchive(io, entries, count);
91
92
93
} /* HOG_openArchive */
94
95
const PHYSFS_Archiver __PHYSFS_Archiver_HOG =
{
96
CURRENT_PHYSFS_ARCHIVER_API_VERSION,
97
98
99
100
{
"HOG",
"Descent I/II HOG file format",
"Bradley Bell <btb@icculus.org>",
101
"https://icculus.org/physfs/",
102
0, /* supportsSymlinks */
104
105
106
107
108
109
110
HOG_openArchive,
UNPK_enumerateFiles,
UNPK_openRead,
UNPK_openWrite,
UNPK_openAppend,
UNPK_remove,
UNPK_mkdir,
111
112
UNPK_stat,
UNPK_closeArchive
115
116
#endif /* defined PHYSFS_SUPPORTS_HOG */
117
/* end of archiver_hog.c ... */