archiver_hog.c
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/*
* 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/)
*
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* Please see the file LICENSE.txt in the source's root directory.
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*
* This file written by Bradley Bell.
* Based on grp.c by Ryan C. Gordon.
*/
#define __PHYSICSFS_INTERNAL__
#include "physfs_internal.h"
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#if PHYSFS_SUPPORTS_HOG
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static int hogLoadEntries(PHYSFS_Io *io, void *unpkarc)
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const PHYSFS_uint64 iolen = io->length(io);
PHYSFS_uint32 pos = 3;
while (pos < iolen)
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PHYSFS_uint32 size;
char name[13];
BAIL_IF_ERRPASS(!__PHYSFS_readAll(io, name, 13), 0);
BAIL_IF_ERRPASS(!__PHYSFS_readAll(io, &size, 4), 0);
name[12] = '\0'; /* just in case. */
pos += 13 + 4;
size = PHYSFS_swapULE32(size);
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BAIL_IF_ERRPASS(!UNPK_addEntry(unpkarc, name, 0, -1, -1, pos, size), 0);
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pos += size;
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/* skip over entry */
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BAIL_IF_ERRPASS(!io->seek(io, pos), 0);
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} /* hogLoadEntries */
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static void *HOG_openArchive(PHYSFS_Io *io, const char *name, int forWriting)
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PHYSFS_uint8 buf[3];
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PHYSFS_uint32 count = 0;
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void *unpkarc = NULL;
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assert(io != NULL); /* shouldn't ever happen. */
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BAIL_IF(forWriting, PHYSFS_ERR_READ_ONLY, NULL);
BAIL_IF_ERRPASS(!__PHYSFS_readAll(io, buf, 3), NULL);
BAIL_IF(memcmp(buf, "DHF", 3) != 0, PHYSFS_ERR_UNSUPPORTED, NULL);
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unpkarc = UNPK_openArchive(io);
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BAIL_IF_ERRPASS(!unpkarc, NULL);
if (!hogLoadEntries(io, unpkarc))
{
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UNPK_abandonArchive(unpkarc);
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return NULL;
} /* if */
return unpkarc;
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} /* HOG_openArchive */
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const PHYSFS_Archiver __PHYSFS_Archiver_HOG =
{
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CURRENT_PHYSFS_ARCHIVER_API_VERSION,
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{
"HOG",
"Descent I/II HOG file format",
"Bradley Bell <btb@icculus.org>",
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"https://icculus.org/physfs/",
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0, /* supportsSymlinks */
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HOG_openArchive,
UNPK_enumerateFiles,
UNPK_openRead,
UNPK_openWrite,
UNPK_openAppend,
UNPK_remove,
UNPK_mkdir,
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UNPK_stat,
UNPK_closeArchive
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#endif /* defined PHYSFS_SUPPORTS_HOG */
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/* end of archiver_hog.c ... */