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physfs/archivers/grp.c

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/*
* GRP support routines for PhysicsFS.
*
* This driver handles BUILD engine archives ("groupfiles"). This format
* (but not this driver) was put together by Ken Silverman.
*
* The format is simple enough. In Ken's words:
*
* What's the .GRP file format?
*
* The ".grp" file format is just a collection of a lot of files stored
* into 1 big one. I tried to make the format as simple as possible: The
* first 12 bytes contains my name, "KenSilverman". The next 4 bytes is
* the number of files that were compacted into the group file. Then for
* each file, there is a 16 byte structure, where the first 12 bytes are
* the filename, and the last 4 bytes are the file's size. The rest of
* the group file is just the raw data packed one after the other in the
* same order as the list of files.
*
* (That info is from http://www.advsys.net/ken/build.htm ...)
*
* As it was never a concern in the DOS-based Duke Nukem days, I treat these
* archives as CASE-INSENSITIVE. Opening "myfile.txt" and "MYFILE.TXT" both
* work, and get the same file.
*
* Please see the file LICENSE in the source's root directory.
*
* This file written by Ryan C. Gordon.
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <fcntl.h>
#include <assert.h>
#include "physfs.h"
#define __PHYSICSFS_INTERNAL__
#include "physfs_internal.h"
#if 0
#if (!defined PHYSFS_SUPPORTS_GRP)
#error PHYSFS_SUPPORTS_GRP must be defined.
#endif
#endif
/* !!! FIXME: Using the same file handle for all reads is a RACE CONDITION! */
typedef struct
{
FILE *handle;
int totalEntries;
} GRPinfo;
typedef struct
{
int startPos;
int curPos;
int size;
} GRPfileinfo;
static void GRP_dirClose(DirHandle *h);
static int GRP_read(FileHandle *handle, void *buffer,
unsigned int objSize, unsigned int objCount);
static int GRP_eof(FileHandle *handle);
static int GRP_tell(FileHandle *handle);
static int GRP_seek(FileHandle *handle, int offset);
static int GRP_fileLength(FileHandle *handle);
static int GRP_fileClose(FileHandle *handle);
static int GRP_isArchive(const char *filename, int forWriting);
static DirHandle *GRP_openArchive(const char *name, int forWriting);
static LinkedStringList *GRP_enumerateFiles(DirHandle *h,
const char *dirname,
int omitSymLinks);
static int GRP_exists(DirHandle *h, const char *name);
static int GRP_isDirectory(DirHandle *h, const char *name);
static int GRP_isSymLink(DirHandle *h, const char *name);
static FileHandle *GRP_openRead(DirHandle *h, const char *name);
static const FileFunctions __PHYSFS_FileFunctions_GRP =
{
GRP_read, /* read() method */
NULL, /* write() method */
GRP_eof, /* eof() method */
GRP_tell, /* tell() method */
GRP_seek, /* seek() method */
GRP_fileLength, /* fileLength() method */
GRP_fileClose /* fileClose() method */
};
const DirFunctions __PHYSFS_DirFunctions_GRP =
{
GRP_isArchive, /* isArchive() method */
GRP_openArchive, /* openArchive() method */
GRP_enumerateFiles, /* enumerateFiles() method */
GRP_exists, /* exists() method */
GRP_isDirectory, /* isDirectory() method */
GRP_isSymLink, /* isSymLink() method */
GRP_openRead, /* openRead() method */
NULL, /* openWrite() method */
NULL, /* openAppend() method */
NULL, /* remove() method */
NULL, /* mkdir() method */
GRP_dirClose /* dirClose() method */
};
const PHYSFS_ArchiveInfo __PHYSFS_ArchiveInfo_GRP =
{
"GRP",
"Build engine Groupfile format",
"Ryan C. Gordon <icculus@clutteredmind.org>",
"http://www.icculus.org/physfs/",
};
static void GRP_dirClose(DirHandle *h)
{
fclose( ((GRPinfo *) h->opaque)->handle );
free(h->opaque);
free(h);
} /* GRP_dirClose */
static int GRP_read(FileHandle *handle, void *buffer,
unsigned int objSize, unsigned int objCount)
{
GRPfileinfo *finfo = (GRPfileinfo *) (handle->opaque);
FILE *fh = (FILE *) (((GRPinfo *) (handle->dirHandle->opaque))->handle);
int bytesLeft = (finfo->startPos + finfo->size) - finfo->curPos;
unsigned int objsLeft = bytesLeft / objSize;
size_t retval = 0;
if (objsLeft < objCount)
objCount = objsLeft;
errno = 0;
BAIL_IF_MACRO(fseek(fh,finfo->curPos,SEEK_SET) == -1,strerror(errno),-1);
errno = 0;
retval = fread(buffer, objSize, objCount, fh);
finfo->curPos += (retval * objSize);
BAIL_IF_MACRO((retval < (size_t) objCount) && (ferror(fh)),
strerror(errno), (int) retval);
return((int) retval);
} /* GRP_read */
static int GRP_eof(FileHandle *handle)
{
GRPfileinfo *finfo = (GRPfileinfo *) (handle->opaque);
return(finfo->curPos >= finfo->startPos + finfo->size);
} /* GRP_eof */
static int GRP_tell(FileHandle *handle)
{
GRPfileinfo *finfo = (GRPfileinfo *) (handle->opaque);
return(finfo->curPos - finfo->startPos);
} /* GRP_tell */
static int GRP_seek(FileHandle *handle, int offset)
{
GRPfileinfo *finfo = (GRPfileinfo *) (handle->opaque);
int newPos = finfo->startPos + offset;
BAIL_IF_MACRO(offset < 0, ERR_INVALID_ARGUMENT, 0);
BAIL_IF_MACRO(newPos > finfo->startPos + finfo->size, ERR_PAST_EOF, 0);
finfo->curPos = newPos;
return(1);
} /* GRP_seek */
static int GRP_fileLength(FileHandle *handle)
{
GRPfileinfo *finfo = (GRPfileinfo *) (handle->opaque);
return(finfo->size);
} /* GRP_fileLength */
static int GRP_fileClose(FileHandle *handle)
{
free(handle->opaque);
free(handle);
return(1);
} /* GRP_fileClose */
static int openGrp(const char *filename, int forWriting, FILE **fh, int *count)
{
char buf[12];
/* !!! FIXME: Get me platform-independent typedefs! */
if (sizeof (int) != 4)
assert(0);
*fh = NULL;
BAIL_IF_MACRO(forWriting, ERR_ARC_IS_READ_ONLY, 0);
errno = 0;
*fh = fopen(filename, "rb");
BAIL_IF_MACRO(*fh == NULL, strerror(errno), 0);
errno = 0;
BAIL_IF_MACRO(fread(buf, 12, 1, *fh) != 1, strerror(errno), 0);
BAIL_IF_MACRO(strncmp(buf, "KenSilverman", 12) != 0,
ERR_UNSUPPORTED_ARCHIVE, 0);
if (fread(count, 4, 1, *fh) != 1)
*count = 0;
return(1);
} /* openGrp */
static int GRP_isArchive(const char *filename, int forWriting)
{
FILE *fh;
int fileCount;
int retval = openGrp(filename, forWriting, &fh, &fileCount);
if (fh != NULL)
fclose(fh);
return(retval);
} /* GRP_isArchive */
static DirHandle *GRP_openArchive(const char *name, int forWriting)
{
FILE *fh;
int fileCount;
DirHandle *retval = malloc(sizeof (DirHandle));
BAIL_IF_MACRO(retval == NULL, ERR_OUT_OF_MEMORY, NULL);
retval->opaque = malloc(sizeof (GRPinfo));
if (retval->opaque == NULL)
{
free(retval);
BAIL_IF_MACRO(1, ERR_OUT_OF_MEMORY, NULL);
} /* if */
if (!openGrp(name, forWriting, &fh, &fileCount))
{
if (fh != NULL)
fclose(fh);
free(retval->opaque);
free(retval);
} /* if */
((GRPinfo *) retval->opaque)->handle = fh;
((GRPinfo *) retval->opaque)->totalEntries = fileCount;
retval->funcs = &__PHYSFS_DirFunctions_GRP;
return(retval);
} /* GRP_openArchive */
static LinkedStringList *GRP_enumerateFiles(DirHandle *h,
const char *dirname,
int omitSymLinks)
{
char buf[16];
GRPinfo *g = (GRPinfo *) (h->opaque);
FILE *fh = g->handle;
int i;
LinkedStringList *retval = NULL;
LinkedStringList *l = NULL;
LinkedStringList *prev = NULL;
if (*dirname != '\0') /* no directories in GRP files. */
return(NULL);
/* jump to first file entry... */
errno = 0;
BAIL_IF_MACRO(fseek(fh, 16, SEEK_SET) == -1, strerror(errno), NULL);
for (i = 0; i < g->totalEntries; i++)
{
errno = 0;
BAIL_IF_MACRO(fread(buf, 16, 1, fh) != 1, strerror(errno), retval);
buf[12] = '\0'; /* FILENAME.EXT is all you get. */
l = (LinkedStringList *) malloc(sizeof (LinkedStringList));
if (l == NULL)
break;
l->str = (char *) malloc(strlen(buf) + 1);
if (l->str == NULL)
{
free(l);
break;
} /* if */
strcpy(l->str, buf);
if (retval == NULL)
retval = l;
else
prev->next = l;
prev = l;
l->next = NULL;
} /* for */
return(retval);
} /* GRP_enumerateFiles */
static int getFileEntry(DirHandle *h, const char *name, int *size)
{
char buf[16];
GRPinfo *g = (GRPinfo *) (h->opaque);
FILE *fh = g->handle;
int i;
char *ptr;
int retval = (g->totalEntries + 1) * 16; /* offset of raw file data */
/* Rule out filenames to avoid unneeded file i/o... */
if (strchr(name, '/') != NULL) /* no directories in groupfiles. */
return(-1);
ptr = strchr(name, '.');
if ((ptr) && (strlen(ptr) > 4)) /* 3 char extension at most. */
return(-1);
if (strlen(name) > 12)
return(-1);
/* jump to first file entry... */
errno = 0;
BAIL_IF_MACRO(fseek(fh, 16, SEEK_SET) == -1, strerror(errno), -1);
for (i = 0; i < g->totalEntries; i++)
{
int fsize;
errno = 0;
BAIL_IF_MACRO(fread(buf, 16, 1, fh) != 1, strerror(errno), -1);
fsize = *((int *) (buf + 12));
buf[12] = '\0'; /* FILENAME.EXT is all you get. */
if (__PHYSFS_platformStricmp(buf, name) == 0)
{
if (size != NULL)
*size = fsize;
return(retval);
} /* if */
retval += fsize;
} /* for */
return(-1); /* not found. */
} /* getFileEntry */
static int GRP_exists(DirHandle *h, const char *name)
{
return(getFileEntry(h, name, NULL) != -1);
} /* GRP_exists */
static int GRP_isDirectory(DirHandle *h, const char *name)
{
return(0); /* never directories in a groupfile. */
} /* GRP_isDirectory */
static int GRP_isSymLink(DirHandle *h, const char *name)
{
return(0); /* never symlinks in a groupfile. */
} /* GRP_isSymLink */
static FileHandle *GRP_openRead(DirHandle *h, const char *name)
{
FileHandle *retval;
GRPfileinfo *finfo;
int size, offset;
offset = getFileEntry(h, name, &size);
BAIL_IF_MACRO(offset == -1, ERR_NO_SUCH_FILE, NULL);
retval = (FileHandle *) malloc(sizeof (FileHandle));
BAIL_IF_MACRO(retval == NULL, ERR_OUT_OF_MEMORY, NULL);
finfo = (GRPfileinfo *) malloc(sizeof (GRPfileinfo));
if (finfo == NULL)
{
free(retval);
BAIL_IF_MACRO(1, ERR_OUT_OF_MEMORY, NULL);
} /* if */
finfo->startPos = offset;
finfo->curPos = offset;
finfo->size = size;
retval->opaque = (void *) finfo;
retval->funcs = &__PHYSFS_FileFunctions_GRP;
retval->dirHandle = h;
return(retval);
} /* GRP_openRead */
/* end of grp.c ... */
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