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Converted to file i/o abstraction, removed race condition.
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@icculus
icculus committed Mar 25, 2002
1 parent 6a0a134 commit 4573c8a
Showing 1 changed file with 93 additions and 63 deletions.
156 changes: 93 additions & 63 deletions archivers/grp.c
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Expand Up @@ -43,19 +43,18 @@
#error PHYSFS_SUPPORTS_GRP must be defined.
#endif

/* !!! FIXME: Using the same file handle for all reads is a RACE CONDITION! */

typedef struct
{
FILE *handle;
void *handle;
char *filename;
PHYSFS_uint32 totalEntries;
} GRPinfo;

typedef struct
{
PHYSFS_uint32 startPos;
PHYSFS_uint32 curPos;
PHYSFS_uint32 size;
void *handle;
PHYSFS_uint64 startPos;
PHYSFS_uint64 size;
} GRPfileinfo;


Expand Down Expand Up @@ -117,7 +116,8 @@ const PHYSFS_ArchiveInfo __PHYSFS_ArchiveInfo_GRP =

static void GRP_dirClose(DirHandle *h)
{
fclose( ((GRPinfo *) h->opaque)->handle );
__PHYSFS_platformClose( ((GRPinfo *) h->opaque)->handle );
free(((GRPinfo *) h->opaque)->filename);
free(h->opaque);
free(h);
} /* GRP_dirClose */
Expand All @@ -127,38 +127,30 @@ static PHYSFS_sint64 GRP_read(FileHandle *handle, void *buffer,
PHYSFS_uint32 objSize, PHYSFS_uint32 objCount)
{
GRPfileinfo *finfo = (GRPfileinfo *) (handle->opaque);
FILE *fh = (FILE *) (((GRPinfo *) (handle->dirHandle->opaque))->handle);
PHYSFS_uint32 bytesLeft = (finfo->startPos + finfo->size) - finfo->curPos;
void *fh = finfo->handle;
PHYSFS_sint64 curPos = __PHYSFS_platformTell(fh);
PHYSFS_uint64 bytesLeft = (finfo->startPos + finfo->size) - curPos;
PHYSFS_uint32 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), (PHYSFS_sint64) retval);

return((PHYSFS_sint64) retval);
return(__PHYSFS_platformRead(fh, buffer, objSize, objCount));
} /* GRP_read */


static int GRP_eof(FileHandle *handle)
{
GRPfileinfo *finfo = (GRPfileinfo *) (handle->opaque);
return(finfo->curPos >= finfo->startPos + finfo->size);
void *fh = finfo->handle;
return(__PHYSFS_platformTell(fh) >= finfo->startPos + finfo->size);
} /* GRP_eof */


static PHYSFS_sint64 GRP_tell(FileHandle *handle)
{
GRPfileinfo *finfo = (GRPfileinfo *) (handle->opaque);
return(finfo->curPos - finfo->startPos);
return(__PHYSFS_platformTell(finfo->handle) - finfo->startPos);
} /* GRP_tell */


Expand All @@ -169,8 +161,7 @@ static int GRP_seek(FileHandle *handle, PHYSFS_uint64 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);
return(__PHYSFS_platformSeek(finfo->handle, newPos));
} /* GRP_seek */


Expand All @@ -183,100 +174,134 @@ static PHYSFS_sint64 GRP_fileLength(FileHandle *handle)

static int GRP_fileClose(FileHandle *handle)
{
GRPfileinfo *finfo = (GRPfileinfo *) (handle->opaque);
BAIL_IF_MACRO(__PHYSFS_platformClose(finfo->handle), NULL, 0);

free(handle->opaque);
free(handle);
return(1);
} /* GRP_fileClose */


static int openGrp(const char *filename, int forWriting, FILE **fh, PHYSFS_sint32 *count)
static int openGrp(const char *filename, int forWriting,
void **fh, PHYSFS_sint32 *count)
{
char buf[12];
PHYSFS_uint8 buf[12];

*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);
*fh = __PHYSFS_platformOpenRead(filename);
BAIL_IF_MACRO(*fh == NULL, NULL, 0);

errno = 0;
BAIL_IF_MACRO(fread(buf, 12, 1, *fh) != 1, strerror(errno), 0);
BAIL_IF_MACRO(memcmp(buf, "KenSilverman", 12) != 0,
ERR_UNSUPPORTED_ARCHIVE, 0);
if (__PHYSFS_platformRead(*fh, buf, 12, 1) != 1)
goto openGrp_failed;

if (memcmp(buf, "KenSilverman", 12) != 0)
{
__PHYSFS_setError(ERR_UNSUPPORTED_ARCHIVE);
goto openGrp_failed;
} /* if */

if (fread(count, sizeof (PHYSFS_sint32), 1, *fh) != 1)
*count = 0;
if (__PHYSFS_platformRead(*fh, count, sizeof (PHYSFS_sint32), 1) != 1)
goto openGrp_failed;

return(1);

openGrp_failed:
if (*fh != NULL)
__PHYSFS_platformClose(*fh);

*count = -1;
*fh = NULL;
return(0);
} /* openGrp */


static int GRP_isArchive(const char *filename, int forWriting)
{
FILE *fh;
void *fh;
int fileCount;
int retval = openGrp(filename, forWriting, &fh, &fileCount);

if (fh != NULL)
fclose(fh);
__PHYSFS_platformClose(fh);

return(retval);
} /* GRP_isArchive */


static DirHandle *GRP_openArchive(const char *name, int forWriting)
{
FILE *fh;
void *fh = NULL;
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);
__PHYSFS_setError(ERR_OUT_OF_MEMORY);
goto GRP_openArchive_failed;
} /* if */

if (!openGrp(name, forWriting, &fh, &fileCount))
((GRPinfo *) retval->opaque)->filename = (char *) malloc(strlen(name) + 1);
if (((GRPinfo *) retval->opaque)->filename == NULL)
{
if (fh != NULL)
fclose(fh);
free(retval->opaque);
free(retval);
__PHYSFS_setError(ERR_OUT_OF_MEMORY);
goto GRP_openArchive_failed;
} /* if */

if (!openGrp(name, forWriting, &fh, &fileCount))
goto GRP_openArchive_failed;

strcpy(((GRPinfo *) retval->opaque)->filename, name);
((GRPinfo *) retval->opaque)->handle = fh;
((GRPinfo *) retval->opaque)->totalEntries = fileCount;
retval->funcs = &__PHYSFS_DirFunctions_GRP;
return(retval);

GRP_openArchive_failed:
if (retval != NULL)
{
if (retval->opaque != NULL)
{
if ( ((GRPinfo *) retval->opaque)->filename != NULL )
free( ((GRPinfo *) retval->opaque)->filename );
free(retval->opaque);
} /* if */
free(retval);
} /* if */

if (fh != NULL)
__PHYSFS_platformClose(fh);

return(NULL);
} /* GRP_openArchive */


static LinkedStringList *GRP_enumerateFiles(DirHandle *h,
const char *dirname,
int omitSymLinks)
{
char buf[16];
PHYSFS_uint8 buf[16];
GRPinfo *g = (GRPinfo *) (h->opaque);
FILE *fh = g->handle;
void *fh = g->handle;
int i;
LinkedStringList *retval = NULL;
LinkedStringList *l = NULL;
LinkedStringList *prev = NULL;

/* !!! FIXME: Does this consider "/" ? */
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);
BAIL_IF_MACRO(!__PHYSFS_platformSeek(fh, 16), NULL, NULL);

for (i = 0; i < g->totalEntries; i++)
{
errno = 0;
BAIL_IF_MACRO(fread(buf, 16, 1, fh) != 1, strerror(errno), retval);
BAIL_IF_MACRO(__PHYSFS_platformRead(fh, buf, 16, 1) != 1, NULL, retval);

buf[12] = '\0'; /* FILENAME.EXT is all you get. */

Expand Down Expand Up @@ -309,9 +334,9 @@ static LinkedStringList *GRP_enumerateFiles(DirHandle *h,
static PHYSFS_sint32 getFileEntry(DirHandle *h, const char *name,
PHYSFS_sint32 *size)
{
char buf[16];
PHYSFS_uint8 buf[16];
GRPinfo *g = (GRPinfo *) (h->opaque);
FILE *fh = g->handle;
void *fh = g->handle;
int i;
char *ptr;
int retval = (g->totalEntries + 1) * 16; /* offset of raw file data */
Expand All @@ -327,19 +352,15 @@ static PHYSFS_sint32 getFileEntry(DirHandle *h, const char *name,
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);
/* jump to first file entry... */
BAIL_IF_MACRO(!__PHYSFS_platformSeek(fh, 16), NULL, -1);

for (i = 0; i < g->totalEntries; i++)
{
PHYSFS_sint32 l = 0;

errno = 0;
BAIL_IF_MACRO(fread(buf, 12, 1, fh) != 1, strerror(errno), -1);

errno = 0;
BAIL_IF_MACRO(fread(&l, sizeof (l), 1, fh) != 1, strerror(errno), -1);
BAIL_IF_MACRO(__PHYSFS_platformRead(fh, buf, 12, 1) != 1, NULL, -1);
BAIL_IF_MACRO(__PHYSFS_platformRead(fh, &l, sizeof (l), 1) != 1, NULL, -1);

buf[12] = '\0'; /* FILENAME.EXT is all you get. */

Expand Down Expand Up @@ -377,9 +398,10 @@ static int GRP_isSymLink(DirHandle *h, const char *name)

static FileHandle *GRP_openRead(DirHandle *h, const char *name)
{
const char *filename = ((GRPinfo *) h->opaque)->filename;
FileHandle *retval;
GRPfileinfo *finfo;
PHYSFS_sint32 size;
PHYSFS_uint32 size;
PHYSFS_sint32 offset;

offset = getFileEntry(h, name, &size);
Expand All @@ -394,8 +416,16 @@ static FileHandle *GRP_openRead(DirHandle *h, const char *name)
BAIL_IF_MACRO(1, ERR_OUT_OF_MEMORY, NULL);
} /* if */

finfo->handle = __PHYSFS_platformOpenRead(filename);
if ( (finfo->handle == NULL) ||
(!__PHYSFS_platformSeek(finfo->handle, offset)) )
{
free(finfo);
free(retval);
return(NULL);
} /* if */

finfo->startPos = offset;
finfo->curPos = offset;
finfo->size = size;
retval->opaque = (void *) finfo;
retval->funcs = &__PHYSFS_FileFunctions_GRP;
Expand Down

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