minivmac4ios/libhfs/file.c

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2016-05-21 13:01:57 +00:00
/*
* libhfs - library for reading and writing Macintosh HFS volumes
* Copyright (C) 1996-1998 Robert Leslie
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*
* $Id: file.c,v 1.9 1998/11/02 22:08:59 rob Exp $
*/
# ifdef HAVE_CONFIG_H
# include "config.h"
# endif
# include <string.h>
# include <errno.h>
# include "libhfs.h"
# include "file.h"
# include "btree.h"
# include "record.h"
# include "volume.h"
/*
* NAME: file->init()
* DESCRIPTION: initialize file structure
*/
void f_init(hfsfile *file, hfsvol *vol, long cnid, const char *name)
{
int i;
file->vol = vol;
file->parid = 0;
strcpy(file->name, name);
file->cat.cdrType = cdrFilRec;
file->cat.cdrResrv2 = 0;
file->cat.u.fil.filFlags = 0;
file->cat.u.fil.filTyp = 0;
file->cat.u.fil.filUsrWds.fdType = 0;
file->cat.u.fil.filUsrWds.fdCreator = 0;
file->cat.u.fil.filUsrWds.fdFlags = 0;
file->cat.u.fil.filUsrWds.fdLocation.v = 0;
file->cat.u.fil.filUsrWds.fdLocation.h = 0;
file->cat.u.fil.filUsrWds.fdFldr = 0;
file->cat.u.fil.filFlNum = cnid;
file->cat.u.fil.filStBlk = 0;
file->cat.u.fil.filLgLen = 0;
file->cat.u.fil.filPyLen = 0;
file->cat.u.fil.filRStBlk = 0;
file->cat.u.fil.filRLgLen = 0;
file->cat.u.fil.filRPyLen = 0;
file->cat.u.fil.filCrDat = 0;
file->cat.u.fil.filMdDat = 0;
file->cat.u.fil.filBkDat = 0;
file->cat.u.fil.filFndrInfo.fdIconID = 0;
for (i = 0; i < 4; ++i)
file->cat.u.fil.filFndrInfo.fdUnused[i] = 0;
file->cat.u.fil.filFndrInfo.fdComment = 0;
file->cat.u.fil.filFndrInfo.fdPutAway = 0;
file->cat.u.fil.filClpSize = 0;
for (i = 0; i < 3; ++i)
{
file->cat.u.fil.filExtRec[i].xdrStABN = 0;
file->cat.u.fil.filExtRec[i].xdrNumABlks = 0;
file->cat.u.fil.filRExtRec[i].xdrStABN = 0;
file->cat.u.fil.filRExtRec[i].xdrNumABlks = 0;
}
file->cat.u.fil.filResrv = 0;
f_selectfork(file, fkData);
file->flags = 0;
file->prev = 0;
file->next = 0;
}
/*
* NAME: file->selectfork()
* DESCRIPTION: choose a fork for file operations
*/
void f_selectfork(hfsfile *file, int fork)
{
file->fork = fork;
memcpy(&file->ext, fork == fkData ?
&file->cat.u.fil.filExtRec : &file->cat.u.fil.filRExtRec,
sizeof(ExtDataRec));
file->fabn = 0;
file->pos = 0;
}
/*
* NAME: file->getptrs()
* DESCRIPTION: make pointers to the current fork's lengths and extents
*/
void f_getptrs(hfsfile *file, ExtDataRec **extrec,
unsigned long **lglen, unsigned long **pylen)
{
if (file->fork == fkData)
{
if (extrec)
*extrec = &file->cat.u.fil.filExtRec;
if (lglen)
*lglen = &file->cat.u.fil.filLgLen;
if (pylen)
*pylen = &file->cat.u.fil.filPyLen;
}
else
{
if (extrec)
*extrec = &file->cat.u.fil.filRExtRec;
if (lglen)
*lglen = &file->cat.u.fil.filRLgLen;
if (pylen)
*pylen = &file->cat.u.fil.filRPyLen;
}
}
/*
* NAME: file->doblock()
* DESCRIPTION: read or write a numbered block from a file
*/
int f_doblock(hfsfile *file, unsigned long num, block *bp,
int (*func)(hfsvol *, unsigned int, unsigned int, block *))
{
unsigned int abnum;
unsigned int blnum;
unsigned int fabn;
int i;
abnum = num / file->vol->lpa;
blnum = num % file->vol->lpa;
/* locate the appropriate extent record */
fabn = file->fabn;
if (abnum < fabn)
{
ExtDataRec *extrec;
f_getptrs(file, &extrec, 0, 0);
fabn = file->fabn = 0;
memcpy(&file->ext, extrec, sizeof(ExtDataRec));
}
else
abnum -= fabn;
while (1)
{
unsigned int n;
for (i = 0; i < 3; ++i)
{
n = file->ext[i].xdrNumABlks;
if (abnum < n)
return func(file->vol, file->ext[i].xdrStABN + abnum, blnum, bp);
fabn += n;
abnum -= n;
}
if (v_extsearch(file, fabn, &file->ext, 0) <= 0)
goto fail;
file->fabn = fabn;
}
fail:
return -1;
}
/*
* NAME: file->addextent()
* DESCRIPTION: add an extent to a file
*/
int f_addextent(hfsfile *file, ExtDescriptor *blocks)
{
hfsvol *vol = file->vol;
ExtDataRec *extrec;
unsigned long *pylen;
unsigned int start, end;
node n;
int i;
f_getptrs(file, &extrec, 0, &pylen);
start = file->fabn;
end = *pylen / vol->mdb.drAlBlkSiz;
n.nnum = 0;
i = -1;
while (start < end)
{
for (i = 0; i < 3; ++i)
{
unsigned int num;
num = file->ext[i].xdrNumABlks;
start += num;
if (start == end)
break;
else if (start > end)
ERROR(EIO, "file extents exceed file physical length");
else if (num == 0)
ERROR(EIO, "empty file extent");
}
if (start == end)
break;
if (v_extsearch(file, start, &file->ext, &n) <= 0)
goto fail;
file->fabn = start;
}
if (i >= 0 &&
file->ext[i].xdrStABN + file->ext[i].xdrNumABlks == blocks->xdrStABN)
file->ext[i].xdrNumABlks += blocks->xdrNumABlks;
else
{
/* create a new extent descriptor */
if (++i < 3)
file->ext[i] = *blocks;
else
{
ExtKeyRec key;
byte record[HFS_MAX_EXTRECLEN];
unsigned int reclen;
/* record is full; create a new one */
file->ext[0] = *blocks;
for (i = 1; i < 3; ++i)
{
file->ext[i].xdrStABN = 0;
file->ext[i].xdrNumABlks = 0;
}
file->fabn = start;
r_makeextkey(&key, file->fork, file->cat.u.fil.filFlNum, end);
r_packextrec(&key, &file->ext, record, &reclen);
if (bt_insert(&vol->ext, record, reclen) == -1)
goto fail;
i = -1;
}
}
if (i >= 0)
{
/* store the modified extent record */
if (file->fabn)
{
if ((n.nnum == 0 &&
v_extsearch(file, file->fabn, 0, &n) <= 0) ||
v_putextrec(&file->ext, &n) == -1)
goto fail;
}
else
memcpy(extrec, &file->ext, sizeof(ExtDataRec));
}
*pylen += blocks->xdrNumABlks * vol->mdb.drAlBlkSiz;
file->flags |= HFS_FILE_UPDATE_CATREC;
return 0;
fail:
return -1;
}
/*
* NAME: file->alloc()
* DESCRIPTION: reserve allocation blocks for a file
*/
long f_alloc(hfsfile *file)
{
hfsvol *vol = file->vol;
unsigned long clumpsz;
ExtDescriptor blocks;
clumpsz = file->cat.u.fil.filClpSize;
if (clumpsz == 0)
{
if (file == &vol->ext.f)
clumpsz = vol->mdb.drXTClpSiz;
else if (file == &vol->cat.f)
clumpsz = vol->mdb.drCTClpSiz;
else
clumpsz = vol->mdb.drClpSiz;
}
blocks.xdrNumABlks = clumpsz / vol->mdb.drAlBlkSiz;
if (v_allocblocks(vol, &blocks) == -1)
goto fail;
if (f_addextent(file, &blocks) == -1)
{
v_freeblocks(vol, &blocks);
goto fail;
}
return blocks.xdrNumABlks;
fail:
return -1;
}
/*
* NAME: file->trunc()
* DESCRIPTION: release allocation blocks unneeded by a file
*/
int f_trunc(hfsfile *file)
{
hfsvol *vol = file->vol;
ExtDataRec *extrec;
unsigned long *lglen, *pylen, alblksz, newpylen;
unsigned int dlen, start, end;
node n;
int i;
if (vol->flags & HFS_VOL_READONLY)
goto done;
f_getptrs(file, &extrec, &lglen, &pylen);
alblksz = vol->mdb.drAlBlkSiz;
newpylen = (*lglen / alblksz + (*lglen % alblksz != 0)) * alblksz;
if (newpylen > *pylen)
ERROR(EIO, "file size exceeds physical length");
else if (newpylen == *pylen)
goto done;
dlen = (*pylen - newpylen) / alblksz;
start = file->fabn;
end = newpylen / alblksz;
if (start >= end)
{
start = file->fabn = 0;
memcpy(&file->ext, extrec, sizeof(ExtDataRec));
}
n.nnum = 0;
i = -1;
while (start < end)
{
for (i = 0; i < 3; ++i)
{
unsigned int num;
num = file->ext[i].xdrNumABlks;
start += num;
if (start >= end)
break;
else if (num == 0)
ERROR(EIO, "empty file extent");
}
if (start >= end)
break;
if (v_extsearch(file, start, &file->ext, &n) <= 0)
goto fail;
file->fabn = start;
}
if (start > end)
{
ExtDescriptor blocks;
file->ext[i].xdrNumABlks -= start - end;
dlen -= start - end;
blocks.xdrStABN = file->ext[i].xdrStABN + file->ext[i].xdrNumABlks;
blocks.xdrNumABlks = start - end;
if (v_freeblocks(vol, &blocks) == -1)
goto fail;
}
*pylen = newpylen;
file->flags |= HFS_FILE_UPDATE_CATREC;
do
{
while (dlen && ++i < 3)
{
unsigned int num;
num = file->ext[i].xdrNumABlks;
start += num;
if (num == 0)
ERROR(EIO, "empty file extent");
else if (num > dlen)
ERROR(EIO, "file extents exceed physical size");
dlen -= num;
if (v_freeblocks(vol, &file->ext[i]) == -1)
goto fail;
file->ext[i].xdrStABN = 0;
file->ext[i].xdrNumABlks = 0;
}
if (file->fabn)
{
if (n.nnum == 0 &&
v_extsearch(file, file->fabn, 0, &n) <= 0)
goto fail;
if (file->ext[0].xdrNumABlks)
{
if (v_putextrec(&file->ext, &n) == -1)
goto fail;
}
else
{
if (bt_delete(&vol->ext, HFS_NODEREC(n, n.rnum)) == -1)
goto fail;
n.nnum = 0;
}
}
else
memcpy(extrec, &file->ext, sizeof(ExtDataRec));
if (dlen)
{
if (v_extsearch(file, start, &file->ext, &n) <= 0)
goto fail;
file->fabn = start;
i = -1;
}
}
while (dlen);
done:
return 0;
fail:
return -1;
}
/*
* NAME: file->flush()
* DESCRIPTION: flush all pending changes to an open file
*/
int f_flush(hfsfile *file)
{
hfsvol *vol = file->vol;
if (vol->flags & HFS_VOL_READONLY)
goto done;
if (file->flags & HFS_FILE_UPDATE_CATREC)
{
node n;
file->cat.u.fil.filStBlk = file->cat.u.fil.filExtRec[0].xdrStABN;
file->cat.u.fil.filRStBlk = file->cat.u.fil.filRExtRec[0].xdrStABN;
if (v_catsearch(vol, file->parid, file->name, 0, 0, &n) <= 0 ||
v_putcatrec(&file->cat, &n) == -1)
goto fail;
file->flags &= ~HFS_FILE_UPDATE_CATREC;
}
done:
return 0;
fail:
return -1;
}