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/***********************************************************************
* *
* This software is part of the ast package *
* Copyright (c) 1985-2009 AT&T Intellectual Property *
* and is licensed under the *
* Common Public License, Version 1.0 *
* by AT&T Intellectual Property *
* *
* A copy of the License is available at *
* http://www.opensource.org/licenses/cpl1.0.txt *
* (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9) *
* *
* Information and Software Systems Research *
* AT&T Research *
* Florham Park NJ *
* *
* Glenn Fowler <gsf@research.att.com> *
* David Korn <dgk@research.att.com> *
* Phong Vo <kpv@research.att.com> *
* *
***********************************************************************/
#include "sfhdr.h"
/* Seek function that knows discipline
**
** Written by Kiem-Phong Vo.
*/
#if __STD_C
Sfoff_t sfsk(Sfio_t* f, Sfoff_t addr, int type, Sfdisc_t* disc)
#else
Sfoff_t sfsk(f,addr,type,disc)
Sfio_t* f;
Sfoff_t addr;
int type;
Sfdisc_t* disc;
#endif
{
Sfoff_t p;
reg Sfdisc_t* dc;
reg ssize_t s;
reg int local, mode;
SFMTXDECL(f);
SFMTXENTER(f, (Sfoff_t)(-1));
GETLOCAL(f,local);
if(!local && !(f->bits&SF_DCDOWN))
{ if((mode = f->mode&SF_RDWR) != (int)f->mode && _sfmode(f,mode,0) < 0)
SFMTXRETURN(f, (Sfoff_t)(-1));
if(SFSYNC(f) < 0)
SFMTXRETURN(f, (Sfoff_t)(-1));
#ifdef MAP_TYPE
if(f->mode == SF_READ && (f->bits&SF_MMAP) && f->data)
{ SFMUNMAP(f, f->data, f->endb-f->data);
f->data = NIL(uchar*);
}
#endif
f->next = f->endb = f->endr = f->endw = f->data;
}
if((type &= (SEEK_SET|SEEK_CUR|SEEK_END)) > SEEK_END)
SFMTXRETURN(f, (Sfoff_t)(-1));
for(;;)
{ dc = disc;
if(f->flags&SF_STRING)
{ SFSTRSIZE(f);
if(type == SEEK_SET)
s = (ssize_t)addr;
else if(type == SEEK_CUR)
s = (ssize_t)(addr + f->here);
else s = (ssize_t)(addr + f->extent);
}
else
{ SFDISC(f,dc,seekf);
if(dc && dc->seekf)
{ SFDCSK(f,addr,type,dc,p);
}
else
{ p = syslseekf(f->file,(sfoff_t)addr,type);
}
if(p >= 0)
SFMTXRETURN(f,p);
s = -1;
}
if(local)
SETLOCAL(f);
switch(_sfexcept(f,SF_SEEK,s,dc))
{
case SF_EDISC:
case SF_ECONT:
if(f->flags&SF_STRING)
SFMTXRETURN(f, (Sfoff_t)s);
goto do_continue;
default:
SFMTXRETURN(f, (Sfoff_t)(-1));
}
do_continue:
for(dc = f->disc; dc; dc = dc->disc)
if(dc == disc)
break;
disc = dc;
}
}
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