sfgetm.c revision 1
/***********************************************************************
* *
* This software is part of the ast package *
* Copyright (c) 1985-2011 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"
/* Read an unsigned long value coded portably for a given range.
**
** Written by Kiem-Phong Vo
*/
#if __STD_C
Sfulong_t sfgetm(Sfio_t* f, Sfulong_t m)
#else
Sfulong_t sfgetm(f, m)
Sfio_t* f;
Sfulong_t m;
#endif
{
Sfulong_t v;
reg uchar *s, *ends, c;
reg int p;
SFMTXDECL(f);
SFMTXENTER(f, (Sfulong_t)(-1));
if(f->mode != SF_READ && _sfmode(f,SF_READ,0) < 0)
SFMTXRETURN(f, (Sfulong_t)(-1));
SFLOCK(f,0);
for(v = 0;; )
{ if(SFRPEEK(f,s,p) <= 0)
{ f->flags |= SF_ERROR;
v = (Sfulong_t)(-1);
goto done;
}
for(ends = s+p; s < ends;)
{ c = *s++;
v = (v << SF_BBITS) | SFBVALUE(c);
if((m >>= SF_BBITS) <= 0)
{ f->next = s;
goto done;
}
}
f->next = s;
}
done:
SFOPEN(f,0);
SFMTXRETURN(f, v);
}