usr/src/lib/libast/common/sfio/sfgetl.c

   1 /***********************************************************************
   2 *                                                                      *
   3 *               This software is part of the ast package               *
   4 *          Copyright (c) 1985-2010 AT&T Intellectual Property          *
   5 *                      and is licensed under the                       *
   6 *                  Common Public License, Version 1.0                  *
   7 *                    by AT&T Intellectual Property                     *
   8 *                                                                      *
   9 *                A copy of the License is available at                 *
  10 *            http://www.opensource.org/licenses/cpl1.0.txt             *
  11 *         (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9)         *
  12 *                                                                      *
  13 *              Information and Software Systems Research               *
  14 *                            AT&T Research                             *
  15 *                           Florham Park NJ                            *
  16 *                                                                      *
  17 *                 Glenn Fowler <gsf@research.att.com>                  *
  18 *                  David Korn <dgk@research.att.com>                   *
  19 *                   Phong Vo <kpv@research.att.com>                    *
  20 *                                                                      *
  21 ***********************************************************************/
  22 #include        "sfhdr.h"
  23
  24 /*      Read a long value coded in a portable format.
  25 **
  26 **      Written by Kiem-Phong Vo
  27 */
  28
  29 #if __STD_C
  30 Sflong_t sfgetl(Sfio_t* f)
  31 #else
  32 Sflong_t sfgetl(f)
  33 Sfio_t* f;
  34 #endif
  35 {
  36         Sflong_t        v;
  37         uchar           *s, *ends, c;
  38         int             p;
  39         SFMTXDECL(f);
  40
  41         SFMTXENTER(f,(Sflong_t)(-1));
  42
  43         if(f->mode != SF_READ && _sfmode(f,SF_READ,0) < 0)
  44                 SFMTXRETURN(f, (Sflong_t)(-1));
  45         SFLOCK(f,0);
  46
  47         for(v = 0;;)
  48         {       if(SFRPEEK(f,s,p) <= 0)
  49                 {       f->flags |= SF_ERROR;
  50                         v = (Sflong_t)(-1);
  51                         goto done;
  52                 }
  53                 for(ends = s+p; s < ends;)
  54                 {       c = *s++;
  55                         if(c&SF_MORE)
  56                                 v = ((Sfulong_t)v << SF_UBITS) | SFUVALUE(c);
  57                         else
  58                         {       /* special translation for this byte */
  59                                 v = ((Sfulong_t)v << SF_SBITS) | SFSVALUE(c);
  60                                 f->next = s;
  61                                 v = (c&SF_SIGN) ? -v-1 : v;
  62                                 goto done;
  63                         }
  64                 }
  65                 f->next = s;
  66         }
  67 done :
  68         SFOPEN(f,0);
  69         SFMTXRETURN(f, v);
  70 }