usr/src/lib/libast/common/sfio/sfsize.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 /*      Get the size of a stream.
  25 **
  26 **      Written by Kiem-Phong Vo.
  27 */
  28 #if __STD_C
  29 Sfoff_t sfsize(Sfio_t* f)
  30 #else
  31 Sfoff_t sfsize(f)
  32 Sfio_t* f;
  33 #endif
  34 {
  35         Sfdisc_t*       disc;
  36         reg int         mode;
  37         Sfoff_t         s;
  38         SFMTXDECL(f);
  39
  40         SFMTXENTER(f, (Sfoff_t)(-1));
  41
  42         if((mode = f->mode&SF_RDWR) != (int)f->mode && _sfmode(f,mode,0) < 0)
  43                 SFMTXRETURN(f, (Sfoff_t)(-1));
  44
  45         if(f->flags&SF_STRING)
  46         {       SFSTRSIZE(f);
  47                 SFMTXRETURN(f, f->extent);
  48         }
  49
  50         SFLOCK(f,0);
  51
  52         s = f->here;
  53
  54         if(f->extent >= 0)
  55         {       if(f->flags&(SF_SHARE|SF_APPENDWR))
  56                 {       for(disc = f->disc; disc; disc = disc->disc)
  57                                 if(disc->seekf)
  58                                         break;
  59                         if(!_sys_stat || disc)
  60                         {       Sfoff_t e;
  61                                 if((e = SFSK(f,0,SEEK_END,disc)) >= 0)
  62                                         f->extent = e;
  63                                 if(SFSK(f,f->here,SEEK_SET,disc) != f->here)
  64                                         f->here = SFSK(f,(Sfoff_t)0,SEEK_CUR,disc);
  65                         }
  66 #if _sys_stat
  67                         else
  68                         {       sfstat_t        st;
  69                                 if(sysfstatf(f->file,&st) < 0)
  70                                         f->extent = -1;
  71                                 else if((f->extent = st.st_size) < f->here)
  72                                         f->here = SFSK(f,(Sfoff_t)0,SEEK_CUR,disc);
  73                         }
  74 #endif
  75                 }
  76
  77                 if((f->flags&(SF_SHARE|SF_PUBLIC)) == (SF_SHARE|SF_PUBLIC))
  78                         f->here = SFSK(f,(Sfoff_t)0,SEEK_CUR,f->disc);
  79         }
  80
  81         if(f->here != s && (f->mode&SF_READ) )
  82         {       /* buffered data is known to be invalid */
  83 #ifdef MAP_TYPE
  84                 if((f->bits&SF_MMAP) && f->data)
  85                 {       SFMUNMAP(f,f->data,f->endb-f->data);
  86                         f->data = NIL(uchar*);
  87                 }
  88 #endif
  89                 f->next = f->endb = f->endr = f->endw = f->data;
  90         }
  91
  92         if(f->here < 0)
  93                 f->extent = -1;
  94         else if(f->extent < f->here)
  95                 f->extent = f->here;
  96
  97         if((s = f->extent) >= 0)
  98         {       if(f->flags&SF_APPENDWR)
  99                         s += (f->next - f->data);
 100                 else if(f->mode&SF_WRITE)
 101                 {       s = f->here + (f->next - f->data);
 102                         if(s < f->extent)
 103                                 s = f->extent;
 104                 }
 105         }
 106
 107         SFOPEN(f,0);
 108         SFMTXRETURN(f, s);
 109 }