#include "sfhdr.h"
#if __STD_C
ssize_t sfread(reg Sfio_t* f, Void_t* buf, reg size_t n)
#else
ssize_t sfread(f,buf,n)
reg Sfio_t* f;
Void_t* buf;
reg size_t n;
#endif
{
reg uchar *s, *begs;
reg ssize_t r;
reg int local, justseek;
SFMTXSTART(f, (ssize_t)(-1));
GETLOCAL(f,local);
justseek = f->bits&SF_JUSTSEEK; f->bits &= ~SF_JUSTSEEK;
if(!buf)
SFMTXRETURN(f, (ssize_t)(-1) );
if(f->mode&SF_PEEK)
{ if(!(f->mode&SF_READ) )
SFMTXRETURN(f, (ssize_t)(-1));
if(f->mode&SF_GETR)
{ if(((uchar*)buf + f->val) != f->next &&
(!f->rsrv || f->rsrv->data != (uchar*)buf) )
SFMTXRETURN(f, (ssize_t)(-1));
f->mode &= ~SF_PEEK;
SFMTXRETURN(f, 0);
}
else
{ if((uchar*)buf != f->next)
SFMTXRETURN(f, (ssize_t)(-1));
f->mode &= ~SF_PEEK;
if(f->mode&SF_PKRD)
{
f->mode &= ~SF_PKRD;
if(n > 0)
n = (r = read(f->file,f->data,n)) < 0 ? 0 : r;
f->endb = f->data+n;
f->here += n;
}
f->next += n;
f->endr = f->endb;
SFMTXRETURN(f, n);
}
}
s = begs = (uchar*)buf;
for(;; f->mode &= ~SF_LOCK)
{
if(SFMODE(f,local) != SF_READ && _sfmode(f,SF_READ,local) < 0)
{ n = s > begs ? s-begs : (size_t)(-1);
SFMTXRETURN(f, (ssize_t)n);
}
SFLOCK(f,local);
if((r = f->endb - f->next) > 0)
{ if(r > (ssize_t)n)
r = (ssize_t)n;
if(s != f->next)
memcpy(s, f->next, r);
f->next += r;
s += r;
n -= r;
}
if(n <= 0)
break;
if(!(f->flags&SF_STRING) && !(f->bits&SF_MMAP) )
{ f->next = f->endb = f->data;
if(SFDIRECT(f,n) ||
((f->flags&SF_SHARE) && f->extent < 0) )
r = (ssize_t)n;
else if(justseek && n <= f->iosz && f->iosz <= f->size)
r = f->iosz;
else r = f->size;
if(r > (ssize_t)n && (r - r/8) <= (ssize_t)n)
r = (ssize_t)n;
if(r == (ssize_t)n && (r = SFRD(f,s,r,f->disc)) >= 0)
{ s += r;
n -= r;
if(r == 0 || n == 0)
break;
}
else goto do_filbuf;
}
else
{ do_filbuf:
if(justseek)
f->bits |= SF_JUSTSEEK;
if(SFFILBUF(f,-1) <= 0)
break;
}
}
SFOPEN(f,local);
r = s-begs;
SFMTXRETURN(f, r);
}