da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin/***********************************************************************
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin* *
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin* This software is part of the ast package *
3e14f97f673e8a630f076077de35afdd43dc1587Roger A. Faulkner* Copyright (c) 1985-2010 AT&T Intellectual Property *
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin* and is licensed under the *
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin* Common Public License, Version 1.0 *
7c2fbfb345896881c631598ee3852ce9ce33fb07April Chin* by AT&T Intellectual Property *
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin* *
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin* A copy of the License is available at *
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin* http://www.opensource.org/licenses/cpl1.0.txt *
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin* (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9) *
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin* *
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin* Information and Software Systems Research *
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin* AT&T Research *
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin* Florham Park NJ *
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin* *
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin* Glenn Fowler <gsf@research.att.com> *
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin* David Korn <dgk@research.att.com> *
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin* Phong Vo <kpv@research.att.com> *
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin* *
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin***********************************************************************/
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#include "sfhdr.h"
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin/* Read n bytes from a stream into a buffer
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin**
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin** Written by Kiem-Phong Vo.
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin*/
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#if __STD_C
7c2fbfb345896881c631598ee3852ce9ce33fb07April Chinssize_t sfread(Sfio_t* f, Void_t* buf, size_t n)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#else
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chinssize_t sfread(f,buf,n)
7c2fbfb345896881c631598ee3852ce9ce33fb07April ChinSfio_t* f; /* read from this stream. */
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chinVoid_t* buf; /* buffer to read into */
7c2fbfb345896881c631598ee3852ce9ce33fb07April Chinsize_t n; /* number of bytes to be read. */
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#endif
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin{
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin reg uchar *s, *begs;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin reg ssize_t r;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin reg int local, justseek;
7c2fbfb345896881c631598ee3852ce9ce33fb07April Chin SFMTXDECL(f);
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
7c2fbfb345896881c631598ee3852ce9ce33fb07April Chin SFMTXENTER(f, (ssize_t)(-1));
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin GETLOCAL(f,local);
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin justseek = f->bits&SF_JUSTSEEK; f->bits &= ~SF_JUSTSEEK;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin if(!buf)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin SFMTXRETURN(f, (ssize_t)(n == 0 ? 0 : -1) );
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin /* release peek lock */
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin if(f->mode&SF_PEEK)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin { if(!(f->mode&SF_READ) )
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin SFMTXRETURN(f, (ssize_t)(-1));
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin if(f->mode&SF_GETR)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin { if(((uchar*)buf + f->val) != f->next &&
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin (!f->rsrv || f->rsrv->data != (uchar*)buf) )
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin SFMTXRETURN(f, (ssize_t)(-1));
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin f->mode &= ~SF_PEEK;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin SFMTXRETURN(f, 0);
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin }
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin else
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin { if((uchar*)buf != f->next)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin SFMTXRETURN(f, (ssize_t)(-1));
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin f->mode &= ~SF_PEEK;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin if(f->mode&SF_PKRD)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin { /* actually read the data now */
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin f->mode &= ~SF_PKRD;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin if(n > 0)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin n = (r = sysreadf(f->file,f->data,n)) < 0 ? 0 : r;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin f->endb = f->data+n;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin f->here += n;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin }
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin f->next += n;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin f->endr = f->endb;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin SFMTXRETURN(f, n);
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin }
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin }
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin s = begs = (uchar*)buf;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin for(;; f->mode &= ~SF_LOCK)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin { /* check stream mode */
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin if(SFMODE(f,local) != SF_READ && _sfmode(f,SF_READ,local) < 0)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin { n = s > begs ? s-begs : (size_t)(-1);
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin SFMTXRETURN(f, (ssize_t)n);
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin }
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin SFLOCK(f,local);
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin if((r = f->endb - f->next) > 0) /* has buffered data */
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin { if(r > (ssize_t)n)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin r = (ssize_t)n;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin if(s != f->next)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin memcpy(s, f->next, r);
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin f->next += r;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin s += r;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin n -= r;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin }
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin if(n <= 0) /* all done */
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin break;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin if(!(f->flags&SF_STRING) && !(f->bits&SF_MMAP) )
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin { f->next = f->endb = f->data;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin /* exact IO is desirable for these cases */
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin if(SFDIRECT(f,n) ||
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin ((f->flags&SF_SHARE) && f->extent < 0) )
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin r = (ssize_t)n;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin else if(justseek && n <= f->iosz && f->iosz <= f->size)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin r = f->iosz; /* limit buffering */
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin else r = f->size; /* full buffering */
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin /* if read almost full size, then just do it direct */
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin if(r > (ssize_t)n && (r - r/8) <= (ssize_t)n)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin r = (ssize_t)n;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin /* read directly to user's buffer */
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin if(r == (ssize_t)n && (r = SFRD(f,s,r,f->disc)) >= 0)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin { s += r;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin n -= r;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin if(r == 0 || n == 0) /* eof or eob */
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin break;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin }
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin else goto do_filbuf;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin }
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin else
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin { do_filbuf:
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin if(justseek)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin f->bits |= SF_JUSTSEEK;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin if(SFFILBUF(f,-1) <= 0)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin break;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin }
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin }
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin SFOPEN(f,local);
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin r = s-begs;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin SFMTXRETURN(f, r);
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin}