common/sfio/sfmove.c

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/*  Move data from one stream to another.
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin**  This code is written so that it'll work even in the presence
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin**  of stacking streams, pool, and discipline.
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin**  If you must change it, be gentle.
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin**
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin**  Written by Kiem-Phong Vo.
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin*/
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#define MAX_SSIZE   ((ssize_t)((~((size_t)0)) >> 1))
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#if __STD_C
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chinSfoff_t sfmove(Sfio_t* fr, Sfio_t* fw, Sfoff_t n, reg int rc)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#else
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chinSfoff_t sfmove(fr,fw,n,rc)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chinSfio_t* fr; /* moving data from this stream */
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chinSfio_t* fw; /* moving data to this stream */
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chinSfoff_t     n;  /* number of bytes/records to move. <0 for unbounded move */
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chinreg int     rc; /* record separator */
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#endif
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin{
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    reg uchar   *cp, *next;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    reg ssize_t r, w;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    reg uchar   *endb;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    reg int     direct;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    Sfoff_t     n_move, sk, cur;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    uchar       *rbuf = NIL(uchar*);
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    ssize_t     rsize = 0;
7c2fbfb345896881c631598ee3852ce9ce33fb07April Chin    SFMTXDECL(fr);
7c2fbfb345896881c631598ee3852ce9ce33fb07April Chin    SFMTXDECL2(fw);
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
7c2fbfb345896881c631598ee3852ce9ce33fb07April Chin    SFMTXENTER(fr, (Sfoff_t)0);
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    if(fw)
7c2fbfb345896881c631598ee3852ce9ce33fb07April Chin        SFMTXBEGIN2(fw, (Sfoff_t)0);
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    for(n_move = 0; n != 0; )
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    {
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin        if(rc >= 0) /* moving records, let sfgetr() deal with record reading */
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin        {   if(!(cp = (uchar*)sfgetr(fr,rc,0)) )
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                n = 0;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin            else
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin            {   r = sfvalue(fr);
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                if(fw && (w = SFWRITE(fw, cp, r)) != r)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                {   if(fr->extent >= 0 )
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                        (void)SFSEEK(fr,(Sfoff_t)(-r),SEEK_CUR);
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                    if(fw->extent >= 0 && w > 0)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                        (void)SFSEEK(fw,(Sfoff_t)(-w),SEEK_CUR);
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                    n = 0;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                }
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                else
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                {   n_move += 1;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                    if(n > 0)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                        n -= 1;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                }
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin            }
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin            continue;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin        }
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin        /* get the streams into the right mode */
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin        if(fr->mode != SF_READ && _sfmode(fr,SF_READ,0) < 0)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin            break;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin        SFLOCK(fr,0);
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin        /* flush the write buffer as necessary to make room */
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin        if(fw)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin        {   if(fw->mode != SF_WRITE && _sfmode(fw,SF_WRITE,0) < 0 )
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                break;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin            SFLOCK(fw,0);
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin            if(fw->next >= fw->endb ||
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin               (fw->next > fw->data && fr->extent < 0 &&
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                (fw->extent < 0 || (fw->flags&SF_SHARE)) ) )
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                if(SFFLSBUF(fw,-1) < 0 )
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                    break;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin        }
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin        else if((cur = SFSEEK(fr, (Sfoff_t)0, SEEK_CUR)) >= 0 )
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin        {   sk = n > 0 ? SFSEEK(fr, n, SEEK_CUR) : SFSEEK(fr, 0, SEEK_END);
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin            if(sk > cur) /* safe to skip over data in current stream */
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin            {   n_move += sk - cur;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                if(n > 0)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                    n -= sk - cur;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                continue;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin            }
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin            /* else: stream unstacking may happen below */
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin        }
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin        /* about to move all, set map to a large amount */
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin        if(n < 0 && (fr->bits&SF_MMAP) && !(fr->bits&SF_MVSIZE) )
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin        {   SFMVSET(fr);
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin            fr->bits |= SF_SEQUENTIAL; /* sequentially access data */
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin        }
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin        /* try reading a block of data */
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin        direct = 0;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin        if((r = fr->endb - (next = fr->next)) <= 0)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin        {   /* amount of data remained to be read */
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin            if((w = n > MAX_SSIZE ? MAX_SSIZE : (ssize_t)n) < 0)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin            {   if(fr->extent < 0)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                    w = fr->data == fr->tiny ? SF_GRAIN : fr->size;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                else if((fr->extent-fr->here) > SF_NMAP*SF_PAGE)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                    w = SF_NMAP*SF_PAGE;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                else    w = (ssize_t)(fr->extent-fr->here);
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin            }
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin            /* use a decent buffer for data transfer but make sure
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin               that if we overread, the left over can be retrieved
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin            */
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin            if(!(fr->flags&SF_STRING) && !(fr->bits&SF_MMAP) &&
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin               (n < 0 || fr->extent >= 0) )
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin            {   reg ssize_t maxw = 4*(_Sfpage > 0 ? _Sfpage : SF_PAGE);
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                /* direct transfer to a seekable write stream */
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                if(fw && fw->extent >= 0 && w <= (fw->endb-fw->next) )
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                {   w = fw->endb - (next = fw->next);
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                    direct = SF_WRITE;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                }
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                else if(w > fr->size && maxw > fr->size)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                {   /* making our own buffer */
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                    if(w >= maxw)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                        w = maxw;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                    else    w = ((w+fr->size-1)/fr->size)*fr->size;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                    if(rsize <= 0 && (rbuf = (uchar*)malloc(w)) )
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                        rsize = w;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                    if(rbuf)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                    {   next = rbuf;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                        w = rsize;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                        direct = SF_STRING;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                    }
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                }
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin            }
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin            if(!direct)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin            {   /* make sure we don't read too far ahead */
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                if(n > 0 && fr->extent < 0 && (fr->flags&SF_SHARE) )
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                {   if((Sfoff_t)(r = fr->size) > n)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                        r = (ssize_t)n;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                }
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                else    r = -1;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                if((r = SFFILBUF(fr,r)) <= 0)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                    break;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                next = fr->next;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin            }
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin            else
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin            {   /* actual amount to be read */
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                if(n > 0 && n < w)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                    w = (ssize_t)n;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                if((r = SFRD(fr,next,w,fr->disc)) > 0)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                    fr->next = fr->endb = fr->endr = fr->data;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                else if(r == 0)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                    break;      /* eof */
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                else    goto again; /* popped stack */
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin            }
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin        }
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin        /* compute the extent of data to be moved */
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin        endb = next+r;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin        if(n > 0)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin        {   if(r > n)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                r = (ssize_t)n;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin            n -= r;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin        }
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin        n_move += r;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin        cp = next+r;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin        if(!direct)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin            fr->next += r;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin        else if((w = endb-cp) > 0)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin        {   /* move left-over to read stream */
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin            if(w > fr->size)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                w = fr->size;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin            memcpy((Void_t*)fr->data,(Void_t*)cp,w);
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin            fr->endb = fr->data+w;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin            if((w = endb - (cp+w)) > 0)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                (void)SFSK(fr,(Sfoff_t)(-w),SEEK_CUR,fr->disc);
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin        }
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin        if(fw)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin        {   if(direct == SF_WRITE)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                fw->next += r;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin            else if(r <= (fw->endb-fw->next) )
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin            {   memcpy((Void_t*)fw->next,(Void_t*)next,r);
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                fw->next += r;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin            }
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin            else if((w = SFWRITE(fw,(Void_t*)next,r)) != r)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin            {   /* a write error happened */
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                if(w > 0)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                {   r -= w;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                    n_move -= r;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                }
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                if(fr->extent >= 0)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                    (void)SFSEEK(fr,(Sfoff_t)(-r),SEEK_CUR);
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                break;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin            }
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin        }
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    again:
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin        SFOPEN(fr,0);
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin        if(fw)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin            SFOPEN(fw,0);
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    }
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    if(n < 0 && (fr->bits&SF_MMAP) && (fr->bits&SF_MVSIZE))
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    {   /* back to normal access mode */
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin        SFMVUNSET(fr);
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin        if((fr->bits&SF_SEQUENTIAL) && (fr->data))
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin            SFMMSEQOFF(fr,fr->data,fr->endb-fr->data);
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin        fr->bits &= ~SF_SEQUENTIAL;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    }
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    if(rbuf)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin        free(rbuf);
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    if(fw)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    {   SFOPEN(fw,0);
7c2fbfb345896881c631598ee3852ce9ce33fb07April Chin        SFMTXEND2(fw);
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    }
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
7c2fbfb345896881c631598ee3852ce9ce33fb07April Chin    SFOPEN(fr,0);
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    SFMTXRETURN(fr, n_move);
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin}