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/***********************************************************************
* *
* This software is part of the ast package *
* Copyright (c) 1985-2009 AT&T Intellectual Property *
* and is licensed under the *
* Common Public License, Version 1.0 *
* by AT&T Intellectual Property *
* *
* A copy of the License is available at *
* http://www.opensource.org/licenses/cpl1.0.txt *
* (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9) *
* *
* Information and Software Systems Research *
* AT&T Research *
* Florham Park NJ *
* *
* Glenn Fowler <gsf@research.att.com> *
* David Korn <dgk@research.att.com> *
* Phong Vo <kpv@research.att.com> *
* *
***********************************************************************/
#include "sfdchdr.h"
/* Discipline to turn on direct IO capability.
** This currently only works for XFS on SGI's.
**
** Written by Kiem-Phong Vo, kpv@research.att.com, 03/18/1998.
*/
#ifndef FDIRECT
#undef F_FIOINFO
#endif
typedef struct _direct_s
{ Sfdisc_t disc; /* Sfio discipline */
int cntl; /* file control flags */
#ifdef F_DIOINFO
struct dioattr dio; /* direct IO params */
#endif
} Direct_t;
/* convert a pointer to an int */
#define P2I(p) (Sfulong_t)((char*)(p) - (char*)0)
#if __STD_C
static ssize_t diordwr(Sfio_t* f, Void_t* buf, size_t n, Direct_t* di, int type)
#else
static ssize_t diordwr(f, buf, n, di, type)
Sfio_t* f;
Void_t* buf;
size_t n;
Direct_t* di;
int type;
#endif
{
size_t rw, done;
ssize_t rv;
done = 0; /* amount processed by direct IO */
rv = 0;
#ifdef F_DIOINFO
if((P2I(buf)%di->dio.d_mem) == 0 &&
(f->here%di->dio.d_miniosz) == 0 && n >= di->dio.d_miniosz )
{ /* direct IO ok, make sure we're in the right mode */
if(!(di->cntl & FDIRECT) )
{ di->cntl |= FDIRECT;
(void)fcntl(f->file, F_SETFL, di->cntl);
}
for(rw = (n/di->dio.d_miniosz)*di->dio.d_miniosz;; )
{ size_t io;
if((io = rw) > di->dio.d_maxiosz )
io = di->dio.d_maxiosz;
if(type == SF_READ)
rv = read(f->file,buf,io);
else rv = write(f->file,buf,io);
if(rv > 0)
{ rw -= rv; done += rv;
buf = (Void_t*)((char*)buf + rv);
}
if(rv < io || rw < di->dio.d_miniosz)
break;
}
}
if(done < n && (di->cntl & FDIRECT) )
{ /* turn off directIO for remaining IO operation */
di->cntl &= ~FDIRECT;
(void)fcntl(f->file, F_SETFL, di->cntl);
}
#endif /*F_DIOINFO*/
if((rw = n-done) > 0 &&
(rv = type == SF_READ ? read(f->file,buf,rw) : write(f->file,buf,rw)) > 0 )
done += rv;
return done ? done : rv;
}
#if __STD_C
static ssize_t dioread(Sfio_t* f, Void_t* buf, size_t n, Sfdisc_t* disc)
#else
static ssize_t dioread(f, buf, n, disc)
Sfio_t* f;
Void_t* buf;
size_t n;
Sfdisc_t* disc;
#endif
{
return diordwr(f, buf, n, (Direct_t*)disc, SF_READ);
}
#if __STD_C
static ssize_t diowrite(Sfio_t* f, const Void_t* buf, size_t n, Sfdisc_t* disc)
#else
static ssize_t diowrite(f, buf, n, disc)
Sfio_t* f;
Void_t* buf;
size_t n;
Sfdisc_t* disc;
#endif
{
return diordwr(f, (Void_t*)buf, n, (Direct_t*)disc, SF_WRITE);
}
#if __STD_C
static int dioexcept(Sfio_t* f, int type, Void_t* data, Sfdisc_t* disc)
#else
static int dioexcept(f,type,data,disc)
Sfio_t* f;
int type;
Void_t* data;
Sfdisc_t* disc;
#endif
{
Direct_t* di = (Direct_t*)disc;
if(type == SF_FINAL || type == SF_DPOP)
{
#ifdef F_DIOINFO
if(di->cntl&FDIRECT)
{ di->cntl &= ~FDIRECT;
(void)fcntl(f->file,F_SETFL,di->cntl);
}
#endif
free(disc);
}
return 0;
}
#if __STD_C
int sfdcdio(Sfio_t* f, size_t bufsize)
#else
int sfdcdio(f, bufsize)
Sfio_t* f;
size_t bufsize;
#endif
{
#ifndef F_DIOINFO
return -1;
#else
int cntl;
struct dioattr dio;
Void_t* buf;
Direct_t* di;
if(f->extent < 0 || (f->flags&SF_STRING))
return -1;
if((cntl = fcntl(f->file,F_GETFL,0)) < 0)
return -1;
if(!(cntl&FDIRECT) )
{ cntl |= FDIRECT;
if(fcntl(f->file,F_SETFL,cntl) < 0)
return -1;
}
if(fcntl(f->file,F_DIOINFO,&dio) < 0)
goto no_direct;
if(bufsize > 0)
bufsize = (bufsize/dio.d_miniosz)*dio.d_miniosz;
if(bufsize <= 0)
bufsize = dio.d_miniosz*64;
if(bufsize > dio.d_maxiosz)
bufsize = dio.d_maxiosz;
if(!(di = (Direct_t*)malloc(sizeof(Direct_t))) )
goto no_direct;
if(!(buf = (Void_t*)memalign(dio.d_mem,bufsize)) )
{ free(di);
goto no_direct;
}
sfsetbuf(f,buf,bufsize);
if(sfsetbuf(f,buf,0) == buf)
sfset(f,SF_MALLOC,1);
else
{ free(buf);
free(di);
goto no_direct;
}
di->disc.readf = dioread;
di->disc.writef = diowrite;
di->disc.seekf = NIL(Sfseek_f);
di->disc.exceptf = dioexcept;
di->cntl = cntl;
di->dio = dio;
if(sfdisc(f,(Sfdisc_t*)di) != (Sfdisc_t*)di)
{ free(di);
no_direct:
cntl &= ~FDIRECT;
(void)fcntl(f->file,F_SETFL,cntl);
return -1;
}
return 0;
#endif /*F_DIOINFO*/
}
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