/* Copyright (C) 2017 Robert Roth

   This file is part of LibGTop.

   Contributed by Robert Roth <robert.roth.off@gmail.com>, February 2017.

   LibGTop is free software; you can redistribute it and/or modify it

   under the terms of the GNU General Public License as published by

   the Free Software Foundation; either version 2 of the License,

   or (at your option) any later version.

   LibGTop is distributed in the hope that it will be useful, but WITHOUT

   ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

   FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

   for more details.

   You should have received a copy of the GNU General Public License

   along with LibGTop; see the file COPYING. If not, write to the

   Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,

   Boston, MA 02110-1301, USA.

*/

#include <config.h>

#include <glibtop.h>

#include <glibtop/procio.h>

#include <glibtop/error.h>

#include <glibtop_suid.h>

static const unsigned long _glibtop_sysdeps_proc_io =

  (1UL << GLIBTOP_PROC_IO_DISK_RBYTES) + (1UL << GLIBTOP_PROC_IO_DISK_WBYTES);

/* Init function. */

void

_glibtop_init_proc_io_p (glibtop *server)

{

	server->sysdeps.proc_io = _glibtop_sysdeps_proc_io;

}

/* Provides detailed information about a process. */

void

glibtop_get_proc_io_p (glibtop *server, glibtop_proc_io *buf,

			 pid_t pid)

{

	memset (buf, 0, sizeof (glibtop_proc_io));

	struct kinfo_proc *pinfo;

	int count;

	glibtop_suid_enter (server);

	/* Get the process information */

	pinfo = kvm_getprocs (server->machine->kd, KERN_PROC_PID, pid, &count);

	if ((pinfo == NULL) || (count != 1)) {

		glibtop_warn_io_r (server, "kvm_getprocs (%d)", pid);

		glibtop_suid_leave (server);

		return;

	}

	glibtop_suid_leave (server);

	/* man getrusage

	   long ru_inblock;         == block input operations

	   long ru_oublock;         == block output operations

	   ru_inblock   the number of times the file system had to perform input.

	   ru_oublock   the number of times the file system had to perform output.

	   And then it says 'account only for real IO'.

	   But if I write 1MB in a process, I can see ru_oublock increased

	   1024. So it's neither a number of operations or times.

	   FIXME: seems the blocksize is 1024 but ...

	*/

	buf->disk_rbytes = pinfo->ki_rusage.ru_inblock << 10;

	buf->disk_wbytes = pinfo->ki_rusage.ru_oublock << 10;

	buf->flags = _glibtop_sysdeps_proc_io;

}