/* Copyright (C) 1998 Joshua Sled
   This file is part of LibGTop 1.0.

   Contributed by Joshua Sled <jsled@xcf.berkeley.edu>, July 1998.

   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/error.h>
#include <glibtop/mem.h>

#include <glibtop_suid.h>

#include <sys/sysctl.h>
#include <sys/vmmeter.h>
#if defined(__NetBSD__)  && (__NetBSD_Version__ < 105020000)
#include <vm/vm_param.h>
#endif

#if defined(__NetBSD__)  && (__NetBSD_Version__ >= 104000000) || defined(__OpenBSD__)
#include <uvm/uvm_extern.h>
#endif

static const unsigned long _glibtop_sysdeps_mem =
(1L << GLIBTOP_MEM_TOTAL) + (1L << GLIBTOP_MEM_USED) +
(1L << GLIBTOP_MEM_FREE) +
(1L << GLIBTOP_MEM_SHARED) +
(1L << GLIBTOP_MEM_BUFFER) +
#if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
(1L << GLIBTOP_MEM_CACHED) +
#endif
(1L << GLIBTOP_MEM_USER) + (1L << GLIBTOP_MEM_LOCKED);

#ifndef LOG1024
#define LOG1024		10
#endif

/* these are for getting the memory statistics */
static int pageshift;		/* log base 2 of the pagesize */

/* define pagetok in terms of pageshift */
#define pagetok(size) ((size) << pageshift)

/* nlist structure for kernel access */
static struct nlist nlst [] = {
#if defined(__NetBSD__)  && (__NetBSD_Version__ >= 104000000) || defined(__OpenBSD__)
	{ "_bufpages" },
	{ 0 }
#else
#if defined(__bsdi__)
	{ "_bufcachemem" },
#elif defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
	{ "_bufspace" },
#else
	{ "_bufpages" },
#endif
	{ "_cnt" },
	{ 0 }
#endif
};

/* MIB array for sysctl */
#ifdef __bsdi__
static int mib [] = { CTL_VM, VM_TOTAL };
#else
static int mib [] = { CTL_VM, VM_METER };
#endif

#if defined(__NetBSD__)  && (__NetBSD_Version__ >= 104000000) || defined(__OpenBSD__)
static int mib_uvmexp [] = { CTL_VM, VM_UVMEXP };
#endif

/* Init function. */

void
_glibtop_init_mem_p (glibtop *server)
{
	register int pagesize;

	if (kvm_nlist (server->machine->kd, nlst) < 0) {
		glibtop_warn_io_r (server, "kvm_nlist (mem)");
		return;
	}

	/* get the page size with "getpagesize" and calculate pageshift
	 * from it */
	pagesize = getpagesize ();
	pageshift = 0;
	while (pagesize > 1) {
		pageshift++;
		pagesize >>= 1;
	}

	/* we only need the amount of log(2)1024 for our conversion */
	pageshift -= LOG1024;

	server->sysdeps.mem = _glibtop_sysdeps_mem;
}

void
glibtop_get_mem_p (glibtop *server, glibtop_mem *buf)
{
	struct vmtotal vmt;
	size_t length_vmt;
#if defined(__NetBSD__)  && (__NetBSD_Version__ >= 104000000) || defined(__OpenBSD__)
	struct uvmexp uvmexp;
	size_t length_uvmexp;
#else
	struct vmmeter vmm;
#endif
	u_int v_used_count;
	u_int v_total_count;
	u_int v_free_count;
	int bufspace;

	glibtop_init_p (server, (1L << GLIBTOP_SYSDEPS_MEM), 0);

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

	if (server->sysdeps.mem == 0)
		return;

	/* [FIXME: On FreeBSD 2.2.6, sysctl () returns an incorrect
	 *         value for `vmt.vm'. We use some code from Unix top
	 *         here.] */

	/* Get the data from sysctl */
	length_vmt = sizeof (vmt);
	if (sysctl (mib, 2, &vmt, &length_vmt, NULL, 0)) {
		glibtop_warn_io_r (server, "sysctl (vmt)");
		return;
	}

#if defined(__NetBSD__)  && (__NetBSD_Version__ >= 104000000) || defined(__OpenBSD__)
	length_uvmexp = sizeof (uvmexp);
	if (sysctl (mib_uvmexp, 2, &uvmexp, &length_uvmexp, NULL, 0)) {
		glibtop_warn_io_r (server, "sysctl (uvmexp)");
		return;
	}
#else
	/* Get the data from kvm_* */
	if (kvm_read (server->machine->kd, nlst[1].n_value,
		      &vmm, sizeof (vmm)) != sizeof (vmm)) {
		glibtop_warn_io_r (server, "kvm_read (cnt)");
		return;
	}
#endif

	if (kvm_read (server->machine->kd, nlst[0].n_value,
		      &bufspace, sizeof (bufspace)) != sizeof (bufspace)) {
		glibtop_warn_io_r (server, "kvm_read (bufspace)");
		return;
	}

	/* convert memory stats to Kbytes */

#if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
	v_total_count = vmm.v_page_count;
#else
#if defined(__NetBSD__)  && (__NetBSD_Version__ >= 104000000) || defined(__OpenBSD__)
	v_total_count = uvmexp.reserve_kernel +
		uvmexp.reserve_pagedaemon +
		uvmexp.free + uvmexp.wired + uvmexp.active +
		uvmexp.inactive;
#else
	v_total_count = vmm.v_kernel_pages +
		vmm.v_free_count + vmm.v_wire_count +
		vmm.v_active_count + vmm.v_inactive_count;
#endif
#endif

#if defined(__NetBSD__)  && (__NetBSD_Version__ >= 104000000) || defined(__OpenBSD__)
	v_used_count = uvmexp.active + uvmexp.inactive;
	v_free_count = uvmexp.free;
#else
	v_used_count = vmm.v_active_count + vmm.v_inactive_count;
	v_free_count = vmm.v_free_count;
#endif

	buf->total = (guint64) pagetok (v_total_count) << LOG1024;
	buf->used  = (guint64) pagetok (v_used_count) << LOG1024;
	buf->free  = (guint64) pagetok (v_free_count) << LOG1024;

#if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
	buf->cached = (guint64) pagetok (vmm.v_cache_count) << LOG1024;
#endif

#if defined(__NetBSD__)  && (__NetBSD_Version__ >= 104000000) || defined(__OpenBSD__)
	buf->locked = (guint64) pagetok (uvmexp.wired) << LOG1024;
#else
	buf->locked = (guint64) pagetok (vmm.v_wire_count) << LOG1024;
#endif

	buf->shared = (guint64) pagetok (vmt.t_rmshr) << LOG1024;

#if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
	buf->buffer = (guint64) bufspace;
#else
	buf->buffer = (guint64) pagetok (bufspace) << LOG1024;
#endif

	/* user */
	buf->user = buf->total - buf->free - buf->shared - buf->buffer;

	/* Set the values to return */
	buf->flags = _glibtop_sysdeps_mem;
}