#include <config.h>

#include <glibtop.h>

#include <glibtop/fsusage.h>

#include <glibtop/error.h>

#include "glibtop_private.h"

#include <glib.h>

#include <unistd.h>

#include <sys/types.h>

#include <sys/stat.h>

#include <linux/kdev_t.h>

#include <sys/statvfs.h>

#include <stdio.h>

#include <string.h>

#include <stdlib.h>

#include <errno.h>

#include <mntent.h>

/*

 * Linux 2.6.x

 * linux/Documentation/iostats.txt

 */

static gboolean

get_device(glibtop* server, const char *mountpoint,

	   char* device, size_t device_size)

{

	const struct mntent *mnt;

	FILE *fp;

	gboolean found = FALSE;

	if (!(fp = setmntent(MOUNTED, "r"))) {

		glibtop_warn_io_r(server, "Could not open %s", MOUNTED);

		goto out;

	}

	while ((mnt = getmntent(fp)))

	{

		/* There can be multiple root mount entries, skip the unuseful one */

		if (!strcmp(mnt->mnt_fsname, "rootfs"))

			continue;

		if (!strcmp(mountpoint, mnt->mnt_dir)) {

			if (!strncmp(mnt->mnt_fsname, "/dev/", 5)) {

				g_strlcpy(device, mnt->mnt_fsname + 5, device_size);

				found = TRUE;

			}

			break;

		}

	}

	endmntent(fp);

out:

	return found;

}

/*

  TRUE if device is like "hda3" and then set prefix to "hda".

 */

static gboolean

is_partition(const char* device, char* prefix, size_t prefix_size)

{

	g_strlcpy(prefix, device, prefix_size);

	for ( ; *prefix; prefix++) {

		if (isdigit(*prefix)) {

			*prefix = '\0';

			return TRUE;

		}

	}

	return FALSE;

}

/*

  Bug #539360.

  /sys/.../stat format is partially defined in

  linux/Documentation/block/stat.txt (looks outdated).  Before linux

  2.5.25, /sys/block/%s/stat and /sys/block/%s/%s/stat were not the

  same, but the following commit changed the latter to have the same

  format and broke compatibility.

  Commit 34e8beac92c27d292938065f8375842d2840767c

  Author: Jerome Marchand <jmarchan@redhat.com>

  Date:   Fri Feb 8 11:04:55 2008 +0100

    Enhanced partition statistics: sysfs

    Reports enhanced partition statistics in sysfs.

    Signed-off-by: Jerome Marchand <jmarchan@redhat.com>

    fs/partitions/check.c |   22 +++++++++++++++++++---

    1 files changed, 19 insertions(+), 3 deletions(-)

 */

static void

get_sys_path(glibtop* server, const char *device, char **stat_path, const char **parse_format)

{

	const char* linux_2_6_25_format = "%*llu %*llu %llu %*llu"

					  "%*llu %*llu %llu %*llu";

	char prefix[32];

	if (is_partition(device, prefix, sizeof prefix)) {

		*stat_path = g_strdup_printf("/sys/block/%s/%s/stat",

					     prefix, device);

		if (server->os_version_code < LINUX_VERSION_CODE(2, 6, 25))

			*parse_format = "%*llu %llu %*llu %llu";

		else

			*parse_format = linux_2_6_25_format;

	}

	else

	{

		*stat_path = g_strdup_printf("/sys/block/%s/stat", device);

		if (server->os_version_code < LINUX_VERSION_CODE(2, 6, 25))

			*parse_format = "%*llu %*llu %llu %*llu %*llu %*llu %llu";

		else

			*parse_format = linux_2_6_25_format;

	}

}

static void linux_2_6_0(glibtop *server, glibtop_fsusage *buf, const char *path)

{

	char *filename = NULL;

	const char *format;

	int ret;

	char buffer[BUFSIZ];

	char device[64];

	if (!get_device(server, path, device, sizeof device))

		goto out;

	get_sys_path(server, device, &filename, &format);

	ret = try_file_to_buffer(buffer, sizeof buffer, "%s", filename);

	if (ret < 0) goto out;

	if (sscanf(buffer, format, &buf->read, &buf->write) != 2) {

		glibtop_warn_io_r(server, "Could not parse %s", filename);

		goto out;

	}

	buf->flags |= (1 << GLIBTOP_FSUSAGE_READ) | (1 << GLIBTOP_FSUSAGE_WRITE);

 out:

	g_free(filename);

}

static void linux_2_4_0(glibtop *server, glibtop_fsusage *buf, const char *path)

{

}

static void

get_fsusage_read_write(glibtop *server, glibtop_fsusage *buf, const char *path)

{

  if(server->os_version_code >= LINUX_VERSION_CODE(2, 6, 0))

    {

      linux_2_6_0(server, buf, path);

    }

  else if(server->os_version_code >= LINUX_VERSION_CODE(2, 4, 0))

    {

      linux_2_4_0(server, buf, path);

    }

}

/* the following comes from sysdeps/common/mountlist.c if copyright matters...

 */

static const unsigned long _glibtop_sysdeps_fsusage =

(1L << GLIBTOP_FSUSAGE_BLOCKS) + (1L << GLIBTOP_FSUSAGE_BFREE)

+ (1L << GLIBTOP_FSUSAGE_BAVAIL) + (1L << GLIBTOP_FSUSAGE_FILES)

+ (1L << GLIBTOP_FSUSAGE_FFREE) + (1L << GLIBTOP_FSUSAGE_BLOCK_SIZE);

void

glibtop_get_fsusage_s(glibtop *server, glibtop_fsusage *buf, const char *path)

{

  struct statvfs fsd;

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

  if (statvfs(path, &fsd) < 0) {

    glibtop_warn_r(server, "statvfs '%s' failed: %s", path, strerror (errno));

    return;

  }

  buf->blocks = fsd.f_blocks;

  buf->bfree  = fsd.f_bfree;

  buf->bavail = (fsd.f_bavail > fsd.f_bfree) ? 0 : fsd.f_bavail;

  buf->files  = fsd.f_files;

  buf->ffree  = fsd.f_ffree;

  buf->block_size = fsd.f_bsize;

  buf->flags = _glibtop_sysdeps_fsusage;

  /* setting additional flags is delegated */

  get_fsusage_read_write(server, buf, path);

}