/*
 * This file is part of Xfce (https://gitlab.xfce.org).
 *
 * zram monitor: local addition, not part of upstream.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES
 * ARE DISCLAIMED.
 */

#ifndef _XFCE_SYSTEMLOAD_ZRAM_H_
#define _XFCE_SYSTEMLOAD_ZRAM_H_

#include <glib.h>

/*
 * Physical RAM occupied by all zram devices, in kB.
 * Returns 0 when there is no zram device or the data cannot be read.
 *
 * This is the number that has to be subtracted from "used memory": pages held
 * by zram are counted as used RAM, yet they are not memory of any process -
 * they are the compressed backing store of the swap.
 */
gulong read_zram_phys (void);

/*
 * zram summary across all devices.
 *
 *   zram      - physical footprint as a percentage of MemTotal (for the bar)
 *   phys_kb   - physical RAM used, kB (mem_used_total from mm_stat)
 *   stored_kb - uncompressed size of the stored pages, kB (orig_data_size)
 *   ratio     - stored/compressed, 0.0 when nothing is stored
 *
 * Returns 0 on success, -1 when there is no zram device.
 */
gint read_zram (gulong *zram, gulong *phys_kb, gulong *stored_kb, gdouble *ratio);

/*
 * Swap totals EXCLUDING zram devices, in kB, read from /proc/swaps.
 *
 * SwapTotal/SwapFree in /proc/meminfo lump zram together with disk swap, and
 * for zram they report the uncompressed size - a number that corresponds to
 * nothing physical. The real question the swap bar should answer is "how much
 * has spilled onto the disk", and that is what this returns.
 *
 * Returns 0 on success, -1 when /proc/swaps cannot be read.
 */
gint read_disk_swap (gulong *total_kb, gulong *used_kb);

#endif /* _XFCE_SYSTEMLOAD_ZRAM_H_ */