/*
 * Copyright (c) 2018 Samsung Electronics Co., Ltd.
 *
 * Licensed under the Flora License, Version 1.1 (the License);
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://floralicense.org/license/
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an AS IS BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef _SYS_STATS_H_
#define _SYS_STATS_H_

/**
 * @brief System's statistics snapshot
 */
struct sys_stats
{
	unsigned long long busy_ticks;
	unsigned long long busy_ticks_delta;
	unsigned long long total_ticks;
	unsigned long long total_ticks_delta;
	unsigned long long memory_used;
	unsigned long long total_memory;
};

/**
 * @brief Calculates average cpu usage between two stats snapshots.
 *
 * @param[in] stats the stats snapshots
 *
 * @return usage the cpu usage as percent.
 */
float sys_stats_get_cpu_usage_percentage(struct sys_stats *stats);

/**
 * @brief Takes system statistics snapshot.
 *
 * @param[out] stats System's statistics snapshot.
 *
 * @return: 0 on success, other value on error
 */
int sys_stats_update(struct sys_stats *stats);

/**
 * @brief Calculates system memory usage.
 *
 * @param[in] stats the stats snapshots
 *
 * @return usage the system memory usage as percent.
 */
float sys_stats_get_memory_usage_percentage(struct sys_stats *stats);

/**
 * @brief Gets system load averages stats.
 *
 * @param[out] a1 one minute average.
 * @param[out] a5 five minute average.
 * @param[out] a15 fifteen minute average.
 *
 * @return: 0 on success, other value on error
 */
int sys_stats_get_load_averages(float *a1, float *a5, float *a15);

#endif