/*

 * Copyright (C) 2017 - 2020 Intel Corporation.

 * All rights reserved.

 *

 * 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(s),

 *    this list of conditions and the following disclaimer.

 * 2. Redistributions in binary form must reproduce the above copyright notice(s),

 *    this list of conditions and the following disclaimer in the documentation

 *    and/or other materials provided with the distribution.

 *

 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER(S) ``AS IS'' AND ANY EXPRESS

 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF

 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO

 * EVENT SHALL THE COPYRIGHT HOLDER(S) BE LIABLE FOR ANY DIRECT, INDIRECT,

 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT

 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR

 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF

 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE

 * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF

 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 */

#pragma once

#include <cstring>

#include <fstream>

class ProcStat

{

public:

    size_t get_virtual_memory_size_bytes()

    {

        get_stat("VmSize", str_value);

        return strtol(str_value, NULL, 10) * 1024;

    }

    size_t get_physical_memory_size_bytes()

    {

        get_stat("VmRSS", str_value);

        return strtol(str_value, NULL, 10) * 1024;

    }

    size_t get_used_swap_space_size_bytes(void)

    {

        get_stat("VmSwap", str_value);

        return strtol(str_value, NULL, 10) * 1024;

    }

private:

    /* We are avoiding to allocate local buffers,

     * since it can produce noise in memory footprint tests.

     */

    char line[1024];

    char current_entry_name[1024];

    char str_value[1024];

    // Note: this function is not thread-safe.

    void get_stat(const char *field_name, char *value)

    {

        char *pos = nullptr;

        std::ifstream file("/proc/self/status", std::ifstream::in);

        if (file.is_open()) {

            while (file.getline(line, sizeof(line))) {

                pos = strstr(line, field_name);

                if (pos) {

                    sscanf(pos, "%64[a-zA-Z_0-9()]: %s", current_entry_name, value);

                    break;

                }

            }

            file.close();

        }

    }

};