/*
 * Author:  David Robert Nadeau
 * Site:    http://NadeauSoftware.com/
 * License: Creative Commons Attribution 3.0 Unported License
 *          http://creativecommons.org/licenses/by/3.0/deed.en_US
 */

/*
 * Modified by Tom van Dijk to remove WIN32 and solaris code
 */

#if defined(__APPLE__) && defined(__MACH__)
#include <unistd.h>
#include <sys/resource.h>
#include <mach/mach.h>
#elif defined(__linux__) || defined(__linux) || defined(linux) || defined(__gnu_linux__)
#include <unistd.h>
#include <sys/resource.h>
#include <stdio.h>
#else
#error "Cannot define getPeakRSS( ) or getCurrentRSS( ) for an unknown OS."
#endif

/**
 * Returns the peak (maximum so far) resident set size (physical
 * memory use) measured in bytes, or zero if the value cannot be
 * determined on this OS.
 */
size_t
getPeakRSS()
{
    struct rusage rusage;
    getrusage(RUSAGE_SELF, &rusage);
#if defined(__APPLE__) && defined(__MACH__)
    return (size_t)rusage.ru_maxrss;
#else
    return (size_t)(rusage.ru_maxrss * 1024L);
#endif
}

/**
 * Returns the current resident set size (physical memory use) measured
 * in bytes, or zero if the value cannot be determined on this OS.
 */
size_t
getCurrentRSS()
{
#if defined(__APPLE__) && defined(__MACH__)
    /* OSX ------------------------------------------------------ */
    struct mach_task_basic_info info;
    mach_msg_type_number_t infoCount = MACH_TASK_BASIC_INFO_COUNT;
    if (task_info(mach_task_self(), MACH_TASK_BASIC_INFO, (task_info_t)&info, &infoCount) != KERN_SUCCESS)
        return (size_t)0L;      /* Can't access? */
    return (size_t)info.resident_size;
#else
    /* Linux ---------------------------------------------------- */
    long rss = 0L;
    FILE *fp = NULL;
    if ((fp = fopen("/proc/self/statm", "r")) == NULL)
        return (size_t)0L;      /* Can't open? */
    if (fscanf(fp, "%*s%ld", &rss) != 1) {
        fclose(fp);
        return (size_t)0L;      /* Can't read? */
    }
    fclose(fp);
    return (size_t)rss * (size_t)sysconf(_SC_PAGESIZE);
#endif
}