#include "get_total_memory.h"

#include <stdexcept>

#include <string>

#if defined(__APPLE__)

#include <sys/types.h>

#include <sys/sysctl.h>

namespace cpputils {

namespace system {

uint64_t get_total_memory() {

uint64_t mem;

size_t size = sizeof(mem);

int result = sysctlbyname("hw.memsize", &mem, &size, nullptr, 0);

if (0 != result) {

throw std::runtime_error("sysctlbyname syscall failed");

}

return mem;

}

}

}

#elif defined(__linux__) || defined(__FreeBSD__)

#include <unistd.h>

namespace cpputils {

namespace system {

uint64_t get_total_memory() {

long numRAMPages = sysconf(_SC_PHYS_PAGES);

long pageSize = sysconf(_SC_PAGESIZE);

return numRAMPages * pageSize;

}

}

}

#elif defined(_MSC_VER)

#include <Windows.h>

namespace cpputils {

namespace system {

uint64_t get_total_memory() {

MEMORYSTATUSEX status;

status.dwLength = sizeof(status);

if (!::GlobalMemoryStatusEx(&status)) {

throw std::runtime_error("Couldn't get system memory information. Error code: " + std::to_string(GetLastError()));

}

return status.ullTotalPhys;

}

}

}

#else

#error Unsupported platform

#endif