module runtime

#define PSAPI_VERSION 2
#include <psapi.h>

// Windows 7+ exports K32GetProcessMemoryInfo from kernel32.dll, so avoid
// depending on psapi.lib during bootstrap builds.
@[typedef]
struct C.PROCESS_MEMORY_COUNTERS {
    cb                         u32
    PageFaultCount             u32
    PeakWorkingSetSize         usize
    WorkingSetSize             usize
    QuotaPeakPagedPoolUsage    usize
    QuotaPagedPoolUsage        usize
    QuotaPeakNonPagedPoolUsage usize
    QuotaNonPagedPoolUsage     usize
    PagefileUsage              usize
    PeakPagefileUsage          usize
}

fn C.K32GetProcessMemoryInfo(voidptr, &C.PROCESS_MEMORY_COUNTERS, u32) bool

// used_memory retrieves the current physical memory usage of the process.
pub fn used_memory() !u64 {
    mut pmc := C.PROCESS_MEMORY_COUNTERS{}
    pmc.cb = u32(sizeof(pmc))
    if C.K32GetProcessMemoryInfo(C.GetCurrentProcess(), &pmc, pmc.cb) {
        return u64(pmc.WorkingSetSize)
    }
    return 0
}