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use std::convert::TryInto;
use std::time::Instant;
use once_cell::sync::Lazy;
static INIT_TIME: Lazy<Instant> = Lazy::new(Instant::now);
pub fn now_including_suspend() -> u64 {
// For Windows:
// Instead of relying on figuring out the underlying functions,
// we can rely on the fact that `Instant::now` maps to [QueryPerformanceCounter] on Windows,
// so by comparing it to another arbitrary timestamp we will get a duration that will include
// suspend time.
// If we use that as a timestamp we can compare later timestamps to it and that will also
// include suspend time.
//
// [QueryPerformanceCounter]: https://docs.microsoft.com/en-us/windows/win32/api/profileapi/nf-profileapi-queryperformancecounter
//
// For other operating systems:
// This fallback is not used on Linux, where it maps to `CLOCK_MONOTONIC`, which does NOT
// include suspend time. But we don't use it there, so no problem.
//
// This fallback is not used on macOS, where it maps to `mach_absolute_time`, which does NOT
// include suspend time. But we don't use it there, so no problem.
//
// For other operating systems we make no guarantees, other than that we won't panic.
let now = Instant::now();
now.checked_duration_since(*INIT_TIME)
.and_then(|diff| diff.as_nanos().try_into().ok())
.unwrap_or(0)
}
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