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| 1 | +use crate::time::Duration; |
| 2 | + |
| 3 | +const SECS_IN_MINUTE: u64 = 60; |
| 4 | +const SECS_IN_HOUR: u64 = SECS_IN_MINUTE * 60; |
| 5 | +const SECS_IN_DAY: u64 = SECS_IN_HOUR * 24; |
| 6 | + |
| 7 | +#[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Debug, Hash)] |
| 8 | +pub struct Instant(Duration); |
| 9 | + |
| 10 | +#[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Debug, Hash)] |
| 11 | +pub struct SystemTime(Duration); |
| 12 | + |
| 13 | +pub const UNIX_EPOCH: SystemTime = SystemTime(Duration::from_secs(0)); |
| 14 | + |
| 15 | +impl Instant { |
| 16 | + pub fn now() -> Instant { |
| 17 | + panic!("time not implemented on this platform") |
| 18 | + } |
| 19 | + |
| 20 | + pub fn checked_sub_instant(&self, other: &Instant) -> Option<Duration> { |
| 21 | + self.0.checked_sub(other.0) |
| 22 | + } |
| 23 | + |
| 24 | + pub fn checked_add_duration(&self, other: &Duration) -> Option<Instant> { |
| 25 | + Some(Instant(self.0.checked_add(*other)?)) |
| 26 | + } |
| 27 | + |
| 28 | + pub fn checked_sub_duration(&self, other: &Duration) -> Option<Instant> { |
| 29 | + Some(Instant(self.0.checked_sub(*other)?)) |
| 30 | + } |
| 31 | +} |
| 32 | + |
| 33 | +impl SystemTime { |
| 34 | + pub fn now() -> SystemTime { |
| 35 | + system_time_internal::now() |
| 36 | + .unwrap_or_else(|| panic!("time not implemented on this platform")) |
| 37 | + } |
| 38 | + |
| 39 | + pub fn sub_time(&self, other: &SystemTime) -> Result<Duration, Duration> { |
| 40 | + self.0.checked_sub(other.0).ok_or_else(|| other.0 - self.0) |
| 41 | + } |
| 42 | + |
| 43 | + pub fn checked_add_duration(&self, other: &Duration) -> Option<SystemTime> { |
| 44 | + Some(SystemTime(self.0.checked_add(*other)?)) |
| 45 | + } |
| 46 | + |
| 47 | + pub fn checked_sub_duration(&self, other: &Duration) -> Option<SystemTime> { |
| 48 | + Some(SystemTime(self.0.checked_sub(*other)?)) |
| 49 | + } |
| 50 | +} |
| 51 | + |
| 52 | +pub(crate) mod system_time_internal { |
| 53 | + use super::super::helpers; |
| 54 | + use super::*; |
| 55 | + use crate::mem::MaybeUninit; |
| 56 | + use crate::ptr::NonNull; |
| 57 | + use r_efi::efi::{RuntimeServices, Time}; |
| 58 | + |
| 59 | + pub fn now() -> Option<SystemTime> { |
| 60 | + let runtime_services: NonNull<RuntimeServices> = helpers::runtime_services()?; |
| 61 | + let mut t: MaybeUninit<Time> = MaybeUninit::uninit(); |
| 62 | + let r = unsafe { |
| 63 | + ((*runtime_services.as_ptr()).get_time)(t.as_mut_ptr(), crate::ptr::null_mut()) |
| 64 | + }; |
| 65 | + |
| 66 | + if r.is_error() { |
| 67 | + return None; |
| 68 | + } |
| 69 | + |
| 70 | + let t = unsafe { t.assume_init() }; |
| 71 | + |
| 72 | + Some(SystemTime(uefi_time_to_duration(t))) |
| 73 | + } |
| 74 | + |
| 75 | + // This algorithm is based on the one described in the post |
| 76 | + // https://blog.reverberate.org/2020/05/12/optimizing-date-algorithms.html |
| 77 | + pub const fn uefi_time_to_duration(t: r_efi::system::Time) -> Duration { |
| 78 | + assert!(t.month <= 12); |
| 79 | + assert!(t.month != 0); |
| 80 | + |
| 81 | + const YEAR_BASE: u32 = 4800; /* Before min year, multiple of 400. */ |
| 82 | + |
| 83 | + // Calculate the number of days since 1/1/1970 |
| 84 | + // Use 1 March as the start |
| 85 | + let (m_adj, overflow): (u32, bool) = (t.month as u32).overflowing_sub(3); |
| 86 | + let (carry, adjust): (u32, u32) = if overflow { (1, 12) } else { (0, 0) }; |
| 87 | + let y_adj: u32 = (t.year as u32) + YEAR_BASE - carry; |
| 88 | + let month_days: u32 = (m_adj.wrapping_add(adjust) * 62719 + 769) / 2048; |
| 89 | + let leap_days: u32 = y_adj / 4 - y_adj / 100 + y_adj / 400; |
| 90 | + let days: u32 = y_adj * 365 + leap_days + month_days + (t.day as u32 - 1) - 2472632; |
| 91 | + |
| 92 | + let localtime_epoch: u64 = (days as u64) * SECS_IN_DAY |
| 93 | + + (t.second as u64) |
| 94 | + + (t.minute as u64) * SECS_IN_MINUTE |
| 95 | + + (t.hour as u64) * SECS_IN_HOUR; |
| 96 | + |
| 97 | + let utc_epoch: u64 = if t.timezone == r_efi::efi::UNSPECIFIED_TIMEZONE { |
| 98 | + localtime_epoch |
| 99 | + } else { |
| 100 | + (localtime_epoch as i64 + (t.timezone as i64) * SECS_IN_MINUTE as i64) as u64 |
| 101 | + }; |
| 102 | + |
| 103 | + Duration::new(utc_epoch, t.nanosecond) |
| 104 | + } |
| 105 | +} |
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