src/libstd/sys/hermit/time.rs

   1 #![allow(dead_code)]
   2
   3 use crate::time::Duration;
   4 use crate::cmp::Ordering;
   5 use crate::convert::TryInto;
   6 use core::hash::{Hash, Hasher};
   7 use crate::sys::hermit::abi;
   8 use crate::sys::hermit::abi::{CLOCK_REALTIME, CLOCK_MONOTONIC, NSEC_PER_SEC};
   9 use crate::sys::hermit::abi::timespec;
  10
  11 #[derive(Copy, Clone, Debug)]
  12 struct Timespec {
  13     t: timespec
  14 }
  15
  16 impl Timespec {
  17     const fn zero() -> Timespec {
  18         Timespec {
  19             t: timespec { tv_sec: 0, tv_nsec: 0 },
  20         }
  21     }
  22
  23     fn sub_timespec(&self, other: &Timespec) -> Result<Duration, Duration> {
  24         if self >= other {
  25             Ok(if self.t.tv_nsec >= other.t.tv_nsec {
  26                 Duration::new((self.t.tv_sec - other.t.tv_sec) as u64,
  27                               (self.t.tv_nsec - other.t.tv_nsec) as u32)
  28             } else {
  29                 Duration::new((self.t.tv_sec - 1 - other.t.tv_sec) as u64,
  30                               self.t.tv_nsec as u32 + (NSEC_PER_SEC as u32) -
  31                               other.t.tv_nsec as u32)
  32             })
  33         } else {
  34             match other.sub_timespec(self) {
  35                 Ok(d) => Err(d),
  36                 Err(d) => Ok(d),
  37             }
  38         }
  39     }
  40
  41     fn checked_add_duration(&self, other: &Duration) -> Option<Timespec> {
  42         let mut secs = other
  43             .as_secs()
  44             .try_into() // <- target type would be `libc::time_t`
  45             .ok()
  46             .and_then(|secs| self.t.tv_sec.checked_add(secs))?;
  47
  48         // Nano calculations can't overflow because nanos are <1B which fit
  49         // in a u32.
  50         let mut nsec = other.subsec_nanos() + self.t.tv_nsec as u32;
  51         if nsec >= NSEC_PER_SEC as u32 {
  52             nsec -= NSEC_PER_SEC as u32;
  53             secs = secs.checked_add(1)?;
  54         }
  55         Some(Timespec {
  56             t: timespec {
  57                 tv_sec: secs,
  58                 tv_nsec: nsec as _,
  59             },
  60         })
  61     }
  62
  63     fn checked_sub_duration(&self, other: &Duration) -> Option<Timespec> {
  64         let mut secs = other
  65             .as_secs()
  66             .try_into() // <- target type would be `libc::time_t`
  67             .ok()
  68             .and_then(|secs| self.t.tv_sec.checked_sub(secs))?;
  69
  70         // Similar to above, nanos can't overflow.
  71         let mut nsec = self.t.tv_nsec as i32 - other.subsec_nanos() as i32;
  72         if nsec < 0 {
  73             nsec += NSEC_PER_SEC as i32;
  74             secs = secs.checked_sub(1)?;
  75         }
  76         Some(Timespec {
  77             t: timespec {
  78                 tv_sec: secs,
  79                 tv_nsec: nsec as _,
  80             },
  81         })
  82     }
  83 }
  84
  85 impl PartialEq for Timespec {
  86     fn eq(&self, other: &Timespec) -> bool {
  87         self.t.tv_sec == other.t.tv_sec && self.t.tv_nsec == other.t.tv_nsec
  88     }
  89 }
  90
  91 impl Eq for Timespec {}
  92
  93 impl PartialOrd for Timespec {
  94     fn partial_cmp(&self, other: &Timespec) -> Option<Ordering> {
  95         Some(self.cmp(other))
  96     }
  97 }
  98
  99 impl Ord for Timespec {
 100     fn cmp(&self, other: &Timespec) -> Ordering {
 101         let me = (self.t.tv_sec, self.t.tv_nsec);
 102         let other = (other.t.tv_sec, other.t.tv_nsec);
 103         me.cmp(&other)
 104     }
 105 }
 106
 107 impl Hash for Timespec {
 108     fn hash<H : Hasher>(&self, state: &mut H) {
 109         self.t.tv_sec.hash(state);
 110         self.t.tv_nsec.hash(state);
 111     }
 112 }
 113
 114 #[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Debug, Hash)]
 115 pub struct Instant {
 116     t: Timespec,
 117 }
 118
 119 impl Instant {
 120     pub fn now() -> Instant {
 121         let mut time: Timespec = Timespec::zero();
 122         let _ = unsafe { abi::clock_gettime(CLOCK_MONOTONIC, &mut time.t as *mut timespec) };
 123
 124         Instant { t: time }
 125     }
 126
 127     pub const fn zero() -> Instant {
 128         Instant { t: Timespec::zero() }
 129     }
 130
 131     pub fn actually_monotonic() -> bool {
 132         true
 133     }
 134
 135     pub fn checked_sub_instant(&self, other: &Instant) -> Option<Duration> {
 136         self.t.sub_timespec(&other.t).ok()
 137     }
 138
 139     pub fn checked_add_duration(&self, other: &Duration) -> Option<Instant> {
 140         Some(Instant { t: self.t.checked_add_duration(other)? })
 141     }
 142
 143     pub fn checked_sub_duration(&self, other: &Duration) -> Option<Instant> {
 144         Some(Instant { t: self.t.checked_sub_duration(other)? })
 145     }
 146 }
 147
 148 #[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash, Debug)]
 149 pub struct SystemTime {
 150     t: Timespec,
 151 }
 152
 153 pub const UNIX_EPOCH: SystemTime = SystemTime {
 154     t: Timespec::zero(),
 155 };
 156
 157 impl SystemTime {
 158     pub fn now() -> SystemTime {
 159         let mut time: Timespec = Timespec::zero();
 160         let _ = unsafe { abi::clock_gettime(CLOCK_REALTIME, &mut time.t as *mut timespec) };
 161
 162         SystemTime { t: time }
 163     }
 164
 165     pub fn sub_time(&self, other: &SystemTime) -> Result<Duration, Duration> {
 166         self.t.sub_timespec(&other.t)
 167     }
 168
 169     pub fn checked_add_duration(&self, other: &Duration) -> Option<SystemTime> {
 170         Some(SystemTime { t: self.t.checked_add_duration(other)? })
 171     }
 172
 173     pub fn checked_sub_duration(&self, other: &Duration) -> Option<SystemTime> {
 174         Some(SystemTime { t: self.t.checked_sub_duration(other)? })
 175     }
 176 }