ctr-std: Add Time module

1 files changed, 239 insertions, 0 deletions

diff --git a/ctr-std/src/sys/unix/time.rs b/ctr-std/src/sys/unix/time.rs
new file mode 100644
index 0000000..3eea581
--- /dev/null
+++ b/ctr-std/src/sys/unix/time.rs
@@ -0,0 +1,239 @@
+// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use cmp::Ordering;
+use libc;
+use time::Duration;
+
+pub use self::inner::{Instant, SystemTime, UNIX_EPOCH};
+
+const NSEC_PER_SEC: u64 = 1_000_000_000;
+
+#[derive(Copy, Clone)]
+struct Timespec {
+    t: libc::timespec,
+}
+
+impl Timespec {
+    fn sub_timespec(&self, other: &Timespec) -> Result<Duration, Duration> {
+        if self >= other {
+            Ok(if self.t.tv_nsec >= other.t.tv_nsec {
+                Duration::new((self.t.tv_sec - other.t.tv_sec) as u64,
+                              (self.t.tv_nsec - other.t.tv_nsec) as u32)
+            } else {
+                Duration::new((self.t.tv_sec - 1 - other.t.tv_sec) as u64,
+                              self.t.tv_nsec as u32 + (NSEC_PER_SEC as u32) -
+                              other.t.tv_nsec as u32)
+            })
+        } else {
+            match other.sub_timespec(self) {
+                Ok(d) => Err(d),
+                Err(d) => Ok(d),
+            }
+        }
+    }
+
+    fn add_duration(&self, other: &Duration) -> Timespec {
+        let secs = (self.t.tv_sec as i64).checked_add(other.as_secs() as i64);
+        let mut secs = secs.expect("overflow when adding duration to time");
+
+        // Nano calculations can't overflow because nanos are <1B which fit
+        // in a u32.
+        let mut nsec = other.subsec_nanos() + self.t.tv_nsec as u32;
+        if nsec >= NSEC_PER_SEC as u32 {
+            nsec -= NSEC_PER_SEC as u32;
+            secs = secs.checked_add(1).expect("overflow when adding \
+                                               duration to time");
+        }
+        Timespec {
+            t: libc::timespec {
+                tv_sec: secs as libc::time_t,
+                tv_nsec: nsec as libc::c_long,
+            },
+        }
+    }
+
+    fn sub_duration(&self, other: &Duration) -> Timespec {
+        let secs = (self.t.tv_sec as i64).checked_sub(other.as_secs() as i64);
+        let mut secs = secs.expect("overflow when subtracting duration \
+                                    from time");
+
+        // Similar to above, nanos can't overflow.
+        let mut nsec = self.t.tv_nsec as i32 - other.subsec_nanos() as i32;
+        if nsec < 0 {
+            nsec += NSEC_PER_SEC as i32;
+            secs = secs.checked_sub(1).expect("overflow when subtracting \
+                                               duration from time");
+        }
+        Timespec {
+            t: libc::timespec {
+                tv_sec: secs as libc::time_t,
+                tv_nsec: nsec as libc::c_long,
+            },
+        }
+    }
+}
+
+impl PartialEq for Timespec {
+    fn eq(&self, other: &Timespec) -> bool {
+        self.t.tv_sec == other.t.tv_sec && self.t.tv_nsec == other.t.tv_nsec
+    }
+}
+
+impl Eq for Timespec {}
+
+impl PartialOrd for Timespec {
+    fn partial_cmp(&self, other: &Timespec) -> Option<Ordering> {
+        Some(self.cmp(other))
+    }
+}
+
+impl Ord for Timespec {
+    fn cmp(&self, other: &Timespec) -> Ordering {
+        let me = (self.t.tv_sec, self.t.tv_nsec);
+        let other = (other.t.tv_sec, other.t.tv_nsec);
+        me.cmp(&other)
+    }
+}
+
+mod inner {
+    use fmt;
+    use libc;
+    use sys::cvt;
+    use time::Duration;
+
+    use super::Timespec;
+
+    #[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord)]
+    pub struct Instant {
+        t: Timespec,
+    }
+
+    #[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord)]
+    pub struct SystemTime {
+        t: Timespec,
+    }
+
+    pub const UNIX_EPOCH: SystemTime = SystemTime {
+        t: Timespec {
+            t: libc::timespec {
+                tv_sec: 0,
+                tv_nsec: 0,
+            },
+        },
+    };
+
+    impl Instant {
+        // devkitARM does not expose monotonic time functions or types,
+        // so we fall back to constructing Instant with gettimeofday(2)
+        pub fn now() -> Instant {
+            use ptr;
+
+            let mut s = libc::timeval {
+                tv_sec: 0,
+                tv_usec: 0,
+            };
+            cvt(unsafe {
+                libc::gettimeofday(&mut s, ptr::null_mut())
+            }).unwrap();
+            return Instant::from(s)
+        }
+
+        pub fn sub_instant(&self, other: &Instant) -> Duration {
+            self.t.sub_timespec(&other.t).unwrap_or_else(|_| {
+                panic!("other was less than the current instant")
+            })
+        }
+
+        pub fn add_duration(&self, other: &Duration) -> Instant {
+            Instant { t: self.t.add_duration(other) }
+        }
+
+        pub fn sub_duration(&self, other: &Duration) -> Instant {
+            Instant { t: self.t.sub_duration(other) }
+        }
+    }
+
+    impl fmt::Debug for Instant {
+        fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+            f.debug_struct("Instant")
+             .field("tv_sec", &self.t.t.tv_sec)
+             .field("tv_nsec", &self.t.t.tv_nsec)
+             .finish()
+        }
+    }
+
+    impl From<libc::timeval> for Instant {
+        fn from(t: libc::timeval) -> Instant {
+            Instant::from(libc::timespec {
+                tv_sec: t.tv_sec,
+                tv_nsec: (t.tv_usec * 1000) as libc::c_long,
+            })
+        }
+    }
+
+    impl From<libc::timespec> for Instant {
+        fn from(t: libc::timespec) -> Instant {
+            Instant { t: Timespec { t: t } }
+        }
+    }
+
+    impl SystemTime {
+        pub fn now() -> SystemTime {
+            use ptr;
+
+            let mut s = libc::timeval {
+                tv_sec: 0,
+                tv_usec: 0,
+            };
+            cvt(unsafe {
+                libc::gettimeofday(&mut s, ptr::null_mut())
+            }).unwrap();
+            return SystemTime::from(s)
+        }
+
+        pub fn sub_time(&self, other: &SystemTime)
+                        -> Result<Duration, Duration> {
+            self.t.sub_timespec(&other.t)
+        }
+
+        pub fn add_duration(&self, other: &Duration) -> SystemTime {
+            SystemTime { t: self.t.add_duration(other) }
+        }
+
+        pub fn sub_duration(&self, other: &Duration) -> SystemTime {
+            SystemTime { t: self.t.sub_duration(other) }
+        }
+    }
+
+    impl From<libc::timeval> for SystemTime {
+        fn from(t: libc::timeval) -> SystemTime {
+            SystemTime::from(libc::timespec {
+                tv_sec: t.tv_sec,
+                tv_nsec: (t.tv_usec * 1000) as libc::c_long,
+            })
+        }
+    }
+
+    impl From<libc::timespec> for SystemTime {
+        fn from(t: libc::timespec) -> SystemTime {
+            SystemTime { t: Timespec { t: t } }
+        }
+    }
+
+    impl fmt::Debug for SystemTime {
+        fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+            f.debug_struct("SystemTime")
+             .field("tv_sec", &self.t.t.tv_sec)
+             .field("tv_nsec", &self.t.t.tv_nsec)
+             .finish()
+        }
+    }
+}