sgx_tstd/src/time/duration.rs - incubator-teaclave-sgx-sdk - Git at Google

 // Copyright (C) 2017-2018 Baidu, Inc. All Rights Reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions
 // are met:
 //
 //  * Redistributions of source code must retain the above copyright
 //    notice, this list of conditions and the following disclaimer.
 //  * Redistributions in binary form must reproduce the above copyright
 //    notice, this list of conditions and the following disclaimer in
 //    the documentation and/or other materials provided with the
 //    distribution.
 //  * Neither the name of Baidu, Inc., nor the names of its
 //    contributors may be used to endorse or promote products derived
 //    from this software without specific prior written permission.
 //
 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 use core::iter::Sum;
 use core::ops::{Add, Sub, Mul, Div, AddAssign, SubAssign, MulAssign, DivAssign};

 const NANOS_PER_SEC: u32 = 1_000_000_000;
 const NANOS_PER_MILLI: u32 = 1_000_000;
 const NANOS_PER_MICRO: u32 = 1_000;
 const MILLIS_PER_SEC: u64 = 1_000;
 const MICROS_PER_SEC: u64 = 1_000_000;

 /// A `Duration` type to represent a span of time, typically used for system
 /// timeouts.
 ///
 /// Each `Duration` is composed of a whole number of seconds and a fractional part
 /// represented in nanoseconds.  If the underlying system does not support
 /// nanosecond-level precision, APIs binding a system timeout will typically round up
 /// the number of nanoseconds.
 ///
 /// `Duration`s implement many common traits, including [`Add`], [`Sub`], and other
 /// [`ops`] traits.
 ///
 #[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Debug, Hash, Default)]
 pub struct Duration {
     secs: u64,
     nanos: u32, // Always 0 <= nanos < NANOS_PER_SEC
 }

 impl Duration {
     /// Creates a new `Duration` from the specified number of whole seconds and
     /// additional nanoseconds.
     ///
     /// If the number of nanoseconds is greater than 1 billion (the number of
     /// nanoseconds in a second), then it will carry over into the seconds provided.
     ///
     /// # Panics
     ///
     /// This constructor will panic if the carry from the nanoseconds overflows
     /// the seconds counter.
     ///
     #[inline]
     pub fn new(secs: u64, nanos: u32) -> Duration {
         let secs = secs.checked_add((nanos / NANOS_PER_SEC) as u64)
             .expect("overflow in Duration::new");
         let nanos = nanos % NANOS_PER_SEC;
         Duration { secs: secs, nanos: nanos }
     }

     /// Creates a new `Duration` from the specified number of whole seconds.
     ///
     #[inline]
     pub const fn from_secs(secs: u64) -> Duration {
         Duration { secs: secs, nanos: 0 }
     }

     /// Creates a new `Duration` from the specified number of milliseconds.
     ///
     #[inline]
     pub const fn from_millis(millis: u64) -> Duration {
         Duration {
             secs: millis / MILLIS_PER_SEC,
             nanos: ((millis % MILLIS_PER_SEC) as u32) * NANOS_PER_MILLI,
         }
     }

     /// Creates a new `Duration` from the specified number of microseconds.
     ///
     #[inline]
     pub const fn from_micros(micros: u64) -> Duration {
         Duration {
             secs: micros / MICROS_PER_SEC,
             nanos: ((micros % MICROS_PER_SEC) as u32) * NANOS_PER_MICRO,
         }
     }

     /// Creates a new `Duration` from the specified number of nanoseconds.
     ///
     #[inline]
     pub const fn from_nanos(nanos: u64) -> Duration {
         Duration {
             secs: nanos / (NANOS_PER_SEC as u64),
             nanos: (nanos % (NANOS_PER_SEC as u64)) as u32,
         }
     }

     /// Returns the number of _whole_ seconds contained by this `Duration`.
     ///
     /// The returned value does not include the fractional (nanosecond) part of the
     /// duration, which can be obtained using [`subsec_nanos`].
     ///
     #[inline]
     pub fn as_secs(&self) -> u64 { self.secs }

     /// Returns the fractional part of this `Duration`, in milliseconds.
     ///
     /// This method does **not** return the length of the duration when
     /// represented by milliseconds. The returned number always represents a
     /// fractional portion of a second (i.e. it is less than one thousand).
     ///
     #[inline]
     pub fn subsec_millis(&self) -> u32 { self.nanos / NANOS_PER_MILLI }

     /// Returns the fractional part of this `Duration`, in microseconds.
     ///
     /// This method does **not** return the length of the duration when
     /// represented by microseconds. The returned number always represents a
     /// fractional portion of a second (i.e. it is less than one million).
     ///
     #[inline]
     pub fn subsec_micros(&self) -> u32 { self.nanos / NANOS_PER_MICRO }

     /// Returns the fractional part of this `Duration`, in nanoseconds.
     ///
     /// This method does **not** return the length of the duration when
     /// represented by nanoseconds. The returned number always represents a
     /// fractional portion of a second (i.e. it is less than one billion).
     ///
     #[inline]
     pub fn subsec_nanos(&self) -> u32 { self.nanos }

     /// Checked `Duration` addition. Computes `self + other`, returning [`None`]
     /// if overflow occurred.
     ///
     #[inline]
     pub fn checked_add(self, rhs: Duration) -> Option<Duration> {
         if let Some(mut secs) = self.secs.checked_add(rhs.secs) {
             let mut nanos = self.nanos + rhs.nanos;
             if nanos >= NANOS_PER_SEC {
                 nanos -= NANOS_PER_SEC;
                 if let Some(new_secs) = secs.checked_add(1) {
                     secs = new_secs;
                 } else {
                     return None;
                 }
             }
             debug_assert!(nanos < NANOS_PER_SEC);
             Some(Duration {
                 secs: secs,
                 nanos: nanos,
             })
         } else {
             None
         }
     }

     /// Checked `Duration` subtraction. Computes `self - other`, returning [`None`]
     /// if the result would be negative or if overflow occurred.
     ///
     #[inline]
     pub fn checked_sub(self, rhs: Duration) -> Option<Duration> {
         if let Some(mut secs) = self.secs.checked_sub(rhs.secs) {
             let nanos = if self.nanos >= rhs.nanos {
                 self.nanos - rhs.nanos
             } else {
                 if let Some(sub_secs) = secs.checked_sub(1) {
                     secs = sub_secs;
                     self.nanos + NANOS_PER_SEC - rhs.nanos
                 } else {
                     return None;
                 }
             };
             debug_assert!(nanos < NANOS_PER_SEC);
             Some(Duration { secs: secs, nanos: nanos })
         } else {
             None
         }
     }

     /// Checked `Duration` multiplication. Computes `self * other`, returning
     /// [`None`] if overflow occurred.
     ///
     #[inline]
     pub fn checked_mul(self, rhs: u32) -> Option<Duration> {
         // Multiply nanoseconds as u64, because it cannot overflow that way.
         let total_nanos = self.nanos as u64 * rhs as u64;
         let extra_secs = total_nanos / (NANOS_PER_SEC as u64);
         let nanos = (total_nanos % (NANOS_PER_SEC as u64)) as u32;
         if let Some(secs) = self.secs
             .checked_mul(rhs as u64)
             .and_then(|s| s.checked_add(extra_secs)) {
             debug_assert!(nanos < NANOS_PER_SEC);
             Some(Duration {
                 secs: secs,
                 nanos: nanos,
             })
         } else {
             None
         }
     }

     /// Checked `Duration` division. Computes `self / other`, returning [`None`]
     /// if `other == 0`.
     ///
     #[inline]
     pub fn checked_div(self, rhs: u32) -> Option<Duration> {
         if rhs != 0 {
             let secs = self.secs / (rhs as u64);
             let carry = self.secs - secs * (rhs as u64);
             let extra_nanos = carry * (NANOS_PER_SEC as u64) / (rhs as u64);
             let nanos = self.nanos / rhs + (extra_nanos as u32);
             debug_assert!(nanos < NANOS_PER_SEC);
             Some(Duration { secs: secs, nanos: nanos })
         } else {
             None
         }
     }
 }

 impl Add for Duration {
     type Output = Duration;

     fn add(self, rhs: Duration) -> Duration {
         self.checked_add(rhs).expect("overflow when adding durations")
     }
 }

 impl AddAssign for Duration {
     fn add_assign(&mut self, rhs: Duration) {
         *self = *self + rhs;
     }
 }

 impl Sub for Duration {
     type Output = Duration;

     fn sub(self, rhs: Duration) -> Duration {
         self.checked_sub(rhs).expect("overflow when subtracting durations")
     }
 }

 impl SubAssign for Duration {
     fn sub_assign(&mut self, rhs: Duration) {
         *self = *self - rhs;
     }
 }

 impl Mul<u32> for Duration {
     type Output = Duration;

     fn mul(self, rhs: u32) -> Duration {
         self.checked_mul(rhs).expect("overflow when multiplying duration by scalar")
     }
 }

 impl MulAssign<u32> for Duration {
     fn mul_assign(&mut self, rhs: u32) {
         *self = *self * rhs;
     }
 }

 impl Div<u32> for Duration {
     type Output = Duration;

     fn div(self, rhs: u32) -> Duration {
         self.checked_div(rhs).expect("divide by zero error when dividing duration by scalar")
     }
 }

 impl DivAssign<u32> for Duration {
     fn div_assign(&mut self, rhs: u32) {
         *self = *self / rhs;
     }
 }

 impl Sum for Duration {
     fn sum<I: Iterator<Item=Duration>>(iter: I) -> Duration {
         iter.fold(Duration::new(0, 0), |a, b| a + b)
     }
 }

 impl<'a> Sum<&'a Duration> for Duration {
     fn sum<I: Iterator<Item=&'a Duration>>(iter: I) -> Duration {
         iter.fold(Duration::new(0, 0), |a, b| a + *b)
     }
 }
	// Copyright (C) 2017-2018 Baidu, Inc. All Rights Reserved.
	//
	// Redistribution and use in source and binary forms, with or without
	// modification, are permitted provided that the following conditions
	// are met:
	//
	// * Redistributions of source code must retain the above copyright
	// notice, this list of conditions and the following disclaimer.
	// * Redistributions in binary form must reproduce the above copyright
	// notice, this list of conditions and the following disclaimer in
	// the documentation and/or other materials provided with the
	// distribution.
	// * Neither the name of Baidu, Inc., nor the names of its
	// contributors may be used to endorse or promote products derived
	// from this software without specific prior written permission.
	//
	// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
	// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
	// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
	// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
	// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
	// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
	// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
	// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

	use core::iter::Sum;
	use core::ops::{Add, Sub, Mul, Div, AddAssign, SubAssign, MulAssign, DivAssign};

	const NANOS_PER_SEC: u32 = 1_000_000_000;
	const NANOS_PER_MILLI: u32 = 1_000_000;
	const NANOS_PER_MICRO: u32 = 1_000;
	const MILLIS_PER_SEC: u64 = 1_000;
	const MICROS_PER_SEC: u64 = 1_000_000;

	/// A `Duration` type to represent a span of time, typically used for system
	/// timeouts.
	///
	/// Each `Duration` is composed of a whole number of seconds and a fractional part
	/// represented in nanoseconds. If the underlying system does not support
	/// nanosecond-level precision, APIs binding a system timeout will typically round up
	/// the number of nanoseconds.
	///
	/// `Duration`s implement many common traits, including [`Add`], [`Sub`], and other
	/// [`ops`] traits.
	///
	#[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Debug, Hash, Default)]
	pub struct Duration {
	secs: u64,
	nanos: u32, // Always 0 <= nanos < NANOS_PER_SEC
	}

	impl Duration {
	/// Creates a new `Duration` from the specified number of whole seconds and
	/// additional nanoseconds.
	///
	/// If the number of nanoseconds is greater than 1 billion (the number of
	/// nanoseconds in a second), then it will carry over into the seconds provided.
	///
	/// # Panics
	///
	/// This constructor will panic if the carry from the nanoseconds overflows
	/// the seconds counter.
	///
	#[inline]
	pub fn new(secs: u64, nanos: u32) -> Duration {
	let secs = secs.checked_add((nanos / NANOS_PER_SEC) as u64)
	.expect("overflow in Duration::new");
	let nanos = nanos % NANOS_PER_SEC;
	Duration { secs: secs, nanos: nanos }
	}

	/// Creates a new `Duration` from the specified number of whole seconds.
	///
	#[inline]
	pub const fn from_secs(secs: u64) -> Duration {
	Duration { secs: secs, nanos: 0 }
	}

	/// Creates a new `Duration` from the specified number of milliseconds.
	///
	#[inline]
	pub const fn from_millis(millis: u64) -> Duration {
	Duration {
	secs: millis / MILLIS_PER_SEC,
	nanos: ((millis % MILLIS_PER_SEC) as u32) * NANOS_PER_MILLI,
	}
	}

	/// Creates a new `Duration` from the specified number of microseconds.
	///
	#[inline]
	pub const fn from_micros(micros: u64) -> Duration {
	Duration {
	secs: micros / MICROS_PER_SEC,
	nanos: ((micros % MICROS_PER_SEC) as u32) * NANOS_PER_MICRO,
	}
	}

	/// Creates a new `Duration` from the specified number of nanoseconds.
	///
	#[inline]
	pub const fn from_nanos(nanos: u64) -> Duration {
	Duration {
	secs: nanos / (NANOS_PER_SEC as u64),
	nanos: (nanos % (NANOS_PER_SEC as u64)) as u32,
	}
	}

	/// Returns the number of _whole_ seconds contained by this `Duration`.
	///
	/// The returned value does not include the fractional (nanosecond) part of the
	/// duration, which can be obtained using [`subsec_nanos`].
	///
	#[inline]
	pub fn as_secs(&self) -> u64 { self.secs }

	/// Returns the fractional part of this `Duration`, in milliseconds.
	///
	/// This method does not return the length of the duration when
	/// represented by milliseconds. The returned number always represents a
	/// fractional portion of a second (i.e. it is less than one thousand).
	///
	#[inline]
	pub fn subsec_millis(&self) -> u32 { self.nanos / NANOS_PER_MILLI }

	/// Returns the fractional part of this `Duration`, in microseconds.
	///
	/// This method does not return the length of the duration when
	/// represented by microseconds. The returned number always represents a
	/// fractional portion of a second (i.e. it is less than one million).
	///
	#[inline]
	pub fn subsec_micros(&self) -> u32 { self.nanos / NANOS_PER_MICRO }

	/// Returns the fractional part of this `Duration`, in nanoseconds.
	///
	/// This method does not return the length of the duration when
	/// represented by nanoseconds. The returned number always represents a
	/// fractional portion of a second (i.e. it is less than one billion).
	///
	#[inline]
	pub fn subsec_nanos(&self) -> u32 { self.nanos }

	/// Checked `Duration` addition. Computes `self + other`, returning [`None`]
	/// if overflow occurred.
	///
	#[inline]
	pub fn checked_add(self, rhs: Duration) -> Option<Duration> {
	if let Some(mut secs) = self.secs.checked_add(rhs.secs) {
	let mut nanos = self.nanos + rhs.nanos;
	if nanos >= NANOS_PER_SEC {
	nanos -= NANOS_PER_SEC;
	if let Some(new_secs) = secs.checked_add(1) {
	secs = new_secs;
	} else {
	return None;
	}
	}
	debug_assert!(nanos < NANOS_PER_SEC);
	Some(Duration {
	secs: secs,
	nanos: nanos,
	})
	} else {
	None
	}
	}

	/// Checked `Duration` subtraction. Computes `self - other`, returning [`None`]
	/// if the result would be negative or if overflow occurred.
	///
	#[inline]
	pub fn checked_sub(self, rhs: Duration) -> Option<Duration> {
	if let Some(mut secs) = self.secs.checked_sub(rhs.secs) {
	let nanos = if self.nanos >= rhs.nanos {
	self.nanos - rhs.nanos
	} else {
	if let Some(sub_secs) = secs.checked_sub(1) {
	secs = sub_secs;
	self.nanos + NANOS_PER_SEC - rhs.nanos
	} else {
	return None;
	}
	};
	debug_assert!(nanos < NANOS_PER_SEC);
	Some(Duration { secs: secs, nanos: nanos })
	} else {
	None
	}
	}

	/// Checked `Duration` multiplication. Computes `self * other`, returning
	/// [`None`] if overflow occurred.
	///
	#[inline]
	pub fn checked_mul(self, rhs: u32) -> Option<Duration> {
	// Multiply nanoseconds as u64, because it cannot overflow that way.
	let total_nanos = self.nanos as u64 * rhs as u64;
	let extra_secs = total_nanos / (NANOS_PER_SEC as u64);
	let nanos = (total_nanos % (NANOS_PER_SEC as u64)) as u32;
	if let Some(secs) = self.secs
	.checked_mul(rhs as u64)
	.and_then(\|s\| s.checked_add(extra_secs)) {
	debug_assert!(nanos < NANOS_PER_SEC);
	Some(Duration {
	secs: secs,
	nanos: nanos,
	})
	} else {
	None
	}
	}

	/// Checked `Duration` division. Computes `self / other`, returning [`None`]
	/// if `other == 0`.
	///
	#[inline]
	pub fn checked_div(self, rhs: u32) -> Option<Duration> {
	if rhs != 0 {
	let secs = self.secs / (rhs as u64);
	let carry = self.secs - secs * (rhs as u64);
	let extra_nanos = carry * (NANOS_PER_SEC as u64) / (rhs as u64);
	let nanos = self.nanos / rhs + (extra_nanos as u32);
	debug_assert!(nanos < NANOS_PER_SEC);
	Some(Duration { secs: secs, nanos: nanos })
	} else {
	None
	}
	}
	}

	impl Add for Duration {
	type Output = Duration;

	fn add(self, rhs: Duration) -> Duration {
	self.checked_add(rhs).expect("overflow when adding durations")
	}
	}

	impl AddAssign for Duration {
	fn add_assign(&mut self, rhs: Duration) {
	self = self + rhs;
	}
	}

	impl Sub for Duration {
	type Output = Duration;

	fn sub(self, rhs: Duration) -> Duration {
	self.checked_sub(rhs).expect("overflow when subtracting durations")
	}
	}

	impl SubAssign for Duration {
	fn sub_assign(&mut self, rhs: Duration) {
	self = self - rhs;
	}
	}

	impl Mul<u32> for Duration {
	type Output = Duration;

	fn mul(self, rhs: u32) -> Duration {
	self.checked_mul(rhs).expect("overflow when multiplying duration by scalar")
	}
	}

	impl MulAssign<u32> for Duration {
	fn mul_assign(&mut self, rhs: u32) {
	self = self * rhs;
	}
	}

	impl Div<u32> for Duration {
	type Output = Duration;

	fn div(self, rhs: u32) -> Duration {
	self.checked_div(rhs).expect("divide by zero error when dividing duration by scalar")
	}
	}

	impl DivAssign<u32> for Duration {
	fn div_assign(&mut self, rhs: u32) {
	self = self / rhs;
	}
	}

	impl Sum for Duration {
	fn sum<I: Iterator<Item=Duration>>(iter: I) -> Duration {
	iter.fold(Duration::new(0, 0), \|a, b\| a + b)
	}
	}

	impl<'a> Sum<&'a Duration> for Duration {
	fn sum<I: Iterator<Item=&'a Duration>>(iter: I) -> Duration {
	iter.fold(Duration::new(0, 0), \|a, b\| a + *b)
	}
	}