Merge pull request #311 from quodlibetor/document-timestamp-nanos-panics

Document timestamp_nanos panics
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Brandon W Maister 2019-04-07 17:40:22 -04:00 committed by GitHub
commit cd2c58816d
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4 changed files with 42 additions and 5 deletions

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@ -28,6 +28,7 @@ default = ["clock"]
clock = ["time"]
[dependencies]
libc = { version = "0.2", default-features = false }
time = { version = "0.1.39", optional = true }
num-integer = { version = "0.1.36", default-features = false }
num-traits = { version = "0.2", default-features = false }

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@ -4,6 +4,8 @@
//! Date and time parsing routines.
#![allow(deprecated)]
use std::usize;
use Weekday;

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@ -5,6 +5,8 @@
* Various scanning routines for the parser.
*/
#![allow(deprecated)]
use Weekday;
use super::{ParseResult, TOO_SHORT, INVALID, OUT_OF_RANGE};

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@ -305,21 +305,33 @@ impl NaiveDateTime {
/// Note that this does *not* account for the timezone!
/// The true "UNIX timestamp" would count seconds since the midnight *UTC* on the epoch.
///
/// # Panics
///
/// Note also that this does reduce the number of years that can be
/// represented from ~584 Billion to ~584. (If this is a problem,
/// please file an issue to let me know what domain needs nanosecond
/// precision over millenia, I'm curious.)
/// represented from ~584 Billion to ~584 years. The dates that can be
/// represented as nanoseconds are between 1677-09-21T00:12:44.0 and
/// 2262-04-11T23:47:16.854775804.
///
/// (If this is a problem, please file an issue to let me know what domain
/// needs nanosecond precision over millenia, I'm curious.)
///
/// # Example
///
/// ~~~~
/// use chrono::NaiveDate;
/// use chrono::{NaiveDate, NaiveDateTime};
///
/// let dt = NaiveDate::from_ymd(1970, 1, 1).and_hms_nano(0, 0, 1, 444);
/// assert_eq!(dt.timestamp_nanos(), 1_000_000_444);
///
/// let dt = NaiveDate::from_ymd(2001, 9, 9).and_hms_nano(1, 46, 40, 555);
/// assert_eq!(dt.timestamp_nanos(), 1_000_000_000_000_000_555);
///
/// const A_BILLION: i64 = 1_000_000_000;
/// let nanos = dt.timestamp_nanos();
/// assert_eq!(nanos, 1_000_000_000_000_000_555);
/// assert_eq!(
/// dt,
/// NaiveDateTime::from_timestamp(nanos / A_BILLION, (nanos % A_BILLION) as u32)
/// );
/// ~~~~
#[inline]
pub fn timestamp_nanos(&self) -> i64 {
@ -2348,4 +2360,24 @@ mod tests {
let time = base + Duration::microseconds(t);
assert_eq!(t, time.signed_duration_since(base).num_microseconds().unwrap());
}
#[test]
fn test_nanosecond_range() {
const A_BILLION: i64 = 1_000_000_000;
let maximum = "2262-04-11T23:47:16.854775804";
let parsed: NaiveDateTime = maximum.parse().unwrap();
let nanos = parsed.timestamp_nanos();
assert_eq!(
parsed,
NaiveDateTime::from_timestamp(nanos / A_BILLION, (nanos % A_BILLION) as u32)
);
let minimum = "1677-09-21T00:12:44.000000000";
let parsed: NaiveDateTime = minimum.parse().unwrap();
let nanos = parsed.timestamp_nanos();
assert_eq!(
parsed,
NaiveDateTime::from_timestamp(nanos / A_BILLION, (nanos % A_BILLION) as u32)
);
}
}