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// This is a part of Chrono.
// See README.md and LICENSE.txt for details.
//! The local (system) time zone.
#[cfg(not(all(target_arch = "wasm32", not(target_os = "wasi"), feature = "wasmbind")))]
use sys::{self, Timespec};
use super::fixed::FixedOffset;
use super::{LocalResult, TimeZone};
#[cfg(not(all(target_arch = "wasm32", not(target_os = "wasi"), feature = "wasmbind")))]
use naive::NaiveTime;
use naive::{NaiveDate, NaiveDateTime};
use {Date, DateTime};
#[cfg(not(all(target_arch = "wasm32", not(target_os = "wasi"), feature = "wasmbind")))]
use {Datelike, Timelike};
/// Converts a `time::Tm` struct into the timezone-aware `DateTime`.
/// This assumes that `time` is working correctly, i.e. any error is fatal.
#[cfg(not(all(target_arch = "wasm32", not(target_os = "wasi"), feature = "wasmbind")))]
fn tm_to_datetime(mut tm: sys::Tm) -> DateTime<Local> {
if tm.tm_sec >= 60 {
tm.tm_nsec += (tm.tm_sec - 59) * 1_000_000_000;
tm.tm_sec = 59;
}
#[cfg(not(windows))]
fn tm_to_naive_date(tm: &sys::Tm) -> NaiveDate {
// from_yo is more efficient than from_ymd (since it's the internal representation).
NaiveDate::from_yo(tm.tm_year + 1900, tm.tm_yday as u32 + 1)
}
#[cfg(windows)]
fn tm_to_naive_date(tm: &sys::Tm) -> NaiveDate {
// ...but tm_yday is broken in Windows (issue #85)
NaiveDate::from_ymd(tm.tm_year + 1900, tm.tm_mon as u32 + 1, tm.tm_mday as u32)
}
let date = tm_to_naive_date(&tm);
let time = NaiveTime::from_hms_nano(
tm.tm_hour as u32,
tm.tm_min as u32,
tm.tm_sec as u32,
tm.tm_nsec as u32,
);
let offset = FixedOffset::east(tm.tm_utcoff);
DateTime::from_utc(date.and_time(time) - offset, offset)
}
/// Converts a local `NaiveDateTime` to the `time::Timespec`.
#[cfg(not(all(target_arch = "wasm32", not(target_os = "wasi"), feature = "wasmbind")))]
fn datetime_to_timespec(d: &NaiveDateTime, local: bool) -> sys::Timespec {
// well, this exploits an undocumented `Tm::to_timespec` behavior
// to get the exact function we want (either `timegm` or `mktime`).
// the number 1 is arbitrary but should be non-zero to trigger `mktime`.
let tm_utcoff = if local { 1 } else { 0 };
let tm = sys::Tm {
tm_sec: d.second() as i32,
tm_min: d.minute() as i32,
tm_hour: d.hour() as i32,
tm_mday: d.day() as i32,
tm_mon: d.month0() as i32, // yes, C is that strange...
tm_year: d.year() - 1900, // this doesn't underflow, we know that d is `NaiveDateTime`.
tm_wday: 0, // to_local ignores this
tm_yday: 0, // and this
tm_isdst: -1,
tm_utcoff: tm_utcoff,
// do not set this, OS APIs are heavily inconsistent in terms of leap second handling
tm_nsec: 0,
};
tm.to_timespec()
}
/// The local timescale. This is implemented via the standard `time` crate.
///
/// Using the [`TimeZone`](./trait.TimeZone.html) methods
/// on the Local struct is the preferred way to construct `DateTime<Local>`
/// instances.
///
/// # Example
///
/// ~~~~
/// use chrono::{Local, DateTime, TimeZone};
///
/// let dt: DateTime<Local> = Local::now();
/// let dt: DateTime<Local> = Local.timestamp(0, 0);
/// ~~~~
#[derive(Copy, Clone, Debug)]
pub struct Local;
impl Local {
/// Returns a `Date` which corresponds to the current date.
pub fn today() -> Date<Local> {
Local::now().date()
}
/// Returns a `DateTime` which corresponds to the current date.
#[cfg(not(all(target_arch = "wasm32", not(target_os = "wasi"), feature = "wasmbind")))]
pub fn now() -> DateTime<Local> {
tm_to_datetime(Timespec::now().local())
}
/// Returns a `DateTime` which corresponds to the current date.
#[cfg(all(target_arch = "wasm32", not(target_os = "wasi"), feature = "wasmbind"))]
pub fn now() -> DateTime<Local> {
use super::Utc;
let now: DateTime<Utc> = super::Utc::now();
// Workaround missing timezone logic in `time` crate
let offset = FixedOffset::west((js_sys::Date::new_0().get_timezone_offset() as i32) * 60);
DateTime::from_utc(now.naive_utc(), offset)
}
}
impl TimeZone for Local {
type Offset = FixedOffset;
fn from_offset(_offset: &FixedOffset) -> Local {
Local
}
// they are easier to define in terms of the finished date and time unlike other offsets
fn offset_from_local_date(&self, local: &NaiveDate) -> LocalResult<FixedOffset> {
self.from_local_date(local).map(|date| *date.offset())
}
fn offset_from_local_datetime(&self, local: &NaiveDateTime) -> LocalResult<FixedOffset> {
self.from_local_datetime(local).map(|datetime| *datetime.offset())
}
fn offset_from_utc_date(&self, utc: &NaiveDate) -> FixedOffset {
*self.from_utc_date(utc).offset()
}
fn offset_from_utc_datetime(&self, utc: &NaiveDateTime) -> FixedOffset {
*self.from_utc_datetime(utc).offset()
}
// override them for avoiding redundant works
fn from_local_date(&self, local: &NaiveDate) -> LocalResult<Date<Local>> {
// this sounds very strange, but required for keeping `TimeZone::ymd` sane.
// in the other words, we use the offset at the local midnight
// but keep the actual date unaltered (much like `FixedOffset`).
let midnight = self.from_local_datetime(&local.and_hms(0, 0, 0));
midnight.map(|datetime| Date::from_utc(*local, *datetime.offset()))
}
#[cfg(all(target_arch = "wasm32", not(target_os = "wasi"), feature = "wasmbind"))]
fn from_local_datetime(&self, local: &NaiveDateTime) -> LocalResult<DateTime<Local>> {
let mut local = local.clone();
// Get the offset from the js runtime
let offset = FixedOffset::west((js_sys::Date::new_0().get_timezone_offset() as i32) * 60);
local -= ::Duration::seconds(offset.local_minus_utc() as i64);
LocalResult::Single(DateTime::from_utc(local, offset))
}
#[cfg(not(all(target_arch = "wasm32", not(target_os = "wasi"), feature = "wasmbind")))]
fn from_local_datetime(&self, local: &NaiveDateTime) -> LocalResult<DateTime<Local>> {
let timespec = datetime_to_timespec(local, true);
// datetime_to_timespec completely ignores leap seconds, so we need to adjust for them
let mut tm = timespec.local();
assert_eq!(tm.tm_nsec, 0);
tm.tm_nsec = local.nanosecond() as i32;
LocalResult::Single(tm_to_datetime(tm))
}
fn from_utc_date(&self, utc: &NaiveDate) -> Date<Local> {
let midnight = self.from_utc_datetime(&utc.and_hms(0, 0, 0));
Date::from_utc(*utc, *midnight.offset())
}
#[cfg(all(target_arch = "wasm32", not(target_os = "wasi"), feature = "wasmbind"))]
fn from_utc_datetime(&self, utc: &NaiveDateTime) -> DateTime<Local> {
// Get the offset from the js runtime
let offset = FixedOffset::west((js_sys::Date::new_0().get_timezone_offset() as i32) * 60);
DateTime::from_utc(*utc, offset)
}
#[cfg(not(all(target_arch = "wasm32", not(target_os = "wasi"), feature = "wasmbind")))]
fn from_utc_datetime(&self, utc: &NaiveDateTime) -> DateTime<Local> {
let timespec = datetime_to_timespec(utc, false);
// datetime_to_timespec completely ignores leap seconds, so we need to adjust for them
let mut tm = timespec.local();
assert_eq!(tm.tm_nsec, 0);
tm.tm_nsec = utc.nanosecond() as i32;
tm_to_datetime(tm)
}
}
#[cfg(test)]
mod tests {
use super::Local;
use offset::TimeZone;
use Datelike;
#[test]
fn test_local_date_sanity_check() {
// issue #27
assert_eq!(Local.ymd(2999, 12, 28).day(), 28);
}
#[test]
fn test_leap_second() {
// issue #123
let today = Local::today();
let dt = today.and_hms_milli(1, 2, 59, 1000);
let timestr = dt.time().to_string();
// the OS API may or may not support the leap second,
// but there are only two sensible options.
assert!(timestr == "01:02:60" || timestr == "01:03:00", "unexpected timestr {:?}", timestr);
let dt = today.and_hms_milli(1, 2, 3, 1234);
let timestr = dt.time().to_string();
assert!(
timestr == "01:02:03.234" || timestr == "01:02:04.234",
"unexpected timestr {:?}",
timestr
);
}
}