fwd/vendor/chrono/src/offset/local/stub.rs
John Doty 9c435dc440 Vendor dependencies
Let's see how I like this workflow.
2022-12-19 08:38:22 -08:00

236 lines
6.9 KiB
Rust

// Copyright 2012-2014 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 std::time::{SystemTime, UNIX_EPOCH};
use super::{FixedOffset, Local};
use crate::{DateTime, Datelike, LocalResult, NaiveDate, NaiveDateTime, NaiveTime, Timelike};
pub(super) fn now() -> DateTime<Local> {
tm_to_datetime(Timespec::now().local())
}
/// Converts a local `NaiveDateTime` to the `time::Timespec`.
#[cfg(not(all(
target_arch = "wasm32",
feature = "wasmbind",
not(any(target_os = "emscripten", target_os = "wasi"))
)))]
pub(super) fn naive_to_local(d: &NaiveDateTime, local: bool) -> LocalResult<DateTime<Local>> {
let tm = 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,
// This seems pretty fake?
tm_utcoff: if local { 1 } else { 0 },
// do not set this, OS APIs are heavily inconsistent in terms of leap second handling
tm_nsec: 0,
};
let spec = Timespec {
sec: match local {
false => utc_tm_to_time(&tm),
true => local_tm_to_time(&tm),
},
nsec: tm.tm_nsec,
};
// Adjust for leap seconds
let mut tm = spec.local();
assert_eq!(tm.tm_nsec, 0);
tm.tm_nsec = d.nanosecond() as i32;
LocalResult::Single(tm_to_datetime(tm))
}
/// 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",
feature = "wasmbind",
not(any(target_os = "emscripten", target_os = "wasi"))
)))]
fn tm_to_datetime(mut tm: Tm) -> DateTime<Local> {
if tm.tm_sec >= 60 {
tm.tm_nsec += (tm.tm_sec - 59) * 1_000_000_000;
tm.tm_sec = 59;
}
let date = NaiveDate::from_yo(tm.tm_year + 1900, tm.tm_yday as u32 + 1);
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_opt(tm.tm_utcoff).unwrap();
DateTime::from_utc(date.and_time(time) - offset, offset)
}
/// A record specifying a time value in seconds and nanoseconds, where
/// nanoseconds represent the offset from the given second.
///
/// For example a timespec of 1.2 seconds after the beginning of the epoch would
/// be represented as {sec: 1, nsec: 200000000}.
struct Timespec {
sec: i64,
nsec: i32,
}
impl Timespec {
/// Constructs a timespec representing the current time in UTC.
fn now() -> Timespec {
let st =
SystemTime::now().duration_since(UNIX_EPOCH).expect("system time before Unix epoch");
Timespec { sec: st.as_secs() as i64, nsec: st.subsec_nanos() as i32 }
}
/// Converts this timespec into the system's local time.
fn local(self) -> Tm {
let mut tm = Tm {
tm_sec: 0,
tm_min: 0,
tm_hour: 0,
tm_mday: 0,
tm_mon: 0,
tm_year: 0,
tm_wday: 0,
tm_yday: 0,
tm_isdst: 0,
tm_utcoff: 0,
tm_nsec: 0,
};
time_to_local_tm(self.sec, &mut tm);
tm.tm_nsec = self.nsec;
tm
}
}
/// Holds a calendar date and time broken down into its components (year, month,
/// day, and so on), also called a broken-down time value.
// FIXME: use c_int instead of i32?
#[repr(C)]
pub(super) struct Tm {
/// Seconds after the minute - [0, 60]
tm_sec: i32,
/// Minutes after the hour - [0, 59]
tm_min: i32,
/// Hours after midnight - [0, 23]
tm_hour: i32,
/// Day of the month - [1, 31]
tm_mday: i32,
/// Months since January - [0, 11]
tm_mon: i32,
/// Years since 1900
tm_year: i32,
/// Days since Sunday - [0, 6]. 0 = Sunday, 1 = Monday, ..., 6 = Saturday.
tm_wday: i32,
/// Days since January 1 - [0, 365]
tm_yday: i32,
/// Daylight Saving Time flag.
///
/// This value is positive if Daylight Saving Time is in effect, zero if
/// Daylight Saving Time is not in effect, and negative if this information
/// is not available.
tm_isdst: i32,
/// Identifies the time zone that was used to compute this broken-down time
/// value, including any adjustment for Daylight Saving Time. This is the
/// number of seconds east of UTC. For example, for U.S. Pacific Daylight
/// Time, the value is `-7*60*60 = -25200`.
tm_utcoff: i32,
/// Nanoseconds after the second - [0, 10<sup>9</sup> - 1]
tm_nsec: i32,
}
fn time_to_tm(ts: i64, tm: &mut Tm) {
let leapyear = |year| -> bool { year % 4 == 0 && (year % 100 != 0 || year % 400 == 0) };
static YTAB: [[i64; 12]; 2] = [
[31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31],
[31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31],
];
let mut year = 1970;
let dayclock = ts % 86400;
let mut dayno = ts / 86400;
tm.tm_sec = (dayclock % 60) as i32;
tm.tm_min = ((dayclock % 3600) / 60) as i32;
tm.tm_hour = (dayclock / 3600) as i32;
tm.tm_wday = ((dayno + 4) % 7) as i32;
loop {
let yearsize = if leapyear(year) { 366 } else { 365 };
if dayno >= yearsize {
dayno -= yearsize;
year += 1;
} else {
break;
}
}
tm.tm_year = (year - 1900) as i32;
tm.tm_yday = dayno as i32;
let mut mon = 0;
while dayno >= YTAB[if leapyear(year) { 1 } else { 0 }][mon] {
dayno -= YTAB[if leapyear(year) { 1 } else { 0 }][mon];
mon += 1;
}
tm.tm_mon = mon as i32;
tm.tm_mday = dayno as i32 + 1;
tm.tm_isdst = 0;
}
fn tm_to_time(tm: &Tm) -> i64 {
let mut y = tm.tm_year as i64 + 1900;
let mut m = tm.tm_mon as i64 + 1;
if m <= 2 {
y -= 1;
m += 12;
}
let d = tm.tm_mday as i64;
let h = tm.tm_hour as i64;
let mi = tm.tm_min as i64;
let s = tm.tm_sec as i64;
(365 * y + y / 4 - y / 100 + y / 400 + 3 * (m + 1) / 5 + 30 * m + d - 719561) * 86400
+ 3600 * h
+ 60 * mi
+ s
}
pub(super) fn time_to_local_tm(sec: i64, tm: &mut Tm) {
// FIXME: Add timezone logic
time_to_tm(sec, tm);
}
pub(super) fn utc_tm_to_time(tm: &Tm) -> i64 {
tm_to_time(tm)
}
pub(super) fn local_tm_to_time(tm: &Tm) -> i64 {
// FIXME: Add timezone logic
tm_to_time(tm)
}