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| 1 | +//! Date and time types. |
| 2 | +
|
| 3 | +use bitflags::bitflags; |
| 4 | +use core::fmt::{self, Display, Formatter}; |
| 5 | + |
| 6 | +/// Date and time representation. |
| 7 | +#[derive(Debug, Default, Copy, Clone, Eq)] |
| 8 | +#[repr(C)] |
| 9 | +pub struct Time { |
| 10 | + /// Year. Valid range: `1900..=9999`. |
| 11 | + pub year: u16, |
| 12 | + |
| 13 | + /// Month. Valid range: `1..=12`. |
| 14 | + pub month: u8, |
| 15 | + |
| 16 | + /// Day of the month. Valid range: `1..=31`. |
| 17 | + pub day: u8, |
| 18 | + |
| 19 | + /// Hour. Valid range: `0..=23`. |
| 20 | + pub hour: u8, |
| 21 | + |
| 22 | + /// Minute. Valid range: `0..=59`. |
| 23 | + pub minute: u8, |
| 24 | + |
| 25 | + /// Second. Valid range: `0..=59`. |
| 26 | + pub second: u8, |
| 27 | + |
| 28 | + /// Unused padding. |
| 29 | + pub pad1: u8, |
| 30 | + |
| 31 | + /// Nanosececond. Valid range: `0..=999_999_999`. |
| 32 | + pub nanosecond: u32, |
| 33 | + |
| 34 | + /// Offset in minutes from UTC. Valid range: `-1440..=1440`, or |
| 35 | + /// [`Time::UNSPECIFIED_TIMEZONE`]. |
| 36 | + pub time_zone: i16, |
| 37 | + |
| 38 | + /// Daylight savings time information. |
| 39 | + pub daylight: Daylight, |
| 40 | + |
| 41 | + /// Unused padding. |
| 42 | + pub pad2: u8, |
| 43 | +} |
| 44 | + |
| 45 | +impl Time { |
| 46 | + /// Indicates the time should be interpreted as local time. |
| 47 | + pub const UNSPECIFIED_TIMEZONE: i16 = 0x07ff; |
| 48 | + |
| 49 | + /// Create an invalid `Time` with all fields set to zero. |
| 50 | + #[must_use] |
| 51 | + pub const fn invalid() -> Self { |
| 52 | + Self { |
| 53 | + year: 0, |
| 54 | + month: 0, |
| 55 | + day: 0, |
| 56 | + hour: 0, |
| 57 | + minute: 0, |
| 58 | + second: 0, |
| 59 | + pad1: 0, |
| 60 | + nanosecond: 0, |
| 61 | + time_zone: 0, |
| 62 | + daylight: Daylight::empty(), |
| 63 | + pad2: 0, |
| 64 | + } |
| 65 | + } |
| 66 | + |
| 67 | + /// True if all fields are within valid ranges, false otherwise. |
| 68 | + #[must_use] |
| 69 | + pub fn is_valid(&self) -> bool { |
| 70 | + (1900..=9999).contains(&self.year) |
| 71 | + && (1..=12).contains(&self.month) |
| 72 | + && (1..=31).contains(&self.day) |
| 73 | + && self.hour <= 23 |
| 74 | + && self.minute <= 59 |
| 75 | + && self.second <= 59 |
| 76 | + && self.nanosecond <= 999_999_999 |
| 77 | + && ((-1440..=1440).contains(&self.time_zone) |
| 78 | + || self.time_zone == Self::UNSPECIFIED_TIMEZONE) |
| 79 | + } |
| 80 | +} |
| 81 | + |
| 82 | +impl Display for Time { |
| 83 | + fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result { |
| 84 | + write!(f, "{:04}-{:02}-{:02} ", self.year, self.month, self.day)?; |
| 85 | + write!( |
| 86 | + f, |
| 87 | + "{:02}:{:02}:{:02}.{:09}", |
| 88 | + self.hour, self.minute, self.second, self.nanosecond |
| 89 | + )?; |
| 90 | + |
| 91 | + if self.time_zone == Self::UNSPECIFIED_TIMEZONE { |
| 92 | + write!(f, " (local)")?; |
| 93 | + } else { |
| 94 | + let offset_in_hours = self.time_zone as f32 / 60.0; |
| 95 | + let integer_part = offset_in_hours as i16; |
| 96 | + // We can't use "offset_in_hours.fract()" because it is part of `std`. |
| 97 | + let fraction_part = offset_in_hours - (integer_part as f32); |
| 98 | + // most time zones |
| 99 | + if fraction_part == 0.0 { |
| 100 | + write!(f, "UTC+{offset_in_hours}")?; |
| 101 | + } |
| 102 | + // time zones with 30min offset (and perhaps other special time zones) |
| 103 | + else { |
| 104 | + write!(f, "UTC+{offset_in_hours:.1}")?; |
| 105 | + } |
| 106 | + } |
| 107 | + |
| 108 | + Ok(()) |
| 109 | + } |
| 110 | +} |
| 111 | + |
| 112 | +/// The padding fields of `Time` are ignored for comparison. |
| 113 | +impl PartialEq for Time { |
| 114 | + fn eq(&self, other: &Time) -> bool { |
| 115 | + self.year == other.year |
| 116 | + && self.month == other.month |
| 117 | + && self.day == other.day |
| 118 | + && self.hour == other.hour |
| 119 | + && self.minute == other.minute |
| 120 | + && self.second == other.second |
| 121 | + && self.nanosecond == other.nanosecond |
| 122 | + && self.time_zone == other.time_zone |
| 123 | + && self.daylight == other.daylight |
| 124 | + } |
| 125 | +} |
| 126 | + |
| 127 | +bitflags! { |
| 128 | + /// A bitmask containing daylight savings time information. |
| 129 | + #[repr(transparent)] |
| 130 | + #[derive(Clone, Copy, Debug, Default, PartialEq, Eq, PartialOrd, Ord)] |
| 131 | + pub struct Daylight: u8 { |
| 132 | + /// Time is affected by daylight savings time. |
| 133 | + const ADJUST_DAYLIGHT = 0x01; |
| 134 | + |
| 135 | + /// Time has been adjusted for daylight savings time. |
| 136 | + const IN_DAYLIGHT = 0x02; |
| 137 | + } |
| 138 | +} |
| 139 | + |
| 140 | +#[cfg(test)] |
| 141 | +mod tests { |
| 142 | + extern crate alloc; |
| 143 | + |
| 144 | + use super::*; |
| 145 | + use alloc::string::ToString; |
| 146 | + |
| 147 | + #[test] |
| 148 | + fn test_time_display() { |
| 149 | + let mut time = Time { |
| 150 | + year: 2023, |
| 151 | + month: 5, |
| 152 | + day: 18, |
| 153 | + hour: 11, |
| 154 | + minute: 29, |
| 155 | + second: 57, |
| 156 | + nanosecond: 123_456_789, |
| 157 | + time_zone: Time::UNSPECIFIED_TIMEZONE, |
| 158 | + daylight: Daylight::empty(), |
| 159 | + pad1: 0, |
| 160 | + pad2: 0, |
| 161 | + }; |
| 162 | + assert_eq!(time.to_string(), "2023-05-18 11:29:57.123456789 (local)"); |
| 163 | + |
| 164 | + time.time_zone = 120; |
| 165 | + assert_eq!(time.to_string(), "2023-05-18 11:29:57.123456789UTC+2"); |
| 166 | + |
| 167 | + time.time_zone = 150; |
| 168 | + assert_eq!(time.to_string(), "2023-05-18 11:29:57.123456789UTC+2.5"); |
| 169 | + } |
| 170 | +} |
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