Merge branch 'odin' of git.hitchhiker-linux.org:jeang3nie/epoch-rs into odin

Cargo.lock

@@ -11,36 +11,36 @@ dependencies = [
 
 [[package]]
 name = "proc-macro2"
-version = "1.0.78"
+version = "1.0.92"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e2422ad645d89c99f8f3e6b88a9fdeca7fabeac836b1002371c4367c8f984aae"
+checksum = "37d3544b3f2748c54e147655edb5025752e2303145b5aefb3c3ea2c78b973bb0"
 dependencies = [
  "unicode-ident",
 ]
 
 [[package]]
 name = "quote"
-version = "1.0.35"
+version = "1.0.37"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "291ec9ab5efd934aaf503a6466c5d5251535d108ee747472c3977cc5acc868ef"
+checksum = "b5b9d34b8991d19d98081b46eacdd8eb58c6f2b201139f7c5f643cc155a633af"
 dependencies = [
  "proc-macro2",
 ]
 
 [[package]]
 name = "serde"
-version = "1.0.196"
+version = "1.0.216"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "870026e60fa08c69f064aa766c10f10b1d62db9ccd4d0abb206472bee0ce3b32"
+checksum = "0b9781016e935a97e8beecf0c933758c97a5520d32930e460142b4cd80c6338e"
 dependencies = [
  "serde_derive",
 ]
 
 [[package]]
 name = "serde_derive"
-version = "1.0.196"
+version = "1.0.216"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "33c85360c95e7d137454dc81d9a4ed2b8efd8fbe19cee57357b32b9771fccb67"
+checksum = "46f859dbbf73865c6627ed570e78961cd3ac92407a2d117204c49232485da55e"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -49,9 +49,9 @@ dependencies = [
 
 [[package]]
 name = "syn"
-version = "2.0.48"
+version = "2.0.90"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0f3531638e407dfc0814761abb7c00a5b54992b849452a0646b7f65c9f770f3f"
+checksum = "919d3b74a5dd0ccd15aeb8f93e7006bd9e14c295087c9896a110f490752bcf31"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -60,6 +60,6 @@ dependencies = [
 
 [[package]]
 name = "unicode-ident"
-version = "1.0.12"
+version = "1.0.14"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3354b9ac3fae1ff6755cb6db53683adb661634f67557942dea4facebec0fee4b"
+checksum = "adb9e6ca4f869e1180728b7950e35922a7fc6397f7b641499e8f3ef06e50dc83"

Cargo.toml

@@ -4,6 +4,8 @@ version = "0.1.0"
 edition = "2021"
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+[features]
+serde = ["dep:serde"]
 
 [dependencies]
-serde = { version = "1.0", features = ["derive"] }
+serde = { version = "1.0", features = ["derive"], optional = true }

README.md

@@ -0,0 +1,19 @@
+Contents
+========
+- [Summary](#summary)
+- [Usage](#usage)
+
+## Summary
+Epoch is a small library for converting Unix timestamps to human readable datetime
+and vice versa. It includes functionality for displaying a DateTime as a human
+readable string, parsing from string, and comparison for equality or ordering.
+
+This crate is ideal when you want a lighter and simpler date/time library than the
+excellent and very complete [chrono](https://crates.io/crates/chrono), which is
+likely overkill for many use cases.
+
+## Usage
+Add epoch to your Cargo.toml
+```Toml
+epoch = { git = "http://git.hitchhiker-linux.org/jeang3nie/epoch-rs.git" }
+```

src/datetime.rs

@@ -1,13 +1,47 @@
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
+
 use {
     crate::{
         month::Month, weekday::Weekday, year::Year, zone::TimeZone, SECONDS_PER_DAY,
         SECONDS_PER_HOUR, SECONDS_PER_MINUTE,
     },
-    serde::{Deserialize, Serialize},
-    std::{cmp, fmt},
+    std::{
+        cmp, fmt,
+        num::TryFromIntError,
+        time::{SystemTime, SystemTimeError, UNIX_EPOCH},
+    },
 };
 
-#[derive(Clone, Debug, Deserialize, Eq, PartialEq, Serialize)]
+#[derive(Debug)]
+pub enum Error {
+    System(SystemTimeError),
+    RangeError,
+}
+
+impl fmt::Display for Error {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            Self::System(e) => write!(f, "{e}"),
+            Self::RangeError => write!(f, "self:?"),
+        }
+    }
+}
+
+impl From<SystemTimeError> for Error {
+    fn from(value: SystemTimeError) -> Self {
+        Self::System(value)
+    }
+}
+
+impl From<TryFromIntError> for Error {
+    fn from(_value: TryFromIntError) -> Self {
+        Self::RangeError
+    }
+}
+
+#[derive(Clone, Copy, Debug, Eq, PartialEq)]
+#[cfg_attr(feature = "serde", derive(Deserialize, Serialize))]
 pub struct DateTime {
     pub year: Year,
     pub month: Month,
@@ -59,39 +93,40 @@ impl DateTime {
         seconds
     }
 
+    #[allow(clippy::missing_panics_doc)]
     /// Converts a Unix timestamp to a `DateTime` struct
     pub fn from_timestamp(ts: i64) -> Self {
         if ts < 0 {
-            let mut seconds: i64 = 0;
-            let mut year = Year::new(-1);
-            while seconds > -year.seconds() {
-                seconds -= year.seconds();
+            let mut seconds: i64 = ts;
+            let mut year = Year::new(1969);
+            while seconds < -year.seconds() {
+                seconds += year.seconds();
                 year = year.previous();
             }
             let mut month = Some(Month::December);
             while month.is_some() {
                 let m = month.unwrap();
-                if seconds > m.seconds(year) {
+                if -seconds < m.seconds(year) {
                     break;
                 }
-                seconds -= m.seconds(year);
+                seconds += m.seconds(year);
                 month = m.previous();
             }
             let month = month.unwrap();
             let mut day = month.days(year);
             while day > 0 && seconds < -SECONDS_PER_DAY {
-                seconds -= SECONDS_PER_HOUR;
+                seconds += SECONDS_PER_DAY;
                 day -= 1;
             }
             let mut hour: i8 = 23;
-            while hour >= 0 && seconds < -SECONDS_PER_HOUR {
-                seconds -= SECONDS_PER_HOUR;
+            while hour > 0 && seconds < -SECONDS_PER_HOUR {
+                seconds += SECONDS_PER_HOUR;
                 hour -= 1;
             }
             let hour = hour.try_into().unwrap();
-            let mut minute: i8 = 60;
-            while minute >= 0 && seconds < -60 {
-                seconds -= 60;
+            let mut minute: i8 = 59;
+            while minute > 0 && seconds < -60 {
+                seconds += 60;
                 minute -= 1;
             }
             let minute = minute.try_into().unwrap();
@@ -145,13 +180,30 @@ impl DateTime {
         }
     }
 
+    #[allow(clippy::missing_panics_doc)]
+    /// Creates a `DateTime` from the system time
+    pub fn now() -> Result<Self, Error> {
+        let now = SystemTime::now().duration_since(UNIX_EPOCH)?;
+        Ok(Self::from_timestamp(i64::try_from(now.as_secs())?))
+    }
+
+    #[allow(clippy::missing_panics_doc)]
+    /// Gets the day of the week for this `DateTime`
     pub fn weekday(&self) -> Weekday {
         let ts = self.timestamp_naive();
-        let days = ts / SECONDS_PER_DAY;
-        let rem = days % 7;
+        let mut days = ts / SECONDS_PER_DAY;
+        // For negative timestamps this number is actually the following day
+        if ts < 0 {
+            days -= 1;
+        }
+        // Rusts `%` operator is modulo, not modulus. We have to use the
+        // operation which will gove the correct answer for either positive
+        // or negative remainders
+        let rem = days.rem_euclid(7);
         rem.try_into().unwrap()
     }
 
+    /// Returns a string representing this date and time in human readable format
     pub fn display(&self) -> String {
         format!(
             "{} {} {} {:0>2}:{:0>2}:{:0>2} {} {}",
@@ -227,6 +279,28 @@ mod tests {
             },
         };
         assert_eq!(dt.weekday(), Weekday::Saturday);
+        dt = DateTime {
+            year: Year::new(1965),
+            month: Month::February,
+            day: 9,
+            hour: 4,
+            minute: 4,
+            second: 37,
+            zone: TimeZone::Utc,
+        };
+        assert_eq!(dt.weekday(), Weekday::Tuesday);
+        dt.day -= 1;
+        assert_eq!(dt.weekday(), Weekday::Monday);
+        dt.day -= 1;
+        assert_eq!(dt.weekday(), Weekday::Sunday);
+        dt.day -= 1;
+        assert_eq!(dt.weekday(), Weekday::Saturday);
+        dt.day -= 1;
+        assert_eq!(dt.weekday(), Weekday::Friday);
+        dt.day -= 1;
+        assert_eq!(dt.weekday(), Weekday::Thursday);
+        dt.day -= 1;
+        assert_eq!(dt.weekday(), Weekday::Wednesday);
     }
 
     #[test]
@@ -268,6 +342,22 @@ mod tests {
         assert_eq!(dt, DateTime::from_timestamp(ts));
     }
 
+    #[test]
+    fn ts_negative() {
+        let ts: i64 = -154382123;
+        let dt = DateTime {
+            year: Year::new(1965),
+            month: Month::February,
+            day: 9,
+            hour: 4,
+            minute: 4,
+            second: 37,
+            zone: TimeZone::Utc,
+        };
+        assert_eq!(dt.timestamp(), ts);
+        assert_eq!(dt, DateTime::from_timestamp(ts));
+    }
+
     #[test]
     fn fmt() {
         let mut dt = DateTime::from_timestamp(1706571482);

src/lib.rs

@@ -8,6 +8,8 @@ pub(crate) mod year;
 pub(crate) mod zone;
 
 pub mod prelude;
+pub use datetime::DateTime;
+pub use datetime::Error as DateTimeError;
 
 pub static SECONDS_PER_MINUTE: i64 = 60;
 pub static SECONDS_PER_HOUR: i64 = 60 * 60;

src/month.rs

@@ -1,12 +1,13 @@
-use std::str::FromStr;
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
 
 use {
     crate::{year::Year, SECONDS_PER_DAY},
-    serde::{Deserialize, Serialize},
-    std::{cmp, error, fmt},
+    std::{cmp, error, fmt, str},
 };
 
-#[derive(Clone, Copy, Debug, Deserialize, Serialize, PartialEq, Eq)]
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+#[cfg_attr(feature = "serde", derive(Deserialize, Serialize))]
 #[repr(u8)]
 pub enum Month {
     Janurary = 1,
@@ -138,7 +139,7 @@ impl fmt::Display for Month {
     }
 }
 
-impl FromStr for Month {
+impl str::FromStr for Month {
     type Err = Error;
 
     fn from_str(s: &str) -> Result<Self, Self::Err> {

src/prelude.rs

@@ -1,5 +1,4 @@
 pub use crate::{
-    datetime::DateTime,
     month::{Error as MonthError, Month},
     weekday::Weekday,
     year::Year,

src/weekday.rs

@@ -1,8 +1,10 @@
-use std::fmt;
-
+#[cfg(feature = "serde")]
 use serde::{Deserialize, Serialize};
 
-#[derive(Clone, Copy, Debug, Deserialize, Eq, PartialEq, Serialize)]
+use std::fmt;
+
+#[derive(Clone, Copy, Debug, Eq, PartialEq)]
+#[cfg_attr(feature = "serde", derive(Deserialize, Serialize))]
 #[repr(u8)]
 pub enum Weekday {
     Thursday,

src/year.rs

@@ -1,10 +1,13 @@
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
+
 use {
     crate::SECONDS_PER_DAY,
-    serde::{Deserialize, Serialize},
     std::{cmp, fmt, num::ParseIntError, str::FromStr},
 };
 
-#[derive(Clone, Copy, Debug, Deserialize, Eq, PartialEq, Serialize)]
+#[derive(Clone, Copy, Debug, Eq, PartialEq)]
+#[cfg_attr(feature = "serde", derive(Deserialize, Serialize))]
 pub enum Year {
     Normal(i32),
     Leap(i32),

src/zone.rs

@@ -1,10 +1,13 @@
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
+
 use {
     crate::SECONDS_PER_HOUR,
-    serde::{Deserialize, Serialize},
     std::{error, fmt, str::FromStr},
 };
 
-#[derive(Clone, Copy, Debug, Deserialize, Eq, PartialEq, Serialize)]
+#[derive(Clone, Copy, Debug, Eq, PartialEq)]
+#[cfg_attr(feature = "serde", derive(Deserialize, Serialize))]
 pub enum Sign {
     Positive,
     Negative,
@@ -23,7 +26,8 @@ impl fmt::Display for Sign {
     }
 }
 
-#[derive(Clone, Copy, Debug, Deserialize, Eq, PartialEq, Serialize)]
+#[derive(Clone, Copy, Debug, Eq, PartialEq)]
+#[cfg_attr(feature = "serde", derive(Deserialize, Serialize))]
 pub enum TimeZone {
     Offset { sign: Sign, hours: u8, minutes: u8 },
     Utc,