Add chrono support

Moved from chronotope/chrono#542

Cargo.toml

@@ -32,6 +32,7 @@ inventory = { version = "0.3.0", optional = true }
 
 # crate integrations that can be added using the eponymous features
 anyhow = { version = "1.0", optional = true }
+chrono = { version = "0.4", path = "../chrono", optional = true }
 eyre = { version = ">= 0.4, < 0.7", optional = true }
 hashbrown = { version = ">= 0.9, < 0.13", optional = true }
 indexmap = { version = ">= 1.6, < 1.8", optional = true }
@@ -41,6 +42,7 @@ serde = { version = "1.0", optional = true }
 
 [dev-dependencies]
 assert_approx_eq = "1.1.0"
+chrono = { version = "0.4", path = "../chrono" }
 criterion = "0.3.5"
 trybuild = "1.0.49"
 rustversion = "1.0"
@@ -56,7 +58,7 @@ widestring = "0.5.1"
 pyo3-build-config = { path = "pyo3-build-config", version = "0.17.1", features = ["resolve-config"] }
 
 [features]
-default = ["macros"]
+default = ["macros", "chrono"]
 
 # Enables macros: #[pyclass], #[pymodule], #[pyfunction] etc.
 macros = ["pyo3-macros", "indoc", "unindent"]
@@ -95,6 +97,7 @@ nightly = []
 full = [
     "macros",
     # "multiple-pymethods", # TODO re-add this when MSRV is greater than 1.62
+    "chrono",
     "num-bigint",
     "num-complex",
     "hashbrown",
@@ -163,5 +166,5 @@ members = [
 
 [package.metadata.docs.rs]
 no-default-features = true
-features = ["macros", "num-bigint", "num-complex", "hashbrown", "serde", "multiple-pymethods", "indexmap", "eyre"]
+features = ["macros", "num-bigint", "num-complex", "hashbrown", "serde", "multiple-pymethods", "indexmap", "eyre", "chrono"]
 rustdoc-args = ["--cfg", "docsrs"]

src/conversions/chrono.rs

@@ -0,0 +1,266 @@
+#![cfg(feature = "chrono")]
+
+//! Conversions to and from [chrono](https://docs.rs/chrono/)’s `Duration`,
+//! `NaiveDate`, `NaiveTime`, `DateTime<Tz>`, `FixedOffset`, and `Utc`.
+//!
+//! # Setup
+//!
+//! To use this feature, add this to your **`Cargo.toml`**:
+//!
+//! ```toml
+//! [dependencies]
+//! # change * to the latest versions
+//! hashbrown = "*"
+// workaround for `extended_key_value_attributes`: https://github.com/rust-lang/rust/issues/82768#issuecomment-803935643
+#![cfg_attr(docsrs, cfg_attr(docsrs, doc = concat!("pyo3 = { version = \"", env!("CARGO_PKG_VERSION"),  "\", features = [\"chrono\"] }")))]
+#![cfg_attr(
+    not(docsrs),
+    doc = "pyo3 = { version = \"*\", features = [\"chrono\"] }"
+)]
+//! ```
+//!
+//! Note that you must use compatible versions of chrono and PyO3.
+//! The required chrono version may vary based on the version of PyO3.
+use crate::exceptions::PyTypeError;
+use crate::types::{
+    timezone_utc, PyDate, PyDateAccess, PyDateTime, PyDelta, PyDeltaAccess, PyTime, PyTimeAccess,
+    PyTzInfo, PyTzInfoAccess,
+};
+use crate::{FromPyObject, IntoPy, PyAny, PyObject, PyResult, PyTryFrom, Python, ToPyObject};
+use chrono::offset::{FixedOffset, Utc};
+use chrono::{
+    div_mod_floor_64, DateTime, Datelike, Duration, NaiveDate, NaiveDateTime, NaiveTime, Offset,
+    TimeZone, Timelike, NANOS_PER_MICRO, SECS_PER_DAY,
+};
+use std::convert::TryInto;
+
+impl ToPyObject for Duration {
+    fn to_object(&self, py: Python<'_>) -> PyObject {
+        let micros = self.nanos / NANOS_PER_MICRO;
+        let (days, secs) = div_mod_floor_64(self.secs, SECS_PER_DAY);
+        // Python will check overflow so even if we reduce the size
+        // it will still overflow.
+        let days = days.try_into().unwrap_or(i32::MAX);
+        let secs = secs.try_into().unwrap_or(i32::MAX);
+
+        // We do not need to check i64 to i32 cast from rust because
+        // python will panic with OverflowError.
+        // Not sure if we need normalize here.
+        let delta = PyDelta::new(py, days, secs, micros, false).expect("Failed to construct delta");
+        delta.into()
+    }
+}
+
+impl IntoPy<PyObject> for Duration {
+    fn into_py(self, py: Python<'_>) -> PyObject {
+        ToPyObject::to_object(&self, py)
+    }
+}
+
+impl FromPyObject<'_> for Duration {
+    fn extract(ob: &PyAny) -> PyResult<Duration> {
+        let delta = <PyDelta as PyTryFrom>::try_from(ob)?;
+        // Python size are much lower than rust size so we do not need bound checks.
+        // 0 <= microseconds < 1000000
+        // 0 <= seconds < 3600*24
+        // -999999999 <= days <= 999999999
+        let secs = delta.get_days() as i64 * SECS_PER_DAY + delta.get_seconds() as i64;
+        let nanos = delta.get_microseconds() * NANOS_PER_MICRO;
+
+        Ok(Duration { secs, nanos })
+    }
+}
+
+impl ToPyObject for NaiveDate {
+    fn to_object(&self, py: Python<'_>) -> PyObject {
+        let mdf = self.mdf();
+        let date = PyDate::new(py, self.year(), mdf.month() as u8, mdf.day() as u8)
+            .expect("Failed to construct date");
+        date.into()
+    }
+}
+
+impl IntoPy<PyObject> for NaiveDate {
+    fn into_py(self, py: Python<'_>) -> PyObject {
+        ToPyObject::to_object(&self, py)
+    }
+}
+
+impl FromPyObject<'_> for NaiveDate {
+    fn extract(ob: &PyAny) -> PyResult<NaiveDate> {
+        let date = <PyDate as PyTryFrom>::try_from(ob)?;
+        Ok(NaiveDate::from_ymd(
+            date.get_year(),
+            date.get_month() as u32,
+            date.get_day() as u32,
+        ))
+    }
+}
+
+impl ToPyObject for NaiveTime {
+    fn to_object(&self, py: Python<'_>) -> PyObject {
+        let (h, m, s) = self.hms();
+        let ns = self.nanosecond();
+        let (ms, fold) = match ns.checked_sub(1_000_000_000) {
+            Some(ns) => (ns / 1000, true),
+            None => (ns / 1000, false),
+        };
+        let time = PyTime::new_with_fold(py, h as u8, m as u8, s as u8, ms, None, fold)
+            .expect("Failed to construct time");
+        time.into()
+    }
+}
+
+impl IntoPy<PyObject> for NaiveTime {
+    fn into_py(self, py: Python<'_>) -> PyObject {
+        ToPyObject::to_object(&self, py)
+    }
+}
+
+impl FromPyObject<'_> for NaiveTime {
+    fn extract(ob: &PyAny) -> PyResult<NaiveTime> {
+        let time = <PyTime as PyTryFrom>::try_from(ob)?;
+        let ms = time.get_fold() as u32 * 1_000_000 + time.get_microsecond();
+        let (h, m, s) = (time.get_hour(), time.get_minute(), time.get_second());
+        Ok(NaiveTime::from_hms_micro(h as u32, m as u32, s as u32, ms))
+    }
+}
+
+impl<Tz: TimeZone> ToPyObject for DateTime<Tz> {
+    fn to_object(&self, py: Python<'_>) -> PyObject {
+        let (date, time) = (self.naive_utc().date(), self.naive_utc().time());
+        let mdf = date.mdf();
+        let (yy, mm, dd) = (date.year(), mdf.month(), mdf.day());
+        let (h, m, s) = time.hms();
+        let ns = time.nanosecond();
+        let (ms, fold) = match ns.checked_sub(1_000_000_000) {
+            Some(ns) => (ns / 1000, true),
+            None => (ns / 1000, false),
+        };
+        let tz = self.offset().fix().to_object(py);
+        let tz = tz.cast_as(py).unwrap();
+        let datetime = PyDateTime::new_with_fold(
+            py,
+            yy,
+            mm as u8,
+            dd as u8,
+            h as u8,
+            m as u8,
+            s as u8,
+            ms,
+            Some(&tz),
+            fold,
+        )
+        .expect("Failed to construct datetime");
+        datetime.into()
+    }
+}
+
+impl<Tz: TimeZone> IntoPy<PyObject> for DateTime<Tz> {
+    fn into_py(self, py: Python<'_>) -> PyObject {
+        ToPyObject::to_object(&self, py)
+    }
+}
+
+impl FromPyObject<'_> for DateTime<FixedOffset> {
+    fn extract(ob: &PyAny) -> PyResult<DateTime<FixedOffset>> {
+        let dt = <PyDateTime as PyTryFrom>::try_from(ob)?;
+        let ms = dt.get_fold() as u32 * 1_000_000 + dt.get_microsecond();
+        let (h, m, s) = (dt.get_hour(), dt.get_minute(), dt.get_second());
+        let tz = if let Some(tzinfo) = dt.get_tzinfo() {
+            tzinfo.extract()?
+        } else {
+            return Err(PyTypeError::new_err("Not datetime.timezone.tzinfo"));
+        };
+        let dt = NaiveDateTime::new(
+            NaiveDate::from_ymd(dt.get_year(), dt.get_month() as u32, dt.get_day() as u32),
+            NaiveTime::from_hms_micro(h as u32, m as u32, s as u32, ms),
+        );
+        Ok(DateTime::from_utc(dt, tz))
+    }
+}
+
+impl FromPyObject<'_> for DateTime<Utc> {
+    fn extract(ob: &PyAny) -> PyResult<DateTime<Utc>> {
+        let dt = <PyDateTime as PyTryFrom>::try_from(ob)?;
+        let ms = dt.get_fold() as u32 * 1_000_000 + dt.get_microsecond();
+        let (h, m, s) = (dt.get_hour(), dt.get_minute(), dt.get_second());
+        let tz = if let Some(tzinfo) = dt.get_tzinfo() {
+            tzinfo.extract()?
+        } else {
+            return Err(PyTypeError::new_err("Not datetime.timezone.utc"));
+        };
+        let dt = NaiveDateTime::new(
+            NaiveDate::from_ymd(dt.get_year(), dt.get_month() as u32, dt.get_day() as u32),
+            NaiveTime::from_hms_micro(h as u32, m as u32, s as u32, ms),
+        );
+        Ok(DateTime::from_utc(dt, tz))
+    }
+}
+
+impl ToPyObject for FixedOffset {
+    fn to_object(&self, py: Python<'_>) -> PyObject {
+        let dt_module = py.import("datetime").expect("Failed to import datetime");
+        let dt_timezone = dt_module
+            .getattr("timezone")
+            .expect("Failed to getattr timezone");
+        let seconds_offset = self.local_minus_utc();
+        let td =
+            PyDelta::new(py, 0, seconds_offset, 0, true).expect("Failed to contruct timedelta");
+        let offset = dt_timezone
+            .call1((td,))
+            .expect("Failed to call timezone with timedelta");
+        offset.into()
+    }
+}
+
+impl IntoPy<PyObject> for FixedOffset {
+    fn into_py(self, py: Python<'_>) -> PyObject {
+        ToPyObject::to_object(&self, py)
+    }
+}
+
+impl FromPyObject<'_> for FixedOffset {
+    /// Convert python tzinfo to rust [`FixedOffset`].
+    ///
+    /// Note that the conversion will result in precision lost in microseconds as chrono offset
+    /// does not supports microseconds.
+    fn extract(ob: &PyAny) -> PyResult<FixedOffset> {
+        let py_tzinfo = <PyTzInfo as PyTryFrom>::try_from(ob)?;
+        let py_timedelta = py_tzinfo.call_method1("utcoffset", (ob.py().None(),))?;
+        let py_timedelta = <PyDelta as PyTryFrom>::try_from(py_timedelta)?;
+        Ok(FixedOffset::east(py_timedelta.get_seconds()))
+    }
+}
+
+impl ToPyObject for Utc {
+    fn to_object(&self, py: Python<'_>) -> PyObject {
+        timezone_utc(py).to_object(py)
+    }
+}
+
+impl IntoPy<PyObject> for Utc {
+    fn into_py(self, py: Python<'_>) -> PyObject {
+        ToPyObject::to_object(&self, py)
+    }
+}
+
+impl FromPyObject<'_> for Utc {
+    fn extract(ob: &PyAny) -> PyResult<Utc> {
+        let py_tzinfo = <PyTzInfo as PyTryFrom>::try_from(ob)?;
+        let py_utc = timezone_utc(ob.py());
+        if py_tzinfo.eq(py_utc)? {
+            Ok(Utc)
+        } else {
+            Err(PyTypeError::new_err("Not datetime.timezone.utc"))
+        }
+    }
+}
+
+#[cfg(test)]
+mod test_chrono {
+    use crate::types::*;
+    use crate::{IntoPy, PyObject, PyTryFrom, Python, ToPyObject};
+
+    // TODO
+}

src/conversions/mod.rs

@@ -2,6 +2,7 @@
 
 pub mod anyhow;
 mod array;
+mod chrono;
 pub mod eyre;
 pub mod hashbrown;
 pub mod indexmap;

src/types/datetime.rs

@@ -473,7 +473,7 @@ impl PyTzInfoAccess for PyTime {
 /// For concrete time zone implementations, see [`timezone_utc`] and
 /// the [`zoneinfo` module](https://docs.python.org/3/library/zoneinfo.html).
 #[repr(transparent)]
-pub struct PyTzInfo(PyAny);
+pub struct PyTzInfo(pub(crate) PyAny);
 pyobject_native_type!(
     PyTzInfo,
     crate::ffi::PyObject,
@@ -487,6 +487,39 @@ pub fn timezone_utc(py: Python<'_>) -> &PyTzInfo {
     unsafe { &*(ensure_datetime_api(py).TimeZone_UTC as *const PyTzInfo) }
 }
 
+/// Equivalent to `datetime.timezone`
+// Not making this public yet as the implementation is slightly different from
+// original cpython.
+// #[crate::pyclass]
+// pub(crate) struct PyTimeZone {
+//     offset: PyDelta,
+//     // name
+// }
+//
+// #[crate::pymethods]
+// impl PyTimeZone {
+//     #[new]
+//     fn new(offset: PyDelta) -> Self {
+//         PyTimeZone { offset }
+//     }
+//
+//     fn utcoffset(&self, dt: &PyDateTime) -> PyDelta {
+//         self.offset
+//     }
+//
+//     fn tzname(&self, dt: &PyDateTime) -> PyString {
+//         todo!("_name_from_offset")
+//     }
+//
+//     fn dst(&self, py: Python<'_>, dt: &PyDateTime) {
+//         py.None()
+//     }
+//
+//     fn fromutc(&self, dt: &PyDateTime) -> PyDelta {
+//         dt.get_tzinfo() + self.offset
+//     }
+// }
+
 /// Bindings for `datetime.timedelta`
 #[repr(transparent)]
 pub struct PyDelta(PyAny);