pyo3/pycell.rs
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//! PyO3's interior mutability primitive.
//!
//! Rust has strict aliasing rules - you can either have any number of immutable (shared) references or one mutable
//! reference. Python's ownership model is the complete opposite of that - any Python object
//! can be referenced any number of times, and mutation is allowed from any reference.
//!
//! PyO3 deals with these differences by employing the [Interior Mutability]
//! pattern. This requires that PyO3 enforces the borrowing rules and it has two mechanisms for
//! doing so:
//! - Statically it can enforce threadsafe access with the [`Python<'py>`](crate::Python) token.
//! All Rust code holding that token, or anything derived from it, can assume that they have
//! safe access to the Python interpreter's state. For this reason all the native Python objects
//! can be mutated through shared references.
//! - However, methods and functions in Rust usually *do* need `&mut` references. While PyO3 can
//! use the [`Python<'py>`](crate::Python) token to guarantee thread-safe access to them, it cannot
//! statically guarantee uniqueness of `&mut` references. As such those references have to be tracked
//! dynamically at runtime, using `PyCell` and the other types defined in this module. This works
//! similar to std's [`RefCell`](std::cell::RefCell) type.
//!
//! # When *not* to use PyCell
//!
//! Usually you can use `&mut` references as method and function receivers and arguments, and you
//! won't need to use `PyCell` directly:
//!
//! ```rust
//! use pyo3::prelude::*;
//!
//! #[pyclass]
//! struct Number {
//! inner: u32,
//! }
//!
//! #[pymethods]
//! impl Number {
//! fn increment(&mut self) {
//! self.inner += 1;
//! }
//! }
//! ```
//!
//! The [`#[pymethods]`](crate::pymethods) proc macro will generate this wrapper function (and more),
//! using `PyCell` under the hood:
//!
//! ```rust,ignore
//! # use pyo3::prelude::*;
//! # #[pyclass]
//! # struct Number {
//! # inner: u32,
//! # }
//! #
//! # #[pymethods]
//! # impl Number {
//! # fn increment(&mut self) {
//! # self.inner += 1;
//! # }
//! # }
//! #
//! // The function which is exported to Python looks roughly like the following
//! unsafe extern "C" fn __pymethod_increment__(
//! _slf: *mut pyo3::ffi::PyObject,
//! _args: *mut pyo3::ffi::PyObject,
//! ) -> *mut pyo3::ffi::PyObject {
//! use :: pyo3 as _pyo3;
//! _pyo3::impl_::trampoline::noargs(_slf, _args, |py, _slf| {
//! # #[allow(deprecated)]
//! let _cell = py
//! .from_borrowed_ptr::<_pyo3::PyAny>(_slf)
//! .downcast::<_pyo3::PyCell<Number>>()?;
//! let mut _ref = _cell.try_borrow_mut()?;
//! let _slf: &mut Number = &mut *_ref;
//! _pyo3::impl_::callback::convert(py, Number::increment(_slf))
//! })
//! }
//! ```
//!
//! # When to use PyCell
//! ## Using pyclasses from Rust
//!
//! However, we *do* need `PyCell` if we want to call its methods from Rust:
//! ```rust
//! # use pyo3::prelude::*;
//! #
//! # #[pyclass]
//! # struct Number {
//! # inner: u32,
//! # }
//! #
//! # #[pymethods]
//! # impl Number {
//! # fn increment(&mut self) {
//! # self.inner += 1;
//! # }
//! # }
//! # fn main() -> PyResult<()> {
//! Python::with_gil(|py| {
//! let n = Py::new(py, Number { inner: 0 })?;
//!
//! // We borrow the guard and then dereference
//! // it to get a mutable reference to Number
//! let mut guard: PyRefMut<'_, Number> = n.bind(py).borrow_mut();
//! let n_mutable: &mut Number = &mut *guard;
//!
//! n_mutable.increment();
//!
//! // To avoid panics we must dispose of the
//! // `PyRefMut` before borrowing again.
//! drop(guard);
//!
//! let n_immutable: &Number = &n.bind(py).borrow();
//! assert_eq!(n_immutable.inner, 1);
//!
//! Ok(())
//! })
//! # }
//! ```
//! ## Dealing with possibly overlapping mutable references
//!
//! It is also necessary to use `PyCell` if you can receive mutable arguments that may overlap.
//! Suppose the following function that swaps the values of two `Number`s:
//! ```
//! # use pyo3::prelude::*;
//! # #[pyclass]
//! # pub struct Number {
//! # inner: u32,
//! # }
//! #[pyfunction]
//! fn swap_numbers(a: &mut Number, b: &mut Number) {
//! std::mem::swap(&mut a.inner, &mut b.inner);
//! }
//! # fn main() {
//! # Python::with_gil(|py| {
//! # let n = Py::new(py, Number{inner: 35}).unwrap();
//! # let n2 = n.clone_ref(py);
//! # assert!(n.is(&n2));
//! # let fun = pyo3::wrap_pyfunction!(swap_numbers, py).unwrap();
//! # fun.call1((n, n2)).expect_err("Managed to create overlapping mutable references. Note: this is undefined behaviour.");
//! # });
//! # }
//! ```
//! When users pass in the same `Number` as both arguments, one of the mutable borrows will
//! fail and raise a `RuntimeError`:
//! ```text
//! >>> a = Number()
//! >>> swap_numbers(a, a)
//! Traceback (most recent call last):
//! File "<stdin>", line 1, in <module>
//! RuntimeError: Already borrowed
//! ```
//!
//! It is better to write that function like this:
//! ```rust,ignore
//! # #![allow(deprecated)]
//! # use pyo3::prelude::*;
//! # #[pyclass]
//! # pub struct Number {
//! # inner: u32,
//! # }
//! #[pyfunction]
//! fn swap_numbers(a: &PyCell<Number>, b: &PyCell<Number>) {
//! // Check that the pointers are unequal
//! if !a.is(b) {
//! std::mem::swap(&mut a.borrow_mut().inner, &mut b.borrow_mut().inner);
//! } else {
//! // Do nothing - they are the same object, so don't need swapping.
//! }
//! }
//! # fn main() {
//! # // With duplicate numbers
//! # Python::with_gil(|py| {
//! # let n = Py::new(py, Number{inner: 35}).unwrap();
//! # let n2 = n.clone_ref(py);
//! # assert!(n.is(&n2));
//! # let fun = pyo3::wrap_pyfunction!(swap_numbers, py).unwrap();
//! # fun.call1((n, n2)).unwrap();
//! # });
//! #
//! # // With two different numbers
//! # Python::with_gil(|py| {
//! # let n = Py::new(py, Number{inner: 35}).unwrap();
//! # let n2 = Py::new(py, Number{inner: 42}).unwrap();
//! # assert!(!n.is(&n2));
//! # let fun = pyo3::wrap_pyfunction!(swap_numbers, py).unwrap();
//! # fun.call1((&n, &n2)).unwrap();
//! # let n: u32 = n.borrow(py).inner;
//! # let n2: u32 = n2.borrow(py).inner;
//! # assert_eq!(n, 42);
//! # assert_eq!(n2, 35);
//! # });
//! # }
//! ```
//! See the [guide] for more information.
//!
//! [guide]: https://pyo3.rs/latest/class.html#pycell-and-interior-mutability "PyCell and interior mutability"
//! [Interior Mutability]: https://doc.rust-lang.org/book/ch15-05-interior-mutability.html "RefCell<T> and the Interior Mutability Pattern - The Rust Programming Language"
use crate::conversion::{AsPyPointer, IntoPyObject};
use crate::exceptions::PyRuntimeError;
use crate::ffi_ptr_ext::FfiPtrExt;
use crate::internal_tricks::{ptr_from_mut, ptr_from_ref};
use crate::pyclass::{boolean_struct::False, PyClass};
use crate::types::any::PyAnyMethods;
use crate::{ffi, Borrowed, Bound, IntoPy, PyErr, PyObject, Python};
use std::convert::Infallible;
use std::fmt;
use std::mem::ManuallyDrop;
use std::ops::{Deref, DerefMut};
pub(crate) mod impl_;
use impl_::{PyClassBorrowChecker, PyClassObjectLayout};
/// A wrapper type for an immutably borrowed value from a [`Bound<'py, T>`].
///
/// See the [`Bound`] documentation for more information.
///
/// # Examples
///
/// You can use [`PyRef`] as an alternative to a `&self` receiver when
/// - you need to access the pointer of the [`Bound`], or
/// - you want to get a super class.
/// ```
/// # use pyo3::prelude::*;
/// #[pyclass(subclass)]
/// struct Parent {
/// basename: &'static str,
/// }
///
/// #[pyclass(extends=Parent)]
/// struct Child {
/// name: &'static str,
/// }
///
/// #[pymethods]
/// impl Child {
/// #[new]
/// fn new() -> (Self, Parent) {
/// (Child { name: "Caterpillar" }, Parent { basename: "Butterfly" })
/// }
///
/// fn format(slf: PyRef<'_, Self>) -> String {
/// // We can get *mut ffi::PyObject from PyRef
/// let refcnt = unsafe { pyo3::ffi::Py_REFCNT(slf.as_ptr()) };
/// // We can get &Self::BaseType by as_ref
/// let basename = slf.as_ref().basename;
/// format!("{}(base: {}, cnt: {})", slf.name, basename, refcnt)
/// }
/// }
/// # Python::with_gil(|py| {
/// # let sub = Py::new(py, Child::new()).unwrap();
/// # pyo3::py_run!(py, sub, "assert sub.format() == 'Caterpillar(base: Butterfly, cnt: 4)', sub.format()");
/// # });
/// ```
///
/// See the [module-level documentation](self) for more information.
#[repr(transparent)]
pub struct PyRef<'p, T: PyClass> {
// TODO: once the GIL Ref API is removed, consider adding a lifetime parameter to `PyRef` to
// store `Borrowed` here instead, avoiding reference counting overhead.
inner: Bound<'p, T>,
}
impl<'p, T: PyClass> PyRef<'p, T> {
/// Returns a `Python` token that is bound to the lifetime of the `PyRef`.
pub fn py(&self) -> Python<'p> {
self.inner.py()
}
}
impl<T, U> AsRef<U> for PyRef<'_, T>
where
T: PyClass<BaseType = U>,
U: PyClass,
{
fn as_ref(&self) -> &T::BaseType {
self.as_super()
}
}
impl<'py, T: PyClass> PyRef<'py, T> {
/// Returns the raw FFI pointer represented by self.
///
/// # Safety
///
/// Callers are responsible for ensuring that the pointer does not outlive self.
///
/// The reference is borrowed; callers should not decrease the reference count
/// when they are finished with the pointer.
#[inline]
pub fn as_ptr(&self) -> *mut ffi::PyObject {
self.inner.as_ptr()
}
/// Returns an owned raw FFI pointer represented by self.
///
/// # Safety
///
/// The reference is owned; when finished the caller should either transfer ownership
/// of the pointer or decrease the reference count (e.g. with [`pyo3::ffi::Py_DecRef`](crate::ffi::Py_DecRef)).
#[inline]
pub fn into_ptr(self) -> *mut ffi::PyObject {
self.inner.clone().into_ptr()
}
#[track_caller]
pub(crate) fn borrow(obj: &Bound<'py, T>) -> Self {
Self::try_borrow(obj).expect("Already mutably borrowed")
}
pub(crate) fn try_borrow(obj: &Bound<'py, T>) -> Result<Self, PyBorrowError> {
let cell = obj.get_class_object();
cell.ensure_threadsafe();
cell.borrow_checker()
.try_borrow()
.map(|_| Self { inner: obj.clone() })
}
}
impl<'p, T, U> PyRef<'p, T>
where
T: PyClass<BaseType = U>,
U: PyClass,
{
/// Gets a `PyRef<T::BaseType>`.
///
/// While `as_ref()` returns a reference of type `&T::BaseType`, this cannot be
/// used to get the base of `T::BaseType`.
///
/// But with the help of this method, you can get hold of instances of the
/// super-superclass when needed.
///
/// # Examples
/// ```
/// # use pyo3::prelude::*;
/// #[pyclass(subclass)]
/// struct Base1 {
/// name1: &'static str,
/// }
///
/// #[pyclass(extends=Base1, subclass)]
/// struct Base2 {
/// name2: &'static str,
/// }
///
/// #[pyclass(extends=Base2)]
/// struct Sub {
/// name3: &'static str,
/// }
///
/// #[pymethods]
/// impl Sub {
/// #[new]
/// fn new() -> PyClassInitializer<Self> {
/// PyClassInitializer::from(Base1 { name1: "base1" })
/// .add_subclass(Base2 { name2: "base2" })
/// .add_subclass(Self { name3: "sub" })
/// }
/// fn name(slf: PyRef<'_, Self>) -> String {
/// let subname = slf.name3;
/// let super_ = slf.into_super();
/// format!("{} {} {}", super_.as_ref().name1, super_.name2, subname)
/// }
/// }
/// # Python::with_gil(|py| {
/// # let sub = Py::new(py, Sub::new()).unwrap();
/// # pyo3::py_run!(py, sub, "assert sub.name() == 'base1 base2 sub'")
/// # });
/// ```
pub fn into_super(self) -> PyRef<'p, U> {
let py = self.py();
PyRef {
inner: unsafe {
ManuallyDrop::new(self)
.as_ptr()
.assume_owned_unchecked(py)
.downcast_into_unchecked()
},
}
}
/// Borrows a shared reference to `PyRef<T::BaseType>`.
///
/// With the help of this method, you can access attributes and call methods
/// on the superclass without consuming the `PyRef<T>`. This method can also
/// be chained to access the super-superclass (and so on).
///
/// # Examples
/// ```
/// # use pyo3::prelude::*;
/// #[pyclass(subclass)]
/// struct Base {
/// base_name: &'static str,
/// }
/// #[pymethods]
/// impl Base {
/// fn base_name_len(&self) -> usize {
/// self.base_name.len()
/// }
/// }
///
/// #[pyclass(extends=Base)]
/// struct Sub {
/// sub_name: &'static str,
/// }
///
/// #[pymethods]
/// impl Sub {
/// #[new]
/// fn new() -> (Self, Base) {
/// (Self { sub_name: "sub_name" }, Base { base_name: "base_name" })
/// }
/// fn sub_name_len(&self) -> usize {
/// self.sub_name.len()
/// }
/// fn format_name_lengths(slf: PyRef<'_, Self>) -> String {
/// format!("{} {}", slf.as_super().base_name_len(), slf.sub_name_len())
/// }
/// }
/// # Python::with_gil(|py| {
/// # let sub = Py::new(py, Sub::new()).unwrap();
/// # pyo3::py_run!(py, sub, "assert sub.format_name_lengths() == '9 8'")
/// # });
/// ```
pub fn as_super(&self) -> &PyRef<'p, U> {
let ptr = ptr_from_ref::<Bound<'p, T>>(&self.inner)
// `Bound<T>` has the same layout as `Bound<T::BaseType>`
.cast::<Bound<'p, T::BaseType>>()
// `Bound<T::BaseType>` has the same layout as `PyRef<T::BaseType>`
.cast::<PyRef<'p, T::BaseType>>();
unsafe { &*ptr }
}
}
impl<T: PyClass> Deref for PyRef<'_, T> {
type Target = T;
#[inline]
fn deref(&self) -> &T {
unsafe { &*self.inner.get_class_object().get_ptr() }
}
}
impl<T: PyClass> Drop for PyRef<'_, T> {
fn drop(&mut self) {
self.inner
.get_class_object()
.borrow_checker()
.release_borrow()
}
}
impl<T: PyClass> IntoPy<PyObject> for PyRef<'_, T> {
fn into_py(self, py: Python<'_>) -> PyObject {
unsafe { PyObject::from_borrowed_ptr(py, self.inner.as_ptr()) }
}
}
impl<T: PyClass> IntoPy<PyObject> for &'_ PyRef<'_, T> {
fn into_py(self, py: Python<'_>) -> PyObject {
unsafe { PyObject::from_borrowed_ptr(py, self.inner.as_ptr()) }
}
}
impl<'py, T: PyClass> IntoPyObject<'py> for PyRef<'py, T> {
type Target = T;
type Output = Bound<'py, T>;
type Error = Infallible;
fn into_pyobject(self, _py: Python<'py>) -> Result<Self::Output, Self::Error> {
Ok(self.inner.clone())
}
}
impl<'a, 'py, T: PyClass> IntoPyObject<'py> for &'a PyRef<'py, T> {
type Target = T;
type Output = Borrowed<'a, 'py, T>;
type Error = Infallible;
fn into_pyobject(self, _py: Python<'py>) -> Result<Self::Output, Self::Error> {
Ok(self.inner.as_borrowed())
}
}
unsafe impl<T: PyClass> AsPyPointer for PyRef<'_, T> {
fn as_ptr(&self) -> *mut ffi::PyObject {
self.inner.as_ptr()
}
}
impl<T: PyClass + fmt::Debug> fmt::Debug for PyRef<'_, T> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
fmt::Debug::fmt(&**self, f)
}
}
/// A wrapper type for a mutably borrowed value from a [`Bound<'py, T>`].
///
/// See the [module-level documentation](self) for more information.
#[repr(transparent)]
pub struct PyRefMut<'p, T: PyClass<Frozen = False>> {
// TODO: once the GIL Ref API is removed, consider adding a lifetime parameter to `PyRef` to
// store `Borrowed` here instead, avoiding reference counting overhead.
inner: Bound<'p, T>,
}
impl<'p, T: PyClass<Frozen = False>> PyRefMut<'p, T> {
/// Returns a `Python` token that is bound to the lifetime of the `PyRefMut`.
pub fn py(&self) -> Python<'p> {
self.inner.py()
}
}
impl<T, U> AsRef<U> for PyRefMut<'_, T>
where
T: PyClass<BaseType = U, Frozen = False>,
U: PyClass<Frozen = False>,
{
fn as_ref(&self) -> &T::BaseType {
PyRefMut::downgrade(self).as_super()
}
}
impl<T, U> AsMut<U> for PyRefMut<'_, T>
where
T: PyClass<BaseType = U, Frozen = False>,
U: PyClass<Frozen = False>,
{
fn as_mut(&mut self) -> &mut T::BaseType {
self.as_super()
}
}
impl<'py, T: PyClass<Frozen = False>> PyRefMut<'py, T> {
/// Returns the raw FFI pointer represented by self.
///
/// # Safety
///
/// Callers are responsible for ensuring that the pointer does not outlive self.
///
/// The reference is borrowed; callers should not decrease the reference count
/// when they are finished with the pointer.
#[inline]
pub fn as_ptr(&self) -> *mut ffi::PyObject {
self.inner.as_ptr()
}
/// Returns an owned raw FFI pointer represented by self.
///
/// # Safety
///
/// The reference is owned; when finished the caller should either transfer ownership
/// of the pointer or decrease the reference count (e.g. with [`pyo3::ffi::Py_DecRef`](crate::ffi::Py_DecRef)).
#[inline]
pub fn into_ptr(self) -> *mut ffi::PyObject {
self.inner.clone().into_ptr()
}
#[inline]
#[track_caller]
pub(crate) fn borrow(obj: &Bound<'py, T>) -> Self {
Self::try_borrow(obj).expect("Already borrowed")
}
pub(crate) fn try_borrow(obj: &Bound<'py, T>) -> Result<Self, PyBorrowMutError> {
let cell = obj.get_class_object();
cell.ensure_threadsafe();
cell.borrow_checker()
.try_borrow_mut()
.map(|_| Self { inner: obj.clone() })
}
pub(crate) fn downgrade(slf: &Self) -> &PyRef<'py, T> {
// `PyRefMut<T>` and `PyRef<T>` have the same layout
unsafe { &*ptr_from_ref(slf).cast() }
}
}
impl<'p, T, U> PyRefMut<'p, T>
where
T: PyClass<BaseType = U, Frozen = False>,
U: PyClass<Frozen = False>,
{
/// Gets a `PyRef<T::BaseType>`.
///
/// See [`PyRef::into_super`] for more.
pub fn into_super(self) -> PyRefMut<'p, U> {
let py = self.py();
PyRefMut {
inner: unsafe {
ManuallyDrop::new(self)
.as_ptr()
.assume_owned_unchecked(py)
.downcast_into_unchecked()
},
}
}
/// Borrows a mutable reference to `PyRefMut<T::BaseType>`.
///
/// With the help of this method, you can mutate attributes and call mutating
/// methods on the superclass without consuming the `PyRefMut<T>`. This method
/// can also be chained to access the super-superclass (and so on).
///
/// See [`PyRef::as_super`] for more.
pub fn as_super(&mut self) -> &mut PyRefMut<'p, U> {
let ptr = ptr_from_mut::<Bound<'p, T>>(&mut self.inner)
// `Bound<T>` has the same layout as `Bound<T::BaseType>`
.cast::<Bound<'p, T::BaseType>>()
// `Bound<T::BaseType>` has the same layout as `PyRefMut<T::BaseType>`,
// and the mutable borrow on `self` prevents aliasing
.cast::<PyRefMut<'p, T::BaseType>>();
unsafe { &mut *ptr }
}
}
impl<T: PyClass<Frozen = False>> Deref for PyRefMut<'_, T> {
type Target = T;
#[inline]
fn deref(&self) -> &T {
unsafe { &*self.inner.get_class_object().get_ptr() }
}
}
impl<T: PyClass<Frozen = False>> DerefMut for PyRefMut<'_, T> {
#[inline]
fn deref_mut(&mut self) -> &mut T {
unsafe { &mut *self.inner.get_class_object().get_ptr() }
}
}
impl<T: PyClass<Frozen = False>> Drop for PyRefMut<'_, T> {
fn drop(&mut self) {
self.inner
.get_class_object()
.borrow_checker()
.release_borrow_mut()
}
}
impl<T: PyClass<Frozen = False>> IntoPy<PyObject> for PyRefMut<'_, T> {
fn into_py(self, py: Python<'_>) -> PyObject {
unsafe { PyObject::from_borrowed_ptr(py, self.inner.as_ptr()) }
}
}
impl<T: PyClass<Frozen = False>> IntoPy<PyObject> for &'_ PyRefMut<'_, T> {
fn into_py(self, py: Python<'_>) -> PyObject {
self.inner.clone().into_py(py)
}
}
impl<'py, T: PyClass<Frozen = False>> IntoPyObject<'py> for PyRefMut<'py, T> {
type Target = T;
type Output = Bound<'py, T>;
type Error = Infallible;
fn into_pyobject(self, _py: Python<'py>) -> Result<Self::Output, Self::Error> {
Ok(self.inner.clone())
}
}
impl<'a, 'py, T: PyClass<Frozen = False>> IntoPyObject<'py> for &'a PyRefMut<'py, T> {
type Target = T;
type Output = Borrowed<'a, 'py, T>;
type Error = Infallible;
fn into_pyobject(self, _py: Python<'py>) -> Result<Self::Output, Self::Error> {
Ok(self.inner.as_borrowed())
}
}
impl<T: PyClass<Frozen = False> + fmt::Debug> fmt::Debug for PyRefMut<'_, T> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
fmt::Debug::fmt(self.deref(), f)
}
}
/// An error type returned by [`Bound::try_borrow`].
///
/// If this error is allowed to bubble up into Python code it will raise a `RuntimeError`.
pub struct PyBorrowError {
_private: (),
}
impl fmt::Debug for PyBorrowError {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.debug_struct("PyBorrowError").finish()
}
}
impl fmt::Display for PyBorrowError {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
fmt::Display::fmt("Already mutably borrowed", f)
}
}
impl From<PyBorrowError> for PyErr {
fn from(other: PyBorrowError) -> Self {
PyRuntimeError::new_err(other.to_string())
}
}
/// An error type returned by [`Bound::try_borrow_mut`].
///
/// If this error is allowed to bubble up into Python code it will raise a `RuntimeError`.
pub struct PyBorrowMutError {
_private: (),
}
impl fmt::Debug for PyBorrowMutError {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.debug_struct("PyBorrowMutError").finish()
}
}
impl fmt::Display for PyBorrowMutError {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
fmt::Display::fmt("Already borrowed", f)
}
}
impl From<PyBorrowMutError> for PyErr {
fn from(other: PyBorrowMutError) -> Self {
PyRuntimeError::new_err(other.to_string())
}
}
#[cfg(test)]
#[cfg(feature = "macros")]
mod tests {
use super::*;
#[crate::pyclass]
#[pyo3(crate = "crate")]
#[derive(Copy, Clone, PartialEq, Eq, Debug)]
struct SomeClass(i32);
#[test]
fn test_as_ptr() {
Python::with_gil(|py| {
let cell = Bound::new(py, SomeClass(0)).unwrap();
let ptr = cell.as_ptr();
assert_eq!(cell.borrow().as_ptr(), ptr);
assert_eq!(cell.borrow_mut().as_ptr(), ptr);
})
}
#[test]
fn test_into_ptr() {
Python::with_gil(|py| {
let cell = Bound::new(py, SomeClass(0)).unwrap();
let ptr = cell.as_ptr();
assert_eq!(cell.borrow().into_ptr(), ptr);
unsafe { ffi::Py_DECREF(ptr) };
assert_eq!(cell.borrow_mut().into_ptr(), ptr);
unsafe { ffi::Py_DECREF(ptr) };
})
}
#[crate::pyclass]
#[pyo3(crate = "crate", subclass)]
struct BaseClass {
val1: usize,
}
#[crate::pyclass]
#[pyo3(crate = "crate", extends=BaseClass, subclass)]
struct SubClass {
val2: usize,
}
#[crate::pyclass]
#[pyo3(crate = "crate", extends=SubClass)]
struct SubSubClass {
val3: usize,
}
#[crate::pymethods]
#[pyo3(crate = "crate")]
impl SubSubClass {
#[new]
fn new(py: Python<'_>) -> crate::Py<SubSubClass> {
let init = crate::PyClassInitializer::from(BaseClass { val1: 10 })
.add_subclass(SubClass { val2: 15 })
.add_subclass(SubSubClass { val3: 20 });
crate::Py::new(py, init).expect("allocation error")
}
fn get_values(self_: PyRef<'_, Self>) -> (usize, usize, usize) {
let val1 = self_.as_super().as_super().val1;
let val2 = self_.as_super().val2;
(val1, val2, self_.val3)
}
fn double_values(mut self_: PyRefMut<'_, Self>) {
self_.as_super().as_super().val1 *= 2;
self_.as_super().val2 *= 2;
self_.val3 *= 2;
}
}
#[test]
fn test_pyref_as_super() {
Python::with_gil(|py| {
let obj = SubSubClass::new(py).into_bound(py);
let pyref = obj.borrow();
assert_eq!(pyref.as_super().as_super().val1, 10);
assert_eq!(pyref.as_super().val2, 15);
assert_eq!(pyref.as_ref().val2, 15); // `as_ref` also works
assert_eq!(pyref.val3, 20);
assert_eq!(SubSubClass::get_values(pyref), (10, 15, 20));
});
}
#[test]
fn test_pyrefmut_as_super() {
Python::with_gil(|py| {
let obj = SubSubClass::new(py).into_bound(py);
assert_eq!(SubSubClass::get_values(obj.borrow()), (10, 15, 20));
{
let mut pyrefmut = obj.borrow_mut();
assert_eq!(pyrefmut.as_super().as_ref().val1, 10);
pyrefmut.as_super().as_super().val1 -= 5;
pyrefmut.as_super().val2 -= 3;
pyrefmut.as_mut().val2 -= 2; // `as_mut` also works
pyrefmut.val3 -= 5;
}
assert_eq!(SubSubClass::get_values(obj.borrow()), (5, 10, 15));
SubSubClass::double_values(obj.borrow_mut());
assert_eq!(SubSubClass::get_values(obj.borrow()), (10, 20, 30));
});
}
#[test]
fn test_pyrefs_in_python() {
Python::with_gil(|py| {
let obj = SubSubClass::new(py);
crate::py_run!(py, obj, "assert obj.get_values() == (10, 15, 20)");
crate::py_run!(py, obj, "assert obj.double_values() is None");
crate::py_run!(py, obj, "assert obj.get_values() == (20, 30, 40)");
});
}
}