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use crate::err::{PyErr, PyResult};
use crate::gil;
use crate::object::PyObject;
use crate::objectprotocol::ObjectProtocol;
use crate::pyclass::{PyClass, PyClassShell};
use crate::pyclass_init::PyClassInitializer;
use crate::type_object::{PyObjectLayout, PyTypeInfo};
use crate::types::PyAny;
use crate::{ffi, IntoPy};
use crate::{AsPyPointer, FromPyObject, IntoPyPointer, Python, ToPyObject};
use std::marker::PhantomData;
use std::mem;
use std::ptr::NonNull;
pub unsafe trait PyNativeType: Sized {
fn py(&self) -> Python {
unsafe { Python::assume_gil_acquired() }
}
}
#[derive(Debug)]
#[repr(transparent)]
pub struct Py<T>(NonNull<ffi::PyObject>, PhantomData<T>);
unsafe impl<T> Send for Py<T> {}
unsafe impl<T> Sync for Py<T> {}
impl<T> Py<T> {
pub fn new(py: Python, value: impl Into<PyClassInitializer<T>>) -> PyResult<Py<T>>
where
T: PyClass,
<T::BaseType as PyTypeInfo>::ConcreteLayout:
crate::type_object::PyObjectSizedLayout<T::BaseType>,
{
let initializer = value.into();
let obj = unsafe { initializer.create_shell(py)? };
let ob = unsafe { Py::from_owned_ptr(obj as _) };
Ok(ob)
}
#[inline]
pub unsafe fn from_owned_ptr(ptr: *mut ffi::PyObject) -> Py<T> {
debug_assert!(
!ptr.is_null() && ffi::Py_REFCNT(ptr) > 0,
format!("REFCNT: {:?} - {:?}", ptr, ffi::Py_REFCNT(ptr))
);
Py(NonNull::new_unchecked(ptr), PhantomData)
}
#[inline]
pub unsafe fn from_owned_ptr_or_panic(ptr: *mut ffi::PyObject) -> Py<T> {
match NonNull::new(ptr) {
Some(nonnull_ptr) => Py(nonnull_ptr, PhantomData),
None => {
crate::err::panic_after_error();
}
}
}
pub unsafe fn from_owned_ptr_or_err(py: Python, ptr: *mut ffi::PyObject) -> PyResult<Py<T>> {
match NonNull::new(ptr) {
Some(nonnull_ptr) => Ok(Py(nonnull_ptr, PhantomData)),
None => Err(PyErr::fetch(py)),
}
}
#[inline]
pub unsafe fn from_borrowed_ptr(ptr: *mut ffi::PyObject) -> Py<T> {
debug_assert!(
!ptr.is_null() && ffi::Py_REFCNT(ptr) > 0,
format!("REFCNT: {:?} - {:?}", ptr, ffi::Py_REFCNT(ptr))
);
ffi::Py_INCREF(ptr);
Py(NonNull::new_unchecked(ptr), PhantomData)
}
#[inline]
pub fn get_refcnt(&self) -> isize {
unsafe { ffi::Py_REFCNT(self.0.as_ptr()) }
}
#[inline]
pub fn clone_ref(&self, _py: Python) -> Py<T> {
unsafe { Py::from_borrowed_ptr(self.0.as_ptr()) }
}
pub(crate) fn into_non_null(self) -> NonNull<ffi::PyObject> {
let pointer = self.0;
mem::forget(self);
pointer
}
}
pub trait AsPyRef<T: PyTypeInfo>: Sized {
fn as_ref(&self, py: Python) -> &T;
}
impl<T: PyTypeInfo> AsPyRef<T> for Py<T> {
fn as_ref(&self, _py: Python) -> &T {
let any = self as *const Py<T> as *const PyAny;
unsafe { T::ConcreteLayout::internal_ref_cast(&*any) }
}
}
impl<T> ToPyObject for Py<T> {
fn to_object(&self, py: Python) -> PyObject {
unsafe { PyObject::from_borrowed_ptr(py, self.as_ptr()) }
}
}
impl<T> IntoPy<PyObject> for Py<T> {
#[inline]
fn into_py(self, _py: Python) -> PyObject {
unsafe { PyObject::from_not_null(self.into_non_null()) }
}
}
impl<T> AsPyPointer for Py<T> {
#[inline]
fn as_ptr(&self) -> *mut ffi::PyObject {
self.0.as_ptr()
}
}
impl<T> IntoPyPointer for Py<T> {
#[inline]
#[must_use]
fn into_ptr(self) -> *mut ffi::PyObject {
self.into_non_null().as_ptr()
}
}
impl<'a, T> std::convert::From<&PyClassShell<T>> for Py<T>
where
T: PyClass,
{
fn from(shell: &PyClassShell<T>) -> Self {
unsafe { Py::from_borrowed_ptr(shell.as_ptr()) }
}
}
impl<'a, T> std::convert::From<&mut PyClassShell<T>> for Py<T>
where
T: PyClass,
{
fn from(shell: &mut PyClassShell<T>) -> Self {
unsafe { Py::from_borrowed_ptr(shell.as_ptr()) }
}
}
impl<T> PartialEq for Py<T> {
#[inline]
fn eq(&self, o: &Py<T>) -> bool {
self.0 == o.0
}
}
impl<T> Drop for Py<T> {
fn drop(&mut self) {
unsafe {
gil::register_pointer(self.0);
}
}
}
impl<T> std::convert::From<Py<T>> for PyObject {
#[inline]
fn from(ob: Py<T>) -> Self {
unsafe { PyObject::from_not_null(ob.into_non_null()) }
}
}
impl<'a, T> std::convert::From<&'a T> for PyObject
where
T: AsPyPointer,
{
fn from(ob: &'a T) -> Self {
unsafe { Py::<T>::from_borrowed_ptr(ob.as_ptr()) }.into()
}
}
impl<'a, T> std::convert::From<&'a mut T> for PyObject
where
T: AsPyPointer,
{
fn from(ob: &'a mut T) -> Self {
unsafe { Py::<T>::from_borrowed_ptr(ob.as_ptr()) }.into()
}
}
impl<'a, T> FromPyObject<'a> for Py<T>
where
T: AsPyPointer,
&'a T: 'a + FromPyObject<'a>,
{
fn extract(ob: &'a PyAny) -> PyResult<Self> {
unsafe {
ob.extract::<&T>()
.map(|val| Py::from_borrowed_ptr(val.as_ptr()))
}
}
}
#[repr(transparent)]
pub struct ManagedPyRef<'p, T: ToPyObject + ?Sized> {
data: *mut ffi::PyObject,
data_type: PhantomData<T>,
_py: Python<'p>,
}
impl<'p, T: ToPyObject> ManagedPyRef<'p, T> {
pub fn from_to_pyobject(py: Python<'p>, to_pyobject: &T) -> Self {
to_pyobject.to_managed_py_ref(py)
}
}
impl<'p, T: ToPyObject> AsPyPointer for ManagedPyRef<'p, T> {
fn as_ptr(&self) -> *mut ffi::PyObject {
self.data
}
}
pub trait ManagedPyRefDispatch: ToPyObject {
fn to_managed_py_ref<'p>(&self, py: Python<'p>) -> ManagedPyRef<'p, Self>;
fn drop_impl(borrowed: &mut ManagedPyRef<Self>);
}
impl<T: ToPyObject + ?Sized> ManagedPyRefDispatch for T {
default fn to_managed_py_ref<'p>(&self, py: Python<'p>) -> ManagedPyRef<'p, Self> {
ManagedPyRef {
data: self.to_object(py).into_ptr(),
data_type: PhantomData,
_py: py,
}
}
default fn drop_impl(borrowed: &mut ManagedPyRef<Self>) {
unsafe { ffi::Py_DECREF(borrowed.data) };
}
}
impl<T: ToPyObject + AsPyPointer + ?Sized> ManagedPyRefDispatch for T {
fn to_managed_py_ref<'p>(&self, py: Python<'p>) -> ManagedPyRef<'p, Self> {
ManagedPyRef {
data: self.as_ptr(),
data_type: PhantomData,
_py: py,
}
}
fn drop_impl(_: &mut ManagedPyRef<T>) {}
}
impl<'p, T: ToPyObject + ?Sized> Drop for ManagedPyRef<'p, T> {
fn drop(&mut self) {
ManagedPyRefDispatch::drop_impl(self);
}
}
#[cfg(test)]
mod test {
use crate::ffi;
use crate::types::PyDict;
use crate::{AsPyPointer, ManagedPyRef, Python};
#[test]
fn borrowed_py_ref_with_to_pointer() {
let gil = Python::acquire_gil();
let py = gil.python();
let native = PyDict::new(py);
let ref_count = unsafe { ffi::Py_REFCNT(native.as_ptr()) };
let borrowed = ManagedPyRef::from_to_pyobject(py, native);
assert_eq!(native.as_ptr(), borrowed.data);
assert_eq!(ref_count, unsafe { ffi::Py_REFCNT(borrowed.data) });
drop(borrowed);
assert_eq!(ref_count, unsafe { ffi::Py_REFCNT(native.as_ptr()) });
}
#[test]
fn borrowed_py_ref_with_to_object() {
let gil = Python::acquire_gil();
let py = gil.python();
let convertible = (1, 2, 3);
let borrowed = ManagedPyRef::from_to_pyobject(py, &convertible);
let ptr = borrowed.data;
unsafe {
ffi::Py_INCREF(ptr);
}
assert_eq!(2, unsafe { ffi::Py_REFCNT(ptr) });
drop(borrowed);
assert_eq!(1, unsafe { ffi::Py_REFCNT(ptr) });
unsafe {
ffi::Py_DECREF(ptr);
}
}
}