Splitted PyTypeCreate of PyTypeObject to remove specialization

Author: konstin

CHANGELOG.md

@@ -29,6 +29,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
  * `IntoPyDictPointer` was replace by `IntoPyDict` which doesn't convert `PyDict` itself anymore and returns a `PyDict` instead of `*mut PyObject`.
  * `PyTuple::new` now takes an `IntoIterator` instead of a slice
  * Updated to syn 0.15
+ * Splitted `PyTypeObject` into `PyTypeObject` without the create method and `PyTypeCreate` with requires `PyObjectAlloc<Self> + PyTypeInfo + Sized`.
 
 ### Fixed
 

guide/src/class.md

@@ -9,7 +9,6 @@ To define python custom class, rust struct needs to be annotated with `#[pyclass
 # extern crate pyo3;
 # use pyo3::prelude::*;
 
-
 #[pyclass]
 struct MyClass {
    num: i32,

pyo3-derive-backend/src/py_class.rs

@@ -127,7 +127,7 @@ fn impl_class(
                                 FREELIST = Box::into_raw(Box::new(
                                     ::pyo3::freelist::FreeList::with_capacity(#freelist)));
 
-                                <#cls as ::pyo3::typeob::PyTypeObject>::init_type();
+                                <#cls as ::pyo3::typeob::PyTypeCreate>::init_type();
                             }
                             &mut *FREELIST
                         }
@@ -204,27 +204,6 @@ fn impl_class(
             }
         }
 
-        impl ::pyo3::typeob::PyTypeObject for #cls {
-            #[inline]
-            fn init_type() {
-                static START: ::std::sync::Once = ::std::sync::ONCE_INIT;
-                START.call_once(|| {
-                    let ty = unsafe{<#cls as ::pyo3::typeob::PyTypeInfo>::type_object()};
-
-                    if (ty.tp_flags & ::pyo3::ffi::Py_TPFLAGS_READY) == 0 {
-                        let gil = ::pyo3::Python::acquire_gil();
-                        let py = gil.python();
-
-                        // automatically initialize the class on-demand
-                        ::pyo3::typeob::initialize_type::<#cls>(py, None)
-                            .map_err(|e| e.print(py))
-                            .expect(format!("An error occurred while initializing class {}",
-                                            <#cls as ::pyo3::typeob::PyTypeInfo>::NAME).as_ref());
-                    }
-                });
-            }
-        }
-
         // TBH I'm not sure what exactely this does and I'm sure there's a better way,
         // but for now it works and it only safe code and it is required to return custom
         // objects, so for now I'm keeping it

src/ffi2/object.rs

@@ -363,7 +363,7 @@ pub type allocfunc =
     unsafe extern "C" fn(arg1: *mut PyTypeObject, arg2: Py_ssize_t) -> *mut PyObject;
 
 #[repr(C)]
-#[derive(Copy)]
+#[derive(Copy, Clone)]
 pub struct PyTypeObject {
     pub ob_refcnt: Py_ssize_t,
     pub ob_type: *mut PyTypeObject,
@@ -416,13 +416,6 @@ pub struct PyTypeObject {
     pub tp_version_tag: c_uint,
 }
 
-impl Clone for PyTypeObject {
-    #[inline]
-    fn clone(&self) -> PyTypeObject {
-        *self
-    }
-}
-
 #[cfg(py_sys_config = "Py_TRACE_REFS")]
 pub const PyTypeObject_INIT: PyTypeObject = PyTypeObject {
     _ob_next: ::std::ptr::null_mut(),

src/instance.rs

@@ -14,6 +14,7 @@ use python::{IntoPyPointer, Python, ToPyPointer};
 use pythonrun;
 use typeob::{PyTypeInfo, PyTypeObject};
 use types::PyObjectRef;
+use typeob::PyTypeCreate;
 
 pub struct PyToken(PhantomData<Rc<()>>);
 
@@ -175,7 +176,7 @@ where
         F: FnOnce(::PyToken) -> T,
         T: PyTypeObject + PyTypeInfo,
     {
-        let ob = <T as PyTypeObject>::create(py)?;
+        let ob = <T as PyTypeCreate>::create(py)?;
         ob.init(f)?;
 
         let ob = unsafe { Py::from_owned_ptr(ob.into_ptr()) };
@@ -189,7 +190,7 @@ where
         F: FnOnce(::PyToken) -> T,
         T: PyTypeObject + PyTypeInfo,
     {
-        let ob = <T as PyTypeObject>::create(py)?;
+        let ob = <T as PyTypeCreate>::create(py)?;
         ob.init(f)?;
 
         unsafe { Ok(py.from_owned_ptr(ob.into_ptr())) }
@@ -202,7 +203,7 @@ where
         F: FnOnce(::PyToken) -> T,
         T: PyTypeObject + PyTypeInfo,
     {
-        let ob = <T as PyTypeObject>::create(py)?;
+        let ob = <T as PyTypeCreate>::create(py)?;
         ob.init(f)?;
 
         unsafe { Ok(py.mut_from_owned_ptr(ob.into_ptr())) }

src/python.rs

@@ -12,7 +12,8 @@ use std;
 use std::ffi::CString;
 use std::marker::PhantomData;
 use std::os::raw::c_int;
-use typeob::{PyObjectAlloc, PyTypeInfo, PyTypeObject};
+use typeob::PyTypeCreate;
+use typeob::{PyTypeInfo, PyTypeObject};
 use types::{PyDict, PyModule, PyObjectRef, PyType};
 
 /// Marker type that indicates that the GIL is currently held.
@@ -253,7 +254,7 @@ impl<'p> Python<'p> {
     pub fn init<T, F>(self, f: F) -> PyResult<Py<T>>
     where
         F: FnOnce(PyToken) -> T,
-        T: PyTypeInfo + PyObjectAlloc<T>,
+        T: PyTypeCreate,
     {
         Py::new(self, f)
     }
@@ -264,7 +265,7 @@ impl<'p> Python<'p> {
     pub fn init_ref<T, F>(self, f: F) -> PyResult<&'p T>
     where
         F: FnOnce(PyToken) -> T,
-        T: PyTypeInfo + PyObjectAlloc<T>,
+        T: PyTypeCreate,
     {
         Py::new_ref(self, f)
     }
@@ -275,7 +276,7 @@ impl<'p> Python<'p> {
     pub fn init_mut<T, F>(self, f: F) -> PyResult<&'p mut T>
     where
         F: FnOnce(PyToken) -> T,
-        T: PyTypeInfo + PyObjectAlloc<T>,
+        T: PyTypeCreate,
     {
         Py::new_mut(self, f)
     }

src/typeob.rs

@@ -217,7 +217,7 @@ where
 
     default unsafe fn alloc(_py: Python) -> PyResult<*mut ffi::PyObject> {
         // TODO: remove this
-        T::init_type();
+        <T as PyTypeCreate>::init_type();
 
         let tp_ptr = T::type_object();
         let alloc = (*tp_ptr).tp_alloc.unwrap_or(ffi::PyType_GenericAlloc);
@@ -256,20 +256,42 @@ where
     }
 }
 
-/// Trait implemented by Python object types that have a corresponding type object.
+/// Python object types that have a corresponding type object.
 pub trait PyTypeObject {
     /// Initialize type object
     fn init_type();
 
     /// Retrieves the type object for this Python object type.
     fn type_object() -> Py<PyType>;
+}
+
+/// Python object types that have a corresponding type object and be
+/// instanciated with [Self::create()]
+pub trait PyTypeCreate: PyObjectAlloc<Self> + PyTypeInfo + Sized {
+    #[inline]
+    fn init_type() {
+        let type_object = unsafe { *<Self as PyTypeInfo>::type_object() };
+
+        if (type_object.tp_flags & ffi::Py_TPFLAGS_READY) == 0 {
+            // automatically initialize the class on-demand
+            let gil = Python::acquire_gil();
+            let py = gil.python();
+
+            initialize_type::<Self>(py, None).unwrap_or_else(|_| {
+                panic!("An error occurred while initializing class {}", Self::NAME)
+            });
+        }
+    }
+
+    #[inline]
+    fn type_object() -> Py<PyType> {
+        <Self as PyTypeObject>::init_type();
+        PyType::new::<Self>()
+    }
 
     /// Create PyRawObject which can be initialized with rust value
     #[must_use]
-    fn create(py: Python) -> PyResult<PyRawObject>
-    where
-        Self: Sized + PyObjectAlloc<Self> + PyTypeInfo,
-    {
+    fn create(py: Python) -> PyResult<PyRawObject> {
         <Self as PyTypeObject>::init_type();
 
         unsafe {
@@ -284,29 +306,18 @@ pub trait PyTypeObject {
     }
 }
 
+impl<T> PyTypeCreate for T where T: PyObjectAlloc<Self> + PyTypeInfo + Sized {}
+
 impl<T> PyTypeObject for T
 where
-    T: PyObjectAlloc<T> + PyTypeInfo,
+    T: PyTypeCreate,
 {
-    #[inline]
-    default fn init_type() {
-        unsafe {
-            if ((*<T>::type_object()).tp_flags & ffi::Py_TPFLAGS_READY) == 0 {
-                // automatically initialize the class on-demand
-                let gil = Python::acquire_gil();
-                let py = gil.python();
-
-                initialize_type::<T>(py, None).unwrap_or_else(|_| {
-                    panic!("An error occurred while initializing class {}", T::NAME)
-                });
-            }
-        }
+    fn init_type() {
+        <T as PyTypeCreate>::init_type()
     }
 
-    #[inline]
-    default fn type_object() -> Py<PyType> {
-        <T as PyTypeObject>::init_type();
-        PyType::new::<T>()
+    fn type_object() -> Py<PyType> {
+        <T as PyTypeCreate>::type_object()
     }
 }
 

src/types/mod.rs

@@ -125,7 +125,7 @@ macro_rules! pyobject_native_type_convert(
             }
         }
 
-        impl<$($type_param,)*> $crate::typeob::PyTypeObject for $name {
+        impl<$($type_param,)*> $crate::typeob::PyTypeCreate for $name {
             #[inline]
             fn init_type() {}
 

src/types/string.rs

@@ -10,8 +10,8 @@ use ffi;
 use instance::{Py, PyObjectWithToken};
 use object::PyObject;
 use python::{Python, ToPyPointer};
-use types::PyObjectRef;
 use types::exceptions;
+use types::PyObjectRef;
 
 /// Represents a Python `string`.
 #[repr(transparent)]
@@ -72,7 +72,7 @@ impl PyString {
             Ok(s) => Ok(Cow::Borrowed(s)),
             Err(e) => Err(PyErr::from_instance(
                 exceptions::UnicodeDecodeError::new_utf8(self.py(), self.as_bytes(), e)?,
-            ))
+            )),
         }
     }
 
@@ -120,12 +120,12 @@ impl PyBytes {
 
 #[cfg(test)]
 mod test {
-    use std::borrow::Cow;
-    use conversion::{FromPyObject, ToPyObject, PyTryFrom};
+    use super::PyString;
+    use conversion::{FromPyObject, PyTryFrom, ToPyObject};
     use instance::AsPyRef;
-    use python::Python;
     use object::PyObject;
-    use super::PyString;
+    use python::Python;
+    use std::borrow::Cow;
 
     #[test]
     fn test_non_bmp() {

src/types/string2.rs

@@ -88,7 +88,7 @@ impl PyString {
             Ok(s) => Ok(Cow::Borrowed(s)),
             Err(e) => Err(PyErr::from_instance(
                 exceptions::UnicodeDecodeError::new_utf8(self.py(), self.as_bytes(), e)?,
-            ))
+            )),
         }
     }
 
@@ -156,9 +156,8 @@ impl PyUnicode {
         unsafe {
             // PyUnicode_AsUTF8String would return null if the pointer did not reference a valid
             // unicode object, but because we have a valid PyUnicode, assume success
-            let data: Py<PyBytes> = Py::from_owned_ptr(
-                ffi::PyUnicode_AsUTF8String(self.0.as_ptr()),
-            );
+            let data: Py<PyBytes> =
+                Py::from_owned_ptr(ffi::PyUnicode_AsUTF8String(self.0.as_ptr()));
             let buffer = ffi::PyBytes_AsString(data.as_ptr()) as *const u8;
             let length = ffi::PyBytes_Size(data.as_ptr()) as usize;
             debug_assert!(!buffer.is_null());
@@ -175,7 +174,7 @@ impl PyUnicode {
             Ok(s) => Ok(Cow::Borrowed(s)),
             Err(e) => Err(PyErr::from_instance(
                 exceptions::UnicodeDecodeError::new_utf8(self.py(), self.as_bytes(), e)?,
-            ))
+            )),
         }
     }
 
@@ -205,12 +204,12 @@ impl std::convert::From<Py<PyUnicode>> for Py<PyString> {
 
 #[cfg(test)]
 mod test {
-    use std::borrow::Cow;
-    use conversion::{FromPyObject, ToPyObject, PyTryFrom};
+    use super::PyString;
+    use conversion::{FromPyObject, PyTryFrom, ToPyObject};
     use instance::AsPyRef;
-    use python::Python;
     use object::PyObject;
-    use super::PyString;
+    use python::Python;
+    use std::borrow::Cow;
 
     #[test]
     fn test_non_bmp() {