From 49de1f1d409056c4796f80388d355fcc1eafb639 Mon Sep 17 00:00:00 2001
From: Nikolay Kim <fafhrd91@gmail.com>
Date: Mon, 10 Jul 2017 00:40:30 +0600
Subject: [PATCH] cleanup cb_unary and gc protcol

---
 src/callback.rs     | 21 ++++++++-------------
 src/class/buffer.rs |  3 ++-
 src/class/gc.rs     | 16 ++++++----------
 src/python.rs       |  9 ---------
 4 files changed, 16 insertions(+), 33 deletions(-)

diff --git a/src/callback.rs b/src/callback.rs
index ff8436dd..cd76e736 100644
--- a/src/callback.rs
+++ b/src/callback.rs
@@ -7,12 +7,11 @@ use std::{any, mem, ptr, isize, io, panic};
 use libc;
 
 use pythonrun;
-use python::{Python, IntoPyPointer};
+use python::{Python, PyDowncastFrom, IntoPyPointer};
 use objects::exc;
 use conversion::IntoPyObject;
 use ffi::{self, Py_hash_t};
 use err::{PyErr, PyResult};
-use instance::{Py, AsPyRef};
 use typeob::PyTypeInfo;
 
 
@@ -180,16 +179,16 @@ pub unsafe fn cb_unary<Slf, F, T, C>(location: &str,
                                      slf: *mut ffi::PyObject, _c: C, f: F) -> C::R
     where F: for<'p> FnOnce(Python<'p>, &'p mut Slf) -> PyResult<T>,
           F: panic::UnwindSafe,
-          Slf: PyTypeInfo,
+          Slf: PyTypeInfo + PyDowncastFrom,
           C: CallbackConverter<T>
 {
     let guard = AbortOnDrop(location);
     let pool = pythonrun::Pool::new();
     let ret = panic::catch_unwind(|| {
         let py = Python::assume_gil_acquired();
-        let slf = Py::<Slf>::from_borrowed_ptr(slf);
+        let mut slf = py.mut_cast_from_borrowed_ptr::<Slf>(slf);
 
-        let result = match f(py, slf.as_mut(py)) {
+        match f(py, slf) {
             Ok(val) => {
                 C::convert(val, py)
             }
@@ -197,9 +196,7 @@ pub unsafe fn cb_unary<Slf, F, T, C>(location: &str,
                 e.restore(py);
                 C::error_value()
             }
-        };
-        py.release(slf);
-        result
+        }
     });
     let ret = match ret {
         Ok(r) => r,
@@ -217,17 +214,15 @@ pub unsafe fn cb_unary<Slf, F, T, C>(location: &str,
 pub unsafe fn cb_unary_unit<Slf, F>(location: &str, slf: *mut ffi::PyObject, f: F) -> c_int
     where F: for<'p> FnOnce(Python<'p>, &'p mut Slf) -> c_int,
           F: panic::UnwindSafe,
-          Slf: PyTypeInfo,
+          Slf: PyTypeInfo  + PyDowncastFrom,
 {
     let guard = AbortOnDrop(location);
     let pool = pythonrun::Pool::new();
     let ret = panic::catch_unwind(|| {
         let py = Python::assume_gil_acquired();
-        let slf = Py::<Slf>::from_borrowed_ptr(slf);
+        let slf = py.mut_cast_from_borrowed_ptr::<Slf>(slf);
 
-        let result = f(py, slf.as_mut(py));
-        py.release(slf);
-        result
+        f(py, slf)
     });
     let ret = match ret {
         Ok(r) => r,
diff --git a/src/class/buffer.rs b/src/class/buffer.rs
index 72a80162..4dc78967 100644
--- a/src/class/buffer.rs
+++ b/src/class/buffer.rs
@@ -10,12 +10,13 @@ use std::os::raw::c_int;
 use ffi;
 use err::PyResult;
 use typeob::PyTypeInfo;
+use python::PyDowncastFrom;
 use callback::UnitCallbackConverter;
 
 
 /// Buffer protocol interface
 #[allow(unused_variables)]
-pub trait PyBufferProtocol<'p> : PyTypeInfo + Sized + 'static
+pub trait PyBufferProtocol<'p> : PyTypeInfo + PyDowncastFrom
 {
     fn bf_getbuffer(&'p self,
                     view: *mut ffi::Py_buffer, flags: c_int) -> Self::Result
diff --git a/src/class/gc.rs b/src/class/gc.rs
index c46ddff5..7e15ae4f 100644
--- a/src/class/gc.rs
+++ b/src/class/gc.rs
@@ -7,14 +7,14 @@ use std::os::raw::{c_int, c_void};
 
 use ffi;
 use callback;
-use python::{Python, ToPyPointer};
+use python::{Python, ToPyPointer, PyDowncastFrom};
 use typeob::PyTypeInfo;
 
 pub struct PyTraverseError(c_int);
 
 /// GC support
 #[allow(unused_variables)]
-pub trait PyGCProtocol<'p> : PyTypeInfo {
+pub trait PyGCProtocol<'p> : PyTypeInfo + PyDowncastFrom {
 
     fn __traverse__(&'p self, visit: PyVisit)
                     -> Result<(), PyTraverseError> { unimplemented!() }
@@ -26,19 +26,15 @@ pub trait PyGCProtocol<'p> : PyTypeInfo {
 pub trait PyGCTraverseProtocol<'p>: PyGCProtocol<'p> {}
 pub trait PyGCClearProtocol<'p>: PyGCProtocol<'p> {}
 
-
-impl<'p, T> PyGCProtocol<'p> for T where T: PyTypeInfo {
-    default fn __traverse__(&'p self, _: PyVisit) -> Result<(), PyTraverseError> {
-        Ok(())
-    }
-    default fn __clear__(&'p mut self) {}
-}
-
 #[doc(hidden)]
 pub trait PyGCProtocolImpl {
     fn update_type_object(type_object: &mut ffi::PyTypeObject);
 }
 
+impl<'p, T> PyGCProtocolImpl for T {
+    default fn update_type_object(_type_object: &mut ffi::PyTypeObject) {}
+}
+
 impl<'p, T> PyGCProtocolImpl for T where T: PyGCProtocol<'p>
 {
     fn update_type_object(type_object: &mut ffi::PyTypeObject) {
diff --git a/src/python.rs b/src/python.rs
index 0fed0226..5d6d5a44 100644
--- a/src/python.rs
+++ b/src/python.rs
@@ -401,15 +401,6 @@ impl<'p> Python<'p> {
             }
         }
     }
-
-    /// Release PyResult<PyObject> object
-    #[inline]
-    pub fn release_res<T>(self, res: PyResult<T>) where T: IntoPyPointer {
-        match res {
-            Ok(ob) => unsafe {ffi::Py_DECREF(ob.into_ptr())},
-            Err(e) => e.release(self)
-        }
-    }
 }
 
 #[cfg(test)]