Intermediate changes

commit_hash:d5b1af16dbe9030537a04c27eb410c88c2f496cd

1 files changed, 157 insertions, 0 deletions

diff --git a/contrib/tools/swig/Lib/python/pyclasses.swg b/contrib/tools/swig/Lib/python/pyclasses.swg
new file mode 100644
index 00000000000..7a9d093657c
--- /dev/null
+++ b/contrib/tools/swig/Lib/python/pyclasses.swg
@@ -0,0 +1,157 @@
+#ifdef __cplusplus
+
+/*
+  SwigPtr_PyObject is used as a replacement of PyObject *, where
+  the INCREF/DECREF are applied as needed.
+
+  You can use SwigPtr_PyObject in a container, such as
+  
+     std::vector<SwigPtr_PyObject>;
+
+  or as a member variable:
+  
+     struct A {
+       SwigPtr_PyObject _obj;
+       A(PyObject *o) : _obj(o) {
+       }
+     };
+
+   or as a input/output value 
+
+     SwigPtr_PyObject func(SwigPtr_PyObject obj) {     
+       SwigPtr_PyObject out = PyString_FromFormat("hello %s", PyObject_AsString(obj));
+       SWIG_Py_DECREF(out);
+       return out;
+     }
+
+   just remember to pair the object creation with the proper DECREF,
+   the same as with plain PyObject *ptr, since SwigPtr_PyObject always add
+   one reference at construction.
+
+   SwigPtr_PyObject is 'visible' at the wrapped side, so you can do:
+
+
+      %template(pyvector) std::vector<swig::SwigPtr_PyObject>;
+
+   and all the proper typemaps will be used.
+   
+*/
+
+namespace swig {
+  %ignore SwigPtr_PyObject;
+  struct SwigPtr_PyObject {};
+  %apply PyObject * {SwigPtr_PyObject};
+  %apply PyObject * const& {SwigPtr_PyObject const&};
+
+  %typemap(typecheck,precedence=SWIG_TYPECHECK_SWIGOBJECT,noblock=1) SwigPtr_PyObject const& "$1 = ($input != 0);"
+
+
+  /* For output */
+  %typemap(out,noblock=1)  SwigPtr_PyObject {
+    $result = (PyObject *)$1;
+    SWIG_Py_INCREF($result);
+  }
+  
+  %typemap(out,noblock=1)  SwigPtr_PyObject const & {
+    $result = (PyObject *)*$1;
+    SWIG_Py_INCREF($result);
+  }
+  
+}
+
+%{
+namespace swig {
+  class SwigPtr_PyObject {
+  protected:
+    PyObject *_obj;
+
+  public:
+    SwigPtr_PyObject() :_obj(0)
+    {
+    }
+
+    SwigPtr_PyObject(const SwigPtr_PyObject& item) : _obj(item._obj)
+    {
+      SWIG_PYTHON_THREAD_BEGIN_BLOCK;
+      SWIG_Py_XINCREF(_obj);
+      SWIG_PYTHON_THREAD_END_BLOCK;
+    }
+    
+    SwigPtr_PyObject(PyObject *obj, bool initial_ref = true) :_obj(obj)
+    {
+      if (initial_ref) {
+        SWIG_PYTHON_THREAD_BEGIN_BLOCK;
+        SWIG_Py_XINCREF(_obj);
+        SWIG_PYTHON_THREAD_END_BLOCK;
+      }
+    }
+    
+    SwigPtr_PyObject & operator=(const SwigPtr_PyObject& item) 
+    {
+      SWIG_PYTHON_THREAD_BEGIN_BLOCK;
+      SWIG_Py_XINCREF(item._obj);
+      SWIG_Py_XDECREF(_obj);
+      _obj = item._obj;
+      SWIG_PYTHON_THREAD_END_BLOCK;
+      return *this;      
+    }
+    
+    ~SwigPtr_PyObject() 
+    {
+      SWIG_PYTHON_THREAD_BEGIN_BLOCK;
+      SWIG_Py_XDECREF(_obj);
+      SWIG_PYTHON_THREAD_END_BLOCK;
+    }
+    
+    operator PyObject *() const
+    {
+      return _obj;
+    }
+
+    PyObject *operator->() const
+    {
+      return _obj;
+    }
+  };
+}
+%}
+
+/*
+  SwigVar_PyObject is used to manage 'in the scope' PyObject * variables,
+  as in
+
+  int func () {
+    SwigVar_PyObject obj = PyString_FromString("hello");
+  }
+
+  ie, 'obj' is created and destructed in the same scope from
+  a python object that carries at least one reference value.
+  
+  SwigVar_PyObject just take care of applying the proper Py_DECREF.
+
+  Hence, this class is purely internal and not visible at the wrapped side.
+ */
+namespace swig {
+  %ignore SwigVar_PyObject;
+  struct SwigVar_PyObject {};
+  %apply PyObject * {SwigVar_PyObject};
+  %apply PyObject * const& {SwigVar_PyObject const&};
+}
+
+%{
+namespace swig {
+  struct SwigVar_PyObject : SwigPtr_PyObject {
+    SwigVar_PyObject(PyObject* obj = 0) : SwigPtr_PyObject(obj, false) { }
+    
+    SwigVar_PyObject & operator = (PyObject* obj)
+    {
+      SWIG_Py_XDECREF(_obj);
+      _obj = obj;
+      return *this;      
+    }
+  };
+}
+%}
+
+
+#endif