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Reference Guide
ObjectProxy.h
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1 // @(#)root/pyroot:$Id$
2 // Author: Wim Lavrijsen, Jan 2005
3 
4 #ifndef PYROOT_OBJECTPROXY_H
5 #define PYROOT_OBJECTPROXY_H
6 
7 //////////////////////////////////////////////////////////////////////////////
8 // //
9 // PyROOT::ObjectProxy //
10 // //
11 // Python-side proxy, encapsulaties a C++ object. //
12 // //
13 //////////////////////////////////////////////////////////////////////////////
14 
15 
16 // Bindings
17 #include "PyRootType.h"
18 #include "Cppyy.h"
19 #include "TCallContext.h"
20 
21 // ROOT
22 #include "DllImport.h"
23 
24 // TODO: have an ObjectProxy derived or alternative type for smart pointers
25 
26 namespace PyROOT {
27 
28  class ObjectProxy {
29  public:
30  enum EFlags { kNone = 0x0, kIsOwner = 0x0001, kIsReference = 0x0002, kIsValue = 0x0004, kIsSmartPtr = 0x0008 };
31 
32  public:
33  void Set( void* address, EFlags flags = kNone )
34  {
35  // Initialize the proxy with the pointer value 'address.'
36  fObject = address;
37  fFlags = flags;
38  }
39 
40  void SetSmartPtr ( void* address, Cppyy::TCppType_t ptrType )
41  {
43  fSmartPtr = address;
44  fSmartPtrType = ptrType;
45  }
46 
47  void* GetObject() const
48  {
49  // Retrieve a pointer to the held C++ object.
50 
51  // We get the raw pointer from the smart pointer each time, in case
52  // it has changed or has been freed.
53  if ( fFlags & kIsSmartPtr ) {
54  // TODO: this is icky and slow
55  std::vector< Cppyy::TCppMethod_t > methods = Cppyy::GetMethodsFromName( fSmartPtrType, "operator->" );
56  std::vector<TParameter> args;
57  return Cppyy::CallR( methods[0], fSmartPtr, &args );
58  }
59 
60  if ( fObject && ( fFlags & kIsReference ) )
61  return *(reinterpret_cast< void** >( const_cast< void* >( fObject ) ));
62  else
63  return const_cast< void* >( fObject ); // may be null
64  }
65 
67  {
68  // Retrieve a pointer to the C++ type; may return NULL.
69  return ((PyRootClass*)Py_TYPE(this))->fCppType;
70  }
71 
72  void HoldOn() { fFlags |= kIsOwner; }
73  void Release() { fFlags &= ~kIsOwner; }
74 
75  public: // public, as the python C-API works with C structs
76  PyObject_HEAD
77  void* fObject;
78  int fFlags;
79  void* fSmartPtr;
81 
82  private: // private, as the python C-API will handle creation
84  };
85 
86 
87 //- object proxy type and type verification ----------------------------------
88  R__EXTERN PyTypeObject ObjectProxy_Type;
89 
90  template< typename T >
91  inline Bool_t ObjectProxy_Check( T* object )
92  {
93  return object && PyObject_TypeCheck( object, &ObjectProxy_Type );
94  }
95 
96  template< typename T >
97  inline Bool_t ObjectProxy_CheckExact( T* object )
98  {
99  return object && Py_TYPE(object) == &ObjectProxy_Type;
100  }
101 
102 
103 //- helper for memory regulation (no PyTypeObject equiv. member in p2.2) -----
105 
106 } // namespace PyROOT
107 
108 #endif // !PYROOT_OBJECTPROXY_H
TCppScope_t TCppType_t
Definition: Cppyy.h:13
Cppyy::TCppType_t fSmartPtrType
Definition: ObjectProxy.h:80
double T(double x)
Definition: ChebyshevPol.h:34
std::vector< TCppMethod_t > GetMethodsFromName(TCppScope_t scope, const std::string &name)
Definition: Cppyy.cxx:690
bool Bool_t
Definition: RtypesCore.h:59
void SetSmartPtr(void *address, Cppyy::TCppType_t ptrType)
Definition: ObjectProxy.h:40
Bool_t ObjectProxy_CheckExact(T *object)
Definition: ObjectProxy.h:97
PyTypeObject ObjectProxy_Type
Bool_t ObjectProxy_Check(T *object)
Definition: ObjectProxy.h:91
void * CallR(TCppMethod_t method, TCppObject_t self, void *args)
Definition: Cppyy.cxx:468
Type object to hold TClassRef instance (this is only semantically a presentation of PyRootType instan...
Definition: PyRootType.h:37
PyObject_HEAD void * fObject
Definition: ObjectProxy.h:77
#define R__EXTERN
Definition: DllImport.h:27
#define Py_TYPE(ob)
Definition: PyROOT.h:151
void * GetObject() const
Definition: ObjectProxy.h:47
void op_dealloc_nofree(ObjectProxy *)
Destroy the held C++ object, if owned; does not deallocate the proxy.
Definition: ObjectProxy.cxx:46
void Set(void *address, EFlags flags=kNone)
Definition: ObjectProxy.h:33
Cppyy::TCppType_t ObjectIsA() const
Definition: ObjectProxy.h:66