Objects/cobject.c

   1
   2 /* Wrap void* pointers to be passed between C modules */
   3
   4 #include "Python.h"
   5
   6
   7 /* Declarations for objects of type PyCObject */
   8
   9 typedef void (*destructor1)(void *);
  10 typedef void (*destructor2)(void *, void*);
  11
  12 static int cobject_deprecation_warning(void)
  13 {
  14     return PyErr_WarnEx(PyExc_PendingDeprecationWarning,
  15         "The CObject type is marked Pending Deprecation in Python 2.7.  "
  16         "Please use capsule objects instead.", 1);
  17 }
  18
  19
  20 PyObject *
  21 PyCObject_FromVoidPtr(void *cobj, void (*destr)(void *))
  22 {
  23     PyCObject *self;
  24
  25     if (cobject_deprecation_warning()) {
  26         return NULL;
  27     }
  28
  29     self = PyObject_NEW(PyCObject, &PyCObject_Type);
  30     if (self == NULL)
  31         return NULL;
  32     self->cobject=cobj;
  33     self->destructor=destr;
  34     self->desc=NULL;
  35
  36     return (PyObject *)self;
  37 }
  38
  39 PyObject *
  40 PyCObject_FromVoidPtrAndDesc(void *cobj, void *desc,
  41                              void (*destr)(void *, void *))
  42 {
  43     PyCObject *self;
  44
  45     if (cobject_deprecation_warning()) {
  46         return NULL;
  47     }
  48
  49     if (!desc) {
  50         PyErr_SetString(PyExc_TypeError,
  51                         "PyCObject_FromVoidPtrAndDesc called with null"
  52                         " description");
  53         return NULL;
  54     }
  55     self = PyObject_NEW(PyCObject, &PyCObject_Type);
  56     if (self == NULL)
  57         return NULL;
  58     self->cobject = cobj;
  59     self->destructor = (destructor1)destr;
  60     self->desc = desc;
  61
  62     return (PyObject *)self;
  63 }
  64
  65 void *
  66 PyCObject_AsVoidPtr(PyObject *self)
  67 {
  68     if (self) {
  69         if (PyCapsule_CheckExact(self)) {
  70             const char *name = PyCapsule_GetName(self);
  71             return (void *)PyCapsule_GetPointer(self, name);
  72         }
  73         if (self->ob_type == &PyCObject_Type)
  74             return ((PyCObject *)self)->cobject;
  75         PyErr_SetString(PyExc_TypeError,
  76                         "PyCObject_AsVoidPtr with non-C-object");
  77     }
  78     if (!PyErr_Occurred())
  79         PyErr_SetString(PyExc_TypeError,
  80                         "PyCObject_AsVoidPtr called with null pointer");
  81     return NULL;
  82 }
  83
  84 void *
  85 PyCObject_GetDesc(PyObject *self)
  86 {
  87     if (self) {
  88         if (self->ob_type == &PyCObject_Type)
  89             return ((PyCObject *)self)->desc;
  90         PyErr_SetString(PyExc_TypeError,
  91                         "PyCObject_GetDesc with non-C-object");
  92     }
  93     if (!PyErr_Occurred())
  94         PyErr_SetString(PyExc_TypeError,
  95                         "PyCObject_GetDesc called with null pointer");
  96     return NULL;
  97 }
  98
  99 void *
 100 PyCObject_Import(char *module_name, char *name)
 101 {
 102     PyObject *m, *c;
 103     void *r = NULL;
 104
 105     if ((m = PyImport_ImportModule(module_name))) {
 106         if ((c = PyObject_GetAttrString(m,name))) {
 107             r = PyCObject_AsVoidPtr(c);
 108             Py_DECREF(c);
 109         }
 110         Py_DECREF(m);
 111     }
 112     return r;
 113 }
 114
 115 int
 116 PyCObject_SetVoidPtr(PyObject *self, void *cobj)
 117 {
 118     PyCObject* cself = (PyCObject*)self;
 119     if (cself == NULL || !PyCObject_Check(cself) ||
 120         cself->destructor != NULL) {
 121         PyErr_SetString(PyExc_TypeError,
 122                         "Invalid call to PyCObject_SetVoidPtr");
 123         return 0;
 124     }
 125     cself->cobject = cobj;
 126     return 1;
 127 }
 128
 129 static void
 130 PyCObject_dealloc(PyCObject *self)
 131 {
 132     if (self->destructor) {
 133         if(self->desc)
 134             ((destructor2)(self->destructor))(self->cobject, self->desc);
 135         else
 136             (self->destructor)(self->cobject);
 137     }
 138     PyObject_DEL(self);
 139 }
 140
 141
 142 PyDoc_STRVAR(PyCObject_Type__doc__,
 143 "C objects to be exported from one extension module to another\n\
 144 \n\
 145 C objects are used for communication between extension modules.  They\n\
 146 provide a way for an extension module to export a C interface to other\n\
 147 extension modules, so that extension modules can use the Python import\n\
 148 mechanism to link to one another.");
 149
 150 PyTypeObject PyCObject_Type = {
 151     PyVarObject_HEAD_INIT(&PyType_Type, 0)
 152     "PyCObject",                /*tp_name*/
 153     sizeof(PyCObject),          /*tp_basicsize*/
 154     0,                          /*tp_itemsize*/
 155     /* methods */
 156     (destructor)PyCObject_dealloc, /*tp_dealloc*/
 157     0,                          /*tp_print*/
 158     0,                          /*tp_getattr*/
 159     0,                          /*tp_setattr*/
 160     0,                          /*tp_compare*/
 161     0,                          /*tp_repr*/
 162     0,                          /*tp_as_number*/
 163     0,                          /*tp_as_sequence*/
 164     0,                          /*tp_as_mapping*/
 165     0,                          /*tp_hash*/
 166     0,                          /*tp_call*/
 167     0,                          /*tp_str*/
 168     0,                          /*tp_getattro*/
 169     0,                          /*tp_setattro*/
 170     0,                          /*tp_as_buffer*/
 171     0,                          /*tp_flags*/
 172     PyCObject_Type__doc__       /*tp_doc*/
 173 };