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
  13 static int deprecation_exception(void)
  14 {
  15     return PyErr_WarnEx(PyExc_PendingDeprecationWarning,
  16              "The CObject API is deprecated as of Python 3.1.  "
  17              "Please convert to using the Capsule API.", 1);
  18 }
  19
  20 PyObject *
  21 PyCObject_FromVoidPtr(void *cobj, void (*destr)(void *))
  22 {
  23     PyCObject *self;
  24
  25     if (deprecation_exception()) {
  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 (deprecation_exception()) {
  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 (self->ob_type == &PyCObject_Type)
  70             return ((PyCObject *)self)->cobject;
  71         PyErr_SetString(PyExc_TypeError,
  72                         "PyCObject_AsVoidPtr with non-C-object");
  73     }
  74     if (!PyErr_Occurred())
  75         PyErr_SetString(PyExc_TypeError,
  76                         "PyCObject_AsVoidPtr called with null pointer");
  77     return NULL;
  78 }
  79
  80 void *
  81 PyCObject_GetDesc(PyObject *self)
  82 {
  83     if (self) {
  84         if (self->ob_type == &PyCObject_Type)
  85             return ((PyCObject *)self)->desc;
  86         PyErr_SetString(PyExc_TypeError,
  87                         "PyCObject_GetDesc with non-C-object");
  88     }
  89     if (!PyErr_Occurred())
  90         PyErr_SetString(PyExc_TypeError,
  91                         "PyCObject_GetDesc called with null pointer");
  92     return NULL;
  93 }
  94
  95 void *
  96 PyCObject_Import(char *module_name, char *name)
  97 {
  98     PyObject *m, *c;
  99     void *r = NULL;
 100
 101     if ((m = PyImport_ImportModule(module_name))) {
 102         if ((c = PyObject_GetAttrString(m,name))) {
 103             r = PyCObject_AsVoidPtr(c);
 104             Py_DECREF(c);
 105         }
 106         Py_DECREF(m);
 107     }
 108     return r;
 109 }
 110
 111 int
 112 PyCObject_SetVoidPtr(PyObject *self, void *cobj)
 113 {
 114     PyCObject* cself = (PyCObject*)self;
 115     if (cself == NULL || !PyCObject_Check(cself) ||
 116         cself->destructor != NULL) {
 117         PyErr_SetString(PyExc_TypeError,
 118                         "Invalid call to PyCObject_SetVoidPtr");
 119         return 0;
 120     }
 121     cself->cobject = cobj;
 122     return 1;
 123 }
 124
 125 static void
 126 PyCObject_dealloc(PyCObject *self)
 127 {
 128     if (self->destructor) {
 129         if(self->desc)
 130             ((destructor2)(self->destructor))(self->cobject, self->desc);
 131         else
 132             (self->destructor)(self->cobject);
 133     }
 134     PyObject_DEL(self);
 135 }
 136
 137
 138 PyDoc_STRVAR(PyCObject_Type__doc__,
 139 "C objects to be exported from one extension module to another\n\
 140 \n\
 141 C objects are used for communication between extension modules.  They\n\
 142 provide a way for an extension module to export a C interface to other\n\
 143 extension modules, so that extension modules can use the Python import\n\
 144 mechanism to link to one another.");
 145
 146 PyTypeObject PyCObject_Type = {
 147     PyVarObject_HEAD_INIT(&PyType_Type, 0)
 148     "PyCObject",                /*tp_name*/
 149     sizeof(PyCObject),          /*tp_basicsize*/
 150     0,                          /*tp_itemsize*/
 151     /* methods */
 152     (destructor)PyCObject_dealloc, /*tp_dealloc*/
 153     0,                          /*tp_print*/
 154     0,                          /*tp_getattr*/
 155     0,                          /*tp_setattr*/
 156     0,                          /*tp_reserved*/
 157     0,                          /*tp_repr*/
 158     0,                          /*tp_as_number*/
 159     0,                          /*tp_as_sequence*/
 160     0,                          /*tp_as_mapping*/
 161     0,                          /*tp_hash*/
 162     0,                          /*tp_call*/
 163     0,                          /*tp_str*/
 164     0,                          /*tp_getattro*/
 165     0,                          /*tp_setattro*/
 166     0,                          /*tp_as_buffer*/
 167     0,                          /*tp_flags*/
 168     PyCObject_Type__doc__       /*tp_doc*/
 169 };