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