Objects/cobject.c

   1 /***********************************************************
   2 Copyright (c) 2000, BeOpen.com.
   3 Copyright (c) 1995-2000, Corporation for National Research Initiatives.
   4 Copyright (c) 1990-1995, Stichting Mathematisch Centrum.
   5 All rights reserved.
   6
   7 See the file "Misc/COPYRIGHT" for information on usage and
   8 redistribution of this file, and for a DISCLAIMER OF ALL WARRANTIES.
   9 ******************************************************************/
  10
  11 /* Wrap void* pointers to be passed between C modules */
  12
  13 #include "Python.h"
  14
  15
  16 /* Declarations for objects of type PyCObject */
  17
  18 typedef void (*destructor1)(void *);
  19 typedef void (*destructor2)(void *, void*);
  20
  21 typedef struct {
  22     PyObject_HEAD
  23     void *cobject;
  24     void *desc;
  25     void (*destructor)(void *);
  26 } PyCObject;
  27
  28 PyObject *
  29 PyCObject_FromVoidPtr(void *cobj, void (*destr)(void *))
  30 {
  31     PyCObject *self;
  32
  33     self = PyObject_NEW(PyCObject, &PyCObject_Type);
  34     if (self == NULL)
  35         return NULL;
  36     self->cobject=cobj;
  37     self->destructor=destr;
  38     self->desc=NULL;
  39
  40     return (PyObject *)self;
  41 }
  42
  43 PyObject *
  44 PyCObject_FromVoidPtrAndDesc(void *cobj, void *desc,
  45                              void (*destr)(void *, void *))
  46 {
  47     PyCObject *self;
  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 static void
 112 PyCObject_dealloc(PyCObject *self)
 113 {
 114     if (self->destructor) {
 115         if(self->desc)
 116             ((destructor2)(self->destructor))(self->cobject, self->desc);
 117         else
 118             (self->destructor)(self->cobject);
 119     }
 120     PyObject_DEL(self);
 121 }
 122
 123
 124 static char PyCObject_Type__doc__[] =
 125 "C objects to be exported from one extension module to another\n\
 126 \n\
 127 C objects are used for communication between extension modules.  They\n\
 128 provide a way for an extension module to export a C interface to other\n\
 129 extension modules, so that extension modules can use the Python import\n\
 130 mechanism to link to one another.";
 131
 132 PyTypeObject PyCObject_Type = {
 133     PyObject_HEAD_INIT(&PyType_Type)
 134     0,                                  /*ob_size*/
 135     "PyCObject",                        /*tp_name*/
 136     sizeof(PyCObject),                  /*tp_basicsize*/
 137     0,                                  /*tp_itemsize*/
 138     /* methods */
 139     (destructor)PyCObject_dealloc,      /*tp_dealloc*/
 140     (printfunc)0,                       /*tp_print*/
 141     (getattrfunc)0,                     /*tp_getattr*/
 142     (setattrfunc)0,                     /*tp_setattr*/
 143     (cmpfunc)0,                         /*tp_compare*/
 144     (reprfunc)0,                        /*tp_repr*/
 145     0,                                  /*tp_as_number*/
 146     0,                                  /*tp_as_sequence*/
 147     0,                                  /*tp_as_mapping*/
 148     (hashfunc)0,                        /*tp_hash*/
 149     (ternaryfunc)0,                     /*tp_call*/
 150     (reprfunc)0,                        /*tp_str*/
 151
 152     /* Space for future expansion */
 153     0L,0L,0L,0L,
 154     PyCObject_Type__doc__               /* Documentation string */
 155 };