Objects/cobject.c

   1 /***********************************************************
   2 Copyright 1991-1995 by Stichting Mathematisch Centrum, Amsterdam,
   3 The Netherlands.
   4
   5                         All Rights Reserved
   6
   7 Permission to use, copy, modify, and distribute this software and its
   8 documentation for any purpose and without fee is hereby granted,
   9 provided that the above copyright notice appear in all copies and that
  10 both that copyright notice and this permission notice appear in
  11 supporting documentation, and that the names of Stichting Mathematisch
  12 Centrum or CWI or Corporation for National Research Initiatives or
  13 CNRI not be used in advertising or publicity pertaining to
  14 distribution of the software without specific, written prior
  15 permission.
  16
  17 While CWI is the initial source for this software, a modified version
  18 is made available by the Corporation for National Research Initiatives
  19 (CNRI) at the Internet address ftp://ftp.python.org.
  20
  21 STICHTING MATHEMATISCH CENTRUM AND CNRI DISCLAIM ALL WARRANTIES WITH
  22 REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF
  23 MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL STICHTING MATHEMATISCH
  24 CENTRUM OR CNRI BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL
  25 DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
  26 PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
  27 TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
  28 PERFORMANCE OF THIS SOFTWARE.
  29
  30 ******************************************************************/
  31
  32 /* Wrap void* pointers to be passed between C modules */
  33
  34 #include "Python.h"
  35
  36
  37 /* Declarations for objects of type PyCObject */
  38
  39 typedef void (*destructor1) Py_PROTO((void *));
  40 typedef void (*destructor2) Py_PROTO((void *, void*));
  41
  42 typedef struct {
  43         PyObject_HEAD
  44         void *cobject;
  45         void *desc;
  46         void (*destructor) Py_PROTO((void *));
  47 } PyCObject;
  48
  49 PyObject *
  50 PyCObject_FromVoidPtr(cobj, destr)
  51         void *cobj;
  52         void (*destr) Py_PROTO((void *));
  53 {
  54         PyCObject *self;
  55
  56         self = PyObject_NEW(PyCObject, &PyCObject_Type);
  57         if (self == NULL)
  58                 return NULL;
  59         self->cobject=cobj;
  60         self->destructor=destr;
  61         self->desc=NULL;
  62         return (PyObject *)self;
  63 }
  64
  65 PyObject *
  66 PyCObject_FromVoidPtrAndDesc(cobj, desc, destr)
  67         void *cobj;
  68         void *desc;
  69         void (*destr) Py_PROTO((void *, void *));
  70 {
  71         PyCObject *self;
  72
  73         if(!desc) {
  74                 PyErr_SetString(PyExc_TypeError,
  75                   "PyCObject_FromVoidPtrAndDesc called with null description");
  76                 return NULL;
  77         }
  78
  79         self = PyObject_NEW(PyCObject, &PyCObject_Type);
  80         if (self == NULL)
  81                 return NULL;
  82         self->cobject=cobj;
  83         self->destructor=(destructor1)destr;
  84         self->desc=desc;
  85         return (PyObject *)self;
  86 }
  87
  88 void *
  89 PyCObject_AsVoidPtr(self)
  90         PyObject *self;
  91 {
  92         if(self)
  93           {
  94             if(self->ob_type == &PyCObject_Type)
  95               return ((PyCObject *)self)->cobject;
  96             PyErr_SetString(PyExc_TypeError,
  97                             "PyCObject_AsVoidPtr with non-C-object");
  98           }
  99         if(! PyErr_Occurred())
 100             PyErr_SetString(PyExc_TypeError,
 101                             "PyCObject_AsVoidPtr called with null pointer");
 102         return NULL;
 103 }
 104
 105 void *
 106 PyCObject_GetDesc(self)
 107         PyObject *self;
 108 {
 109         if(self)
 110           {
 111             if(self->ob_type == &PyCObject_Type)
 112               return ((PyCObject *)self)->desc;
 113             PyErr_SetString(PyExc_TypeError,
 114                             "PyCObject_GetDesc with non-C-object");
 115           }
 116         if(! PyErr_Occurred())
 117             PyErr_SetString(PyExc_TypeError,
 118                             "PyCObject_GetDesc called with null pointer");
 119         return NULL;
 120 }
 121
 122 void *
 123 PyCObject_Import(module_name, name)
 124      char *module_name;
 125      char *name;
 126 {
 127   PyObject *m, *c;
 128   void *r=NULL;
 129
 130   if((m=PyImport_ImportModule(module_name)))
 131     {
 132       if((c=PyObject_GetAttrString(m,name)))
 133         {
 134           r=PyCObject_AsVoidPtr(c);
 135           Py_DECREF(c);
 136         }
 137       Py_DECREF(m);
 138     }
 139
 140   return r;
 141 }
 142
 143 static void
 144 PyCObject_dealloc(self)
 145         PyCObject *self;
 146 {
 147         if(self->destructor)
 148           {
 149             if(self->desc)
 150                   ((destructor2)(self->destructor))(self->cobject, self->desc);
 151             else
 152                   (self->destructor)(self->cobject);
 153           }
 154         PyMem_DEL(self);
 155 }
 156
 157
 158 static char PyCObject_Type__doc__[] =
 159 "C objects to be exported from one extension module to another\n\
 160 \n\
 161 C objects are used for communication between extension modules.  They\n\
 162 provide a way for an extension module to export a C interface to other\n\
 163 extension modules, so that extension modules can use the Python import\n\
 164 mechanism to link to one another.\n"
 165 ;
 166
 167 PyTypeObject PyCObject_Type = {
 168         PyObject_HEAD_INIT(&PyType_Type)
 169         0,                              /*ob_size*/
 170         "PyCObject",                    /*tp_name*/
 171         sizeof(PyCObject),              /*tp_basicsize*/
 172         0,                              /*tp_itemsize*/
 173         /* methods */
 174         (destructor)PyCObject_dealloc,  /*tp_dealloc*/
 175         (printfunc)0,           /*tp_print*/
 176         (getattrfunc)0, /*tp_getattr*/
 177         (setattrfunc)0, /*tp_setattr*/
 178         (cmpfunc)0,             /*tp_compare*/
 179         (reprfunc)0,            /*tp_repr*/
 180         0,                      /*tp_as_number*/
 181         0,              /*tp_as_sequence*/
 182         0,              /*tp_as_mapping*/
 183         (hashfunc)0,            /*tp_hash*/
 184         (ternaryfunc)0,         /*tp_call*/
 185         (reprfunc)0,            /*tp_str*/
 186
 187         /* Space for future expansion */
 188         0L,0L,0L,0L,
 189         PyCObject_Type__doc__ /* Documentation string */
 190 };