gi/pygi-struct.c

   1 /* -*- Mode: C; c-basic-offset: 4 -*-
   2  * vim: tabstop=4 shiftwidth=4 expandtab
   3  *
   4  * Copyright (C) 2009 Simon van der Linden <svdlinden@src.gnome.org>
   5  *
   6  *   pygi-struct.c: wrapper to handle non-registered structures.
   7  *
   8  * This library is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public
  10  * License as published by the Free Software Foundation; either
  11  * version 2.1 of the License, or (at your option) any later version.
  12  *
  13  * This library is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public
  19  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
  20  */
  21
  22 #include "pygi-struct.h"
  23 #include "pygi-foreign.h"
  24 #include "pygi-info.h"
  25 #include "pygi-type.h"
  26 #include "pygi-type.h"
  27 #include "pygpointer.h"
  28 #include "pygi-python-compat.h"
  29
  30 #include <girepository.h>
  31
  32
  33 static GIBaseInfo *
  34 struct_get_info (PyTypeObject *type)
  35 {
  36     PyObject *py_info;
  37     GIBaseInfo *info = NULL;
  38
  39     py_info = PyObject_GetAttrString ((PyObject *)type, "__info__");
  40     if (py_info == NULL) {
  41         return NULL;
  42     }
  43     if (!PyObject_TypeCheck (py_info, &PyGIStructInfo_Type) &&
  44             !PyObject_TypeCheck (py_info, &PyGIUnionInfo_Type)) {
  45         PyErr_Format (PyExc_TypeError, "attribute '__info__' must be %s or %s, not %s",
  46                       PyGIStructInfo_Type.tp_name,
  47                       PyGIUnionInfo_Type.tp_name,
  48                       Py_TYPE(py_info)->tp_name);
  49         goto out;
  50     }
  51
  52     info = ( (PyGIBaseInfo *) py_info)->info;
  53     g_base_info_ref (info);
  54
  55 out:
  56     Py_DECREF (py_info);
  57
  58     return info;
  59 }
  60
  61 static void
  62 struct_dealloc (PyGIStruct *self)
  63 {
  64     GIBaseInfo *info;
  65     PyObject *error_type, *error_value, *error_traceback;
  66     gboolean have_error = !!PyErr_Occurred ();
  67
  68     if (have_error)
  69         PyErr_Fetch (&error_type, &error_value, &error_traceback);
  70
  71     info = struct_get_info (Py_TYPE (self));
  72
  73     if (info != NULL && g_struct_info_is_foreign ( (GIStructInfo *) info)) {
  74         pygi_struct_foreign_release (info, pyg_pointer_get_ptr (self));
  75     } else if (self->free_on_dealloc) {
  76         g_free (pyg_pointer_get_ptr (self));
  77     }
  78
  79     if (info != NULL) {
  80         g_base_info_unref (info);
  81     }
  82
  83     if (have_error)
  84         PyErr_Restore (error_type, error_value, error_traceback);
  85
  86     Py_TYPE (self)->tp_free ((PyObject *)self);
  87 }
  88
  89 static PyObject *
  90 struct_new (PyTypeObject *type,
  91             PyObject     *args,
  92             PyObject     *kwargs)
  93 {
  94     static char *kwlist[] = { NULL };
  95
  96     GIBaseInfo *info;
  97     gsize size;
  98     gpointer pointer;
  99     PyObject *self = NULL;
 100
 101     if (!PyArg_ParseTupleAndKeywords (args, kwargs, "", kwlist)) {
 102         return NULL;
 103     }
 104
 105     info = struct_get_info ( type );
 106     if (info == NULL) {
 107         if (PyErr_ExceptionMatches (PyExc_AttributeError)) {
 108             PyErr_Format (PyExc_TypeError, "missing introspection information");
 109         }
 110         return NULL;
 111     }
 112
 113     size = g_struct_info_get_size ( (GIStructInfo *) info);
 114     if (size == 0) {
 115         PyErr_Format (PyExc_TypeError,
 116             "struct cannot be created directly; try using a constructor, see: help(%s.%s)",
 117             g_base_info_get_namespace (info),
 118             g_base_info_get_name (info));
 119         goto out;
 120     }
 121     pointer = g_try_malloc0 (size);
 122     if (pointer == NULL) {
 123         PyErr_NoMemory();
 124         goto out;
 125     }
 126
 127     self = pygi_struct_new (type, pointer, TRUE);
 128     if (self == NULL) {
 129         g_free (pointer);
 130     }
 131
 132 out:
 133     g_base_info_unref (info);
 134
 135     return (PyObject *) self;
 136 }
 137
 138 static int
 139 struct_init (PyObject *self,
 140               PyObject *args,
 141               PyObject *kwargs)
 142 {
 143     /* Don't call PyGPointer's init, which raises an exception. */
 144     return 0;
 145 }
 146
 147 PYGLIB_DEFINE_TYPE("gi.Struct", PyGIStruct_Type, PyGIStruct);
 148
 149
 150 PyObject *
 151 pygi_struct_new_from_g_type (GType g_type,
 152                              gpointer      pointer,
 153                              gboolean      free_on_dealloc)
 154 {
 155     PyGIStruct *self;
 156     PyTypeObject *type;
 157
 158     type = (PyTypeObject *)pygi_type_import_by_g_type (g_type);
 159
 160     if (!type)
 161         type = (PyTypeObject *)&PyGIStruct_Type; /* fallback */
 162
 163     if (!PyType_IsSubtype (type, &PyGIStruct_Type)) {
 164         PyErr_SetString (PyExc_TypeError, "must be a subtype of gi.Struct");
 165         return NULL;
 166     }
 167
 168     self = (PyGIStruct *) type->tp_alloc (type, 0);
 169     if (self == NULL) {
 170         return NULL;
 171     }
 172
 173     pyg_pointer_set_ptr (self, pointer);
 174     ( (PyGPointer *) self)->gtype = g_type;
 175     self->free_on_dealloc = free_on_dealloc;
 176
 177     return (PyObject *) self;
 178 }
 179
 180
 181 PyObject *
 182 pygi_struct_new (PyTypeObject *type,
 183                  gpointer      pointer,
 184                  gboolean      free_on_dealloc)
 185 {
 186     PyGIStruct *self;
 187     GType g_type;
 188
 189     if (!PyType_IsSubtype (type, &PyGIStruct_Type)) {
 190         PyErr_SetString (PyExc_TypeError, "must be a subtype of gi.Struct");
 191         return NULL;
 192     }
 193
 194     self = (PyGIStruct *) type->tp_alloc (type, 0);
 195     if (self == NULL) {
 196         return NULL;
 197     }
 198
 199     g_type = pyg_type_from_object ( (PyObject *) type);
 200
 201     pyg_pointer_set_ptr (self, pointer);
 202     ( (PyGPointer *) self)->gtype = g_type;
 203     self->free_on_dealloc = free_on_dealloc;
 204
 205     return (PyObject *) self;
 206 }
 207
 208 static PyObject *
 209 struct_repr(PyGIStruct *self)
 210 {
 211     PyObject* repr;
 212     GIBaseInfo *info;
 213     PyGPointer *pointer = (PyGPointer *)self;
 214
 215     info = struct_get_info (Py_TYPE (self));
 216     if (info == NULL)
 217         return NULL;
 218
 219     repr = PYGLIB_PyUnicode_FromFormat ("<%s.%s object at %p (%s at %p)>",
 220                                         g_base_info_get_namespace (info),
 221                                         g_base_info_get_name (info),
 222                                         self, g_type_name (pointer->gtype),
 223                                         pointer->pointer);
 224
 225     g_base_info_unref (info);
 226
 227     return repr;
 228 }
 229
 230 /**
 231  * Returns 0 on success, or -1 and sets an exception.
 232  */
 233 int
 234 pygi_struct_register_types (PyObject *m)
 235 {
 236     Py_TYPE(&PyGIStruct_Type) = &PyType_Type;
 237     g_assert (Py_TYPE (&PyGPointer_Type) != NULL);
 238     PyGIStruct_Type.tp_base = &PyGPointer_Type;
 239     PyGIStruct_Type.tp_new = (newfunc) struct_new;
 240     PyGIStruct_Type.tp_init = (initproc) struct_init;
 241     PyGIStruct_Type.tp_dealloc = (destructor) struct_dealloc;
 242     PyGIStruct_Type.tp_flags = (Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE);
 243     PyGIStruct_Type.tp_repr = (reprfunc)struct_repr;
 244
 245     if (PyType_Ready (&PyGIStruct_Type) < 0)
 246         return -1;
 247     Py_INCREF ((PyObject *) &PyGIStruct_Type);
 248     if (PyModule_AddObject (m, "Struct", (PyObject *) &PyGIStruct_Type) < 0) {
 249         Py_DECREF ((PyObject *) &PyGIStruct_Type);
 250         return -1;
 251     }
 252
 253     return 0;
 254 }