/src/glib/gio/ginitable.c

Source (jump to first uncovered line)
/* GIO - GLib Input, Output and Streaming Library
 *
 * Copyright (C) 2009 Red Hat, Inc.
 *
 * SPDX-License-Identifier: LGPL-2.1-or-later
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General
 * Public License along with this library; if not, see <http://www.gnu.org/licenses/>.
 *
 * Author: Alexander Larsson <alexl@redhat.com>
 */

#include "config.h"
#include "ginitable.h"
#include "glibintl.h"


/**
 * SECTION:ginitable
 * @short_description: Failable object initialization interface
 * @include: gio/gio.h
 * @see_also: #GAsyncInitable
 *
 * #GInitable is implemented by objects that can fail during
 * initialization. If an object implements this interface then
 * it must be initialized as the first thing after construction,
 * either via g_initable_init() or g_async_initable_init_async()
 * (the latter is only available if it also implements #GAsyncInitable).
 *
 * If the object is not initialized, or initialization returns with an
 * error, then all operations on the object except g_object_ref() and
 * g_object_unref() are considered to be invalid, and have undefined
 * behaviour. They will often fail with g_critical() or g_warning(), but
 * this must not be relied on.
 *
 * Users of objects implementing this are not intended to use
 * the interface method directly, instead it will be used automatically
 * in various ways. For C applications you generally just call
 * g_initable_new() directly, or indirectly via a foo_thing_new() wrapper.
 * This will call g_initable_init() under the cover, returning %NULL and
 * setting a #GError on failure (at which point the instance is
 * unreferenced).
 *
 * For bindings in languages where the native constructor supports
 * exceptions the binding could check for objects implementing %GInitable
 * during normal construction and automatically initialize them, throwing
 * an exception on failure.
 */

typedef GInitableIface GInitableInterface;
G_DEFINE_INTERFACE (GInitable, g_initable, G_TYPE_OBJECT)

static void
g_initable_default_init (GInitableInterface *iface)
{
}

/**
 * g_initable_init:
 * @initable: a #GInitable.
 * @cancellable: optional #GCancellable object, %NULL to ignore.
 * @error: a #GError location to store the error occurring, or %NULL to
 * ignore.
 *
 * Initializes the object implementing the interface.
 *
 * This method is intended for language bindings. If writing in C,
 * g_initable_new() should typically be used instead.
 *
 * The object must be initialized before any real use after initial
 * construction, either with this function or g_async_initable_init_async().
 *
 * Implementations may also support cancellation. If @cancellable is not %NULL,
 * then initialization can be cancelled by triggering the cancellable object
 * from another thread. If the operation was cancelled, the error
 * %G_IO_ERROR_CANCELLED will be returned. If @cancellable is not %NULL and
 * the object doesn't support cancellable initialization the error
 * %G_IO_ERROR_NOT_SUPPORTED will be returned.
 *
 * If the object is not initialized, or initialization returns with an
 * error, then all operations on the object except g_object_ref() and
 * g_object_unref() are considered to be invalid, and have undefined
 * behaviour. See the [introduction][ginitable] for more details.
 *
 * Callers should not assume that a class which implements #GInitable can be
 * initialized multiple times, unless the class explicitly documents itself as
 * supporting this. Generally, a class’ implementation of init() can assume
 * (and assert) that it will only be called once. Previously, this documentation
 * recommended all #GInitable implementations should be idempotent; that
 * recommendation was relaxed in GLib 2.54.
 *
 * If a class explicitly supports being initialized multiple times, it is
 * recommended that the method is idempotent: multiple calls with the same
 * arguments should return the same results. Only the first call initializes
 * the object; further calls return the result of the first call.
 *
 * One reason why a class might need to support idempotent initialization is if
 * it is designed to be used via the singleton pattern, with a
 * #GObjectClass.constructor that sometimes returns an existing instance.
 * In this pattern, a caller would expect to be able to call g_initable_init()
 * on the result of g_object_new(), regardless of whether it is in fact a new
 * instance.
 *
 * Returns: %TRUE if successful. If an error has occurred, this function will
 *     return %FALSE and set @error appropriately if present.
 *
 * Since: 2.22
 */
gboolean
g_initable_init (GInitable     *initable,
     GCancellable  *cancellable,
     GError       **error)
{
  GInitableIface *iface;

  g_return_val_if_fail (G_IS_INITABLE (initable), FALSE);

  iface = G_INITABLE_GET_IFACE (initable);

  return (* iface->init) (initable, cancellable, error);
}

/**
 * g_initable_new:
 * @object_type: a #GType supporting #GInitable.
 * @cancellable: optional #GCancellable object, %NULL to ignore.
 * @error: a #GError location to store the error occurring, or %NULL to
 *    ignore.
 * @first_property_name: (nullable): the name of the first property, or %NULL if no
 *     properties
 * @...:  the value if the first property, followed by and other property
 *    value pairs, and ended by %NULL.
 *
 * Helper function for constructing #GInitable object. This is
 * similar to g_object_new() but also initializes the object
 * and returns %NULL, setting an error on failure.
 *
 * Returns: (type GObject.Object) (transfer full): a newly allocated
 *      #GObject, or %NULL on error
 *
 * Since: 2.22
 */
gpointer
g_initable_new (GType          object_type,
    GCancellable  *cancellable,
    GError       **error,
    const gchar   *first_property_name,
    ...)
{
  GObject *object;
  va_list var_args;

  va_start (var_args, first_property_name);
  object = g_initable_new_valist (object_type,
          first_property_name, var_args,
          cancellable, error);
  va_end (var_args);

  return object;
}

/**
 * g_initable_newv:
 * @object_type: a #GType supporting #GInitable.
 * @n_parameters: the number of parameters in @parameters
 * @parameters: (array length=n_parameters): the parameters to use to construct the object
 * @cancellable: optional #GCancellable object, %NULL to ignore.
 * @error: a #GError location to store the error occurring, or %NULL to
 *     ignore.
 *
 * Helper function for constructing #GInitable object. This is
 * similar to g_object_newv() but also initializes the object
 * and returns %NULL, setting an error on failure.
 *
 * Returns: (type GObject.Object) (transfer full): a newly allocated
 *      #GObject, or %NULL on error
 *
 * Since: 2.22
 * Deprecated: 2.54: Use g_object_new_with_properties() and
 * g_initable_init() instead. See #GParameter for more information.
 */
G_GNUC_BEGIN_IGNORE_DEPRECATIONS
gpointer
g_initable_newv (GType          object_type,
     guint          n_parameters,
     GParameter    *parameters,
     GCancellable  *cancellable,
     GError       **error)
{
  GObject *obj;

  g_return_val_if_fail (G_TYPE_IS_INITABLE (object_type), NULL);

  obj = g_object_newv (object_type, n_parameters, parameters);

  if (!g_initable_init (G_INITABLE (obj), cancellable, error))
    {
      g_object_unref (obj);
      return NULL;
    }

  return (gpointer)obj;
}
G_GNUC_END_IGNORE_DEPRECATIONS

/**
 * g_initable_new_valist:
 * @object_type: a #GType supporting #GInitable.
 * @first_property_name: the name of the first property, followed by
 * the value, and other property value pairs, and ended by %NULL.
 * @var_args: The var args list generated from @first_property_name.
 * @cancellable: optional #GCancellable object, %NULL to ignore.
 * @error: a #GError location to store the error occurring, or %NULL to
 *     ignore.
 *
 * Helper function for constructing #GInitable object. This is
 * similar to g_object_new_valist() but also initializes the object
 * and returns %NULL, setting an error on failure.
 *
 * Returns: (type GObject.Object) (transfer full): a newly allocated
 *      #GObject, or %NULL on error
 *
 * Since: 2.22
 */
GObject*
g_initable_new_valist (GType          object_type,
           const gchar   *first_property_name,
           va_list        var_args,
           GCancellable  *cancellable,
           GError       **error)
{
  GObject *obj;

  g_return_val_if_fail (G_TYPE_IS_INITABLE (object_type), NULL);

  obj = g_object_new_valist (object_type,
           first_property_name,
           var_args);

  if (!g_initable_init (G_INITABLE (obj), cancellable, error))
    {
      g_object_unref (obj);
      return NULL;
    }

  return obj;
}

Coverage Report

Created: 2025-06-13 06:55

Line	Count	Source (jump to first uncovered line)
1		/* GIO - GLib Input, Output and Streaming Library
2		*
3		* Copyright (C) 2009 Red Hat, Inc.
4		*
5		* SPDX-License-Identifier: LGPL-2.1-or-later
6		*
7		* This library is free software; you can redistribute it and/or
8		* modify it under the terms of the GNU Lesser General Public
9		* License as published by the Free Software Foundation; either
10		* version 2.1 of the License, or (at your option) any later version.
11		*
12		* This library is distributed in the hope that it will be useful,
13		* but WITHOUT ANY WARRANTY; without even the implied warranty of
14		* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15		* Lesser General Public License for more details.
16		*
17		* You should have received a copy of the GNU Lesser General
18		* Public License along with this library; if not, see <http://www.gnu.org/licenses/>.
19		*
20		* Author: Alexander Larsson <alexl@redhat.com>
21		*/
22
23		#include "config.h"
24		#include "ginitable.h"
25		#include "glibintl.h"
26
27
28		/**
29		* SECTION:ginitable
30		* @short_description: Failable object initialization interface
31		* @include: gio/gio.h
32		* @see_also: #GAsyncInitable
33		*
34		* #GInitable is implemented by objects that can fail during
35		* initialization. If an object implements this interface then
36		* it must be initialized as the first thing after construction,
37		* either via g_initable_init() or g_async_initable_init_async()
38		* (the latter is only available if it also implements #GAsyncInitable).
39		*
40		* If the object is not initialized, or initialization returns with an
41		* error, then all operations on the object except g_object_ref() and
42		* g_object_unref() are considered to be invalid, and have undefined
43		* behaviour. They will often fail with g_critical() or g_warning(), but
44		* this must not be relied on.
45		*
46		* Users of objects implementing this are not intended to use
47		* the interface method directly, instead it will be used automatically
48		* in various ways. For C applications you generally just call
49		* g_initable_new() directly, or indirectly via a foo_thing_new() wrapper.
50		* This will call g_initable_init() under the cover, returning %NULL and
51		* setting a #GError on failure (at which point the instance is
52		* unreferenced).
53		*
54		* For bindings in languages where the native constructor supports
55		* exceptions the binding could check for objects implementing %GInitable
56		* during normal construction and automatically initialize them, throwing
57		* an exception on failure.
58		*/
59
60		typedef GInitableIface GInitableInterface;
61		G_DEFINE_INTERFACE (GInitable, g_initable, G_TYPE_OBJECT)
62
63		static void
64		g_initable_default_init (GInitableInterface *iface)
65	0	{
66	0	}
67
68		/**
69		* g_initable_init:
70		* @initable: a #GInitable.
71		* @cancellable: optional #GCancellable object, %NULL to ignore.
72		* @error: a #GError location to store the error occurring, or %NULL to
73		* ignore.
74		*
75		* Initializes the object implementing the interface.
76		*
77		* This method is intended for language bindings. If writing in C,
78		* g_initable_new() should typically be used instead.
79		*
80		* The object must be initialized before any real use after initial
81		* construction, either with this function or g_async_initable_init_async().
82		*
83		* Implementations may also support cancellation. If @cancellable is not %NULL,
84		* then initialization can be cancelled by triggering the cancellable object
85		* from another thread. If the operation was cancelled, the error
86		* %G_IO_ERROR_CANCELLED will be returned. If @cancellable is not %NULL and
87		* the object doesn't support cancellable initialization the error
88		* %G_IO_ERROR_NOT_SUPPORTED will be returned.
89		*
90		* If the object is not initialized, or initialization returns with an
91		* error, then all operations on the object except g_object_ref() and
92		* g_object_unref() are considered to be invalid, and have undefined
93		* behaviour. See the [introduction][ginitable] for more details.
94		*
95		* Callers should not assume that a class which implements #GInitable can be
96		* initialized multiple times, unless the class explicitly documents itself as
97		* supporting this. Generally, a class’ implementation of init() can assume
98		* (and assert) that it will only be called once. Previously, this documentation
99		* recommended all #GInitable implementations should be idempotent; that
100		* recommendation was relaxed in GLib 2.54.
101		*
102		* If a class explicitly supports being initialized multiple times, it is
103		* recommended that the method is idempotent: multiple calls with the same
104		* arguments should return the same results. Only the first call initializes
105		* the object; further calls return the result of the first call.
106		*
107		* One reason why a class might need to support idempotent initialization is if
108		* it is designed to be used via the singleton pattern, with a
109		* #GObjectClass.constructor that sometimes returns an existing instance.
110		* In this pattern, a caller would expect to be able to call g_initable_init()
111		* on the result of g_object_new(), regardless of whether it is in fact a new
112		* instance.
113		*
114		* Returns: %TRUE if successful. If an error has occurred, this function will
115		* return %FALSE and set @error appropriately if present.
116		*
117		* Since: 2.22
118		*/
119		gboolean
120		g_initable_init (GInitable *initable,
121		GCancellable *cancellable,
122		GError **error)
123	0	{
124	0	GInitableIface *iface;
125
126	0	g_return_val_if_fail (G_IS_INITABLE (initable), FALSE);
127
128	0	iface = G_INITABLE_GET_IFACE (initable);
129
130	0	return (* iface->init) (initable, cancellable, error);
131	0	}
132
133		/**
134		* g_initable_new:
135		* @object_type: a #GType supporting #GInitable.
136		* @cancellable: optional #GCancellable object, %NULL to ignore.
137		* @error: a #GError location to store the error occurring, or %NULL to
138		* ignore.
139		* @first_property_name: (nullable): the name of the first property, or %NULL if no
140		* properties
141		* @...: the value if the first property, followed by and other property
142		* value pairs, and ended by %NULL.
143		*
144		* Helper function for constructing #GInitable object. This is
145		* similar to g_object_new() but also initializes the object
146		* and returns %NULL, setting an error on failure.
147		*
148		* Returns: (type GObject.Object) (transfer full): a newly allocated
149		* #GObject, or %NULL on error
150		*
151		* Since: 2.22
152		*/
153		gpointer
154		g_initable_new (GType object_type,
155		GCancellable *cancellable,
156		GError **error,
157		const gchar *first_property_name,
158		...)
159	0	{
160	0	GObject *object;
161	0	va_list var_args;
162
163	0	va_start (var_args, first_property_name);
164	0	object = g_initable_new_valist (object_type,
165	0	first_property_name, var_args,
166	0	cancellable, error);
167	0	va_end (var_args);
168
169	0	return object;
170	0	}
171
172		/**
173		* g_initable_newv:
174		* @object_type: a #GType supporting #GInitable.
175		* @n_parameters: the number of parameters in @parameters
176		* @parameters: (array length=n_parameters): the parameters to use to construct the object
177		* @cancellable: optional #GCancellable object, %NULL to ignore.
178		* @error: a #GError location to store the error occurring, or %NULL to
179		* ignore.
180		*
181		* Helper function for constructing #GInitable object. This is
182		* similar to g_object_newv() but also initializes the object
183		* and returns %NULL, setting an error on failure.
184		*
185		* Returns: (type GObject.Object) (transfer full): a newly allocated
186		* #GObject, or %NULL on error
187		*
188		* Since: 2.22
189		* Deprecated: 2.54: Use g_object_new_with_properties() and
190		* g_initable_init() instead. See #GParameter for more information.
191		*/
192		G_GNUC_BEGIN_IGNORE_DEPRECATIONS
193		gpointer
194		g_initable_newv (GType object_type,
195		guint n_parameters,
196		GParameter *parameters,
197		GCancellable *cancellable,
198		GError **error)
199	0	{
200	0	GObject *obj;
201
202	0	g_return_val_if_fail (G_TYPE_IS_INITABLE (object_type), NULL);
203
204	0	obj = g_object_newv (object_type, n_parameters, parameters);
205
206	0	if (!g_initable_init (G_INITABLE (obj), cancellable, error))
207	0	{
208	0	g_object_unref (obj);
209	0	return NULL;
210	0	}
211
212	0	return (gpointer)obj;
213	0	}
214		G_GNUC_END_IGNORE_DEPRECATIONS
215
216		/**
217		* g_initable_new_valist:
218		* @object_type: a #GType supporting #GInitable.
219		* @first_property_name: the name of the first property, followed by
220		* the value, and other property value pairs, and ended by %NULL.
221		* @var_args: The var args list generated from @first_property_name.
222		* @cancellable: optional #GCancellable object, %NULL to ignore.
223		* @error: a #GError location to store the error occurring, or %NULL to
224		* ignore.
225		*
226		* Helper function for constructing #GInitable object. This is
227		* similar to g_object_new_valist() but also initializes the object
228		* and returns %NULL, setting an error on failure.
229		*
230		* Returns: (type GObject.Object) (transfer full): a newly allocated
231		* #GObject, or %NULL on error
232		*
233		* Since: 2.22
234		*/
235		GObject*
236		g_initable_new_valist (GType object_type,
237		const gchar *first_property_name,
238		va_list var_args,
239		GCancellable *cancellable,
240		GError **error)
241	0	{
242	0	GObject *obj;
243
244	0	g_return_val_if_fail (G_TYPE_IS_INITABLE (object_type), NULL);
245
246	0	obj = g_object_new_valist (object_type,
247	0	first_property_name,
248	0	var_args);
249
250	0	if (!g_initable_init (G_INITABLE (obj), cancellable, error))
251	0	{
252	0	g_object_unref (obj);
253	0	return NULL;
254	0	}
255
256	0	return obj;
257	0	}