/src/glib/gio/ginitable.c

Source (jump to first uncovered line)
/* GIO - GLib Input, Output and Streaming Library
 *
 * Copyright (C) 2009 Red Hat, Inc.
 *
 * 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: 2025-07-01 07:09

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