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Found using: find . -name '*.c' | xargs grep 'or %NULL' | grep ' \* @' | grep -v '@error' | grep -v allow-none
1036 lines
32 KiB
C
1036 lines
32 KiB
C
/*
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* Copyright © 2009, 2010 Codethink Limited
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* Copyright © 2010 Red Hat, Inc.
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2 of the licence, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, write to the
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* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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* Boston, MA 02111-1307, USA.
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*
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* Authors: Ryan Lortie <desrt@desrt.ca>
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* Matthias Clasen <mclasen@redhat.com>
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*/
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#include "config.h"
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#include "gsettingsbackendinternal.h"
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#include "gsimplepermission.h"
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#include "giomodule-priv.h"
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#include <string.h>
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#include <stdlib.h>
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#include <glib.h>
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#include <glibintl.h>
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G_DEFINE_ABSTRACT_TYPE (GSettingsBackend, g_settings_backend, G_TYPE_OBJECT)
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typedef struct _GSettingsBackendClosure GSettingsBackendClosure;
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typedef struct _GSettingsBackendWatch GSettingsBackendWatch;
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struct _GSettingsBackendPrivate
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{
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GSettingsBackendWatch *watches;
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GMutex lock;
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};
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/* For g_settings_backend_sync_default(), we only want to actually do
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* the sync if the backend already exists. This avoids us creating an
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* entire GSettingsBackend in order to call a do-nothing sync()
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* operation on it. This variable lets us avoid that.
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*/
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static gboolean g_settings_has_backend;
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/**
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* SECTION:gsettingsbackend
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* @title: GSettingsBackend
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* @short_description: Interface for settings backend implementations
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* @include: gio/gsettingsbackend.h
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* @see_also: #GSettings, #GIOExtensionPoint
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*
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* The #GSettingsBackend interface defines a generic interface for
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* non-strictly-typed data that is stored in a hierarchy. To implement
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* an alternative storage backend for #GSettings, you need to implement
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* the #GSettingsBackend interface and then make it implement the
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* extension point #G_SETTINGS_BACKEND_EXTENSION_POINT_NAME.
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*
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* The interface defines methods for reading and writing values, a
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* method for determining if writing of certain values will fail
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* (lockdown) and a change notification mechanism.
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*
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* The semantics of the interface are very precisely defined and
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* implementations must carefully adhere to the expectations of
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* callers that are documented on each of the interface methods.
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*
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* Some of the GSettingsBackend functions accept or return a #GTree.
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* These trees always have strings as keys and #GVariant as values.
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* g_settings_backend_create_tree() is a convenience function to create
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* suitable trees.
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*
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* <note><para>
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* The #GSettingsBackend API is exported to allow third-party
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* implementations, but does not carry the same stability guarantees
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* as the public GIO API. For this reason, you have to define the
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* C preprocessor symbol #G_SETTINGS_ENABLE_BACKEND before including
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* <filename>gio/gsettingsbackend.h</filename>
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* </para></note>
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**/
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static gboolean
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is_key (const gchar *key)
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{
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gint length;
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gint i;
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g_return_val_if_fail (key != NULL, FALSE);
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g_return_val_if_fail (key[0] == '/', FALSE);
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for (i = 1; key[i]; i++)
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g_return_val_if_fail (key[i] != '/' || key[i + 1] != '/', FALSE);
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length = i;
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g_return_val_if_fail (key[length - 1] != '/', FALSE);
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return TRUE;
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}
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static gboolean
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is_path (const gchar *path)
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{
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gint length;
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gint i;
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g_return_val_if_fail (path != NULL, FALSE);
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g_return_val_if_fail (path[0] == '/', FALSE);
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for (i = 1; path[i]; i++)
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g_return_val_if_fail (path[i] != '/' || path[i + 1] != '/', FALSE);
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length = i;
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g_return_val_if_fail (path[length - 1] == '/', FALSE);
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return TRUE;
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}
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struct _GSettingsBackendWatch
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{
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GObject *target;
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const GSettingsListenerVTable *vtable;
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GMainContext *context;
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GSettingsBackendWatch *next;
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};
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struct _GSettingsBackendClosure
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{
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void (*function) (GObject *target,
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GSettingsBackend *backend,
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const gchar *name,
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gpointer data1,
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gpointer data2);
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GSettingsBackend *backend;
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GObject *target;
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gchar *name;
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gpointer data1;
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GBoxedFreeFunc data1_free;
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gpointer data2;
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};
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static void
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g_settings_backend_watch_weak_notify (gpointer data,
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GObject *where_the_object_was)
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{
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GSettingsBackend *backend = data;
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GSettingsBackendWatch **ptr;
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/* search and remove */
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g_mutex_lock (&backend->priv->lock);
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for (ptr = &backend->priv->watches; *ptr; ptr = &(*ptr)->next)
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if ((*ptr)->target == where_the_object_was)
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{
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GSettingsBackendWatch *tmp = *ptr;
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*ptr = tmp->next;
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g_slice_free (GSettingsBackendWatch, tmp);
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g_mutex_unlock (&backend->priv->lock);
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return;
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}
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/* we didn't find it. that shouldn't happen. */
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g_assert_not_reached ();
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}
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/*< private >
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* g_settings_backend_watch:
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* @backend: a #GSettingsBackend
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* @target: the GObject (typically GSettings instance) to call back to
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* @context: (allow-none): a #GMainContext, or %NULL
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* ...: callbacks...
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*
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* Registers a new watch on a #GSettingsBackend.
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*
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* note: %NULL @context does not mean "default main context" but rather,
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* "it is okay to dispatch in any context". If the default main context
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* is specifically desired then it must be given.
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*
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* note also: if you want to get meaningful values for the @origin_tag
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* that appears as an argument to some of the callbacks, you *must* have
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* @context as %NULL. Otherwise, you are subject to cross-thread
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* dispatching and whatever owned @origin_tag at the time that the event
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* occurred may no longer own it. This is a problem if you consider that
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* you may now be the new owner of that address and mistakenly think
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* that the event in question originated from yourself.
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*
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* tl;dr: If you give a non-%NULL @context then you must ignore the
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* value of @origin_tag given to any callbacks.
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**/
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void
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g_settings_backend_watch (GSettingsBackend *backend,
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const GSettingsListenerVTable *vtable,
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GObject *target,
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GMainContext *context)
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{
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GSettingsBackendWatch *watch;
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/* For purposes of discussion, we assume that our target is a
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* GSettings instance.
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*
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* Our strategy to defend against the final reference dropping on the
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* GSettings object in a thread other than the one that is doing the
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* dispatching is as follows:
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*
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* 1) hold a GObject reference on the GSettings during an outstanding
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* dispatch. This ensures that the delivery is always possible.
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*
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* 2) hold a weak reference on the GSettings at other times. This
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* allows us to receive early notification of pending destruction
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* of the object. At this point, it is still safe to obtain a
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* reference on the GObject to keep it alive, so #1 will work up
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* to that point. After that point, we'll have been able to drop
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* the watch from the list.
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*
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* Note, in particular, that it's not possible to simply have an
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* "unwatch" function that gets called from the finalize function of
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* the GSettings instance because, by that point it is no longer
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* possible to keep the object alive using g_object_ref() and we would
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* have no way of knowing this.
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*
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* Note also that we do not need to hold a reference on the main
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* context here since the GSettings instance does that for us and we
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* will receive the weak notify long before it is dropped. We don't
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* even need to hold it during dispatches because our reference on the
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* GSettings will prevent the finalize from running and dropping the
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* ref on the context.
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*
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* All access to the list holds a mutex. We have some strategies to
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* avoid some of the pain that would be associated with that.
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*/
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watch = g_slice_new (GSettingsBackendWatch);
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watch->context = context;
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watch->vtable = vtable;
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watch->target = target;
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g_object_weak_ref (target, g_settings_backend_watch_weak_notify, backend);
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/* linked list prepend */
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g_mutex_lock (&backend->priv->lock);
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watch->next = backend->priv->watches;
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backend->priv->watches = watch;
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g_mutex_unlock (&backend->priv->lock);
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}
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void
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g_settings_backend_unwatch (GSettingsBackend *backend,
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GObject *target)
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{
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/* Our caller surely owns a reference on 'target', so the order of
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* these two calls is unimportant.
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*/
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g_object_weak_unref (target, g_settings_backend_watch_weak_notify, backend);
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g_settings_backend_watch_weak_notify (backend, target);
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}
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static gboolean
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g_settings_backend_invoke_closure (gpointer user_data)
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{
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GSettingsBackendClosure *closure = user_data;
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closure->function (closure->target, closure->backend, closure->name,
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closure->data1, closure->data2);
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closure->data1_free (closure->data1);
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g_object_unref (closure->backend);
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g_object_unref (closure->target);
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g_free (closure->name);
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g_slice_free (GSettingsBackendClosure, closure);
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return FALSE;
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}
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static gpointer
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pointer_id (gpointer a)
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{
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return a;
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}
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static void
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pointer_ignore (gpointer a)
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{
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}
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static void
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g_settings_backend_dispatch_signal (GSettingsBackend *backend,
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gsize function_offset,
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const gchar *name,
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gpointer data1,
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GBoxedCopyFunc data1_copy,
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GBoxedFreeFunc data1_free,
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gpointer data2)
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{
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GSettingsBackendWatch *suffix, *watch, *next;
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if (data1_copy == NULL)
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data1_copy = pointer_id;
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if (data1_free == NULL)
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data1_free = pointer_ignore;
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/* We're in a little bit of a tricky situation here. We need to hold
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* a lock while traversing the list, but we don't want to hold the
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* lock while calling back into user code.
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*
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* Since we're not holding the lock while we call user code, we can't
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* render the list immutable. We can, however, store a pointer to a
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* given suffix of the list and render that suffix immutable.
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*
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* Adds will never modify the suffix since adds always come in the
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* form of prepends. We can also prevent removes from modifying the
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* suffix since removes only happen in response to the last reference
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* count dropping -- so just add a reference to everything in the
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* suffix.
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*/
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g_mutex_lock (&backend->priv->lock);
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suffix = backend->priv->watches;
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for (watch = suffix; watch; watch = watch->next)
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g_object_ref (watch->target);
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g_mutex_unlock (&backend->priv->lock);
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/* The suffix is now immutable, so this is safe. */
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for (watch = suffix; watch; watch = next)
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{
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GSettingsBackendClosure *closure;
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closure = g_slice_new (GSettingsBackendClosure);
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closure->backend = g_object_ref (backend);
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closure->target = watch->target; /* we took our ref above */
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closure->function = G_STRUCT_MEMBER (void *, watch->vtable,
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function_offset);
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closure->name = g_strdup (name);
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closure->data1 = data1_copy (data1);
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closure->data1_free = data1_free;
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closure->data2 = data2;
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/* we do this here because 'watch' may not live to the end of this
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* iteration of the loop (since we may unref the target below).
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*/
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next = watch->next;
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if (watch->context)
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g_main_context_invoke (watch->context,
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g_settings_backend_invoke_closure,
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closure);
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else
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g_settings_backend_invoke_closure (closure);
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}
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}
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/**
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* g_settings_backend_changed:
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* @backend: a #GSettingsBackend implementation
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* @key: the name of the key
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* @origin_tag: the origin tag
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*
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* Signals that a single key has possibly changed. Backend
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* implementations should call this if a key has possibly changed its
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* value.
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*
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* @key must be a valid key (ie starting with a slash, not containing
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* '//', and not ending with a slash).
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*
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* The implementation must call this function during any call to
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* g_settings_backend_write(), before the call returns (except in the
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* case that no keys are actually changed and it cares to detect this
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* fact). It may not rely on the existence of a mainloop for
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* dispatching the signal later.
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*
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* The implementation may call this function at any other time it likes
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* in response to other events (such as changes occurring outside of the
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* program). These calls may originate from a mainloop or may originate
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* in response to any other action (including from calls to
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* g_settings_backend_write()).
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*
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* In the case that this call is in response to a call to
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* g_settings_backend_write() then @origin_tag must be set to the same
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* value that was passed to that call.
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*
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* Since: 2.26
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**/
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void
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g_settings_backend_changed (GSettingsBackend *backend,
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const gchar *key,
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gpointer origin_tag)
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{
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g_return_if_fail (G_IS_SETTINGS_BACKEND (backend));
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g_return_if_fail (is_key (key));
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g_settings_backend_dispatch_signal (backend,
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G_STRUCT_OFFSET (GSettingsListenerVTable,
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changed),
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key, origin_tag, NULL, NULL, NULL);
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}
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/**
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* g_settings_backend_keys_changed:
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* @backend: a #GSettingsBackend implementation
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* @path: the path containing the changes
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* @items: (array zero-terminated=1): the %NULL-terminated list of changed keys
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* @origin_tag: the origin tag
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*
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* Signals that a list of keys have possibly changed. Backend
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* implementations should call this if keys have possibly changed their
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* values.
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*
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* @path must be a valid path (ie starting and ending with a slash and
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* not containing '//'). Each string in @items must form a valid key
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* name when @path is prefixed to it (ie: each item must not start or
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* end with '/' and must not contain '//').
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*
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* The meaning of this signal is that any of the key names resulting
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* from the contatenation of @path with each item in @items may have
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* changed.
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*
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* The same rules for when notifications must occur apply as per
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* g_settings_backend_changed(). These two calls can be used
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* interchangeably if exactly one item has changed (although in that
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* case g_settings_backend_changed() is definitely preferred).
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*
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* For efficiency reasons, the implementation should strive for @path to
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* be as long as possible (ie: the longest common prefix of all of the
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* keys that were changed) but this is not strictly required.
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*
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* Since: 2.26
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*/
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void
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g_settings_backend_keys_changed (GSettingsBackend *backend,
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const gchar *path,
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gchar const * const *items,
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gpointer origin_tag)
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{
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g_return_if_fail (G_IS_SETTINGS_BACKEND (backend));
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g_return_if_fail (is_path (path));
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/* XXX: should do stricter checking (ie: inspect each item) */
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g_return_if_fail (items != NULL);
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g_settings_backend_dispatch_signal (backend,
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G_STRUCT_OFFSET (GSettingsListenerVTable,
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keys_changed),
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path, (gpointer) items,
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(GBoxedCopyFunc) g_strdupv,
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(GBoxedFreeFunc) g_strfreev,
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origin_tag);
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}
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|
|
/**
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* g_settings_backend_path_changed:
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* @backend: a #GSettingsBackend implementation
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* @path: the path containing the changes
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* @origin_tag: the origin tag
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*
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* Signals that all keys below a given path may have possibly changed.
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* Backend implementations should call this if an entire path of keys
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* have possibly changed their values.
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*
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* @path must be a valid path (ie starting and ending with a slash and
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* not containing '//').
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*
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* The meaning of this signal is that any of the key which has a name
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* starting with @path may have changed.
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*
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* The same rules for when notifications must occur apply as per
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* g_settings_backend_changed(). This call might be an appropriate
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* reasponse to a 'reset' call but implementations are also free to
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* explicitly list the keys that were affected by that call if they can
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* easily do so.
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*
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* For efficiency reasons, the implementation should strive for @path to
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* be as long as possible (ie: the longest common prefix of all of the
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* keys that were changed) but this is not strictly required. As an
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* example, if this function is called with the path of "/" then every
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* single key in the application will be notified of a possible change.
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*
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* Since: 2.26
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*/
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void
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g_settings_backend_path_changed (GSettingsBackend *backend,
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const gchar *path,
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gpointer origin_tag)
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{
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g_return_if_fail (G_IS_SETTINGS_BACKEND (backend));
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g_return_if_fail (is_path (path));
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g_settings_backend_dispatch_signal (backend,
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G_STRUCT_OFFSET (GSettingsListenerVTable,
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path_changed),
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path, origin_tag, NULL, NULL, NULL);
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}
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|
|
/**
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|
* g_settings_backend_writable_changed:
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* @backend: a #GSettingsBackend implementation
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* @key: the name of the key
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*
|
|
* Signals that the writability of a single key has possibly changed.
|
|
*
|
|
* Since GSettings performs no locking operations for itself, this call
|
|
* will always be made in response to external events.
|
|
*
|
|
* Since: 2.26
|
|
**/
|
|
void
|
|
g_settings_backend_writable_changed (GSettingsBackend *backend,
|
|
const gchar *key)
|
|
{
|
|
g_return_if_fail (G_IS_SETTINGS_BACKEND (backend));
|
|
g_return_if_fail (is_key (key));
|
|
|
|
g_settings_backend_dispatch_signal (backend,
|
|
G_STRUCT_OFFSET (GSettingsListenerVTable,
|
|
writable_changed),
|
|
key, NULL, NULL, NULL, NULL);
|
|
}
|
|
|
|
/**
|
|
* g_settings_backend_path_writable_changed:
|
|
* @backend: a #GSettingsBackend implementation
|
|
* @path: the name of the path
|
|
*
|
|
* Signals that the writability of all keys below a given path may have
|
|
* changed.
|
|
*
|
|
* Since GSettings performs no locking operations for itself, this call
|
|
* will always be made in response to external events.
|
|
*
|
|
* Since: 2.26
|
|
**/
|
|
void
|
|
g_settings_backend_path_writable_changed (GSettingsBackend *backend,
|
|
const gchar *path)
|
|
{
|
|
g_return_if_fail (G_IS_SETTINGS_BACKEND (backend));
|
|
g_return_if_fail (is_path (path));
|
|
|
|
g_settings_backend_dispatch_signal (backend,
|
|
G_STRUCT_OFFSET (GSettingsListenerVTable,
|
|
path_writable_changed),
|
|
path, NULL, NULL, NULL, NULL);
|
|
}
|
|
|
|
typedef struct
|
|
{
|
|
const gchar **keys;
|
|
GVariant **values;
|
|
gint prefix_len;
|
|
gchar *prefix;
|
|
} FlattenState;
|
|
|
|
static gboolean
|
|
g_settings_backend_flatten_one (gpointer key,
|
|
gpointer value,
|
|
gpointer user_data)
|
|
{
|
|
FlattenState *state = user_data;
|
|
const gchar *skey = key;
|
|
gint i;
|
|
|
|
g_return_val_if_fail (is_key (key), TRUE);
|
|
|
|
/* calculate longest common prefix */
|
|
if (state->prefix == NULL)
|
|
{
|
|
gchar *last_byte;
|
|
|
|
/* first key? just take the prefix up to the last '/' */
|
|
state->prefix = g_strdup (skey);
|
|
last_byte = strrchr (state->prefix, '/') + 1;
|
|
state->prefix_len = last_byte - state->prefix;
|
|
*last_byte = '\0';
|
|
}
|
|
else
|
|
{
|
|
/* find the first character that does not match. we will
|
|
* definitely find one because the prefix ends in '/' and the key
|
|
* does not. also: no two keys in the tree are the same.
|
|
*/
|
|
for (i = 0; state->prefix[i] == skey[i]; i++);
|
|
|
|
/* check if we need to shorten the prefix */
|
|
if (state->prefix[i] != '\0')
|
|
{
|
|
/* find the nearest '/', terminate after it */
|
|
while (state->prefix[i - 1] != '/')
|
|
i--;
|
|
|
|
state->prefix[i] = '\0';
|
|
state->prefix_len = i;
|
|
}
|
|
}
|
|
|
|
|
|
/* save the entire item into the array.
|
|
* the prefixes will be removed later.
|
|
*/
|
|
*state->keys++ = key;
|
|
|
|
if (state->values)
|
|
*state->values++ = value;
|
|
|
|
return FALSE;
|
|
}
|
|
|
|
/**
|
|
* g_settings_backend_flatten_tree:
|
|
* @tree: a #GTree containing the changes
|
|
* @path: (out): the location to save the path
|
|
* @keys: (out) (transfer container) (array zero-terminated=1): the
|
|
* location to save the relative keys
|
|
* @values: (out) (allow-none) (transfer container) (array zero-terminated=1):
|
|
* the location to save the values, or %NULL
|
|
*
|
|
* Calculate the longest common prefix of all keys in a tree and write
|
|
* out an array of the key names relative to that prefix and,
|
|
* optionally, the value to store at each of those keys.
|
|
*
|
|
* You must free the value returned in @path, @keys and @values using
|
|
* g_free(). You should not attempt to free or unref the contents of
|
|
* @keys or @values.
|
|
*
|
|
* Since: 2.26
|
|
**/
|
|
void
|
|
g_settings_backend_flatten_tree (GTree *tree,
|
|
gchar **path,
|
|
const gchar ***keys,
|
|
GVariant ***values)
|
|
{
|
|
FlattenState state = { 0, };
|
|
gsize nnodes;
|
|
|
|
nnodes = g_tree_nnodes (tree);
|
|
|
|
*keys = state.keys = g_new (const gchar *, nnodes + 1);
|
|
state.keys[nnodes] = NULL;
|
|
|
|
if (values != NULL)
|
|
{
|
|
*values = state.values = g_new (GVariant *, nnodes + 1);
|
|
state.values[nnodes] = NULL;
|
|
}
|
|
|
|
g_tree_foreach (tree, g_settings_backend_flatten_one, &state);
|
|
g_return_if_fail (*keys + nnodes == state.keys);
|
|
|
|
*path = state.prefix;
|
|
while (nnodes--)
|
|
*--state.keys += state.prefix_len;
|
|
}
|
|
|
|
/**
|
|
* g_settings_backend_changed_tree:
|
|
* @backend: a #GSettingsBackend implementation
|
|
* @tree: a #GTree containing the changes
|
|
* @origin_tag: the origin tag
|
|
*
|
|
* This call is a convenience wrapper. It gets the list of changes from
|
|
* @tree, computes the longest common prefix and calls
|
|
* g_settings_backend_changed().
|
|
*
|
|
* Since: 2.26
|
|
**/
|
|
void
|
|
g_settings_backend_changed_tree (GSettingsBackend *backend,
|
|
GTree *tree,
|
|
gpointer origin_tag)
|
|
{
|
|
const gchar **keys;
|
|
gchar *path;
|
|
|
|
g_return_if_fail (G_IS_SETTINGS_BACKEND (backend));
|
|
|
|
g_settings_backend_flatten_tree (tree, &path, &keys, NULL);
|
|
|
|
#ifdef DEBUG_CHANGES
|
|
{
|
|
gint i;
|
|
|
|
g_print ("----\n");
|
|
g_print ("changed_tree(): prefix %s\n", path);
|
|
for (i = 0; keys[i]; i++)
|
|
g_print (" %s\n", keys[i]);
|
|
g_print ("----\n");
|
|
}
|
|
#endif
|
|
|
|
g_settings_backend_keys_changed (backend, path, keys, origin_tag);
|
|
g_free (path);
|
|
g_free (keys);
|
|
}
|
|
|
|
/*< private >
|
|
* g_settings_backend_read:
|
|
* @backend: a #GSettingsBackend implementation
|
|
* @key: the key to read
|
|
* @expected_type: a #GVariantType
|
|
* @default_value: if the default value should be returned
|
|
*
|
|
* Reads a key. This call will never block.
|
|
*
|
|
* If the key exists, the value associated with it will be returned.
|
|
* If the key does not exist, %NULL will be returned.
|
|
*
|
|
* The returned value will be of the type given in @expected_type. If
|
|
* the backend stored a value of a different type then %NULL will be
|
|
* returned.
|
|
*
|
|
* If @default_value is %TRUE then this gets the default value from the
|
|
* backend (ie: the one that the backend would contain if
|
|
* g_settings_reset() were called).
|
|
*
|
|
* Returns: the value that was read, or %NULL
|
|
*/
|
|
GVariant *
|
|
g_settings_backend_read (GSettingsBackend *backend,
|
|
const gchar *key,
|
|
const GVariantType *expected_type,
|
|
gboolean default_value)
|
|
{
|
|
GVariant *value;
|
|
|
|
value = G_SETTINGS_BACKEND_GET_CLASS (backend)
|
|
->read (backend, key, expected_type, default_value);
|
|
|
|
if (value != NULL)
|
|
value = g_variant_take_ref (value);
|
|
|
|
if G_UNLIKELY (value && !g_variant_is_of_type (value, expected_type))
|
|
{
|
|
g_variant_unref (value);
|
|
value = NULL;
|
|
}
|
|
|
|
return value;
|
|
}
|
|
|
|
/*< private >
|
|
* g_settings_backend_write:
|
|
* @backend: a #GSettingsBackend implementation
|
|
* @key: the name of the key
|
|
* @value: a #GVariant value to write to this key
|
|
* @origin_tag: the origin tag
|
|
*
|
|
* Writes exactly one key.
|
|
*
|
|
* This call does not fail. During this call a
|
|
* #GSettingsBackend::changed signal will be emitted if the value of the
|
|
* key has changed. The updated key value will be visible to any signal
|
|
* callbacks.
|
|
*
|
|
* One possible method that an implementation might deal with failures is
|
|
* to emit a second "changed" signal (either during this call, or later)
|
|
* to indicate that the affected keys have suddenly "changed back" to their
|
|
* old values.
|
|
*
|
|
* Returns: %TRUE if the write succeeded, %FALSE if the key was not writable
|
|
*/
|
|
gboolean
|
|
g_settings_backend_write (GSettingsBackend *backend,
|
|
const gchar *key,
|
|
GVariant *value,
|
|
gpointer origin_tag)
|
|
{
|
|
gboolean success;
|
|
|
|
g_variant_ref_sink (value);
|
|
success = G_SETTINGS_BACKEND_GET_CLASS (backend)
|
|
->write (backend, key, value, origin_tag);
|
|
g_variant_unref (value);
|
|
|
|
return success;
|
|
}
|
|
|
|
/*< private >
|
|
* g_settings_backend_write_keys:
|
|
* @backend: a #GSettingsBackend implementation
|
|
* @values: a #GTree containing key-value pairs to write
|
|
* @origin_tag: the origin tag
|
|
*
|
|
* Writes one or more keys. This call will never block.
|
|
*
|
|
* The key of each item in the tree is the key name to write to and the
|
|
* value is a #GVariant to write. The proper type of #GTree for this
|
|
* call can be created with g_settings_backend_create_tree(). This call
|
|
* might take a reference to the tree; you must not modified the #GTree
|
|
* after passing it to this call.
|
|
*
|
|
* This call does not fail. During this call a #GSettingsBackend::changed
|
|
* signal will be emitted if any keys have been changed. The new values of
|
|
* all updated keys will be visible to any signal callbacks.
|
|
*
|
|
* One possible method that an implementation might deal with failures is
|
|
* to emit a second "changed" signal (either during this call, or later)
|
|
* to indicate that the affected keys have suddenly "changed back" to their
|
|
* old values.
|
|
*/
|
|
gboolean
|
|
g_settings_backend_write_tree (GSettingsBackend *backend,
|
|
GTree *tree,
|
|
gpointer origin_tag)
|
|
{
|
|
return G_SETTINGS_BACKEND_GET_CLASS (backend)
|
|
->write_tree (backend, tree, origin_tag);
|
|
}
|
|
|
|
/*< private >
|
|
* g_settings_backend_reset:
|
|
* @backend: a #GSettingsBackend implementation
|
|
* @key: the name of a key
|
|
* @origin_tag: the origin tag
|
|
*
|
|
* "Resets" the named key to its "default" value (ie: after system-wide
|
|
* defaults, mandatory keys, etc. have been taken into account) or possibly
|
|
* unsets it.
|
|
*/
|
|
void
|
|
g_settings_backend_reset (GSettingsBackend *backend,
|
|
const gchar *key,
|
|
gpointer origin_tag)
|
|
{
|
|
G_SETTINGS_BACKEND_GET_CLASS (backend)
|
|
->reset (backend, key, origin_tag);
|
|
}
|
|
|
|
/*< private >
|
|
* g_settings_backend_get_writable:
|
|
* @backend: a #GSettingsBackend implementation
|
|
* @key: the name of a key
|
|
*
|
|
* Finds out if a key is available for writing to. This is the
|
|
* interface through which 'lockdown' is implemented. Locked down
|
|
* keys will have %FALSE returned by this call.
|
|
*
|
|
* You should not write to locked-down keys, but if you do, the
|
|
* implementation will deal with it.
|
|
*
|
|
* Returns: %TRUE if the key is writable
|
|
*/
|
|
gboolean
|
|
g_settings_backend_get_writable (GSettingsBackend *backend,
|
|
const gchar *key)
|
|
{
|
|
return G_SETTINGS_BACKEND_GET_CLASS (backend)
|
|
->get_writable (backend, key);
|
|
}
|
|
|
|
/*< private >
|
|
* g_settings_backend_unsubscribe:
|
|
* @backend: a #GSettingsBackend
|
|
* @name: a key or path to subscribe to
|
|
*
|
|
* Reverses the effect of a previous call to
|
|
* g_settings_backend_subscribe().
|
|
*/
|
|
void
|
|
g_settings_backend_unsubscribe (GSettingsBackend *backend,
|
|
const char *name)
|
|
{
|
|
G_SETTINGS_BACKEND_GET_CLASS (backend)
|
|
->unsubscribe (backend, name);
|
|
}
|
|
|
|
/*< private >
|
|
* g_settings_backend_subscribe:
|
|
* @backend: a #GSettingsBackend
|
|
* @name: a key or path to subscribe to
|
|
*
|
|
* Requests that change signals be emitted for events on @name.
|
|
*/
|
|
void
|
|
g_settings_backend_subscribe (GSettingsBackend *backend,
|
|
const gchar *name)
|
|
{
|
|
G_SETTINGS_BACKEND_GET_CLASS (backend)
|
|
->subscribe (backend, name);
|
|
}
|
|
|
|
static void
|
|
g_settings_backend_finalize (GObject *object)
|
|
{
|
|
GSettingsBackend *backend = G_SETTINGS_BACKEND (object);
|
|
|
|
g_mutex_clear (&backend->priv->lock);
|
|
|
|
G_OBJECT_CLASS (g_settings_backend_parent_class)
|
|
->finalize (object);
|
|
}
|
|
|
|
static void
|
|
ignore_subscription (GSettingsBackend *backend,
|
|
const gchar *key)
|
|
{
|
|
}
|
|
|
|
static void
|
|
g_settings_backend_init (GSettingsBackend *backend)
|
|
{
|
|
backend->priv = G_TYPE_INSTANCE_GET_PRIVATE (backend,
|
|
G_TYPE_SETTINGS_BACKEND,
|
|
GSettingsBackendPrivate);
|
|
g_mutex_init (&backend->priv->lock);
|
|
}
|
|
|
|
static void
|
|
g_settings_backend_class_init (GSettingsBackendClass *class)
|
|
{
|
|
GObjectClass *gobject_class = G_OBJECT_CLASS (class);
|
|
|
|
class->subscribe = ignore_subscription;
|
|
class->unsubscribe = ignore_subscription;
|
|
|
|
gobject_class->finalize = g_settings_backend_finalize;
|
|
|
|
g_type_class_add_private (class, sizeof (GSettingsBackendPrivate));
|
|
}
|
|
|
|
static void
|
|
g_settings_backend_variant_unref0 (gpointer data)
|
|
{
|
|
if (data != NULL)
|
|
g_variant_unref (data);
|
|
}
|
|
|
|
/*< private >
|
|
* g_settings_backend_create_tree:
|
|
*
|
|
* This is a convenience function for creating a tree that is compatible
|
|
* with g_settings_backend_write(). It merely calls g_tree_new_full()
|
|
* with strcmp(), g_free() and g_variant_unref().
|
|
*
|
|
* Returns: a new #GTree
|
|
*/
|
|
GTree *
|
|
g_settings_backend_create_tree (void)
|
|
{
|
|
return g_tree_new_full ((GCompareDataFunc) strcmp, NULL,
|
|
g_free, g_settings_backend_variant_unref0);
|
|
}
|
|
|
|
static gboolean
|
|
g_settings_backend_verify (gpointer impl)
|
|
{
|
|
GSettingsBackend *backend = impl;
|
|
|
|
if (strcmp (G_OBJECT_TYPE_NAME (backend), "GMemorySettingsBackend") == 0 &&
|
|
g_strcmp0 (g_getenv ("GSETTINGS_BACKEND"), "memory") != 0)
|
|
{
|
|
g_message ("Using the 'memory' GSettings backend. Your settings "
|
|
"will not be saved or shared with other applications.");
|
|
}
|
|
|
|
g_settings_has_backend = TRUE;
|
|
return TRUE;
|
|
}
|
|
|
|
/**
|
|
* g_settings_backend_get_default:
|
|
*
|
|
* Returns the default #GSettingsBackend. It is possible to override
|
|
* the default by setting the <envar>GSETTINGS_BACKEND</envar>
|
|
* environment variable to the name of a settings backend.
|
|
*
|
|
* The user gets a reference to the backend.
|
|
*
|
|
* Returns: (transfer full): the default #GSettingsBackend
|
|
*
|
|
* Since: 2.28
|
|
*/
|
|
GSettingsBackend *
|
|
g_settings_backend_get_default (void)
|
|
{
|
|
GSettingsBackend *backend;
|
|
|
|
backend = _g_io_module_get_default (G_SETTINGS_BACKEND_EXTENSION_POINT_NAME,
|
|
"GSETTINGS_BACKEND",
|
|
g_settings_backend_verify);
|
|
return g_object_ref (backend);
|
|
}
|
|
|
|
/*< private >
|
|
* g_settings_backend_get_permission:
|
|
* @backend: a #GSettingsBackend
|
|
* @path: a path
|
|
*
|
|
* Gets the permission object associated with writing to keys below
|
|
* @path on @backend.
|
|
*
|
|
* If this is not implemented in the backend, then a %TRUE
|
|
* #GSimplePermission is returned.
|
|
*
|
|
* Returns: a non-%NULL #GPermission. Free with g_object_unref()
|
|
*/
|
|
GPermission *
|
|
g_settings_backend_get_permission (GSettingsBackend *backend,
|
|
const gchar *path)
|
|
{
|
|
GSettingsBackendClass *class = G_SETTINGS_BACKEND_GET_CLASS (backend);
|
|
|
|
if (class->get_permission)
|
|
return class->get_permission (backend, path);
|
|
|
|
return g_simple_permission_new (TRUE);
|
|
}
|
|
|
|
/*< private >
|
|
* g_settings_backend_sync_default:
|
|
*
|
|
* Syncs the default backend.
|
|
*/
|
|
void
|
|
g_settings_backend_sync_default (void)
|
|
{
|
|
if (g_settings_has_backend)
|
|
{
|
|
GSettingsBackendClass *class;
|
|
GSettingsBackend *backend;
|
|
|
|
backend = g_settings_backend_get_default ();
|
|
class = G_SETTINGS_BACKEND_GET_CLASS (backend);
|
|
|
|
if (class->sync)
|
|
class->sync (backend);
|
|
}
|
|
}
|