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/*
* Copyright © 2009, 2010 Codethink Limited
*
* 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: Ryan Lortie <desrt@desrt.ca>
*/
#include "config.h"
#include "gdelayedsettingsbackend.h"
#include "gsettingsbackendinternal.h"
#include <string.h>
struct _GDelayedSettingsBackendPrivate
{
GSettingsBackend *backend;
GMutex lock;
GTree *delayed;
GMainContext *owner_context;
gpointer owner;
};
G_DEFINE_TYPE_WITH_PRIVATE (GDelayedSettingsBackend,
g_delayed_settings_backend,
G_TYPE_SETTINGS_BACKEND)
static gboolean
invoke_notify_unapplied (gpointer data)
{
g_object_notify (data, "has-unapplied");
g_object_unref (data);
return FALSE;
}
static void
g_delayed_settings_backend_notify_unapplied (GDelayedSettingsBackend *delayed)
{
GMainContext *target_context;
GObject *target;
g_mutex_lock (&delayed->priv->lock);
if (delayed->priv->owner)
{
target_context = delayed->priv->owner_context;
target = g_object_ref (delayed->priv->owner);
}
else
{
target_context = NULL;
target = NULL;
}
g_mutex_unlock (&delayed->priv->lock);
if (target != NULL)
g_main_context_invoke (target_context, invoke_notify_unapplied, target);
}
static GVariant *
g_delayed_settings_backend_read (GSettingsBackend *backend,
const gchar *key,
const GVariantType *expected_type,
gboolean default_value)
{
GDelayedSettingsBackend *delayed = G_DELAYED_SETTINGS_BACKEND (backend);
gpointer result = NULL;
if (!default_value)
{
g_mutex_lock (&delayed->priv->lock);
if (g_tree_lookup_extended (delayed->priv->delayed, key, NULL, &result))
{
/* NULL in the tree means we should consult the default value */
if (result != NULL)
g_variant_ref (result);
else
default_value = TRUE;
}
g_mutex_unlock (&delayed->priv->lock);
}
if (result == NULL)
result = g_settings_backend_read (delayed->priv->backend, key,
expected_type, default_value);
return result;
}
static GVariant *
g_delayed_settings_backend_read_user_value (GSettingsBackend *backend,
const gchar *key,
const GVariantType *expected_type)
{
GDelayedSettingsBackend *delayed = G_DELAYED_SETTINGS_BACKEND (backend);
gboolean value_found = FALSE;
gpointer result = NULL;
/* If we find an explicit NULL in our changeset then we want to return
* NULL (because the user value has been reset).
*
* Otherwise, chain up.
*/
g_mutex_lock (&delayed->priv->lock);
value_found = g_tree_lookup_extended (delayed->priv->delayed, key, NULL, &result);
if (result)
g_variant_ref (result);
g_mutex_unlock (&delayed->priv->lock);
if (value_found)
return result;
return g_settings_backend_read_user_value (delayed->priv->backend, key, expected_type);
}
static gboolean
g_delayed_settings_backend_write (GSettingsBackend *backend,
const gchar *key,
GVariant *value,
gpointer origin_tag)
{
GDelayedSettingsBackend *delayed = G_DELAYED_SETTINGS_BACKEND (backend);
gboolean was_empty;
g_mutex_lock (&delayed->priv->lock);
was_empty = g_tree_nnodes (delayed->priv->delayed) == 0;
g_tree_insert (delayed->priv->delayed, g_strdup (key),
g_variant_ref_sink (value));
g_mutex_unlock (&delayed->priv->lock);
g_settings_backend_changed (backend, key, origin_tag);
if (was_empty)
g_delayed_settings_backend_notify_unapplied (delayed);
return TRUE;
}
static gboolean
add_to_tree (gpointer key,
gpointer value,
gpointer user_data)
{
/* A value may be %NULL if its key has been reset */
g_tree_insert (user_data, g_strdup (key), (value != NULL) ? g_variant_ref (value) : NULL);
return FALSE;
}
static gboolean
g_delayed_settings_backend_write_tree (GSettingsBackend *backend,
GTree *tree,
gpointer origin_tag)
{
GDelayedSettingsBackend *delayed = G_DELAYED_SETTINGS_BACKEND (backend);
gboolean was_empty;
g_mutex_lock (&delayed->priv->lock);
was_empty = g_tree_nnodes (delayed->priv->delayed) == 0;
g_tree_foreach (tree, add_to_tree, delayed->priv->delayed);
g_mutex_unlock (&delayed->priv->lock);
g_settings_backend_changed_tree (backend, tree, origin_tag);
if (was_empty)
g_delayed_settings_backend_notify_unapplied (delayed);
return TRUE;
}
static gboolean
g_delayed_settings_backend_get_writable (GSettingsBackend *backend,
const gchar *name)
{
GDelayedSettingsBackend *delayed = G_DELAYED_SETTINGS_BACKEND (backend);
return g_settings_backend_get_writable (delayed->priv->backend, name);
}
static void
g_delayed_settings_backend_reset (GSettingsBackend *backend,
const gchar *key,
gpointer origin_tag)
{
GDelayedSettingsBackend *delayed = G_DELAYED_SETTINGS_BACKEND (backend);
gboolean was_empty;
g_mutex_lock (&delayed->priv->lock);
was_empty = g_tree_nnodes (delayed->priv->delayed) == 0;
g_tree_insert (delayed->priv->delayed, g_strdup (key), NULL);
g_mutex_unlock (&delayed->priv->lock);
g_settings_backend_changed (backend, key, origin_tag);
if (was_empty)
g_delayed_settings_backend_notify_unapplied (delayed);
}
static void
g_delayed_settings_backend_subscribe (GSettingsBackend *backend,
const char *name)
{
GDelayedSettingsBackend *delayed = G_DELAYED_SETTINGS_BACKEND (backend);
g_settings_backend_subscribe (delayed->priv->backend, name);
}
static void
g_delayed_settings_backend_unsubscribe (GSettingsBackend *backend,
const char *name)
{
GDelayedSettingsBackend *delayed = G_DELAYED_SETTINGS_BACKEND (backend);
g_settings_backend_unsubscribe (delayed->priv->backend, name);
}
static GPermission *
g_delayed_settings_backend_get_permission (GSettingsBackend *backend,
const gchar *path)
{
GDelayedSettingsBackend *delayed = G_DELAYED_SETTINGS_BACKEND (backend);
return g_settings_backend_get_permission (delayed->priv->backend, path);
}
/* method calls */
gboolean
g_delayed_settings_backend_get_has_unapplied (GDelayedSettingsBackend *delayed)
{
/* we don't need to lock for this... */
return g_tree_nnodes (delayed->priv->delayed) > 0;
}
void
g_delayed_settings_backend_apply (GDelayedSettingsBackend *delayed)
{
if (g_tree_nnodes (delayed->priv->delayed) > 0)
{
gboolean success;
GTree *tmp;
g_mutex_lock (&delayed->priv->lock);
tmp = delayed->priv->delayed;
delayed->priv->delayed = g_settings_backend_create_tree ();
success = g_settings_backend_write_tree (delayed->priv->backend,
tmp, delayed->priv);
g_mutex_unlock (&delayed->priv->lock);
if (!success)
g_settings_backend_changed_tree (G_SETTINGS_BACKEND (delayed),
tmp, NULL);
g_tree_unref (tmp);
g_delayed_settings_backend_notify_unapplied (delayed);
}
}
void
g_delayed_settings_backend_revert (GDelayedSettingsBackend *delayed)
{
if (g_tree_nnodes (delayed->priv->delayed) > 0)
{
GTree *tmp;
g_mutex_lock (&delayed->priv->lock);
tmp = delayed->priv->delayed;
delayed->priv->delayed = g_settings_backend_create_tree ();
g_mutex_unlock (&delayed->priv->lock);
g_settings_backend_changed_tree (G_SETTINGS_BACKEND (delayed), tmp, NULL);
g_tree_unref (tmp);
g_delayed_settings_backend_notify_unapplied (delayed);
}
}
/* change notification */
static void
delayed_backend_changed (GObject *target,
GSettingsBackend *backend,
const gchar *key,
gpointer origin_tag)
{
GDelayedSettingsBackend *delayed = G_DELAYED_SETTINGS_BACKEND (target);
if (origin_tag != delayed->priv)
g_settings_backend_changed (G_SETTINGS_BACKEND (delayed),
key, origin_tag);
}
static void
delayed_backend_keys_changed (GObject *target,
GSettingsBackend *backend,
const gchar *path,
gpointer origin_tag,
const gchar * const *items)
{
GDelayedSettingsBackend *delayed = G_DELAYED_SETTINGS_BACKEND (target);
if (origin_tag != delayed->priv)
g_settings_backend_keys_changed (G_SETTINGS_BACKEND (delayed),
path, items, origin_tag);
}
static void
delayed_backend_path_changed (GObject *target,
GSettingsBackend *backend,
const gchar *path,
gpointer origin_tag)
{
GDelayedSettingsBackend *delayed = G_DELAYED_SETTINGS_BACKEND (target);
if (origin_tag != delayed->priv)
g_settings_backend_path_changed (G_SETTINGS_BACKEND (delayed),
path, origin_tag);
}
static void
delayed_backend_writable_changed (GObject *target,
GSettingsBackend *backend,
const gchar *key)
{
GDelayedSettingsBackend *delayed = G_DELAYED_SETTINGS_BACKEND (target);
gboolean last_one = FALSE;
g_mutex_lock (&delayed->priv->lock);
if (g_tree_lookup (delayed->priv->delayed, key) != NULL &&
!g_settings_backend_get_writable (delayed->priv->backend, key))
{
/* drop the key from our changeset if it just became read-only.
* no need to signal since the writable change below implies it.
*
* note that the item in the tree may very well be set to NULL in
* the case that the user stored a reset. we intentionally don't
* drop the key in this case since a reset will always succeed
* (even against a non-writable key).
*/
g_tree_remove (delayed->priv->delayed, key);
/* if that was the only key... */
last_one = g_tree_nnodes (delayed->priv->delayed) == 0;
}
g_mutex_unlock (&delayed->priv->lock);
if (last_one)
g_delayed_settings_backend_notify_unapplied (delayed);
g_settings_backend_writable_changed (G_SETTINGS_BACKEND (delayed), key);
}
/* slow method until we get foreach-with-remove in GTree
*/
typedef struct
{
const gchar *path;
const gchar **keys;
gsize index;
} CheckPrefixState;
static gboolean
check_prefix (gpointer key,
gpointer value,
gpointer data)
{
CheckPrefixState *state = data;
if (g_str_has_prefix (key, state->path))
state->keys[state->index++] = key;
return FALSE;
}
static void
delayed_backend_path_writable_changed (GObject *target,
GSettingsBackend *backend,
const gchar *path)
{
GDelayedSettingsBackend *delayed = G_DELAYED_SETTINGS_BACKEND (target);
gboolean last_one = FALSE;
gsize n_keys;
g_mutex_lock (&delayed->priv->lock);
n_keys = g_tree_nnodes (delayed->priv->delayed);
if (n_keys > 0)
{
CheckPrefixState state = { path, g_new (const gchar *, n_keys), 0 };
gsize i;
/* collect a list of possibly-affected keys (ie: matching the path) */
g_tree_foreach (delayed->priv->delayed, check_prefix, &state);
/* drop the keys that have been affected.
*
* don't drop 'reset' keys (see above) */
for (i = 0; i < state.index; i++)
if (g_tree_lookup (delayed->priv->delayed, state.keys[i]) != NULL &&
!g_settings_backend_get_writable (delayed->priv->backend,
state.keys[i]))
g_tree_remove (delayed->priv->delayed, state.keys[i]);
g_free (state.keys);
last_one = g_tree_nnodes (delayed->priv->delayed) == 0;
}
g_mutex_unlock (&delayed->priv->lock);
if (last_one)
g_delayed_settings_backend_notify_unapplied (delayed);
g_settings_backend_path_writable_changed (G_SETTINGS_BACKEND (delayed),
path);
}
static void
g_delayed_settings_backend_finalize (GObject *object)
{
GDelayedSettingsBackend *delayed = G_DELAYED_SETTINGS_BACKEND (object);
g_mutex_clear (&delayed->priv->lock);
g_object_unref (delayed->priv->backend);
g_tree_unref (delayed->priv->delayed);
/* if our owner is still alive, why are we finalizing? */
g_assert (delayed->priv->owner == NULL);
G_OBJECT_CLASS (g_delayed_settings_backend_parent_class)
->finalize (object);
}
static void
g_delayed_settings_backend_class_init (GDelayedSettingsBackendClass *class)
{
GSettingsBackendClass *backend_class = G_SETTINGS_BACKEND_CLASS (class);
GObjectClass *object_class = G_OBJECT_CLASS (class);
backend_class->read = g_delayed_settings_backend_read;
backend_class->read_user_value = g_delayed_settings_backend_read_user_value;
backend_class->write = g_delayed_settings_backend_write;
backend_class->write_tree = g_delayed_settings_backend_write_tree;
backend_class->reset = g_delayed_settings_backend_reset;
backend_class->get_writable = g_delayed_settings_backend_get_writable;
backend_class->subscribe = g_delayed_settings_backend_subscribe;
backend_class->unsubscribe = g_delayed_settings_backend_unsubscribe;
backend_class->get_permission = g_delayed_settings_backend_get_permission;
object_class->finalize = g_delayed_settings_backend_finalize;
}
static void
g_delayed_settings_backend_init (GDelayedSettingsBackend *delayed)
{
delayed->priv = g_delayed_settings_backend_get_instance_private (delayed);
delayed->priv->delayed = g_settings_backend_create_tree ();
g_mutex_init (&delayed->priv->lock);
}
static void
g_delayed_settings_backend_disown (gpointer data,
GObject *where_the_object_was)
{
GDelayedSettingsBackend *delayed = data;
g_mutex_lock (&delayed->priv->lock);
delayed->priv->owner_context = NULL;
delayed->priv->owner = NULL;
g_mutex_unlock (&delayed->priv->lock);
}
GDelayedSettingsBackend *
g_delayed_settings_backend_new (GSettingsBackend *backend,
gpointer owner,
GMainContext *owner_context)
{
static GSettingsListenerVTable vtable = {
delayed_backend_changed,
delayed_backend_path_changed,
delayed_backend_keys_changed,
delayed_backend_writable_changed,
delayed_backend_path_writable_changed
};
GDelayedSettingsBackend *delayed;
delayed = g_object_new (G_TYPE_DELAYED_SETTINGS_BACKEND, NULL);
delayed->priv->backend = g_object_ref (backend);
delayed->priv->owner_context = owner_context;
delayed->priv->owner = owner;
g_object_weak_ref (owner, g_delayed_settings_backend_disown, delayed);
g_settings_backend_watch (delayed->priv->backend,
&vtable, G_OBJECT (delayed), NULL);
return delayed;
}