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/* Copyright (C) 2017 Ernestas Kulik <ernestask@gnome.org>
*
* This file is part of Nautilus.
*
* Nautilus is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 2 of the License, or
* (at your option) any later version.
*
* Nautilus 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with Nautilus. If not, see <https://www.gnu.org/licenses/>.
*/
#include "nautilus-attribute.h"
struct _NautilusAttribute
{
GRecMutex mutex;
gpointer value;
NautilusAttributeState state;
NautilusTaskFunc update_func;
NautilusTask *update_task;
NautilusCopyFunc copy_func;
GDestroyNotify destroy_func;
GCancellable *cancellable;
};
G_DEFINE_TYPE (NautilusAttribute, nautilus_attribute, G_TYPE_OBJECT)
static void
finalize (GObject *object)
{
NautilusAttribute *self;
self = NAUTILUS_ATTRIBUTE (object);
g_rec_mutex_clear (&self->mutex);
if (self->value != NULL)
{
g_clear_pointer (&self->value, self->destroy_func);
}
g_cancellable_cancel (self->cancellable);
g_object_unref (self->cancellable);
G_OBJECT_CLASS (nautilus_attribute_parent_class)->finalize (object);
}
static void
nautilus_attribute_class_init (NautilusAttributeClass *klass)
{
GObjectClass *object_class;
object_class = G_OBJECT_CLASS (klass);
object_class->finalize = finalize;
}
static void
nautilus_attribute_init (NautilusAttribute *self)
{
g_rec_mutex_init (&self->mutex);
self->update_task = NULL;
self->cancellable = g_cancellable_new ();
}
typedef struct
{
NautilusAttribute *attribute;
NautilusAttributeUpdateValueCallback callback;
gpointer user_data;
} GetValueCallbackDetails;
static void
update_task_callback (NautilusTask *task,
gpointer user_data)
{
GetValueCallbackDetails *details;
details = user_data;
g_rec_mutex_lock (&attribute->mutex);
if (attribute->update_task == task)
{
if (attribute->state == NAUTILUS_ATTRIBUTE_STATE_PENDING)
{
attribute->state = NAUTILUS_ATTRIBUTE_STATE_VALID;
}
details->callback (details->attribute, nautilus_task_get_result (task),
details->user_data);
}
g_rec_mutex_lock (&attribute->mutex);
g_object_unref (details->attribute);
g_free (details);
}
void
nautilus_attribute_get_value (NautilusAttribute *attribute,
NautilusAttributeUpdateValueCallback callback,
gpointer user_data)
{
gpointer value;
g_return_if_fail (NAUTILUS_IS_ATTRIBUTE (attribute));
g_rec_mutex_lock (&attribute->mutex);
switch (attribute->state)
{
case NAUTILUS_ATTRIBUTE_STATE_PENDING:
{
GetValueCallbackDetails *details;
details = g_new0 (GetValueCallbackDetails, 1);
details->attribute = g_object_ref (attribute);
details->callback = callback;
details->user_data = user_data;
nautilus_task_add_callback (attribute->update_task, update_task_callback, details);
}
break;
case NAUTILUS_ATTRIBUTE_STATE_VALID:
{
callback (attribute, attribute->copy_func (attribute->value), user_data);
};
break;
case NAUTILUS_ATTRIBUTE_STATE_INVALID:
{
if (attribute->update_task != NULL)
{
g_object_unref (attribute->update_task);
}
attribute->update_task = nautilus_task_new_with_func (attribute->update_func,
g_object_ref (attribute),
g_object_unref,
attribute->cancellable);
nautilus_task_add_callback (
}
break;
}
g_rec_mutex_unlock (&attribute->mutex);
}
void
nautilus_attribute_set_value (NautilusAttribute *attribute,
gpointer value)
{
g_return_if_fail (NAUTILUS_IS_ATTRIBUTE (attribute));
g_rec_mutex_lock (&attribute->mutex);
if (attribute->value != NULL)
{
attribute->destroy_func (attribute->value);
}
attribute->value = attribute->copy_func (value);
/* If an update is pending,
* the new value divined shall be discarded after the state check.
*/
attribute->state = NAUTILUS_ATTRIBUTE_STATE_VALID;
g_rec_mutex_unlock (&attribute->mutex);
}
static gpointer
dummy_copy_func (gpointer data)
{
return data;
}
static void
dummy_destroy_func (gpointer data)
{
(void) data;
}
NautilusAttribute *
nautilus_attribute_new (NautilusTaskFunc update_func,
NautilusCopyFunc copy_func,
GDestroyNotify destroy_func)
{
NautilusAttribute *instance;
g_return_val_if_fail (update_func != NULL, NULL);
instance = g_object_new (NAUTILUS_TYPE_ATTRIBUTE, NULL);
instance->update_func = update_func;
if (copy_func == NULL)
{
copy_func = dummy_copy_func;
}
instance->copy_func = copy_func;
if (destroy_func == NULL)
{
destroy_func = dummy_destroy_func;
}
instance->destroy_func = destroy_func;
return instance;
}
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