glib/gio/gliststore.c
Philip Withnall c9aba16af3 gliststore: Store validity of last_position explicitly
Rather than storing it as an invalid value in last_position, store it as
a separate boolean.

This introduces no functional changes, but should fix some warnings from
MSVC.

Signed-off-by: Philip Withnall <withnall@endlessm.com>

https://gitlab.gnome.org/GNOME/glib/issues/1500
2019-01-18 15:22:19 +00:00

497 lines
13 KiB
C

/*
* Copyright 2015 Lars Uebernickel
* Copyright 2015 Ryan Lortie
*
* 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/>.
*
* Authors:
* Lars Uebernickel <lars@uebernic.de>
* Ryan Lortie <desrt@desrt.ca>
*/
#include "config.h"
#include "gliststore.h"
#include "glistmodel.h"
/**
* SECTION:gliststore
* @title: GListStore
* @short_description: A simple implementation of #GListModel
* @include: gio/gio.h
*
* #GListStore is a simple implementation of #GListModel that stores all
* items in memory.
*
* It provides insertions, deletions, and lookups in logarithmic time
* with a fast path for the common case of iterating the list linearly.
*/
/**
* GListStore:
*
* #GListStore is an opaque data structure and can only be accessed
* using the following functions.
**/
struct _GListStore
{
GObject parent_instance;
GType item_type;
GSequence *items;
/* cache */
guint last_position;
GSequenceIter *last_iter;
gboolean last_position_valid;
};
enum
{
PROP_0,
PROP_ITEM_TYPE,
N_PROPERTIES
};
static void g_list_store_iface_init (GListModelInterface *iface);
G_DEFINE_TYPE_WITH_CODE (GListStore, g_list_store, G_TYPE_OBJECT,
G_IMPLEMENT_INTERFACE (G_TYPE_LIST_MODEL, g_list_store_iface_init));
static void
g_list_store_items_changed (GListStore *store,
guint position,
guint removed,
guint added)
{
/* check if the iter cache may have been invalidated */
if (position <= store->last_position)
{
store->last_iter = NULL;
store->last_position = 0;
store->last_position_valid = FALSE;
}
g_list_model_items_changed (G_LIST_MODEL (store), position, removed, added);
}
static void
g_list_store_dispose (GObject *object)
{
GListStore *store = G_LIST_STORE (object);
g_clear_pointer (&store->items, g_sequence_free);
G_OBJECT_CLASS (g_list_store_parent_class)->dispose (object);
}
static void
g_list_store_get_property (GObject *object,
guint property_id,
GValue *value,
GParamSpec *pspec)
{
GListStore *store = G_LIST_STORE (object);
switch (property_id)
{
case PROP_ITEM_TYPE:
g_value_set_gtype (value, store->item_type);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
}
}
static void
g_list_store_set_property (GObject *object,
guint property_id,
const GValue *value,
GParamSpec *pspec)
{
GListStore *store = G_LIST_STORE (object);
switch (property_id)
{
case PROP_ITEM_TYPE: /* construct-only */
g_assert (g_type_is_a (g_value_get_gtype (value), G_TYPE_OBJECT));
store->item_type = g_value_get_gtype (value);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
}
}
static void
g_list_store_class_init (GListStoreClass *klass)
{
GObjectClass *object_class = G_OBJECT_CLASS (klass);
object_class->dispose = g_list_store_dispose;
object_class->get_property = g_list_store_get_property;
object_class->set_property = g_list_store_set_property;
/**
* GListStore:item-type:
*
* The type of items contained in this list store. Items must be
* subclasses of #GObject.
*
* Since: 2.44
**/
g_object_class_install_property (object_class, PROP_ITEM_TYPE,
g_param_spec_gtype ("item-type", "", "", G_TYPE_OBJECT,
G_PARAM_CONSTRUCT_ONLY | G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
}
static GType
g_list_store_get_item_type (GListModel *list)
{
GListStore *store = G_LIST_STORE (list);
return store->item_type;
}
static guint
g_list_store_get_n_items (GListModel *list)
{
GListStore *store = G_LIST_STORE (list);
return g_sequence_get_length (store->items);
}
static gpointer
g_list_store_get_item (GListModel *list,
guint position)
{
GListStore *store = G_LIST_STORE (list);
GSequenceIter *it = NULL;
if (store->last_position_valid)
{
if (position < G_MAXUINT && store->last_position == position + 1)
it = g_sequence_iter_prev (store->last_iter);
else if (position > 0 && store->last_position == position - 1)
it = g_sequence_iter_next (store->last_iter);
else if (store->last_position == position)
it = store->last_iter;
}
if (it == NULL)
it = g_sequence_get_iter_at_pos (store->items, position);
store->last_iter = it;
store->last_position = position;
store->last_position_valid = TRUE;
if (g_sequence_iter_is_end (it))
return NULL;
else
return g_object_ref (g_sequence_get (it));
}
static void
g_list_store_iface_init (GListModelInterface *iface)
{
iface->get_item_type = g_list_store_get_item_type;
iface->get_n_items = g_list_store_get_n_items;
iface->get_item = g_list_store_get_item;
}
static void
g_list_store_init (GListStore *store)
{
store->items = g_sequence_new (g_object_unref);
store->last_position = 0;
store->last_position_valid = FALSE;
}
/**
* g_list_store_new:
* @item_type: the #GType of items in the list
*
* Creates a new #GListStore with items of type @item_type. @item_type
* must be a subclass of #GObject.
*
* Returns: a new #GListStore
* Since: 2.44
*/
GListStore *
g_list_store_new (GType item_type)
{
/* We only allow GObjects as item types right now. This might change
* in the future.
*/
g_return_val_if_fail (g_type_is_a (item_type, G_TYPE_OBJECT), NULL);
return g_object_new (G_TYPE_LIST_STORE,
"item-type", item_type,
NULL);
}
/**
* g_list_store_insert:
* @store: a #GListStore
* @position: the position at which to insert the new item
* @item: (type GObject): the new item
*
* Inserts @item into @store at @position. @item must be of type
* #GListStore:item-type or derived from it. @position must be smaller
* than the length of the list, or equal to it to append.
*
* This function takes a ref on @item.
*
* Use g_list_store_splice() to insert multiple items at the same time
* efficiently.
*
* Since: 2.44
*/
void
g_list_store_insert (GListStore *store,
guint position,
gpointer item)
{
GSequenceIter *it;
g_return_if_fail (G_IS_LIST_STORE (store));
g_return_if_fail (g_type_is_a (G_OBJECT_TYPE (item), store->item_type));
g_return_if_fail (position <= g_sequence_get_length (store->items));
it = g_sequence_get_iter_at_pos (store->items, position);
g_sequence_insert_before (it, g_object_ref (item));
g_list_store_items_changed (store, position, 0, 1);
}
/**
* g_list_store_insert_sorted:
* @store: a #GListStore
* @item: (type GObject): the new item
* @compare_func: (scope call): pairwise comparison function for sorting
* @user_data: (closure): user data for @compare_func
*
* Inserts @item into @store at a position to be determined by the
* @compare_func.
*
* The list must already be sorted before calling this function or the
* result is undefined. Usually you would approach this by only ever
* inserting items by way of this function.
*
* This function takes a ref on @item.
*
* Returns: the position at which @item was inserted
*
* Since: 2.44
*/
guint
g_list_store_insert_sorted (GListStore *store,
gpointer item,
GCompareDataFunc compare_func,
gpointer user_data)
{
GSequenceIter *it;
guint position;
g_return_val_if_fail (G_IS_LIST_STORE (store), 0);
g_return_val_if_fail (g_type_is_a (G_OBJECT_TYPE (item), store->item_type), 0);
g_return_val_if_fail (compare_func != NULL, 0);
it = g_sequence_insert_sorted (store->items, g_object_ref (item), compare_func, user_data);
position = g_sequence_iter_get_position (it);
g_list_store_items_changed (store, position, 0, 1);
return position;
}
/**
* g_list_store_sort:
* @store: a #GListStore
* @compare_func: (scope call): pairwise comparison function for sorting
* @user_data: (closure): user data for @compare_func
*
* Sort the items in @store according to @compare_func.
*
* Since: 2.46
*/
void
g_list_store_sort (GListStore *store,
GCompareDataFunc compare_func,
gpointer user_data)
{
gint n_items;
g_return_if_fail (G_IS_LIST_STORE (store));
g_return_if_fail (compare_func != NULL);
g_sequence_sort (store->items, compare_func, user_data);
n_items = g_sequence_get_length (store->items);
g_list_store_items_changed (store, 0, n_items, n_items);
}
/**
* g_list_store_append:
* @store: a #GListStore
* @item: (type GObject): the new item
*
* Appends @item to @store. @item must be of type #GListStore:item-type.
*
* This function takes a ref on @item.
*
* Use g_list_store_splice() to append multiple items at the same time
* efficiently.
*
* Since: 2.44
*/
void
g_list_store_append (GListStore *store,
gpointer item)
{
guint n_items;
g_return_if_fail (G_IS_LIST_STORE (store));
g_return_if_fail (g_type_is_a (G_OBJECT_TYPE (item), store->item_type));
n_items = g_sequence_get_length (store->items);
g_sequence_append (store->items, g_object_ref (item));
g_list_store_items_changed (store, n_items, 0, 1);
}
/**
* g_list_store_remove:
* @store: a #GListStore
* @position: the position of the item that is to be removed
*
* Removes the item from @store that is at @position. @position must be
* smaller than the current length of the list.
*
* Use g_list_store_splice() to remove multiple items at the same time
* efficiently.
*
* Since: 2.44
*/
void
g_list_store_remove (GListStore *store,
guint position)
{
GSequenceIter *it;
g_return_if_fail (G_IS_LIST_STORE (store));
it = g_sequence_get_iter_at_pos (store->items, position);
g_return_if_fail (!g_sequence_iter_is_end (it));
g_sequence_remove (it);
g_list_store_items_changed (store, position, 1, 0);
}
/**
* g_list_store_remove_all:
* @store: a #GListStore
*
* Removes all items from @store.
*
* Since: 2.44
*/
void
g_list_store_remove_all (GListStore *store)
{
guint n_items;
g_return_if_fail (G_IS_LIST_STORE (store));
n_items = g_sequence_get_length (store->items);
g_sequence_remove_range (g_sequence_get_begin_iter (store->items),
g_sequence_get_end_iter (store->items));
g_list_store_items_changed (store, 0, n_items, 0);
}
/**
* g_list_store_splice:
* @store: a #GListStore
* @position: the position at which to make the change
* @n_removals: the number of items to remove
* @additions: (array length=n_additions) (element-type GObject): the items to add
* @n_additions: the number of items to add
*
* Changes @store by removing @n_removals items and adding @n_additions
* items to it. @additions must contain @n_additions items of type
* #GListStore:item-type. %NULL is not permitted.
*
* This function is more efficient than g_list_store_insert() and
* g_list_store_remove(), because it only emits
* #GListModel::items-changed once for the change.
*
* This function takes a ref on each item in @additions.
*
* The parameters @position and @n_removals must be correct (ie:
* @position + @n_removals must be less than or equal to the length of
* the list at the time this function is called).
*
* Since: 2.44
*/
void
g_list_store_splice (GListStore *store,
guint position,
guint n_removals,
gpointer *additions,
guint n_additions)
{
GSequenceIter *it;
guint n_items;
g_return_if_fail (G_IS_LIST_STORE (store));
g_return_if_fail (position + n_removals >= position); /* overflow */
n_items = g_sequence_get_length (store->items);
g_return_if_fail (position + n_removals <= n_items);
it = g_sequence_get_iter_at_pos (store->items, position);
if (n_removals)
{
GSequenceIter *end;
end = g_sequence_iter_move (it, n_removals);
g_sequence_remove_range (it, end);
it = end;
}
if (n_additions)
{
gint i;
for (i = 0; i < n_additions; i++)
{
if G_UNLIKELY (!g_type_is_a (G_OBJECT_TYPE (additions[i]), store->item_type))
{
g_critical ("%s: item %d is a %s instead of a %s. GListStore is now in an undefined state.",
G_STRFUNC, i, G_OBJECT_TYPE_NAME (additions[i]), g_type_name (store->item_type));
return;
}
g_sequence_insert_before (it, g_object_ref (additions[i]));
}
}
g_list_store_items_changed (store, position, n_removals, n_additions);
}