glib/gio/gliststore.c

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/*
* Copyright 2015 Lars Uebernickel
* Copyright 2015 Ryan Lortie
*
* 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/>.
*
* Authors:
* Lars Uebernickel <lars@uebernic.de>
* Ryan Lortie <desrt@desrt.ca>
*/
#include "config.h"
#include "gliststore.h"
#include "glistmodel.h"
/**
* GListStore:
*
* `GListStore` is a simple implementation of [iface@Gio.ListModel] 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.
*/
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,
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PROP_N_ITEMS,
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 GParamSpec *properties[N_PROPERTIES] = { NULL, };
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);
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if (removed != added)
g_object_notify_by_pspec (G_OBJECT (store), properties[PROP_N_ITEMS]);
}
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;
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case PROP_N_ITEMS:
g_value_set_uint (value, g_sequence_get_length (store->items));
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
**/
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properties[PROP_ITEM_TYPE] =
g_param_spec_gtype ("item-type", NULL, NULL, G_TYPE_OBJECT,
G_PARAM_CONSTRUCT_ONLY | G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS);
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/**
* GListStore:n-items:
*
* The number of items contained in this list store.
*
* Since: 2.74
**/
properties[PROP_N_ITEMS] =
g_param_spec_uint ("n-items", NULL, NULL, 0, G_MAXUINT, 0,
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G_PARAM_READABLE | G_PARAM_STATIC_STRINGS);
g_object_class_install_properties (object_class, N_PROPERTIES, properties);
}
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 <= (guint) 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) (closure user_data): pairwise comparison function for sorting
* @user_data: 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) (closure user_data): pairwise comparison function for sorting
* @user_data: 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)
{
guint 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);
}
static gboolean
simple_equal (gconstpointer a,
gconstpointer b,
gpointer equal_func)
{
return ((GEqualFunc) equal_func) (a, b);
}
/**
* g_list_store_find_with_equal_func:
* @store: a #GListStore
* @item: (type GObject) (nullable): an item
* @equal_func: (scope call): A custom equality check function
* @position: (out) (optional): the first position of @item, if it was found.
*
* Looks up the given @item in the list store by looping over the items and
* comparing them with @equal_func until the first occurrence of @item which
* matches. If @item was not found, then @position will not be set, and this
* method will return %FALSE.
*
* @item is always passed as second parameter to @equal_func.
*
* Since GLib 2.76 it is possible to pass `NULL` for @item.
*
* Returns: Whether @store contains @item. If it was found, @position will be
* set to the position where @item occurred for the first time.
*
* Since: 2.64
*/
gboolean
g_list_store_find_with_equal_func (GListStore *store,
gpointer item,
GEqualFunc equal_func,
guint *position)
{
g_return_val_if_fail (equal_func != NULL, FALSE);
return g_list_store_find_with_equal_func_full (store, item, simple_equal,
equal_func, position);
}
/**
* g_list_store_find_with_equal_func_full:
* @store: a #GListStore
* @item: (type GObject) (nullable): an item
* @equal_func: (scope call) (closure user_data): A custom equality check function
* @user_data: user data for @equal_func
* @position: (out) (optional): the first position of @item, if it was found.
*
* Like g_list_store_find_with_equal_func() but with an additional @user_data
* that is passed to @equal_func.
*
* @item is always passed as second parameter to @equal_func.
*
* Since GLib 2.76 it is possible to pass `NULL` for @item.
*
* Returns: Whether @store contains @item. If it was found, @position will be
* set to the position where @item occurred for the first time.
*
* Since: 2.74
*/
gboolean
g_list_store_find_with_equal_func_full (GListStore *store,
gpointer item,
GEqualFuncFull equal_func,
gpointer user_data,
guint *position)
{
GSequenceIter *iter, *begin, *end;
g_return_val_if_fail (G_IS_LIST_STORE (store), FALSE);
g_return_val_if_fail (item == NULL || g_type_is_a (G_OBJECT_TYPE (item), store->item_type),
FALSE);
g_return_val_if_fail (equal_func != NULL, FALSE);
/* NOTE: We can't use g_sequence_lookup() or g_sequence_search(), because we
* can't assume the sequence is sorted. */
begin = g_sequence_get_begin_iter (store->items);
end = g_sequence_get_end_iter (store->items);
iter = begin;
while (iter != end)
{
gpointer iter_item;
iter_item = g_sequence_get (iter);
if (equal_func (iter_item, item, user_data))
{
if (position)
*position = g_sequence_iter_get_position (iter);
return TRUE;
}
iter = g_sequence_iter_next (iter);
}
return FALSE;
}
/**
* g_list_store_find:
* @store: a #GListStore
* @item: (type GObject): an item
* @position: (out) (optional): the first position of @item, if it was found.
*
* Looks up the given @item in the list store by looping over the items until
* the first occurrence of @item. If @item was not found, then @position will
* not be set, and this method will return %FALSE.
*
* If you need to compare the two items with a custom comparison function, use
* g_list_store_find_with_equal_func() with a custom #GEqualFunc instead.
*
* Returns: Whether @store contains @item. If it was found, @position will be
* set to the position where @item occurred for the first time.
*
* Since: 2.64
*/
gboolean
g_list_store_find (GListStore *store,
gpointer item,
guint *position)
{
return g_list_store_find_with_equal_func (store,
item,
g_direct_equal,
position);
}