gio/gliststore.c - third_party/glib - Git at Google

 /*
  * 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;
 };

 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 = -1u;
     }

   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 */
       store->item_type = g_value_get_gtype (value);
       if (!g_type_is_a (store->item_type, G_TYPE_OBJECT))
         g_critical ("GListStore cannot store items of type '%s'. Items must be GObjects.",
                     g_type_name (store->item_type));
       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 != -1u)
     {
       if (store->last_position == position + 1)
         it = g_sequence_iter_prev (store->last_iter);
       else if (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;

   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 = -1u;
 }

 /**
  * 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;
             }

           it = g_sequence_insert_before (it, g_object_ref (additions[i]));
           it = g_sequence_iter_next (it);
         }
     }

   g_list_store_items_changed (store, position, n_removals, n_additions);
 }
	/*
	* 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;
	};

	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 = -1u;
	}

	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 */
	store->item_type = g_value_get_gtype (value);
	if (!g_type_is_a (store->item_type, G_TYPE_OBJECT))
	g_critical ("GListStore cannot store items of type '%s'. Items must be GObjects.",
	g_type_name (store->item_type));
	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 != -1u)
	{
	if (store->last_position == position + 1)
	it = g_sequence_iter_prev (store->last_iter);
	else if (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;

	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 = -1u;
	}

	/**
	* 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;
	}

	it = g_sequence_insert_before (it, g_object_ref (additions[i]));
	it = g_sequence_iter_next (it);
	}
	}

	g_list_store_items_changed (store, position, n_removals, n_additions);
	}