src/libudev/libudev-list.c - systemd-stable - Rivoreo Source Code Repositories

 /* SPDX-License-Identifier: LGPL-2.1+ */
 /***
   This file is part of systemd.

   Copyright 2008-2012 Kay Sievers <kay@vrfy.org>

   systemd 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.

   systemd 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 systemd; If not, see <http://www.gnu.org/licenses/>.
 ***/

 #include <errno.h>
 #include <stddef.h>
 #include <stdlib.h>
 #include <string.h>

 #include "alloc-util.h"
 #include "libudev-private.h"

 /**
  * SECTION:libudev-list
  * @short_description: list operation
  *
  * Libudev list operations.
  */

 /**
  * udev_list_entry:
  *
  * Opaque object representing one entry in a list. An entry contains
  * contains a name, and optionally a value.
  */
 struct udev_list_entry {
         struct udev_list_node node;
         struct udev_list *list;
         char *name;
         char *value;
         int num;
 };

 /* the list's head points to itself if empty */
 void udev_list_node_init(struct udev_list_node *list)
 {
         list->next = list;
         list->prev = list;
 }

 int udev_list_node_is_empty(struct udev_list_node *list)
 {
         return list->next == list;
 }

 static void udev_list_node_insert_between(struct udev_list_node *new,
                                           struct udev_list_node *prev,
                                           struct udev_list_node *next)
 {
         next->prev = new;
         new->next = next;
         new->prev = prev;
         prev->next = new;
 }

 void udev_list_node_append(struct udev_list_node *new, struct udev_list_node *list)
 {
         udev_list_node_insert_between(new, list->prev, list);
 }

 void udev_list_node_remove(struct udev_list_node *entry)
 {
         struct udev_list_node *prev = entry->prev;
         struct udev_list_node *next = entry->next;

         next->prev = prev;
         prev->next = next;

         entry->prev = NULL;
         entry->next = NULL;
 }

 /* return list entry which embeds this node */
 static inline struct udev_list_entry *list_node_to_entry(struct udev_list_node *node)
 {
         return container_of(node, struct udev_list_entry, node);
 }

 void udev_list_init(struct udev *udev, struct udev_list *list, bool unique)
 {
         memzero(list, sizeof(struct udev_list));
         list->udev = udev;
         list->unique = unique;
         udev_list_node_init(&list->node);
 }

 /* insert entry into a list as the last element  */
 static void udev_list_entry_append(struct udev_list_entry *new, struct udev_list *list)
 {
         /* inserting before the list head make the node the last node in the list */
         udev_list_node_insert_between(&new->node, list->node.prev, &list->node);
         new->list = list;
 }

 /* insert entry into a list, before a given existing entry */
 static void udev_list_entry_insert_before(struct udev_list_entry *new, struct udev_list_entry *entry)
 {
         udev_list_node_insert_between(&new->node, entry->node.prev, &entry->node);
         new->list = entry->list;
 }

 /* binary search in sorted array */
 static int list_search(struct udev_list *list, const char *name)
 {
         unsigned int first, last;

         first = 0;
         last = list->entries_cur;
         while (first < last) {
                 unsigned int i;
                 int cmp;

                 i = (first + last)/2;
                 cmp = strcmp(name, list->entries[i]->name);
                 if (cmp < 0)
                         last = i;
                 else if (cmp > 0)
                         first = i+1;
                 else
                         return i;
         }

         /* not found, return negative insertion-index+1 */
         return -(first+1);
 }

 struct udev_list_entry *udev_list_entry_add(struct udev_list *list, const char *name, const char *value)
 {
         struct udev_list_entry *entry;
         int i = 0;

         if (list->unique) {
                 /* lookup existing name or insertion-index */
                 i = list_search(list, name);
                 if (i >= 0) {
                         entry = list->entries[i];

                         free(entry->value);
                         if (value == NULL) {
                                 entry->value = NULL;
                                 return entry;
                         }
                         entry->value = strdup(value);
                         if (entry->value == NULL)
                                 return NULL;
                         return entry;
                 }
         }

         /* add new name */
         entry = new0(struct udev_list_entry, 1);
         if (entry == NULL)
                 return NULL;

         entry->name = strdup(name);
         if (entry->name == NULL)
                 return mfree(entry);

         if (value != NULL) {
                 entry->value = strdup(value);
                 if (entry->value == NULL) {
                         free(entry->name);
                         return mfree(entry);
                 }
         }

         if (list->unique) {
                 /* allocate or enlarge sorted array if needed */
                 if (list->entries_cur >= list->entries_max) {
                         struct udev_list_entry **entries;
                         unsigned int add;

                         add = list->entries_max;
                         if (add < 1)
                                 add = 64;
                         entries = realloc(list->entries, (list->entries_max + add) * sizeof(struct udev_list_entry *));
                         if (entries == NULL) {
                                 free(entry->name);
                                 free(entry->value);
                                 return mfree(entry);
                         }
                         list->entries = entries;
                         list->entries_max += add;
                 }

                 /* the negative i returned the insertion index */
                 i = (-i)-1;

                 /* insert into sorted list */
                 if ((unsigned int)i < list->entries_cur)
                         udev_list_entry_insert_before(entry, list->entries[i]);
                 else
                         udev_list_entry_append(entry, list);

                 /* insert into sorted array */
                 memmove(&list->entries[i+1], &list->entries[i],
                         (list->entries_cur - i) * sizeof(struct udev_list_entry *));
                 list->entries[i] = entry;
                 list->entries_cur++;
         } else {
                 udev_list_entry_append(entry, list);
         }

         return entry;
 }

 void udev_list_entry_delete(struct udev_list_entry *entry)
 {
         if (entry->list->entries != NULL) {
                 int i;
                 struct udev_list *list = entry->list;

                 /* remove entry from sorted array */
                 i = list_search(list, entry->name);
                 if (i >= 0) {
                         memmove(&list->entries[i], &list->entries[i+1],
                                 ((list->entries_cur-1) - i) * sizeof(struct udev_list_entry *));
                         list->entries_cur--;
                 }
         }

         udev_list_node_remove(&entry->node);
         free(entry->name);
         free(entry->value);
         free(entry);
 }

 void udev_list_cleanup(struct udev_list *list)
 {
         struct udev_list_entry *entry_loop;
         struct udev_list_entry *entry_tmp;

         list->entries = mfree(list->entries);
         list->entries_cur = 0;
         list->entries_max = 0;
         udev_list_entry_foreach_safe(entry_loop, entry_tmp, udev_list_get_entry(list))
                 udev_list_entry_delete(entry_loop);
 }

 struct udev_list_entry *udev_list_get_entry(struct udev_list *list)
 {
         if (udev_list_node_is_empty(&list->node))
                 return NULL;
         return list_node_to_entry(list->node.next);
 }

 /**
  * udev_list_entry_get_next:
  * @list_entry: current entry
  *
  * Get the next entry from the list.
  *
  * Returns: udev_list_entry, #NULL if no more entries are available.
  */
 _public_ struct udev_list_entry *udev_list_entry_get_next(struct udev_list_entry *list_entry)
 {
         struct udev_list_node *next;

         if (list_entry == NULL)
                 return NULL;
         next = list_entry->node.next;
         /* empty list or no more entries */
         if (next == &list_entry->list->node)
                 return NULL;
         return list_node_to_entry(next);
 }

 /**
  * udev_list_entry_get_by_name:
  * @list_entry: current entry
  * @name: name string to match
  *
  * Lookup an entry in the list with a certain name.
  *
  * Returns: udev_list_entry, #NULL if no matching entry is found.
  */
 _public_ struct udev_list_entry *udev_list_entry_get_by_name(struct udev_list_entry *list_entry, const char *name)
 {
         int i;

         if (list_entry == NULL)
                 return NULL;

         if (!list_entry->list->unique)
                 return NULL;

         i = list_search(list_entry->list, name);
         if (i < 0)
                 return NULL;
         return list_entry->list->entries[i];
 }

 /**
  * udev_list_entry_get_name:
  * @list_entry: current entry
  *
  * Get the name of a list entry.
  *
  * Returns: the name string of this entry.
  */
 _public_ const char *udev_list_entry_get_name(struct udev_list_entry *list_entry)
 {
         if (list_entry == NULL)
                 return NULL;
         return list_entry->name;
 }

 /**
  * udev_list_entry_get_value:
  * @list_entry: current entry
  *
  * Get the value of list entry.
  *
  * Returns: the value string of this entry.
  */
 _public_ const char *udev_list_entry_get_value(struct udev_list_entry *list_entry)
 {
         if (list_entry == NULL)
                 return NULL;
         return list_entry->value;
 }

 int udev_list_entry_get_num(struct udev_list_entry *list_entry)
 {
         if (list_entry == NULL)
                 return -EINVAL;
         return list_entry->num;
 }

 void udev_list_entry_set_num(struct udev_list_entry *list_entry, int num)
 {
         if (list_entry == NULL)
                 return;
         list_entry->num = num;
 }
	/* SPDX-License-Identifier: LGPL-2.1+ */
	/***
	This file is part of systemd.

	Copyright 2008-2012 Kay Sievers <kay@vrfy.org>

	systemd 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.

	systemd 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 systemd; If not, see <http://www.gnu.org/licenses/>.
	***/

	#include <errno.h>
	#include <stddef.h>
	#include <stdlib.h>
	#include <string.h>

	#include "alloc-util.h"
	#include "libudev-private.h"

	/**
	* SECTION:libudev-list
	* @short_description: list operation
	*
	* Libudev list operations.
	*/

	/**
	* udev_list_entry:
	*
	* Opaque object representing one entry in a list. An entry contains
	* contains a name, and optionally a value.
	*/
	struct udev_list_entry {
	struct udev_list_node node;
	struct udev_list *list;
	char *name;
	char *value;
	int num;
	};

	/* the list's head points to itself if empty */
	void udev_list_node_init(struct udev_list_node *list)
	{
	list->next = list;
	list->prev = list;
	}

	int udev_list_node_is_empty(struct udev_list_node *list)
	{
	return list->next == list;
	}

	static void udev_list_node_insert_between(struct udev_list_node *new,
	struct udev_list_node *prev,
	struct udev_list_node *next)
	{
	next->prev = new;
	new->next = next;
	new->prev = prev;
	prev->next = new;
	}

	void udev_list_node_append(struct udev_list_node new, struct udev_list_node list)
	{
	udev_list_node_insert_between(new, list->prev, list);
	}

	void udev_list_node_remove(struct udev_list_node *entry)
	{
	struct udev_list_node *prev = entry->prev;
	struct udev_list_node *next = entry->next;

	next->prev = prev;
	prev->next = next;

	entry->prev = NULL;
	entry->next = NULL;
	}

	/* return list entry which embeds this node */
	static inline struct udev_list_entry list_node_to_entry(struct udev_list_node node)
	{
	return container_of(node, struct udev_list_entry, node);
	}

	void udev_list_init(struct udev udev, struct udev_list list, bool unique)
	{
	memzero(list, sizeof(struct udev_list));
	list->udev = udev;
	list->unique = unique;
	udev_list_node_init(&list->node);
	}

	/* insert entry into a list as the last element */
	static void udev_list_entry_append(struct udev_list_entry new, struct udev_list list)
	{
	/* inserting before the list head make the node the last node in the list */
	udev_list_node_insert_between(&new->node, list->node.prev, &list->node);
	new->list = list;
	}

	/* insert entry into a list, before a given existing entry */
	static void udev_list_entry_insert_before(struct udev_list_entry new, struct udev_list_entry entry)
	{
	udev_list_node_insert_between(&new->node, entry->node.prev, &entry->node);
	new->list = entry->list;
	}

	/* binary search in sorted array */
	static int list_search(struct udev_list list, const char name)
	{
	unsigned int first, last;

	first = 0;
	last = list->entries_cur;
	while (first < last) {
	unsigned int i;
	int cmp;

	i = (first + last)/2;
	cmp = strcmp(name, list->entries[i]->name);
	if (cmp < 0)
	last = i;
	else if (cmp > 0)
	first = i+1;
	else
	return i;
	}

	/* not found, return negative insertion-index+1 */
	return -(first+1);
	}

	struct udev_list_entry udev_list_entry_add(struct udev_list list, const char name, const char value)
	{
	struct udev_list_entry *entry;
	int i = 0;

	if (list->unique) {
	/* lookup existing name or insertion-index */
	i = list_search(list, name);
	if (i >= 0) {
	entry = list->entries[i];

	free(entry->value);
	if (value == NULL) {
	entry->value = NULL;
	return entry;
	}
	entry->value = strdup(value);
	if (entry->value == NULL)
	return NULL;
	return entry;
	}
	}

	/* add new name */
	entry = new0(struct udev_list_entry, 1);
	if (entry == NULL)
	return NULL;

	entry->name = strdup(name);
	if (entry->name == NULL)
	return mfree(entry);

	if (value != NULL) {
	entry->value = strdup(value);
	if (entry->value == NULL) {
	free(entry->name);
	return mfree(entry);
	}
	}

	if (list->unique) {
	/* allocate or enlarge sorted array if needed */
	if (list->entries_cur >= list->entries_max) {
	struct udev_list_entry **entries;
	unsigned int add;

	add = list->entries_max;
	if (add < 1)
	add = 64;
	entries = realloc(list->entries, (list->entries_max + add) * sizeof(struct udev_list_entry *));
	if (entries == NULL) {
	free(entry->name);
	free(entry->value);
	return mfree(entry);
	}
	list->entries = entries;
	list->entries_max += add;
	}

	/* the negative i returned the insertion index */
	i = (-i)-1;

	/* insert into sorted list */
	if ((unsigned int)i < list->entries_cur)
	udev_list_entry_insert_before(entry, list->entries[i]);
	else
	udev_list_entry_append(entry, list);

	/* insert into sorted array */
	memmove(&list->entries[i+1], &list->entries[i],
	(list->entries_cur - i) * sizeof(struct udev_list_entry *));
	list->entries[i] = entry;
	list->entries_cur++;
	} else {
	udev_list_entry_append(entry, list);
	}

	return entry;
	}

	void udev_list_entry_delete(struct udev_list_entry *entry)
	{
	if (entry->list->entries != NULL) {
	int i;
	struct udev_list *list = entry->list;

	/* remove entry from sorted array */
	i = list_search(list, entry->name);
	if (i >= 0) {
	memmove(&list->entries[i], &list->entries[i+1],
	((list->entries_cur-1) - i) * sizeof(struct udev_list_entry *));
	list->entries_cur--;
	}
	}

	udev_list_node_remove(&entry->node);
	free(entry->name);
	free(entry->value);
	free(entry);
	}

	void udev_list_cleanup(struct udev_list *list)
	{
	struct udev_list_entry *entry_loop;
	struct udev_list_entry *entry_tmp;

	list->entries = mfree(list->entries);
	list->entries_cur = 0;
	list->entries_max = 0;
	udev_list_entry_foreach_safe(entry_loop, entry_tmp, udev_list_get_entry(list))
	udev_list_entry_delete(entry_loop);
	}

	struct udev_list_entry udev_list_get_entry(struct udev_list list)
	{
	if (udev_list_node_is_empty(&list->node))
	return NULL;
	return list_node_to_entry(list->node.next);
	}

	/**
	* udev_list_entry_get_next:
	* @list_entry: current entry
	*
	* Get the next entry from the list.
	*
	* Returns: udev_list_entry, #NULL if no more entries are available.
	*/
	_public_ struct udev_list_entry udev_list_entry_get_next(struct udev_list_entry list_entry)
	{
	struct udev_list_node *next;

	if (list_entry == NULL)
	return NULL;
	next = list_entry->node.next;
	/* empty list or no more entries */
	if (next == &list_entry->list->node)
	return NULL;
	return list_node_to_entry(next);
	}

	/**
	* udev_list_entry_get_by_name:
	* @list_entry: current entry
	* @name: name string to match
	*
	* Lookup an entry in the list with a certain name.
	*
	* Returns: udev_list_entry, #NULL if no matching entry is found.
	*/
	_public_ struct udev_list_entry udev_list_entry_get_by_name(struct udev_list_entry list_entry, const char *name)
	{
	int i;

	if (list_entry == NULL)
	return NULL;

	if (!list_entry->list->unique)
	return NULL;

	i = list_search(list_entry->list, name);
	if (i < 0)
	return NULL;
	return list_entry->list->entries[i];
	}

	/**
	* udev_list_entry_get_name:
	* @list_entry: current entry
	*
	* Get the name of a list entry.
	*
	* Returns: the name string of this entry.
	*/
	_public_ const char udev_list_entry_get_name(struct udev_list_entry list_entry)
	{
	if (list_entry == NULL)
	return NULL;
	return list_entry->name;
	}

	/**
	* udev_list_entry_get_value:
	* @list_entry: current entry
	*
	* Get the value of list entry.
	*
	* Returns: the value string of this entry.
	*/
	_public_ const char udev_list_entry_get_value(struct udev_list_entry list_entry)
	{
	if (list_entry == NULL)
	return NULL;
	return list_entry->value;
	}

	int udev_list_entry_get_num(struct udev_list_entry *list_entry)
	{
	if (list_entry == NULL)
	return -EINVAL;
	return list_entry->num;
	}

	void udev_list_entry_set_num(struct udev_list_entry *list_entry, int num)
	{
	if (list_entry == NULL)
	return;
	list_entry->num = num;
	}