libudev-list.c revision ad29a9f14fa8b1932c0e418bfcf1c10ce6a35a33
17N/A/*
17N/A * libudev - interface to udev device information
17N/A *
17N/A * Copyright (C) 2008 Kay Sievers <kay.sievers@vrfy.org>
17N/A *
17N/A * This library is free software; you can redistribute it and/or
17N/A * modify it under the terms of the GNU Lesser General Public
17N/A * License as published by the Free Software Foundation; either
17N/A * version 2.1 of the License, or (at your option) any later version.
17N/A */
17N/A
17N/A#include <stdio.h>
17N/A#include <stdlib.h>
17N/A#include <stddef.h>
17N/A#include <unistd.h>
17N/A#include <errno.h>
17N/A#include <string.h>
17N/A
17N/A#include "libudev.h"
17N/A#include "libudev-private.h"
17N/A
17N/A/**
17N/A * SECTION:libudev-list
17N/A * @short_description: list operation
17N/A *
17N/A * Libudev list operations.
17N/A */
17N/A
17N/A/**
17N/A * udev_list_entry:
156N/A *
17N/A * Opaque object representing one entry in a list. An entry contains
17N/A * contains a name, and optionally a value.
17N/A */
17N/Astruct udev_list_entry {
17N/A struct udev_list_node node;
17N/A struct udev_list *list;
17N/A char *name;
17N/A char *value;
17N/A int num;
17N/A};
156N/A
17N/A/* the list's head points to itself if empty */
17N/Avoid udev_list_node_init(struct udev_list_node *list)
17N/A{
17N/A list->next = list;
17N/A list->prev = list;
17N/A}
17N/A
17N/Aint udev_list_node_is_empty(struct udev_list_node *list)
17N/A{
17N/A return list->next == list;
17N/A}
17N/A
17N/Astatic void udev_list_node_insert_between(struct udev_list_node *new,
17N/A struct udev_list_node *prev,
17N/A struct udev_list_node *next)
17N/A{
17N/A next->prev = new;
17N/A new->next = next;
17N/A new->prev = prev;
17N/A prev->next = new;
17N/A}
49N/A
17N/Avoid udev_list_node_append(struct udev_list_node *new, struct udev_list_node *list)
17N/A{
17N/A udev_list_node_insert_between(new, list->prev, list);
17N/A}
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 struct udev_list_entry *list_node_to_entry(struct udev_list_node *node)
{
char *list;
list = (char *)node;
list -= offsetof(struct udev_list_entry, node);
return (struct udev_list_entry *)list;
}
void udev_list_init(struct udev *udev, struct udev_list *list, bool unique)
{
memset(list, 0x00, 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 */
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 */
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];
dbg(list->udev, "'%s' is already in the list\n", name);
free(entry->value);
if (value == NULL) {
entry->value = NULL;
dbg(list->udev, "'%s' value unset\n", name);
return entry;
}
entry->value = strdup(value);
if (entry->value == NULL)
return NULL;
dbg(list->udev, "'%s' value replaced with '%s'\n", name, value);
return entry;
}
}
/* add new name */
entry = calloc(1, sizeof(struct udev_list_entry));
if (entry == NULL)
return NULL;
entry->name = strdup(name);
if (entry->name == NULL) {
free(entry);
return NULL;
}
if (value != NULL) {
entry->value = strdup(value);
if (entry->value == NULL) {
free(entry->name);
free(entry);
return NULL;
}
}
if (list->unique) {
/* allocate or enlarge sorted array if needed */
if (list->entries_cur >= list->entries_max) {
unsigned int add;
add = list->entries_max;
if (add < 1)
add = 64;
list->entries = realloc(list->entries, (list->entries_max + add) * sizeof(struct udev_list_entry *));
if (list->entries == NULL) {
free(entry->name);
free(entry->value);
return NULL;
}
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);
}
dbg(list->udev, "'%s=%s' added\n", entry->name, entry->value);
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;
free(list->entries);
list->entries = NULL;
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
*
* Returns: the next entry from the list, #NULL is no more entries are found.
*/
UDEV_EXPORT 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
*
* Returns: the entry where @name matched, #NULL if no matching entry is found.
*/
UDEV_EXPORT 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
*
* Returns: the name string of this entry.
*/
UDEV_EXPORT 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
*
* Returns: the value string of this entry.
*/
UDEV_EXPORT 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;
}