--- /dev/null
+/*
+ * libudev - interface to udev device information
+ *
+ * Copyright (C) 2008 Kay Sievers <kay.sievers@vrfy.org>
+ *
+ * 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.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stddef.h>
+#include <unistd.h>
+#include <errno.h>
+#include <string.h>
+
+#include "libudev.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 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];
+
+ 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 = 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);
+ }
+
+ 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.
+ */
+_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
+ *
+ * Returns: the entry where @name matched, #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
+ *
+ * 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
+ *
+ * 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;
+}
~ianmdlvl / elogind.git / blobdiff