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/*
* node_list.c
*
* Created on: Mar 8, 2011
* Author: posixninja
*
* Copyright (c) 2011 Joshua Hill. All Rights Reserved.
*
* 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, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "node.h"
#include "node_list.h"
void node_list_destroy(node_list_t list)
{
free(list);
}
node_list_t node_list_create()
{
node_list_t list = (node_list_t)calloc(1, sizeof(struct node_list));
if (list == NULL) {
return NULL;
}
// Initialize structure
list->begin = NULL;
list->end = NULL;
list->count = 0;
return list;
}
int node_list_add(node_list_t list, node_t node)
{
if (!list || !node) return NODE_ERR_INVALID_ARG;
// Find the last element in the list
node_t last = list->end;
// Setup our new node as the new last element
node->next = NULL;
node->prev = last;
// Set the next element of our old "last" element
if (last) {
// but only if the node list is not empty
last->next = node;
} else {
// otherwise this is the start of the list
list->begin = node;
}
// Set the lists prev to the new last element
list->end = node;
// Increment our node count for this list
list->count++;
return NODE_ERR_SUCCESS;
}
int node_list_insert(node_list_t list, unsigned int node_index, node_t node)
{
if (!list || !node) return NODE_ERR_INVALID_ARG;
if (node_index > list->count) return NODE_ERR_INVALID_ARG;
if (node_index == list->count) {
return node_list_add(list, node);
}
// Get the first element in the list
node_t cur = list->begin;
node_t prev = NULL;
for (unsigned int pos = 0; pos < node_index; pos++) {
if (!cur) return NODE_ERR_INVALID_ARG;
prev = cur;
cur = cur->next;
}
// insert node before cur
node->prev = prev;
node->next = cur;
if (prev) {
prev->next = node;
} else {
list->begin = node;
}
if (cur) {
cur->prev = node;
} else {
// should not happen with bounds above, but keeps things consistent
list->end = node;
}
// Increment our node count for this list
list->count++;
return NODE_ERR_SUCCESS;
}
// Returns removed index (>=0) on success, or NODE_ERR_* (<0) on failure.
int node_list_remove(node_list_t list, node_t node)
{
if (!list || !node) return NODE_ERR_INVALID_ARG;
if (list->count == 0) return NODE_ERR_NOT_FOUND;
int node_index = 0;
for (node_t n = list->begin; n; n = n->next, node_index++) {
if (node != n) continue;
node_t newnode = node->next;
if (node->prev) {
node->prev->next = newnode;
} else {
// we just removed the first element
list->begin = newnode;
}
if (newnode) {
newnode->prev = node->prev;
} else {
// we removed the last element, set new end
list->end = node->prev;
}
// fully detach node from list
node->prev = NULL;
node->next = NULL;
list->count--;
return node_index;
}
return NODE_ERR_NOT_FOUND;
}
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