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lib/plist/node_list.c

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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 "list.h"
+#include "node.h"
+#include "node_list.h"
+
+void node_list_destroy(node_list_t* list) {
+	if(list != NULL) {
+		list_destroy((list_t*) list);
+	}
+}
+
+node_list_t* node_list_create() {
+	node_list_t* list = (node_list_t*) malloc(sizeof(node_list_t));
+	if(list == NULL) {
+		return NULL;
+	}
+	memset(list, '\0', sizeof(node_list_t));
+
+	// Initialize structure
+	list_init((list_t*) list);
+	list->count = 0;
+	return list;
+}
+
+int node_list_add(node_list_t* list, node_t* node) {
+	if (!list || !node) return -1;
+
+	// 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;
+	}
+
+	// Set the lists prev to the new last element
+	list->end = node;
+
+	// Increment our node count for this list
+	list->count++;
+	return 0;
+}
+
+int node_list_insert(node_list_t* list, unsigned int node_index, node_t* node) {
+	if (!list || !node) return -1;
+	if (node_index >= list->count) {
+		return node_list_add(list, node);
+	}
+
+	// Get the first element in the list
+	node_t* cur = list->begin;
+
+	unsigned int pos = 0;
+	node_t* prev = NULL;
+
+	if (node_index > 0) {
+		while (pos < node_index) {
+			prev = cur;
+			cur = cur->next;
+			pos++;
+		}
+	}
+
+	if (prev) {
+		// Set previous node
+		node->prev = prev;
+		// Set next node of our new node to next node of the previous node
+		node->next = prev->next;
+		// Set next node of previous node to our new node
+		prev->next = node;
+	} else {
+		node->prev = NULL;
+		// get old first element in list
+		node->next = list->begin;
+		// set new node as first element in list
+		list->begin = node;
+	}
+
+	if (node->next == NULL) {
+		// Set the lists prev to the new last element
+		list->end = node;
+	} else {
+		// set prev of the new next element to our node
+		node->next->prev = node;
+	}
+
+	// Increment our node count for this list
+	list->count++;
+	return 0;
+}
+
+int node_list_remove(node_list_t* list, node_t* node) {
+	if (!list || !node) return -1;
+	if (list->count == 0) return -1;
+
+	int node_index = 0;
+	node_t* n;
+	for (n = list->begin; n; n = n->next) {
+		if (node == n) {
+			node_t* newnode = node->next;
+			if (node->prev) {
+				node->prev->next = newnode;
+				if (newnode) {
+					newnode->prev = node->prev;
+				} else {
+					// last element in the list
+					list->end = node->prev;
+				}
+			} else {
+				// we just removed the first element
+				if (newnode) {
+					newnode->prev = NULL;
+				}
+				list->begin = newnode;
+			}
+			list->count--;
+			return node_index;
+		}
+		node_index++;
+	}	
+	return -1;
+}
+