structure: add LinkedList0

structure/LinkedList0.h

@@ -0,0 +1,195 @@
+/**
+ * @file LinkedList0.h
+ * @author Ambroz Bizjak <ambrop7@gmail.com>
+ * 
+ * @section LICENSE
+ * 
+ * This file is part of BadVPN.
+ * 
+ * BadVPN is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2
+ * as published by the Free Software Foundation.
+ * 
+ * BadVPN 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 General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ * 
+ * @section DESCRIPTION
+ * 
+ * Very simple doubly linked list, with only a 'first' pointer an no 'last'
+ * pointer.
+ */
+
+#ifndef BADVPN_STRUCTURE_LINKEDLIST0_H
+#define BADVPN_STRUCTURE_LINKEDLIST0_H
+
+#include <stddef.h>
+
+#include <misc/debug.h>
+
+/**
+ * Linked list node.
+ */
+typedef struct LinkedList0Node_t
+{
+    struct LinkedList0Node_t *p;
+    struct LinkedList0Node_t *n;
+} LinkedList0Node;
+
+/**
+ * Simple doubly linked list.
+ */
+typedef struct
+{
+    LinkedList0Node *first;
+} LinkedList0;
+
+/**
+ * Initializes the linked list.
+ * 
+ * @param list list to initialize
+ */
+static void LinkedList0_Init (LinkedList0 *list);
+
+/**
+ * Determines if the list is empty.
+ * 
+ * @param list the list
+ * @return 1 if empty, 0 if not
+ */
+static int LinkedList0_IsEmpty (LinkedList0 *list);
+
+/**
+ * Returns the first node of the list.
+ * 
+ * @param list the list
+ * @return first node of the list, or NULL if the list is empty
+ */
+static LinkedList0Node * LinkedList0_GetFirst (LinkedList0 *list);
+
+/**
+ * Inserts a node to the beginning of the list.
+ * 
+ * @param list the list
+ * @param node uninitialized node to insert
+ */
+static void LinkedList0_Prepend (LinkedList0 *list, LinkedList0Node *node);
+
+/**
+ * Inserts a node before a given node.
+ * 
+ * @param list the list
+ * @param node uninitialized node to insert
+ * @param target node in the list to insert before
+ */
+static void LinkedList0_InsertBefore (LinkedList0 *list, LinkedList0Node *node, LinkedList0Node *target);
+
+/**
+ * Inserts a node after a given node.
+ * 
+ * @param list the list
+ * @param node uninitialized node to insert
+ * @param target node in the list to insert after
+ */
+static void LinkedList0_InsertAfter (LinkedList0 *list, LinkedList0Node *node, LinkedList0Node *target);
+
+/**
+ * Removes a node from the list.
+ * 
+ * @param list the list
+ * @param node node to remove
+ */
+static void LinkedList0_Remove (LinkedList0 *list, LinkedList0Node *node);
+
+/**
+ * Returns the next node of a given node.
+ * 
+ * @param node reference node
+ * @return next node, or NULL if none
+ */
+static LinkedList0Node * LinkedList0Node_Next (LinkedList0Node *node);
+
+/**
+ * Returns the previous node of a given node.
+ * 
+ * @param node reference node
+ * @return previous node, or NULL if none
+ */
+static LinkedList0Node * LinkedList0Node_Prev (LinkedList0Node *node);
+
+void LinkedList0_Init (LinkedList0 *list)
+{
+    list->first = NULL;
+}
+
+int LinkedList0_IsEmpty (LinkedList0 *list)
+{
+    return (!list->first);
+}
+
+LinkedList0Node * LinkedList0_GetFirst (LinkedList0 *list)
+{
+    return (list->first);
+}
+
+void LinkedList0_Prepend (LinkedList0 *list, LinkedList0Node *node)
+{
+    node->p = NULL;
+    node->n = list->first;
+    if (list->first) {
+        list->first->p = node;
+    }
+    list->first = node;
+}
+
+void LinkedList0_InsertBefore (LinkedList0 *list, LinkedList0Node *node, LinkedList0Node *target)
+{
+    node->p = target->p;
+    node->n = target;
+    if (target->p) {
+        target->p->n = node;
+    } else {
+        list->first = node;
+    }
+    target->p = node;
+}
+
+void LinkedList0_InsertAfter (LinkedList0 *list, LinkedList0Node *node, LinkedList0Node *target)
+{
+    node->p = target;
+    node->n = target->n;
+    if (target->n) {
+        target->n->p = node;
+    }
+    target->n = node;
+}
+
+void LinkedList0_Remove (LinkedList0 *list, LinkedList0Node *node)
+{
+    // remove from list
+    if (node->p) {
+        node->p->n = node->n;
+    } else {
+        list->first = node->n;
+    }
+    if (node->n) {
+        node->n->p = node->p;
+    }
+}
+
+LinkedList0Node * LinkedList0Node_Next (LinkedList0Node *node)
+{
+    return node->n;
+}
+
+LinkedList0Node * LinkedList0Node_Prev (LinkedList0Node *node)
+{
+    return node->p;
+}
+
+#endif