/*
-Copyright (C) 2020 David "Cloudwalk" Knapp
+Copyright (C) 2020-2021 David Knapp (Cloudwalk)
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
*/
-// com_list.c - generic doubly linked list interface, inspired by Linux list.h
+// com_list.h - generic doubly linked list interface, adapted from Linux list.h
+
+#ifndef LIST_H
+#define LIST_H
#include <stddef.h>
+#include "qtypes.h"
+#include "qdefs.h"
typedef struct llist_s
{
struct llist_s *next;
} llist_t;
-#define List_Head_Reset(name) { &(name), &(name) }
+#define LIST_HEAD_INIT(name) { &(name), &(name) }
+
+#define LIST_HEAD(name) \
+ struct llist_s name = LIST_HEAD_INIT(name)
+
+/*
+ * Get the struct for this entry
+ */
+#define List_Entry(ptr, type, member) ContainerOf(ptr, type, member)
+
+/*
+ * Get the first element from a list
+ * The list is expected to not be empty
+ */
+#define List_First_Entry(ptr, type, member) List_Entry((ptr)->next, type, member)
-#define List_Container(ptr, type, member) ContainerOf(ptr, type, member)
+/*
+ * Get the last element from the list
+ * The list is expected to not be empty
+ */
+#define List_Last_Entry(ptr, type, member) List_Entry((ptr)->prev, type, member)
-#define List_ForEach(pos, head) \
+/*
+ * Get the first element from the list, but return NULL if it's empty
+ */
+#define List_First_Entry_Or_Null(ptr, type, member) ({ \
+ struct llist_s *head__ = (ptr); \
+ struct llist_s *pos__ = head__->next; \
+ pos__ != head__ ? List_Entry(pos__, type, member) : NULL; \
+})
+
+/*
+ * Get the next element in the list
+ */
+#define List_Next_Entry(pos, member) \
+ List_Entry((pos)->member.next, Q_typeof(*(pos)), member)
+
+/*
+ * Get the prev element in the list
+ */
+#define List_Prev_Entry(pos, member) \
+ List_Entry((pos)->member.prev, Q_typeof(*(pos)), member)
+
+/*
+ * Iterate over a list
+ */
+#define List_For_Each(pos, head) \
for (pos = (head)->next; pos != (head); pos = pos->next)
-#define List_ForEach_Prev(pos, head) \
+/*
+ * Continue iteration over a list, after the current position
+ */
+#define List_For_Each_Continue(pos, head) \
+ for (pos = pos->next; pos != (head); pos = pos->next)
+
+/*
+ * Iterate over a list backwards
+ */
+#define List_For_Each_Prev(pos, head) \
for (pos = (head)->prev; pos != (head); pos = pos->prev)
-void List_Add(llist_t *node, llist_t *start);
-void List_Add_Tail(llist_t *node, llist_t *start);
-void List_Delete(llist_t *node);
-void List_Delete_Init(llist_t *node);
-void List_Replace(llist_t *old, llist_t *_new);
-void List_Swap(llist_t *node1, llist_t *node2);
-void List_Move(llist_t *list, llist_t *start);
-void List_Move_Tail(llist_t *list, llist_t *start);
-void List_Bulk_Move_Tail(llist_t *start, llist_t *first, llist_t *last);
-void List_Rotate_Left(llist_t *head);
-void List_Rotate_To_Front(llist_t *list, llist_t *head);
-void List_Splice(const llist_t *list, llist_t *head);
-void List_Splice_Tail(const llist_t *list, llist_t *head);
-qbool List_IsFirst(llist_t *list, llist_t *start);
-qbool List_IsLast(llist_t *list, llist_t *start);
-qbool List_IsEmpty(const llist_t *list);
\ No newline at end of file
+/*
+ * Iterate over a list, safe against removal of list entry
+ */
+#define List_For_Each_Safe(pos, n, head) \
+ for (pos = (head)->next, n = pos->next; pos != (head); \
+ pos = n, n = pos->next)
+/*
+ * Iterate over a list backwards, safe against removal of list entry
+ */
+#define List_For_Each_Prev_Safe(pos, n, head) \
+ for (pos = (head)->prev, n = pos->prev; \
+ pos != (head); \
+ pos = n, n = pos->prev)
+/*
+ * Test if the entry points to the head of the list
+ */
+#define List_Entry_Is_Head(pos, head, member) \
+ (&pos->member == (head))
+
+/*
+ * Iterate over a list of a given type
+ */
+#define List_For_Each_Entry(pos, head, member) \
+ for (pos = List_First_Entry(head, Q_typeof(*pos), member); \
+ !List_Entry_Is_Head(pos, head, member); \
+ pos = List_Next_Entry(pos, member))
+
+/*
+ * Iterate over a list of a given type backwards
+ */
+#define List_For_Each_Prev_Entry(pos, head, member) \
+ for (pos = List_Last_Entry(head, Q_typeof(*pos), member); \
+ !List_Entry_Is_Head(pos, head, member); \
+ pos = List_Prev_Entry(pos, member))
+
+/*
+ * Prepares a pos entry for use as a start point in List_For_Each_Entry_Continue()
+ */
+#define List_Prepare_Entry(pos, head, member) \
+ ((pos) ? : List_Entry(head, Q_typeof(*pos), member))
+
+/*
+ * Continue iteration over a list of a given type, after the current position
+ */
+#define List_For_Each_Entry_Continue(pos, head, member) \
+ for (pos = List_Next_Entry(pos, member); \
+ !List_Entry_Is_Head(pos, head, member); \
+ pos = List_Next_Entry(pos, member))
+
+/*
+ * Continue iteration over a list of a given type backwards, after the current position
+ */
+#define List_For_Each_Prev_Entry_Continue(pos, head, member) \
+ for (pos = List_Prev_Entry(pos, member); \
+ !List_Entry_Is_Head(pos, head, member); \
+ pos = List_Prev_Entry(pos, member))
+
+/*
+ * Continue iteration over a list of a given type, from the current position
+ */
+#define List_For_Each_Entry_From(pos, head, member) \
+ for (; !List_Entry_Is_Head(pos, head, member); \
+ pos = List_Next_Entry(pos, member))
+
+/*
+ * Continue iteration over a list of a given type backwards, from the current position
+ */
+#define List_For_Each_Prev_Entry_From(pos, head, member) \
+ for (; !List_Entry_Is_Head(pos, head, member); \
+ pos = List_Prev_Entry(pos, member))
+
+/*
+ * Iterate over a list of a given type, safe against removal of list entry
+ */
+#define List_For_Each_Entry_Safe(pos, n, head, member) \
+ for (pos = List_First_Entry(head, Q_typeof(*pos), member), \
+ n = List_Next_Entry(pos, member); \
+ !List_Entry_Is_Head(pos, head, member); \
+ pos = n, n = List_Next_Entry(n, member))
+/*
+ * Continue iteration over a list of a given type, after the current position, safe against removal of list entry
+ */
+#define List_For_Each_Entry_Safe_Continue(pos, n, head, member) \
+ for (pos = List_Next_Entry(pos, member), \
+ n = List_Next_Entry(pos, member); \
+ !List_Entry_Is_Head(pos, head, member); \
+ pos = n, n = List_Next_Entry(n, member))
+
+/*
+ * Continue iteration over a list of a given type, from the current position, safe against removal of list entry
+ */
+#define List_For_Each_Entry_Safe_From(pos, n, head, member) \
+ for (n = List_Next_Entry(pos, member); \
+ !List_Entry_Is_Head(pos, head, member); \
+ pos = n, n = List_Next_Entry(n, member))
+
+
+/*
+ * Iterate over a list of a given type backwards, safe against removal of list entry
+ */
+#define List_For_Each_Prev_Entry_Safe(pos, n, head, member) \
+ for (pos = List_Last_Entry(head, Q_typeof(*pos), member), \
+ n = List_Prev_Entry(pos, member); \
+ !List_Entry_Is_Head(pos, head, member); \
+ pos = n, n = List_Prev_Entry(n, member))
+
+/*
+ * Reset a stale List_For_Each_Entry_Safe loop
+ */
+#define List_Safe_Reset_Next(pos, n, member) \
+ n = List_Next_Entry(pos, member)
+
+static inline qbool List_Is_Empty(const llist_t *list)
+{
+ return list->next == list;
+}
+
+/*
+ * Creates a new linked list. Initializes the head to point to itself.
+ * If it's a list header, the result is an empty list.
+ */
+static inline void List_Create(llist_t *list)
+{
+ list->next = list->prev = NULL;
+}
+
+/*
+ * Insert a node between two known nodes.
+ *
+ * Only use when prev and next are known.
+ */
+static inline void __List_Add(llist_t *node, llist_t *prev, llist_t *next)
+{
+ next->prev = node;
+ node->next = next;
+ node->prev = prev;
+ prev->next = node;
+}
+
+/*
+ * Insert a node immediately after head.
+ */
+static inline void List_Add(llist_t *node, llist_t *head)
+{
+ __List_Add(node, head, head->next);
+}
+
+/*
+ * Insert a node immediately before head.
+ */
+static inline void List_Add_Tail(llist_t *node, llist_t *head)
+{
+ __List_Add(node, head->prev, head);
+}
+
+/*
+ * Bridge prev and next together, when removing the parent of them.
+ */
+static inline void __List_Delete(llist_t *prev, llist_t *next)
+{
+ next->prev = prev;
+ prev->next = next;
+}
+
+/*
+ * Redundant?
+ */
+static inline void __List_Delete_Node(llist_t *node)
+{
+ __List_Delete(node->prev, node->next);
+}
+
+/*
+ * Removes a node from its list. Sets its pointers to NULL.
+ */
+static inline void List_Delete(llist_t *node)
+{
+ __List_Delete_Node(node);
+ node->next = node->prev = NULL;
+}
+
+/*
+ * Removes a node from its list. Reinitialize it.
+ */
+static inline void List_Delete_Init(llist_t *node)
+{
+ __List_Delete_Node(node);
+ node->next = node->prev = node;
+}
+
+/*
+ * Replace old with new. Old is overwritten if empty.
+ */
+static inline void List_Replace(llist_t *old, llist_t *_new)
+{
+ _new->next = old->next;
+ _new->next->prev = _new;
+ _new->prev = old->prev;
+ _new->prev->next = _new;
+ old->next = old->prev = old;
+}
+
+/*
+ * Replace old with new. Initialize old.
+ * Old is overwritten if empty.
+ */
+static inline void List_Replace_Init(llist_t *old, llist_t *_new)
+{
+ List_Replace(old, _new);
+ List_Create(old);
+}
+
+/*
+ * Swap node1 with node2 in place.
+ */
+static inline void List_Swap(llist_t *node1, llist_t *node2)
+{
+ llist_t *pos = node2->prev;
+ List_Delete_Init(node2);
+ List_Replace(node1, node2);
+ if(pos == node1)
+ pos = node2;
+ List_Add(node1, pos);
+}
+
+/*
+ * Delete list from its... list, then insert after head.
+ */
+static inline void List_Move(llist_t *list, llist_t *head)
+{
+ __List_Delete_Node(list);
+ List_Add(list, head);
+}
+
+/*
+ * Delete list from its... list, then insert before head.
+ */
+static inline void List_Move_Tail(llist_t *list, llist_t *head)
+{
+ __List_Delete_Node(list);
+ List_Add_Tail(list, head);
+}
+
+/*
+ * Move the first node of a range of nodes immediately after head.
+ * All three parameters must belong to the same list.
+ */
+
+static inline void List_Bulk_Move_Tail(llist_t *head, llist_t *first, llist_t *last)
+{
+ first->prev->next = last->next;
+ last->next->prev = first->prev;
+
+ head->prev->next = first;
+ first->prev = head->prev;
+
+ last->next = head;
+ head->prev = last;
+}
+
+/*
+ * Shift the head to the right (like rotating a wheel counterclockwise).
+ * The node immediately to the right becomes the new head.
+ */
+static inline void List_Rotate_Left(llist_t *head)
+{
+ llist_t *first;
+
+ if (!List_Is_Empty(head))
+ {
+ first = head->next;
+ List_Move_Tail(first, head);
+ }
+}
+
+/*
+ * Make list the new head.
+ */
+static inline void List_Rotate_To_Front(llist_t *list, llist_t *head)
+{
+ List_Move_Tail(head, list);
+}
+
+/*
+ * Concatenate two lists. The head of list will be discarded.
+ */
+static inline void __List_Splice(const llist_t *list, llist_t *prev, llist_t *next)
+{
+ llist_t *first = list->next;
+ llist_t *last = list->prev;
+
+ first->prev = prev;
+ prev->next = first;
+
+ last->next = next;
+ next->prev = last;
+}
+
+/*
+ * Concatenate two lists. The first node of list will be inserted after head.
+ */
+static inline void List_Splice(const llist_t *list, llist_t *head)
+{
+ if(!List_Is_Empty(list))
+ __List_Splice(list, head, head->next);
+}
+
+/*
+ * Concatenate two lists. The tail of list will be inserted before head.
+ */
+static inline void List_Splice_Tail(const llist_t *list, llist_t *head)
+{
+ if (!List_Is_Empty(list))
+ __List_Splice(list, head->prev, head);
+}
+
+static inline qbool List_Is_First(llist_t *list, llist_t *start)
+{
+ return list->prev == start;
+}
+
+static inline qbool List_Is_Last(llist_t *list, llist_t *start)
+{
+ return list->next == start;
+}
+
+#endif
projects / xonotic / darkplaces.git / blobdiff