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+/* Copyright (C) 2011 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz>
+
+ This program is free software: you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation, either version 3 of the License, or
+ (at your option) any later version.
+
+ This program 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, see <http://www.gnu.org/licenses/>.
+ */
+/*
+ * BIRD Library -- Linked Lists
+ *
+ * (c) 1998 Martin Mares <mj@ucw.cz>
+ *
+ * Can be freely distributed and used under the terms of the GNU GPL.
+ */
+
+#ifndef _BIRD_LISTS_H_
+#define _BIRD_LISTS_H_
+
+/*
+ * I admit the list structure is very tricky and also somewhat awkward,
+ * but it's both efficient and easy to manipulate once one understands the
+ * basic trick: The list head always contains two synthetic nodes which are
+ * always present in the list: the head and the tail. But as the `next'
+ * entry of the tail and the `prev' entry of the head are both NULL, the
+ * nodes can overlap each other:
+ *
+ * head head_node.next
+ * null head_node.prev tail_node.next
+ * tail tail_node.prev
+ */
+
+#include <string.h> // size_t
+
+typedef struct node {
+ struct node *next, *prev;
+} node;
+
+typedef struct list { /* In fact two overlayed nodes */
+ struct node *head, *null, *tail;
+} list;
+
+#define NODE (node *)
+#define HEAD(list) ((void *)((list).head))
+#define TAIL(list) ((void *)((list).tail))
+#define WALK_LIST(n,list) for(n=HEAD(list);(NODE (n))->next; \
+ n=(void *)((NODE (n))->next))
+#define WALK_LIST_DELSAFE(n,nxt,list) \
+ for(n=HEAD(list); (nxt=(void *)((NODE (n))->next)); n=(void *) nxt)
+/* WALK_LIST_FIRST supposes that called code removes each processed node */
+#define WALK_LIST_FIRST(n,list) \
+ while(n=HEAD(list), (NODE (n))->next)
+#define WALK_LIST_BACKWARDS(n,list) for(n=TAIL(list);(NODE (n))->prev; \
+ n=(void *)((NODE (n))->prev))
+#define WALK_LIST_BACKWARDS_DELSAFE(n,prv,list) \
+ for(n=TAIL(list); prv=(void *)((NODE (n))->prev); n=(void *) prv)
+
+#define EMPTY_LIST(list) (!(list).head->next)
+
+/*! \brief Free every node in the list. */
+#define WALK_LIST_FREE(list) \
+ do { \
+ node *n=0,*nxt=0; \
+ WALK_LIST_DELSAFE(n,nxt,list) { \
+ free(n); \
+ } \
+ } while(0)
+
+void add_tail(list *, node *);
+void add_head(list *, node *);
+void rem_node(node *);
+void add_tail_list(list *, list *);
+void init_list(list *);
+void insert_node(node *, node *);
+void list_dup(list *dst, list *src, size_t itemsz);
+
+/*!
+ * \brief List item for string lists.
+ */
+typedef struct strnode_t {
+ node n;
+ char *str;
+} strnode_t;
+
+/*! \todo This is broken atm.
+#ifndef _BIRD_LISTS_C_
+#define LIST_INLINE extern inline
+#include "knot/lib/lists.c"
+#undef LIST_INLINE
+#else
+#define LIST_INLINE
+#endif
+*/
+#define LIST_INLINE
+
+#endif