When purging nodes, only delete them if nobody references them anymore.
[tinc] / src / edge.c
1 /*
2     edge.c -- edge tree management
3     Copyright (C) 2000-2003 Guus Sliepen <guus@sliepen.eu.org>,
4                   2000-2003 Ivo Timmermans <ivo@o2w.nl>
5
6     This program is free software; you can redistribute it and/or modify
7     it under the terms of the GNU General Public License as published by
8     the Free Software Foundation; either version 2 of the License, or
9     (at your option) any later version.
10
11     This program is distributed in the hope that it will be useful,
12     but WITHOUT ANY WARRANTY; without even the implied warranty of
13     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14     GNU General Public License for more details.
15
16     You should have received a copy of the GNU General Public License
17     along with this program; if not, write to the Free Software
18     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19
20     $Id: edge.c,v 1.1.2.26 2003/08/22 11:18:42 guus Exp $
21 */
22
23 #include "system.h"
24
25 #include "avl_tree.h"
26 #include "edge.h"
27 #include "logger.h"
28 #include "netutl.h"
29 #include "node.h"
30 #include "utils.h"
31 #include "xalloc.h"
32
33 avl_tree_t *edge_weight_tree;   /* Tree with all edges, sorted on weight */
34
35 static int edge_compare(const edge_t *a, const edge_t *b)
36 {
37         return strcmp(a->to->name, b->to->name);
38 }
39
40 static int edge_weight_compare(const edge_t *a, const edge_t *b)
41 {
42         int result;
43
44         result = a->weight - b->weight;
45
46         if(result)
47                 return result;
48
49         result = strcmp(a->from->name, b->from->name);
50
51         if(result)
52                 return result;
53
54         return strcmp(a->to->name, b->to->name);
55 }
56
57 void init_edges(void)
58 {
59         cp();
60
61         edge_weight_tree = avl_alloc_tree((avl_compare_t) edge_weight_compare, NULL);
62 }
63
64 avl_tree_t *new_edge_tree(void)
65 {
66         cp();
67
68         return avl_alloc_tree((avl_compare_t) edge_compare, (avl_action_t) free_edge);
69 }
70
71 void free_edge_tree(avl_tree_t *edge_tree)
72 {
73         cp();
74
75         avl_delete_tree(edge_tree);
76 }
77
78 void exit_edges(void)
79 {
80         cp();
81
82         avl_delete_tree(edge_weight_tree);
83 }
84
85 /* Creation and deletion of connection elements */
86
87 edge_t *new_edge(void)
88 {
89         cp();
90
91         return (edge_t *) xmalloc_and_zero(sizeof(edge_t));
92 }
93
94 void free_edge(edge_t *e)
95 {
96         cp();
97         
98         sockaddrfree(&e->address);
99
100         free(e);
101 }
102
103 void edge_add(edge_t *e)
104 {
105         cp();
106
107         avl_insert(edge_weight_tree, e);
108         avl_insert(e->from->edge_tree, e);
109
110         e->reverse = lookup_edge(e->to, e->from);
111
112         if(e->reverse)
113                 e->reverse->reverse = e;
114 }
115
116 void edge_del(edge_t *e)
117 {
118         cp();
119
120         if(e->reverse)
121                 e->reverse->reverse = NULL;
122
123         avl_delete(edge_weight_tree, e);
124         avl_delete(e->from->edge_tree, e);
125 }
126
127 edge_t *lookup_edge(node_t *from, node_t *to)
128 {
129         edge_t v;
130         
131         cp();
132
133         v.from = from;
134         v.to = to;
135
136         return avl_search(from->edge_tree, &v);
137 }
138
139 void dump_edges(void)
140 {
141         avl_node_t *node, *node2;
142         node_t *n;
143         edge_t *e;
144         char *address;
145
146         cp();
147
148         logger(LOG_DEBUG, _("Edges:"));
149
150         for(node = node_tree->head; node; node = node->next) {
151                 n = (node_t *) node->data;
152                 for(node2 = n->edge_tree->head; node2; node2 = node2->next) {
153                         e = (edge_t *) node2->data;
154                         address = sockaddr2hostname(&e->address);
155                         logger(LOG_DEBUG, _(" %s to %s at %s options %lx weight %d"),
156                                    e->from->name, e->to->name, address, e->options, e->weight);
157                         free(address);
158                 }
159         }
160
161         logger(LOG_DEBUG, _("End of edges."));
162 }