git.meshlink.io Git - meshlink/blob - src/edge.c

   1 /*
   2     edge.c -- edge tree management
   3     Copyright (C) 2000-2013 Guus Sliepen <guus@meshlink.io>,
   4                   2000-2005 Ivo Timmermans
   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 along
  17     with this program; if not, write to the Free Software Foundation, Inc.,
  18     51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  19 */
  20
  21 #include "system.h"
  22
  23 #include "splay_tree.h"
  24 #include "edge.h"
  25 #include "logger.h"
  26 #include "netutl.h"
  27 #include "node.h"
  28 #include "utils.h"
  29 #include "xalloc.h"
  30
  31 splay_tree_t *edge_weight_tree;
  32
  33 static int edge_compare(const edge_t *a, const edge_t *b) {
  34         return strcmp(a->to->name, b->to->name);
  35 }
  36
  37 static int edge_weight_compare(const edge_t *a, const edge_t *b) {
  38         int result;
  39
  40         result = a->weight - b->weight;
  41
  42         if(result)
  43                 return result;
  44
  45         result = strcmp(a->from->name, b->from->name);
  46
  47         if(result)
  48                 return result;
  49
  50         return strcmp(a->to->name, b->to->name);
  51 }
  52
  53 void init_edges(void) {
  54         edge_weight_tree = splay_alloc_tree((splay_compare_t) edge_weight_compare, NULL);
  55 }
  56
  57 splay_tree_t *new_edge_tree(void) {
  58         return splay_alloc_tree((splay_compare_t) edge_compare, (splay_action_t) free_edge);
  59 }
  60
  61 void free_edge_tree(splay_tree_t *edge_tree) {
  62         splay_delete_tree(edge_tree);
  63 }
  64
  65 void exit_edges(void) {
  66         splay_delete_tree(edge_weight_tree);
  67 }
  68
  69 /* Creation and deletion of connection elements */
  70
  71 edge_t *new_edge(void) {
  72         return xzalloc(sizeof(edge_t));
  73 }
  74
  75 void free_edge(edge_t *e) {
  76         sockaddrfree(&e->address);
  77
  78         free(e);
  79 }
  80
  81 void edge_add(edge_t *e) {
  82         splay_insert(edge_weight_tree, e);
  83         splay_insert(e->from->edge_tree, e);
  84
  85         e->reverse = lookup_edge(e->to, e->from);
  86
  87         if(e->reverse)
  88                 e->reverse->reverse = e;
  89 }
  90
  91 void edge_del(edge_t *e) {
  92         if(e->reverse)
  93                 e->reverse->reverse = NULL;
  94
  95         splay_delete(edge_weight_tree, e);
  96         splay_delete(e->from->edge_tree, e);
  97 }
  98
  99 edge_t *lookup_edge(node_t *from, node_t *to) {
 100         edge_t v;
 101
 102         v.from = from;
 103         v.to = to;
 104
 105         return splay_search(from->edge_tree, &v);
 106 }