Use splay trees instead of AVL trees.

[tinc] / src / graph.c

diff --git a/src/graph.c b/src/graph.c
index 491a59f..5bf6361 100644 (file)
--- a/src/graph.c
+++ b/src/graph.c
@@ -1,7 +1,7 @@
 /*
     graph.c -- graph algorithms
-    Copyright (C) 2001-2004 Guus Sliepen <guus@tinc-vpn.org>,
-                  2001-2004 Ivo Timmermans <ivo@tinc-vpn.org>
+    Copyright (C) 2001-2006 Guus Sliepen <guus@tinc-vpn.org>,
+                  2001-2005 Ivo Timmermans
 
     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
@@ -46,7 +46,8 @@
 
 #include "system.h"
 
-#include "avl_tree.h"
+#include "splay_tree.h"
+#include "config.h"
 #include "connection.h"
 #include "device.h"
 #include "edge.h"
@@ -62,9 +63,8 @@
    Please note that sorting on weight is already done by add_edge().
 */
 
-void mst_kruskal(void)
-{
-       avl_node_t *node, *next;
+void mst_kruskal(void) {
+       splay_node_t *node, *next;
        edge_t *e;
        node_t *n;
        connection_t *c;
@@ -98,7 +98,13 @@ void mst_kruskal(void)
 
        /* Starting point */
 
-       ((edge_t *) edge_weight_tree->head->data)->from->status.visited = true;
+       for(node = edge_weight_tree->head; node; node = node->next) {
+               e = node->data;
+               if(e->from->status.reachable) {
+                       e->from->status.visited = true;
+                       break;
+               }
+       }
 
        /* Add safe edges */
 
@@ -140,9 +146,8 @@ void mst_kruskal(void)
    Running time: O(E)
 */
 
-void sssp_bfs(void)
-{
-       avl_node_t *node, *next, *to;
+void sssp_bfs(void) {
+       splay_node_t *node, *next, *to;
        edge_t *e;
        node_t *n;
        list_t *todo_list;
@@ -218,7 +223,7 @@ void sssp_bfs(void)
                        e->to->options = e->options;
 
                        if(sockaddrcmp(&e->to->address, &e->address)) {
-                               node = avl_unlink(node_udp_tree, e->to);
+                               node = splay_unlink(node_udp_tree, e->to);
                                sockaddrfree(&e->to->address);
                                sockaddrcpy(&e->to->address, &e->address);
 
@@ -228,7 +233,7 @@ void sssp_bfs(void)
                                e->to->hostname = sockaddr2hostname(&e->to->address);
 
                                if(node)
-                                       avl_insert_node(node_udp_tree, node);
+                                       splay_insert_node(node_udp_tree, node);
 
                                if(e->to->options & OPTION_PMTU_DISCOVERY) {
                                        e->to->mtuprobes = 0;
@@ -260,11 +265,11 @@ void sssp_bfs(void)
                        if(n->status.reachable) {
                                ifdebug(TRAFFIC) logger(LOG_DEBUG, _("Node %s (%s) became reachable"),
                                           n->name, n->hostname);
-                               avl_insert(node_udp_tree, n);
+                               splay_insert(node_udp_tree, n);
                        } else {
                                ifdebug(TRAFFIC) logger(LOG_DEBUG, _("Node %s (%s) became unreachable"),
                                           n->name, n->hostname);
-                               avl_delete(node_udp_tree, n);
+                               splay_delete(node_udp_tree, n);
                        }
 
                        n->status.validkey = false;
@@ -283,6 +288,8 @@ void sssp_bfs(void)
                        asprintf(&envp[5], "REMOTEPORT=%s", port);
                        envp[6] = NULL;
 
+                       execute_script(n->status.reachable ? "host-up" : "host-down", envp);
+
                        asprintf(&name,
                                         n->status.reachable ? "hosts/%s-up" : "hosts/%s-down",
                                         n->name);
@@ -300,8 +307,72 @@ void sssp_bfs(void)
        }
 }
 
-void graph(void)
-{
-       mst_kruskal();
+/* Dump nodes and edges to a graphviz file.
+          
+   The file can be converted to an image with
+   dot -Tpng graph_filename -o image_filename.png -Gconcentrate=true
+*/
+
+static void dump_graph(int fd, short events, void *data) {
+       splay_node_t *node;
+       node_t *n;
+       edge_t *e;
+       char *filename = NULL, *tmpname = NULL;
+       FILE *file;
+       
+       if(!get_config_string(lookup_config(config_tree, "GraphDumpFile"), &filename))
+               return;
+
+       ifdebug(PROTOCOL) logger(LOG_NOTICE, "Dumping graph");
+       
+       if(filename[0] == '|') {
+               file = popen(filename + 1, "w");
+       } else {
+               asprintf(&tmpname, "%s.new", filename);
+               file = fopen(tmpname, "w");
+       }
+
+       if(!file) {
+               logger(LOG_ERR, "Unable to open graph dump file %s: %s", filename, strerror(errno));
+               free(tmpname);
+               return;
+       }
+
+       fprintf(file, "digraph {\n");
+       
+       /* dump all nodes first */
+       for(node = node_tree->head; node; node = node->next) {
+               n = node->data;
+               fprintf(file, " %s [label = \"%s\"];\n", n->name, n->name);
+       }
+
+       /* now dump all edges */
+       for(node = edge_weight_tree->head; node; node = node->next) {
+               e = node->data;
+               fprintf(file, " %s -> %s;\n", e->from->name, e->to->name);
+       }
+
+       fprintf(file, "}\n");   
+       
+       if(filename[0] == '|') {
+               pclose(file);
+       } else {
+               fclose(file);
+#ifdef HAVE_MINGW
+               unlink(filename);
+#endif
+               rename(tmpname, filename);
+               free(tmpname);
+       }
+}
+
+void graph(void) {
+       static struct event ev;
+
        sssp_bfs();
+       mst_kruskal();
+
+       if(!timeout_initialized(&ev))
+               timeout_set(&ev, dump_graph, NULL);
+       event_add(&ev, &(struct timeval){5, 0});
 }