3 /* a generic graph library. */
5 /* Copyright (c) 2006 Darina Dimitrova, Arnaud Legrand. */
6 /* All rights reserved. */
8 /* This program is free software; you can redistribute it and/or modify it
9 * under the terms of the license (GNU LGPL) which comes with this package. */
12 #include "xbt/sysdep.h"
14 #include "xbt/graph.h"
15 #include "graph_private.h"
16 #include "xbt/graphxml_parse.h"
23 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(xbt_graph, xbt, "Graph");
27 /** @brief Constructor
30 xbt_graph_t xbt_graph_new_graph(unsigned short int directed, void *data)
32 xbt_graph_t graph = NULL;
33 graph = xbt_new0(struct xbt_graph, 1);
34 graph->directed = directed;
36 graph->nodes = xbt_dynar_new(sizeof(xbt_node_t), NULL);
37 graph->edges = xbt_dynar_new(sizeof(xbt_edge_t), NULL);
42 /** @brief add a node to the given graph */
43 xbt_node_t xbt_graph_new_node(xbt_graph_t g, void *data)
45 xbt_node_t node = NULL;
46 node = xbt_new0(struct xbt_node, 1);
49 /* only the "out" field is used */
50 node->in = xbt_dynar_new(sizeof(xbt_edge_t), NULL);
52 node->out = xbt_dynar_new(sizeof(xbt_edge_t), NULL);
53 node->position_x = -1.0;
54 node->position_y = -1.0;
56 xbt_dynar_push(g->nodes, &node);
61 /** @brief add an edge to the given graph */
62 xbt_edge_t xbt_graph_new_edge(xbt_graph_t g,
63 xbt_node_t src, xbt_node_t dst, void *data)
65 xbt_edge_t edge = NULL;
67 edge = xbt_new0(struct xbt_edge, 1);
68 xbt_dynar_push(src->out, &edge);
70 xbt_dynar_push(dst->in, &edge);
71 else /* only the "out" field is used */
72 xbt_dynar_push(dst->out, &edge);
78 xbt_dynar_push(g->edges, &edge);
83 xbt_edge_t xbt_graph_get_edge(xbt_graph_t g, xbt_node_t src, xbt_node_t dst)
88 xbt_dynar_foreach(src->out, cursor, edge) {
89 DEBUG3("%p = %p--%p",edge,edge->src,edge->dst);
90 if((edge->src==src) && (edge->dst==dst)) return edge;
93 xbt_dynar_foreach(src->out, cursor, edge) {
94 DEBUG3("%p = %p--%p",edge,edge->src,edge->dst);
95 if((edge->dst==src) && (edge->src==dst)) return edge;
101 void *xbt_graph_node_get_data(xbt_node_t node)
106 void xbt_graph_node_set_data(xbt_node_t node, void *data)
111 void *xbt_graph_edge_get_data(xbt_edge_t edge)
116 void xbt_graph_edge_set_data(xbt_edge_t edge, void *data)
121 /** @brief Destructor
122 * @param g: poor victim
123 * @param node_free_function: function to use to free data associated to each node
124 * @param edge_free_function: function to use to free data associated to each edge
125 * @param graph_free_function: function to use to free data associated to g
127 * Free the graph structure.
129 void xbt_graph_free_graph(xbt_graph_t g,
130 void_f_pvoid_t * node_free_function,
131 void_f_pvoid_t * edge_free_function,
132 void_f_pvoid_t * graph_free_function)
135 xbt_node_t node = NULL;
136 xbt_edge_t edge = NULL;
139 xbt_dynar_foreach(g->nodes, cursor, node) {
140 xbt_dynar_free(&(node->out));
141 xbt_dynar_free(&(node->in));
142 if (node_free_function)
143 (*node_free_function)(node->data);
146 xbt_dynar_foreach(g->edges, cursor, edge) {
147 if (edge_free_function)
148 (*edge_free_function)(edge->data);
151 xbt_dynar_foreach(g->nodes, cursor, node)
153 xbt_dynar_free(&(g->nodes));
155 xbt_dynar_foreach(g->edges, cursor, edge)
157 xbt_dynar_free(&(g->edges));
158 if(graph_free_function) (*graph_free_function)(g->data);
165 /** @brief remove the given node from the given graph */
166 void xbt_graph_free_node(xbt_graph_t g, xbt_node_t n,
167 void_f_pvoid_t * node_free_function,
168 void_f_pvoid_t * edge_free_function)
173 xbt_node_t node = NULL;
174 xbt_edge_t edge = NULL;
176 nbr = xbt_dynar_length(g->edges);
178 for (i = 0; i < nbr; i++) {
179 xbt_dynar_get_cpy(g->edges, cursor, &edge);
181 if ((edge->dst == n) || (edge->src == n)) {
182 xbt_graph_free_edge(g, edge, edge_free_function);
187 if ((node_free_function) && (n->data))
188 node_free_function(n->data);
191 xbt_dynar_foreach(g->nodes, cursor, node)
193 xbt_dynar_cursor_rm(g->nodes, &cursor);
195 xbt_dynar_free(&(n->in));
196 xbt_dynar_free(&(n->out));
203 /** @brief remove the given edge from the given graph */
204 void xbt_graph_free_edge(xbt_graph_t g, xbt_edge_t e,
205 void_f_pvoid_t *free_function)
209 xbt_edge_t edge = NULL;
211 if ((free_function) && (e->data))
212 (*free_function)(e->data);
214 xbt_dynar_foreach(g->edges, cursor, edge) {
217 idx = __xbt_find_in_dynar(edge->dst->in, edge);
218 xbt_dynar_remove_at(edge->dst->in, idx, NULL);
219 } else { /* only the out field is used */
220 idx = __xbt_find_in_dynar(edge->dst->out, edge);
221 xbt_dynar_remove_at(edge->dst->out, idx, NULL);
224 idx = __xbt_find_in_dynar(edge->src->out, edge);
225 xbt_dynar_remove_at(edge->src->out, idx, NULL);
227 xbt_dynar_cursor_rm(g->edges, &cursor);
234 int __xbt_find_in_dynar(xbt_dynar_t dynar, void *p)
240 xbt_dynar_foreach(dynar, cursor, tmp) {
247 /** @brief Retrieve the graph's nodes as a dynar */
248 xbt_dynar_t xbt_graph_get_nodes(xbt_graph_t g)
253 /** @brief Retrieve the graph's edges as a dynar */
254 xbt_dynar_t xbt_graph_get_edges(xbt_graph_t g)
259 /** @brief Retrieve the node at the source of the given edge */
260 xbt_node_t xbt_graph_edge_get_source(xbt_edge_t e)
266 /** @brief Retrieve the node being the target of the given edge */
267 xbt_node_t xbt_graph_edge_get_target(xbt_edge_t e)
273 /** @brief Set the weight of the given edge */
274 void xbt_graph_edge_set_length(xbt_edge_t e, double length)
280 double xbt_graph_edge_get_length(xbt_edge_t e)
286 /** @brief construct the adjacency matrix corresponding to the given graph
288 * The weights are the distances between nodes
290 double *xbt_graph_get_length_matrix(xbt_graph_t g)
296 xbt_edge_t edge = NULL;
297 xbt_node_t node = NULL;
300 # define D(u,v) d[(u)*n+(v)]
301 n = xbt_dynar_length(g->nodes);
303 d = (double *) xbt_new0(double, n * n);
305 for (i = 0; i < n * n; i++) {
309 xbt_dynar_foreach(g->nodes, cursor, node) {
311 D(cursor, cursor) = 0;
313 xbt_dynar_foreach(node->out, in_cursor, edge) {
314 if (edge->dst == node)
315 idx = __xbt_find_in_dynar(g->nodes, edge->src);
316 else /*case of undirected graphs */
317 idx = __xbt_find_in_dynar(g->nodes, edge->dst);
318 D(cursor, idx) = edge->length;
327 /** @brief Floyd-Warshall algorithm for shortest path finding
331 * The Floyd–Warshall algorithm takes as input an adjacency matrix
332 * representation of a weighted, directed graph (V, E). The weight of a
333 * path between two vertices is the sum of the weights of the edges along
334 * that path. The edges E of the graph may have negative weights, but the
335 * graph must not have any negative weight cycles. The algorithm computes,
336 * for each pair of vertices, the minimum weight among all paths between
337 * the two vertices. The running time complexity is Θ(|V|3).
339 void xbt_floyd_algorithm(xbt_graph_t g, double *adj, double *d,
344 n = xbt_dynar_length(g->nodes);
346 # define D(u,v) d[(u)*n+(v)]
347 # define P(u,v) p[(u)*n+(v)]
349 for (i = 0; i < n * n; i++) {
354 for (i = 0; i < n; i++) {
355 for (j = 0; j < n; j++) {
357 P(i, j) = *((xbt_node_t *) xbt_dynar_get_ptr(g->nodes, i));
362 for (k = 0; k < n; k++) {
363 for (i = 0; i < n; i++) {
364 for (j = 0; j < n; j++) {
365 if ((D(i, k) != -1) && (D(k, j) != -1)) {
366 if ((D(i, j) == -1) || (D(i, j) > D(i, k) + D(k, j))) {
367 D(i, j) = D(i, k) + D(k, j);
381 /** @brief computes all-pairs shortest paths */
382 xbt_node_t *xbt_graph_shortest_paths(xbt_graph_t g)
392 # define P(u,v) p[(u)*n+(v)]
393 # define R(u,v) r[(u)*n+(v)]
395 n = xbt_dynar_length(g->nodes);
396 adj = xbt_graph_get_length_matrix(g);
397 d = xbt_new0(double, n * n);
398 p = xbt_new0(xbt_node_t, n * n);
399 r = xbt_new0(xbt_node_t, n * n);
401 xbt_floyd_algorithm(g, adj, d, p);
403 for (i = 0; i < n; i++) {
404 for (j = 0; j < n; j++) {
407 while ((P(i, k)) && (__xbt_find_in_dynar(g->nodes, P(i, k)) != i)) {
408 k = __xbt_find_in_dynar(g->nodes, P(i, k));
412 R(i, j) = *((xbt_node_t *) xbt_dynar_get_ptr(g->nodes, k));
425 /** @brief Extract a spanning tree of the given graph */
426 xbt_edge_t *xbt_graph_spanning_tree_prim(xbt_graph_t g)
429 int tree_size_max = xbt_dynar_length(g->nodes) - 1;
430 xbt_edge_t *tree = xbt_new0(xbt_edge_t, tree_size_max);
432 xbt_node_t node = NULL;
433 xbt_dynar_t edge_list = NULL;
434 xbt_heap_t heap = xbt_heap_new(10, NULL);
437 xbt_assert0(!(g->directed),
438 "Spanning trees do not make sense on directed graphs");
440 xbt_dynar_foreach(g->nodes, cursor, node) {
441 node->xbtdata = NULL;
444 node = xbt_dynar_getfirst_as(g->nodes, xbt_node_t);
445 node->xbtdata = (void *) 1;
446 edge_list = node->out;
447 xbt_dynar_foreach(edge_list, cursor, e)
448 xbt_heap_push(heap, e, -(e->length));
450 while ((edge = xbt_heap_pop(heap))) {
451 if ((edge->src->xbtdata) && (edge->dst->xbtdata))
453 tree[tree_size++] = edge;
454 if (!(edge->src->xbtdata)) {
455 edge->src->xbtdata = (void *) 1;
456 edge_list = edge->src->out;
457 xbt_dynar_foreach(edge_list, cursor, e) {
458 xbt_heap_push(heap, e, -(e->length));
461 edge->dst->xbtdata = (void *) 1;
462 edge_list = edge->dst->out;
463 xbt_dynar_foreach(edge_list, cursor, e) {
464 xbt_heap_push(heap, e, -(e->length));
467 if (tree_size == tree_size_max)
476 /** @brief Topological sort on the given graph
480 * In graph theory, a topological sort of a directed acyclic graph (DAG) is
481 * a linear ordering of its nodes which is compatible with the partial
482 * order R induced on the nodes where x comes before y (xRy) if there's a
483 * directed path from x to y in the DAG. An equivalent definition is that
484 * each node comes before all nodes to which it has edges. Every DAG has at
485 * least one topological sort, and may have many.
487 xbt_node_t *xbt_graph_topo_sort(xbt_graph_t g)
495 n = xbt_dynar_length(g->nodes);
498 sorted = xbt_malloc(n * sizeof(xbt_node_t));
500 xbt_dynar_foreach(g->nodes, cursor, node)
501 node->xbtdata = xbt_new0(int, 1);
503 xbt_dynar_foreach(g->nodes, cursor, node)
504 xbt_graph_depth_visit(g, node, sorted, &idx);
506 xbt_dynar_foreach(g->nodes, cursor, node) {
508 node->xbtdata = NULL;
514 /** @brief First-depth graph traversal */
515 void xbt_graph_depth_visit(xbt_graph_t g, xbt_node_t n,
516 xbt_node_t * sorted, int *idx)
521 if (*((int *) (n->xbtdata)) == ALREADY_EXPLORED)
523 else if (*((int *) (n->xbtdata)) == CURRENTLY_EXPLORING)
524 THROW0(0, 0, "There is a cycle");
526 *((int *) (n->xbtdata)) = CURRENTLY_EXPLORING;
528 xbt_dynar_foreach(n->out, cursor, edge) {
529 xbt_graph_depth_visit(g, edge->dst, sorted, idx);
532 *((int *) (n->xbtdata)) = ALREADY_EXPLORED;
533 sorted[(*idx)--] = n;
537 /********************* Import and Export ******************/
538 static xbt_graph_t parsed_graph = NULL;
539 static xbt_dict_t parsed_nodes = NULL;
541 static void *(*__parse_node_label_and_data) (xbt_node_t, const char *,
542 const char *) = NULL;
543 static void *(*__parse_edge_label_and_data) (xbt_edge_t, const char *,
544 const char *) = NULL;
546 static void __parse_graph_begin(void)
549 if (A_graphxml_graph_isDirected == A_graphxml_graph_isDirected_true)
550 parsed_graph = xbt_graph_new_graph(1, NULL);
552 parsed_graph = xbt_graph_new_graph(0, NULL);
554 parsed_nodes = xbt_dict_new();
557 static void __parse_graph_end(void)
559 xbt_dict_free(&parsed_nodes);
563 static void __parse_node(void)
565 xbt_node_t node = xbt_graph_new_node(parsed_graph, NULL);
567 DEBUG1("<node name=\"%s\"/>", A_graphxml_node_name);
568 if (__parse_node_label_and_data)
569 node->data = __parse_node_label_and_data(node, A_graphxml_node_label,
570 A_graphxml_node_data);
571 xbt_graph_parse_get_double(&(node->position_x),
572 A_graphxml_node_position_x);
573 xbt_graph_parse_get_double(&(node->position_y),
574 A_graphxml_node_position_y);
576 xbt_dict_set(parsed_nodes, A_graphxml_node_name, (void *) node, NULL);
579 static void __parse_edge(void)
581 xbt_edge_t edge = xbt_graph_new_edge(parsed_graph,
582 xbt_dict_get(parsed_nodes,
583 A_graphxml_edge_source),
584 xbt_dict_get(parsed_nodes,
585 A_graphxml_edge_target),
588 if (__parse_edge_label_and_data)
589 edge->data = __parse_edge_label_and_data(edge, A_graphxml_edge_label,
590 A_graphxml_edge_data);
592 xbt_graph_parse_get_double(&(edge->length), A_graphxml_edge_length);
594 DEBUG3("<edge source=\"%s\" target=\"%s\" length=\"%f\"/>",
595 (char *) (edge->src)->data,
596 (char *) (edge->dst)->data, xbt_graph_edge_get_length(edge));
599 /** @brief Import a graph from a file following the GraphXML format */
600 xbt_graph_t xbt_graph_read(const char *filename,
601 void *(node_label_and_data) (xbt_node_t,
604 void *(edge_label_and_data) (xbt_edge_t,
609 xbt_graph_t graph = NULL;
611 __parse_node_label_and_data = node_label_and_data;
612 __parse_edge_label_and_data = edge_label_and_data;
614 xbt_graph_parse_reset_parser();
616 STag_graphxml_graph_fun = __parse_graph_begin;
617 ETag_graphxml_graph_fun = __parse_graph_end;
618 ETag_graphxml_node_fun = __parse_node;
619 ETag_graphxml_edge_fun = __parse_edge;
621 xbt_graph_parse_open(filename);
622 xbt_assert1((!xbt_graph_parse()), "Parse error in %s", filename);
623 xbt_graph_parse_close();
625 graph = parsed_graph;
631 /** @brief Export the given graph in the GraphViz formatting for visualization */
632 void xbt_graph_export_graphviz(xbt_graph_t g, const char *filename,
633 const char *(node_name) (xbt_node_t),
634 const char *(edge_name) (xbt_edge_t))
637 xbt_node_t node = NULL;
638 xbt_edge_t edge = NULL;
640 const char *name = NULL;
642 file = fopen(filename, "w");
643 xbt_assert1(file, "Failed to open %s \n", filename);
646 fprintf(file, "digraph test {\n");
648 fprintf(file, "graph test {\n");
650 fprintf(file, " graph [overlap=scale]\n");
652 fprintf(file, " node [shape=box, style=filled]\n");
654 " node [width=.3, height=.3, style=filled, color=skyblue]\n\n");
656 xbt_dynar_foreach(g->nodes, cursor, node) {
657 fprintf(file, " \"%p\" ", node);
658 if ((node_name) && ((name = node_name(node))))
659 fprintf(file, "[label=\"%s\"]", name);
660 fprintf(file, ";\n");
662 xbt_dynar_foreach(g->edges, cursor, edge) {
664 fprintf(file, " \"%p\" -> \"%p\"", edge->src, edge->dst);
666 fprintf(file, " \"%p\" -- \"%p\"", edge->src, edge->dst);
667 if ((edge_name) && ((name = edge_name(edge))))
668 fprintf(file, "[label=\"%s\"]", name);
669 fprintf(file, ";\n");
671 fprintf(file, "}\n");
675 /** @brief Export the given graph in the GraphXML format */
676 void xbt_graph_export_graphxml(xbt_graph_t g, const char *filename,
677 const char *(node_name) (xbt_node_t),
678 const char *(edge_name) (xbt_edge_t),
679 const char *(node_data_print) (void *),
680 const char *(edge_data_print) (void *))
683 xbt_node_t node = NULL;
684 xbt_edge_t edge = NULL;
686 const char *name = NULL;
688 file = fopen(filename, "w");
689 xbt_assert1(file, "Failed to open %s \n", filename);
691 fprintf(file, "<?xml version='1.0'?>\n");
692 fprintf(file, "<!DOCTYPE graph SYSTEM \"graphxml.dtd\">\n");
694 fprintf(file, "<graph isDirected=\"true\">\n");
696 fprintf(file, "<graph isDirected=\"false\">\n");
697 xbt_dynar_foreach(g->nodes, cursor, node) {
698 fprintf(file, " <node name=\"%p\" ", node);
699 if ((node_name) && ((name = node_name(node))))
700 fprintf(file, "label=\"%s\" ", name);
701 if ((node_data_print) && ((name = node_data_print(node->data))))
702 fprintf(file, "data=\"%s\" ", name);
703 fprintf(file, ">\n");
705 xbt_dynar_foreach(g->edges, cursor, edge) {
706 fprintf(file, " <edge source=\"%p\" target =\"%p\" ",
707 edge->src, edge->dst);
708 if ((edge_name) && ((name = edge_name(edge))))
709 fprintf(file, "label=\"%s\" ", name);
710 if (edge->length >= 0.0)
711 fprintf(file, "length=\"%g\" ", edge->length);
712 if ((edge_data_print) && ((name = edge_data_print(edge->data))))
713 fprintf(file, "data=\"%s\" ", name);
714 fprintf(file, ">\n");
716 fprintf(file, "</graph>\n");