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(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);
48 node->in = xbt_dynar_new(sizeof(xbt_edge_t), NULL);
49 node->out = xbt_dynar_new(sizeof(xbt_edge_t), NULL);
50 node->position_x = -1.0;
51 node->position_y = -1.0;
53 xbt_dynar_push(g->nodes, &node);
58 /** @brief add an edge to the given graph */
59 xbt_edge_t xbt_graph_new_edge(xbt_graph_t g,
60 xbt_node_t src, xbt_node_t dst, void *data)
62 xbt_edge_t edge = NULL;
65 edge = xbt_new0(struct xbt_edge, 1);
66 xbt_dynar_push(src->out, &edge);
68 xbt_dynar_push(dst->in, &edge);
69 else /* only the "out" field is used */
70 xbt_dynar_push(dst->out, &edge);
76 xbt_dynar_push(src->in, &edge);
77 xbt_dynar_push(dst->out, &edge);
81 xbt_dynar_push(g->edges, &edge);
86 void *xbt_graph_node_get_data(xbt_node_t node)
91 void *xbt_graph_edge_get_data(xbt_edge_t edge)
97 * @param l: poor victim
99 * Free the graph structure.
101 void xbt_graph_free_graph(xbt_graph_t g,
102 void node_free_function(void *ptr),
103 void edge_free_function(void *ptr),
104 void graph_free_function(void *ptr))
107 xbt_node_t node = NULL;
108 xbt_edge_t edge = NULL;
111 xbt_dynar_foreach(g->nodes, cursor, node) {
112 xbt_dynar_free(&(node->out));
113 xbt_dynar_free(&(node->in));
114 if (node_free_function)
115 node_free_function(node->data);
118 xbt_dynar_foreach(g->edges, cursor, edge) {
119 if (edge_free_function)
120 edge_free_function(edge->data);
123 xbt_dynar_foreach(g->nodes, cursor, node)
125 xbt_dynar_free(&(g->nodes));
127 xbt_dynar_foreach(g->edges, cursor, edge)
129 xbt_dynar_free(&(g->edges));
137 /** @brief remove the given node from the given graph */
138 void xbt_graph_free_node(xbt_graph_t g, xbt_node_t n,
139 void_f_pvoid_t * node_free_function,
140 void_f_pvoid_t * edge_free_function)
145 xbt_node_t node = NULL;
146 xbt_edge_t edge = NULL;
148 nbr = xbt_dynar_length(g->edges);
150 for (i = 0; i < nbr; i++) {
151 xbt_dynar_cursor_get(g->edges, &cursor, &edge);
153 if ((edge->dst == n) || (edge->src == n)) {
154 xbt_graph_free_edge(g, edge, edge_free_function);
156 xbt_dynar_cursor_step(g->edges, &cursor);
159 if ((node_free_function) && (n->data))
160 node_free_function(n->data);
163 xbt_dynar_foreach(g->nodes, cursor, node)
165 xbt_dynar_cursor_rm(g->nodes, &cursor);
167 xbt_dynar_free(&(n->in));
168 xbt_dynar_free(&(n->out));
175 /** @brief remove the given edge from the given graph */
176 void xbt_graph_free_edge(xbt_graph_t g, xbt_edge_t e,
177 void free_function(void *ptr))
181 xbt_edge_t edge = NULL;
183 if ((free_function) && (e->data))
184 free_function(e->data);
186 xbt_dynar_foreach(g->edges, cursor, edge) {
189 idx = __xbt_find_in_dynar(edge->dst->in, edge);
190 xbt_dynar_remove_at(edge->dst->in, idx, NULL);
191 } else { /* only the out field is used */
192 idx = __xbt_find_in_dynar(edge->dst->out, edge);
193 xbt_dynar_remove_at(edge->dst->out, idx, NULL);
196 idx = __xbt_find_in_dynar(edge->src->out, edge);
197 xbt_dynar_remove_at(edge->src->out, idx, NULL);
199 xbt_dynar_cursor_rm(g->edges, &cursor);
206 int __xbt_find_in_dynar(xbt_dynar_t dynar, void *p)
212 xbt_dynar_foreach(dynar, cursor, tmp) {
219 /** @brief Retrieve the graph's nodes as a dynar */
220 xbt_dynar_t xbt_graph_get_nodes(xbt_graph_t g)
225 /** @brief Retrieve the graph's edges as a dynar */
226 xbt_dynar_t xbt_graph_get_edges(xbt_graph_t g)
231 /** @brief Retrieve the node at the source of the given edge */
232 xbt_node_t xbt_graph_edge_get_source(xbt_edge_t e)
238 /** @brief Retrieve the node being the target of the given edge */
239 xbt_node_t xbt_graph_edge_get_target(xbt_edge_t e)
245 /** @brief Set the weight of the given edge */
246 void xbt_graph_edge_set_length(xbt_edge_t e, double length)
252 double xbt_graph_edge_get_length(xbt_edge_t e)
258 /** @brief construct the adjacency matrix corresponding to the given graph
260 * The weights are the distances between nodes
262 double *xbt_graph_get_length_matrix(xbt_graph_t g)
268 xbt_edge_t edge = NULL;
269 xbt_node_t node = NULL;
272 # define D(u,v) d[(u)*n+(v)]
273 n = xbt_dynar_length(g->nodes);
275 d = (double *) xbt_new0(double, n * n);
277 for (i = 0; i < n * n; i++) {
281 xbt_dynar_foreach(g->nodes, cursor, node) {
283 D(cursor, cursor) = 0;
285 xbt_dynar_foreach(node->out, in_cursor, edge) {
286 if (edge->dst == node)
287 idx = __xbt_find_in_dynar(g->nodes, edge->src);
288 else /*case of undirected graphs */
289 idx = __xbt_find_in_dynar(g->nodes, edge->dst);
290 D(cursor, idx) = edge->length;
299 /** @brief Floyd-Warshall algorithm for shortest path finding
303 * The Floyd–Warshall algorithm takes as input an adjacency matrix
304 * representation of a weighted, directed graph (V, E). The weight of a
305 * path between two vertices is the sum of the weights of the edges along
306 * that path. The edges E of the graph may have negative weights, but the
307 * graph must not have any negative weight cycles. The algorithm computes,
308 * for each pair of vertices, the minimum weight among all paths between
309 * the two vertices. The running time complexity is Θ(|V|3).
311 void xbt_floyd_algorithm(xbt_graph_t g, double *adj, double *d,
316 n = xbt_dynar_length(g->nodes);
318 # define D(u,v) d[(u)*n+(v)]
319 # define P(u,v) p[(u)*n+(v)]
321 for (i = 0; i < n * n; i++) {
326 for (i = 0; i < n; i++) {
327 for (j = 0; j < n; j++) {
329 P(i, j) = *((xbt_node_t *) xbt_dynar_get_ptr(g->nodes, i));
334 for (k = 0; k < n; k++) {
335 for (i = 0; i < n; i++) {
336 for (j = 0; j < n; j++) {
337 if ((D(i, k) != -1) && (D(k, j) != -1)) {
338 if ((D(i, j) == -1) || (D(i, j) > D(i, k) + D(k, j))) {
339 D(i, j) = D(i, k) + D(k, j);
353 /** @brief computes all-pairs shortest paths */
354 xbt_node_t *xbt_graph_shortest_paths(xbt_graph_t g)
364 # define P(u,v) p[(u)*n+(v)]
365 # define R(u,v) r[(u)*n+(v)]
367 n = xbt_dynar_length(g->nodes);
368 adj = xbt_graph_get_length_matrix(g);
369 d = xbt_new0(double, n * n);
370 p = xbt_new0(xbt_node_t, n * n);
371 r = xbt_new0(xbt_node_t, n * n);
373 xbt_floyd_algorithm(g, adj, d, p);
375 for (i = 0; i < n; i++) {
376 for (j = 0; j < n; j++) {
379 while ((P(i, k)) && (__xbt_find_in_dynar(g->nodes, P(i, k)) != i)) {
380 k = __xbt_find_in_dynar(g->nodes, P(i, k));
384 R(i, j) = *((xbt_node_t *) xbt_dynar_get_ptr(g->nodes, k));
397 /** @brief Extract a spanning tree of the given graph */
398 xbt_edge_t *xbt_graph_spanning_tree_prim(xbt_graph_t g)
401 int tree_size_max = xbt_dynar_length(g->nodes) - 1;
402 xbt_edge_t *tree = xbt_new0(xbt_edge_t, tree_size_max);
404 xbt_node_t node = NULL;
405 xbt_dynar_t edge_list = NULL;
406 xbt_heap_t heap = xbt_heap_new(10, NULL);
409 xbt_assert0(!(g->directed),
410 "Spanning trees do not make sense on directed graphs");
412 xbt_dynar_foreach(g->nodes, cursor, node) {
413 node->xbtdata = NULL;
416 node = xbt_dynar_getfirst_as(g->nodes, xbt_node_t);
417 node->xbtdata = (void *) 1;
418 edge_list = node->out;
419 xbt_dynar_foreach(edge_list, cursor, e)
420 xbt_heap_push(heap, e, -(e->length));
422 while ((edge = xbt_heap_pop(heap))) {
423 if ((edge->src->xbtdata) && (edge->dst->xbtdata))
425 tree[tree_size++] = edge;
426 if (!(edge->src->xbtdata)) {
427 edge->src->xbtdata = (void *) 1;
428 edge_list = edge->src->out;
429 xbt_dynar_foreach(edge_list, cursor, e) {
430 xbt_heap_push(heap, e, -(e->length));
433 edge->dst->xbtdata = (void *) 1;
434 edge_list = edge->dst->out;
435 xbt_dynar_foreach(edge_list, cursor, e) {
436 xbt_heap_push(heap, e, -(e->length));
439 if (tree_size == tree_size_max)
448 /** @brief Topological sort on the given graph
452 * In graph theory, a topological sort of a directed acyclic graph (DAG) is
453 * a linear ordering of its nodes which is compatible with the partial
454 * order R induced on the nodes where x comes before y (xRy) if there's a
455 * directed path from x to y in the DAG. An equivalent definition is that
456 * each node comes before all nodes to which it has edges. Every DAG has at
457 * least one topological sort, and may have many.
459 xbt_node_t *xbt_graph_topo_sort(xbt_graph_t g)
467 n = xbt_dynar_length(g->nodes);
470 sorted = xbt_malloc(n * sizeof(xbt_node_t));
472 xbt_dynar_foreach(g->nodes, cursor, node)
473 node->xbtdata = xbt_new0(int, 1);
475 xbt_dynar_foreach(g->nodes, cursor, node)
476 xbt_graph_depth_visit(g, node, sorted, &idx);
478 xbt_dynar_foreach(g->nodes, cursor, node) {
480 node->xbtdata = NULL;
486 /** @brief First-depth graph traversal */
487 void xbt_graph_depth_visit(xbt_graph_t g, xbt_node_t n,
488 xbt_node_t * sorted, int *idx)
493 if (*((int *) (n->xbtdata)) == ALREADY_EXPLORED)
495 else if (*((int *) (n->xbtdata)) == CURRENTLY_EXPLORING)
496 THROW0(0, 0, "There is a cycle");
498 *((int *) (n->xbtdata)) = CURRENTLY_EXPLORING;
500 xbt_dynar_foreach(n->out, cursor, edge) {
501 xbt_graph_depth_visit(g, edge->dst, sorted, idx);
504 *((int *) (n->xbtdata)) = ALREADY_EXPLORED;
505 sorted[(*idx)--] = n;
509 /********************* Import and Export ******************/
510 static xbt_graph_t parsed_graph = NULL;
511 static xbt_dict_t parsed_nodes = NULL;
513 static void *(*__parse_node_label_and_data) (xbt_node_t, const char *,
514 const char *) = NULL;
515 static void *(*__parse_edge_label_and_data) (xbt_edge_t, const char *,
516 const char *) = NULL;
518 static void __parse_graph_begin(void)
521 if (A_graphxml_graph_isDirected == A_graphxml_graph_isDirected_true)
522 parsed_graph = xbt_graph_new_graph(1, NULL);
524 parsed_graph = xbt_graph_new_graph(0, NULL);
526 parsed_nodes = xbt_dict_new();
529 static void __parse_graph_end(void)
531 xbt_dict_free(&parsed_nodes);
535 static void __parse_node(void)
537 xbt_node_t node = xbt_graph_new_node(parsed_graph, NULL);
539 DEBUG1("<node name=\"%s\"/>", A_graphxml_node_name);
540 if (__parse_node_label_and_data)
541 node->data = __parse_node_label_and_data(node, A_graphxml_node_label,
542 A_graphxml_node_data);
543 xbt_graph_parse_get_double(&(node->position_x),
544 A_graphxml_node_position_x);
545 xbt_graph_parse_get_double(&(node->position_y),
546 A_graphxml_node_position_y);
548 xbt_dict_set(parsed_nodes, A_graphxml_node_name, (void *) node, NULL);
551 static void __parse_edge(void)
553 xbt_edge_t edge = xbt_graph_new_edge(parsed_graph,
554 xbt_dict_get(parsed_nodes,
555 A_graphxml_edge_source),
556 xbt_dict_get(parsed_nodes,
557 A_graphxml_edge_target),
560 if (__parse_edge_label_and_data)
561 edge->data = __parse_edge_label_and_data(edge, A_graphxml_edge_label,
562 A_graphxml_edge_data);
564 xbt_graph_parse_get_double(&(edge->length), A_graphxml_edge_length);
566 DEBUG3("<edge source=\"%s\" target=\"%s\" length=\"%f\"/>",
567 (char *) (edge->src)->data,
568 (char *) (edge->dst)->data, xbt_graph_edge_get_length(edge));
571 /** @brief Import a graph from a file following the GraphXML format */
572 xbt_graph_t xbt_graph_read(const char *filename,
573 void *(node_label_and_data) (xbt_node_t,
576 void *(edge_label_and_data) (xbt_edge_t,
581 xbt_graph_t graph = NULL;
583 __parse_node_label_and_data = node_label_and_data;
584 __parse_edge_label_and_data = edge_label_and_data;
586 xbt_graph_parse_reset_parser();
588 STag_graphxml_graph_fun = __parse_graph_begin;
589 ETag_graphxml_graph_fun = __parse_graph_end;
590 ETag_graphxml_node_fun = __parse_node;
591 ETag_graphxml_edge_fun = __parse_edge;
593 xbt_graph_parse_open(filename);
594 xbt_assert1((!xbt_graph_parse()), "Parse error in %s", filename);
595 xbt_graph_parse_close();
597 graph = parsed_graph;
603 /** @brief Export the given graph in the GraphViz formatting for visualization */
604 void xbt_graph_export_graphviz(xbt_graph_t g, const char *filename,
605 const char *(node_name) (xbt_node_t),
606 const char *(edge_name) (xbt_edge_t))
609 xbt_node_t node = NULL;
610 xbt_edge_t edge = NULL;
612 const char *name = NULL;
614 file = fopen(filename, "w");
615 xbt_assert1(file, "Failed to open %s \n", filename);
618 fprintf(file, "digraph test {\n");
620 fprintf(file, "graph test {\n");
622 fprintf(file, " graph [overlap=scale]\n");
624 fprintf(file, " node [shape=box, style=filled]\n");
626 " node [width=.3, height=.3, style=filled, color=skyblue]\n\n");
628 xbt_dynar_foreach(g->nodes, cursor, node) {
629 fprintf(file, " \"%p\" ", node);
630 if ((node_name) && ((name = node_name(node))))
631 fprintf(file, "[label=\"%s\"]", name);
632 fprintf(file, ";\n");
634 xbt_dynar_foreach(g->edges, cursor, edge) {
636 fprintf(file, " \"%p\" -> \"%p\"", edge->src, edge->dst);
638 fprintf(file, " \"%p\" -- \"%p\"", edge->src, edge->dst);
639 if ((edge_name) && ((name = edge_name(edge))))
640 fprintf(file, "[label=\"%s\"]", name);
641 fprintf(file, ";\n");
643 fprintf(file, "}\n");
647 /** @brief Export the given graph in the GraphXML format */
648 void xbt_graph_export_graphxml(xbt_graph_t g, const char *filename,
649 const char *(node_name) (xbt_node_t),
650 const char *(edge_name) (xbt_edge_t),
651 const char *(node_data_print) (void *),
652 const char *(edge_data_print) (void *))
655 xbt_node_t node = NULL;
656 xbt_edge_t edge = NULL;
658 const char *name = NULL;
660 file = fopen(filename, "w");
661 xbt_assert1(file, "Failed to open %s \n", filename);
663 fprintf(file, "<?xml version='1.0'?>\n");
664 fprintf(file, "<!DOCTYPE graph SYSTEM \"graphxml.dtd\">\n");
666 fprintf(file, "<graph isDirected=\"true\">\n");
668 fprintf(file, "<graph isDirected=\"false\">\n");
669 xbt_dynar_foreach(g->nodes, cursor, node) {
670 fprintf(file, " <node name=\"%p\" ", node);
671 if ((node_name) && ((name = node_name(node))))
672 fprintf(file, "label=\"%s\" ", name);
673 if ((node_data_print) && ((name = node_data_print(node->data))))
674 fprintf(file, "data=\"%s\" ", name);
675 fprintf(file, ">\n");
677 xbt_dynar_foreach(g->edges, cursor, edge) {
678 fprintf(file, " <edge source=\"%p\" target =\"%p\" ",
679 edge->src, edge->dst);
680 if ((edge_name) && ((name = edge_name(edge))))
681 fprintf(file, "label=\"%s\" ", name);
682 if (edge->length >= 0.0)
683 fprintf(file, "length=\"%g\" ", edge->length);
684 if ((edge_data_print) && ((name = edge_data_print(edge->data))))
685 fprintf(file, "data=\"%s\" ", name);
686 fprintf(file, ">\n");
688 fprintf(file, "</graph>\n");