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 l: poor victim
124 * Free the graph structure.
126 void xbt_graph_free_graph(xbt_graph_t g,
127 void node_free_function(void *ptr),
128 void edge_free_function(void *ptr),
129 void graph_free_function(void *ptr))
132 xbt_node_t node = NULL;
133 xbt_edge_t edge = NULL;
136 xbt_dynar_foreach(g->nodes, cursor, node) {
137 xbt_dynar_free(&(node->out));
138 xbt_dynar_free(&(node->in));
139 if (node_free_function)
140 node_free_function(node->data);
143 xbt_dynar_foreach(g->edges, cursor, edge) {
144 if (edge_free_function)
145 edge_free_function(edge->data);
148 xbt_dynar_foreach(g->nodes, cursor, node)
150 xbt_dynar_free(&(g->nodes));
152 xbt_dynar_foreach(g->edges, cursor, edge)
154 xbt_dynar_free(&(g->edges));
162 /** @brief remove the given node from the given graph */
163 void xbt_graph_free_node(xbt_graph_t g, xbt_node_t n,
164 void_f_pvoid_t * node_free_function,
165 void_f_pvoid_t * edge_free_function)
170 xbt_node_t node = NULL;
171 xbt_edge_t edge = NULL;
173 nbr = xbt_dynar_length(g->edges);
175 for (i = 0; i < nbr; i++) {
176 xbt_dynar_cursor_get(g->edges, &cursor, &edge);
178 if ((edge->dst == n) || (edge->src == n)) {
179 xbt_graph_free_edge(g, edge, edge_free_function);
181 xbt_dynar_cursor_step(g->edges, &cursor);
184 if ((node_free_function) && (n->data))
185 node_free_function(n->data);
188 xbt_dynar_foreach(g->nodes, cursor, node)
190 xbt_dynar_cursor_rm(g->nodes, &cursor);
192 xbt_dynar_free(&(n->in));
193 xbt_dynar_free(&(n->out));
200 /** @brief remove the given edge from the given graph */
201 void xbt_graph_free_edge(xbt_graph_t g, xbt_edge_t e,
202 void free_function(void *ptr))
206 xbt_edge_t edge = NULL;
208 if ((free_function) && (e->data))
209 free_function(e->data);
211 xbt_dynar_foreach(g->edges, cursor, edge) {
214 idx = __xbt_find_in_dynar(edge->dst->in, edge);
215 xbt_dynar_remove_at(edge->dst->in, idx, NULL);
216 } else { /* only the out field is used */
217 idx = __xbt_find_in_dynar(edge->dst->out, edge);
218 xbt_dynar_remove_at(edge->dst->out, idx, NULL);
221 idx = __xbt_find_in_dynar(edge->src->out, edge);
222 xbt_dynar_remove_at(edge->src->out, idx, NULL);
224 xbt_dynar_cursor_rm(g->edges, &cursor);
231 int __xbt_find_in_dynar(xbt_dynar_t dynar, void *p)
237 xbt_dynar_foreach(dynar, cursor, tmp) {
244 /** @brief Retrieve the graph's nodes as a dynar */
245 xbt_dynar_t xbt_graph_get_nodes(xbt_graph_t g)
250 /** @brief Retrieve the graph's edges as a dynar */
251 xbt_dynar_t xbt_graph_get_edges(xbt_graph_t g)
256 /** @brief Retrieve the node at the source of the given edge */
257 xbt_node_t xbt_graph_edge_get_source(xbt_edge_t e)
263 /** @brief Retrieve the node being the target of the given edge */
264 xbt_node_t xbt_graph_edge_get_target(xbt_edge_t e)
270 /** @brief Set the weight of the given edge */
271 void xbt_graph_edge_set_length(xbt_edge_t e, double length)
277 double xbt_graph_edge_get_length(xbt_edge_t e)
283 /** @brief construct the adjacency matrix corresponding to the given graph
285 * The weights are the distances between nodes
287 double *xbt_graph_get_length_matrix(xbt_graph_t g)
293 xbt_edge_t edge = NULL;
294 xbt_node_t node = NULL;
297 # define D(u,v) d[(u)*n+(v)]
298 n = xbt_dynar_length(g->nodes);
300 d = (double *) xbt_new0(double, n * n);
302 for (i = 0; i < n * n; i++) {
306 xbt_dynar_foreach(g->nodes, cursor, node) {
308 D(cursor, cursor) = 0;
310 xbt_dynar_foreach(node->out, in_cursor, edge) {
311 if (edge->dst == node)
312 idx = __xbt_find_in_dynar(g->nodes, edge->src);
313 else /*case of undirected graphs */
314 idx = __xbt_find_in_dynar(g->nodes, edge->dst);
315 D(cursor, idx) = edge->length;
324 /** @brief Floyd-Warshall algorithm for shortest path finding
328 * The Floyd–Warshall algorithm takes as input an adjacency matrix
329 * representation of a weighted, directed graph (V, E). The weight of a
330 * path between two vertices is the sum of the weights of the edges along
331 * that path. The edges E of the graph may have negative weights, but the
332 * graph must not have any negative weight cycles. The algorithm computes,
333 * for each pair of vertices, the minimum weight among all paths between
334 * the two vertices. The running time complexity is Θ(|V|3).
336 void xbt_floyd_algorithm(xbt_graph_t g, double *adj, double *d,
341 n = xbt_dynar_length(g->nodes);
343 # define D(u,v) d[(u)*n+(v)]
344 # define P(u,v) p[(u)*n+(v)]
346 for (i = 0; i < n * n; i++) {
351 for (i = 0; i < n; i++) {
352 for (j = 0; j < n; j++) {
354 P(i, j) = *((xbt_node_t *) xbt_dynar_get_ptr(g->nodes, i));
359 for (k = 0; k < n; k++) {
360 for (i = 0; i < n; i++) {
361 for (j = 0; j < n; j++) {
362 if ((D(i, k) != -1) && (D(k, j) != -1)) {
363 if ((D(i, j) == -1) || (D(i, j) > D(i, k) + D(k, j))) {
364 D(i, j) = D(i, k) + D(k, j);
378 /** @brief computes all-pairs shortest paths */
379 xbt_node_t *xbt_graph_shortest_paths(xbt_graph_t g)
389 # define P(u,v) p[(u)*n+(v)]
390 # define R(u,v) r[(u)*n+(v)]
392 n = xbt_dynar_length(g->nodes);
393 adj = xbt_graph_get_length_matrix(g);
394 d = xbt_new0(double, n * n);
395 p = xbt_new0(xbt_node_t, n * n);
396 r = xbt_new0(xbt_node_t, n * n);
398 xbt_floyd_algorithm(g, adj, d, p);
400 for (i = 0; i < n; i++) {
401 for (j = 0; j < n; j++) {
404 while ((P(i, k)) && (__xbt_find_in_dynar(g->nodes, P(i, k)) != i)) {
405 k = __xbt_find_in_dynar(g->nodes, P(i, k));
409 R(i, j) = *((xbt_node_t *) xbt_dynar_get_ptr(g->nodes, k));
422 /** @brief Extract a spanning tree of the given graph */
423 xbt_edge_t *xbt_graph_spanning_tree_prim(xbt_graph_t g)
426 int tree_size_max = xbt_dynar_length(g->nodes) - 1;
427 xbt_edge_t *tree = xbt_new0(xbt_edge_t, tree_size_max);
429 xbt_node_t node = NULL;
430 xbt_dynar_t edge_list = NULL;
431 xbt_heap_t heap = xbt_heap_new(10, NULL);
434 xbt_assert0(!(g->directed),
435 "Spanning trees do not make sense on directed graphs");
437 xbt_dynar_foreach(g->nodes, cursor, node) {
438 node->xbtdata = NULL;
441 node = xbt_dynar_getfirst_as(g->nodes, xbt_node_t);
442 node->xbtdata = (void *) 1;
443 edge_list = node->out;
444 xbt_dynar_foreach(edge_list, cursor, e)
445 xbt_heap_push(heap, e, -(e->length));
447 while ((edge = xbt_heap_pop(heap))) {
448 if ((edge->src->xbtdata) && (edge->dst->xbtdata))
450 tree[tree_size++] = edge;
451 if (!(edge->src->xbtdata)) {
452 edge->src->xbtdata = (void *) 1;
453 edge_list = edge->src->out;
454 xbt_dynar_foreach(edge_list, cursor, e) {
455 xbt_heap_push(heap, e, -(e->length));
458 edge->dst->xbtdata = (void *) 1;
459 edge_list = edge->dst->out;
460 xbt_dynar_foreach(edge_list, cursor, e) {
461 xbt_heap_push(heap, e, -(e->length));
464 if (tree_size == tree_size_max)
473 /** @brief Topological sort on the given graph
477 * In graph theory, a topological sort of a directed acyclic graph (DAG) is
478 * a linear ordering of its nodes which is compatible with the partial
479 * order R induced on the nodes where x comes before y (xRy) if there's a
480 * directed path from x to y in the DAG. An equivalent definition is that
481 * each node comes before all nodes to which it has edges. Every DAG has at
482 * least one topological sort, and may have many.
484 xbt_node_t *xbt_graph_topo_sort(xbt_graph_t g)
492 n = xbt_dynar_length(g->nodes);
495 sorted = xbt_malloc(n * sizeof(xbt_node_t));
497 xbt_dynar_foreach(g->nodes, cursor, node)
498 node->xbtdata = xbt_new0(int, 1);
500 xbt_dynar_foreach(g->nodes, cursor, node)
501 xbt_graph_depth_visit(g, node, sorted, &idx);
503 xbt_dynar_foreach(g->nodes, cursor, node) {
505 node->xbtdata = NULL;
511 /** @brief First-depth graph traversal */
512 void xbt_graph_depth_visit(xbt_graph_t g, xbt_node_t n,
513 xbt_node_t * sorted, int *idx)
518 if (*((int *) (n->xbtdata)) == ALREADY_EXPLORED)
520 else if (*((int *) (n->xbtdata)) == CURRENTLY_EXPLORING)
521 THROW0(0, 0, "There is a cycle");
523 *((int *) (n->xbtdata)) = CURRENTLY_EXPLORING;
525 xbt_dynar_foreach(n->out, cursor, edge) {
526 xbt_graph_depth_visit(g, edge->dst, sorted, idx);
529 *((int *) (n->xbtdata)) = ALREADY_EXPLORED;
530 sorted[(*idx)--] = n;
534 /********************* Import and Export ******************/
535 static xbt_graph_t parsed_graph = NULL;
536 static xbt_dict_t parsed_nodes = NULL;
538 static void *(*__parse_node_label_and_data) (xbt_node_t, const char *,
539 const char *) = NULL;
540 static void *(*__parse_edge_label_and_data) (xbt_edge_t, const char *,
541 const char *) = NULL;
543 static void __parse_graph_begin(void)
546 if (A_graphxml_graph_isDirected == A_graphxml_graph_isDirected_true)
547 parsed_graph = xbt_graph_new_graph(1, NULL);
549 parsed_graph = xbt_graph_new_graph(0, NULL);
551 parsed_nodes = xbt_dict_new();
554 static void __parse_graph_end(void)
556 xbt_dict_free(&parsed_nodes);
560 static void __parse_node(void)
562 xbt_node_t node = xbt_graph_new_node(parsed_graph, NULL);
564 DEBUG1("<node name=\"%s\"/>", A_graphxml_node_name);
565 if (__parse_node_label_and_data)
566 node->data = __parse_node_label_and_data(node, A_graphxml_node_label,
567 A_graphxml_node_data);
568 xbt_graph_parse_get_double(&(node->position_x),
569 A_graphxml_node_position_x);
570 xbt_graph_parse_get_double(&(node->position_y),
571 A_graphxml_node_position_y);
573 xbt_dict_set(parsed_nodes, A_graphxml_node_name, (void *) node, NULL);
576 static void __parse_edge(void)
578 xbt_edge_t edge = xbt_graph_new_edge(parsed_graph,
579 xbt_dict_get(parsed_nodes,
580 A_graphxml_edge_source),
581 xbt_dict_get(parsed_nodes,
582 A_graphxml_edge_target),
585 if (__parse_edge_label_and_data)
586 edge->data = __parse_edge_label_and_data(edge, A_graphxml_edge_label,
587 A_graphxml_edge_data);
589 xbt_graph_parse_get_double(&(edge->length), A_graphxml_edge_length);
591 DEBUG3("<edge source=\"%s\" target=\"%s\" length=\"%f\"/>",
592 (char *) (edge->src)->data,
593 (char *) (edge->dst)->data, xbt_graph_edge_get_length(edge));
596 /** @brief Import a graph from a file following the GraphXML format */
597 xbt_graph_t xbt_graph_read(const char *filename,
598 void *(node_label_and_data) (xbt_node_t,
601 void *(edge_label_and_data) (xbt_edge_t,
606 xbt_graph_t graph = NULL;
608 __parse_node_label_and_data = node_label_and_data;
609 __parse_edge_label_and_data = edge_label_and_data;
611 xbt_graph_parse_reset_parser();
613 STag_graphxml_graph_fun = __parse_graph_begin;
614 ETag_graphxml_graph_fun = __parse_graph_end;
615 ETag_graphxml_node_fun = __parse_node;
616 ETag_graphxml_edge_fun = __parse_edge;
618 xbt_graph_parse_open(filename);
619 xbt_assert1((!xbt_graph_parse()), "Parse error in %s", filename);
620 xbt_graph_parse_close();
622 graph = parsed_graph;
628 /** @brief Export the given graph in the GraphViz formatting for visualization */
629 void xbt_graph_export_graphviz(xbt_graph_t g, const char *filename,
630 const char *(node_name) (xbt_node_t),
631 const char *(edge_name) (xbt_edge_t))
634 xbt_node_t node = NULL;
635 xbt_edge_t edge = NULL;
637 const char *name = NULL;
639 file = fopen(filename, "w");
640 xbt_assert1(file, "Failed to open %s \n", filename);
643 fprintf(file, "digraph test {\n");
645 fprintf(file, "graph test {\n");
647 fprintf(file, " graph [overlap=scale]\n");
649 fprintf(file, " node [shape=box, style=filled]\n");
651 " node [width=.3, height=.3, style=filled, color=skyblue]\n\n");
653 xbt_dynar_foreach(g->nodes, cursor, node) {
654 fprintf(file, " \"%p\" ", node);
655 if ((node_name) && ((name = node_name(node))))
656 fprintf(file, "[label=\"%s\"]", name);
657 fprintf(file, ";\n");
659 xbt_dynar_foreach(g->edges, cursor, edge) {
661 fprintf(file, " \"%p\" -> \"%p\"", edge->src, edge->dst);
663 fprintf(file, " \"%p\" -- \"%p\"", edge->src, edge->dst);
664 if ((edge_name) && ((name = edge_name(edge))))
665 fprintf(file, "[label=\"%s\"]", name);
666 fprintf(file, ";\n");
668 fprintf(file, "}\n");
672 /** @brief Export the given graph in the GraphXML format */
673 void xbt_graph_export_graphxml(xbt_graph_t g, const char *filename,
674 const char *(node_name) (xbt_node_t),
675 const char *(edge_name) (xbt_edge_t),
676 const char *(node_data_print) (void *),
677 const char *(edge_data_print) (void *))
680 xbt_node_t node = NULL;
681 xbt_edge_t edge = NULL;
683 const char *name = NULL;
685 file = fopen(filename, "w");
686 xbt_assert1(file, "Failed to open %s \n", filename);
688 fprintf(file, "<?xml version='1.0'?>\n");
689 fprintf(file, "<!DOCTYPE graph SYSTEM \"graphxml.dtd\">\n");
691 fprintf(file, "<graph isDirected=\"true\">\n");
693 fprintf(file, "<graph isDirected=\"false\">\n");
694 xbt_dynar_foreach(g->nodes, cursor, node) {
695 fprintf(file, " <node name=\"%p\" ", node);
696 if ((node_name) && ((name = node_name(node))))
697 fprintf(file, "label=\"%s\" ", name);
698 if ((node_data_print) && ((name = node_data_print(node->data))))
699 fprintf(file, "data=\"%s\" ", name);
700 fprintf(file, ">\n");
702 xbt_dynar_foreach(g->edges, cursor, edge) {
703 fprintf(file, " <edge source=\"%p\" target =\"%p\" ",
704 edge->src, edge->dst);
705 if ((edge_name) && ((name = edge_name(edge))))
706 fprintf(file, "label=\"%s\" ", name);
707 if (edge->length >= 0.0)
708 fprintf(file, "length=\"%g\" ", edge->length);
709 if ((edge_data_print) && ((name = edge_data_print(edge->data))))
710 fprintf(file, "data=\"%s\" ", name);
711 fprintf(file, ">\n");
713 fprintf(file, "</graph>\n");