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_node_set_data(xbt_node_t node, void *data)
97 void *xbt_graph_edge_get_data(xbt_edge_t edge)
102 /** @brief Destructor
103 * @param l: poor victim
105 * Free the graph structure.
107 void xbt_graph_free_graph(xbt_graph_t g,
108 void node_free_function(void *ptr),
109 void edge_free_function(void *ptr),
110 void graph_free_function(void *ptr))
113 xbt_node_t node = NULL;
114 xbt_edge_t edge = NULL;
117 xbt_dynar_foreach(g->nodes, cursor, node) {
118 xbt_dynar_free(&(node->out));
119 xbt_dynar_free(&(node->in));
120 if (node_free_function)
121 node_free_function(node->data);
124 xbt_dynar_foreach(g->edges, cursor, edge) {
125 if (edge_free_function)
126 edge_free_function(edge->data);
129 xbt_dynar_foreach(g->nodes, cursor, node)
131 xbt_dynar_free(&(g->nodes));
133 xbt_dynar_foreach(g->edges, cursor, edge)
135 xbt_dynar_free(&(g->edges));
143 /** @brief remove the given node from the given graph */
144 void xbt_graph_free_node(xbt_graph_t g, xbt_node_t n,
145 void_f_pvoid_t * node_free_function,
146 void_f_pvoid_t * edge_free_function)
151 xbt_node_t node = NULL;
152 xbt_edge_t edge = NULL;
154 nbr = xbt_dynar_length(g->edges);
156 for (i = 0; i < nbr; i++) {
157 xbt_dynar_cursor_get(g->edges, &cursor, &edge);
159 if ((edge->dst == n) || (edge->src == n)) {
160 xbt_graph_free_edge(g, edge, edge_free_function);
162 xbt_dynar_cursor_step(g->edges, &cursor);
165 if ((node_free_function) && (n->data))
166 node_free_function(n->data);
169 xbt_dynar_foreach(g->nodes, cursor, node)
171 xbt_dynar_cursor_rm(g->nodes, &cursor);
173 xbt_dynar_free(&(n->in));
174 xbt_dynar_free(&(n->out));
181 /** @brief remove the given edge from the given graph */
182 void xbt_graph_free_edge(xbt_graph_t g, xbt_edge_t e,
183 void free_function(void *ptr))
187 xbt_edge_t edge = NULL;
189 if ((free_function) && (e->data))
190 free_function(e->data);
192 xbt_dynar_foreach(g->edges, cursor, edge) {
195 idx = __xbt_find_in_dynar(edge->dst->in, edge);
196 xbt_dynar_remove_at(edge->dst->in, idx, NULL);
197 } else { /* only the out field is used */
198 idx = __xbt_find_in_dynar(edge->dst->out, edge);
199 xbt_dynar_remove_at(edge->dst->out, idx, NULL);
202 idx = __xbt_find_in_dynar(edge->src->out, edge);
203 xbt_dynar_remove_at(edge->src->out, idx, NULL);
205 xbt_dynar_cursor_rm(g->edges, &cursor);
212 int __xbt_find_in_dynar(xbt_dynar_t dynar, void *p)
218 xbt_dynar_foreach(dynar, cursor, tmp) {
225 /** @brief Retrieve the graph's nodes as a dynar */
226 xbt_dynar_t xbt_graph_get_nodes(xbt_graph_t g)
231 /** @brief Retrieve the graph's edges as a dynar */
232 xbt_dynar_t xbt_graph_get_edges(xbt_graph_t g)
237 /** @brief Retrieve the node at the source of the given edge */
238 xbt_node_t xbt_graph_edge_get_source(xbt_edge_t e)
244 /** @brief Retrieve the node being the target of the given edge */
245 xbt_node_t xbt_graph_edge_get_target(xbt_edge_t e)
251 /** @brief Set the weight of the given edge */
252 void xbt_graph_edge_set_length(xbt_edge_t e, double length)
258 double xbt_graph_edge_get_length(xbt_edge_t e)
264 /** @brief construct the adjacency matrix corresponding to the given graph
266 * The weights are the distances between nodes
268 double *xbt_graph_get_length_matrix(xbt_graph_t g)
274 xbt_edge_t edge = NULL;
275 xbt_node_t node = NULL;
278 # define D(u,v) d[(u)*n+(v)]
279 n = xbt_dynar_length(g->nodes);
281 d = (double *) xbt_new0(double, n * n);
283 for (i = 0; i < n * n; i++) {
287 xbt_dynar_foreach(g->nodes, cursor, node) {
289 D(cursor, cursor) = 0;
291 xbt_dynar_foreach(node->out, in_cursor, edge) {
292 if (edge->dst == node)
293 idx = __xbt_find_in_dynar(g->nodes, edge->src);
294 else /*case of undirected graphs */
295 idx = __xbt_find_in_dynar(g->nodes, edge->dst);
296 D(cursor, idx) = edge->length;
305 /** @brief Floyd-Warshall algorithm for shortest path finding
309 * The Floyd–Warshall algorithm takes as input an adjacency matrix
310 * representation of a weighted, directed graph (V, E). The weight of a
311 * path between two vertices is the sum of the weights of the edges along
312 * that path. The edges E of the graph may have negative weights, but the
313 * graph must not have any negative weight cycles. The algorithm computes,
314 * for each pair of vertices, the minimum weight among all paths between
315 * the two vertices. The running time complexity is Θ(|V|3).
317 void xbt_floyd_algorithm(xbt_graph_t g, double *adj, double *d,
322 n = xbt_dynar_length(g->nodes);
324 # define D(u,v) d[(u)*n+(v)]
325 # define P(u,v) p[(u)*n+(v)]
327 for (i = 0; i < n * n; i++) {
332 for (i = 0; i < n; i++) {
333 for (j = 0; j < n; j++) {
335 P(i, j) = *((xbt_node_t *) xbt_dynar_get_ptr(g->nodes, i));
340 for (k = 0; k < n; k++) {
341 for (i = 0; i < n; i++) {
342 for (j = 0; j < n; j++) {
343 if ((D(i, k) != -1) && (D(k, j) != -1)) {
344 if ((D(i, j) == -1) || (D(i, j) > D(i, k) + D(k, j))) {
345 D(i, j) = D(i, k) + D(k, j);
359 /** @brief computes all-pairs shortest paths */
360 xbt_node_t *xbt_graph_shortest_paths(xbt_graph_t g)
370 # define P(u,v) p[(u)*n+(v)]
371 # define R(u,v) r[(u)*n+(v)]
373 n = xbt_dynar_length(g->nodes);
374 adj = xbt_graph_get_length_matrix(g);
375 d = xbt_new0(double, n * n);
376 p = xbt_new0(xbt_node_t, n * n);
377 r = xbt_new0(xbt_node_t, n * n);
379 xbt_floyd_algorithm(g, adj, d, p);
381 for (i = 0; i < n; i++) {
382 for (j = 0; j < n; j++) {
385 while ((P(i, k)) && (__xbt_find_in_dynar(g->nodes, P(i, k)) != i)) {
386 k = __xbt_find_in_dynar(g->nodes, P(i, k));
390 R(i, j) = *((xbt_node_t *) xbt_dynar_get_ptr(g->nodes, k));
403 /** @brief Extract a spanning tree of the given graph */
404 xbt_edge_t *xbt_graph_spanning_tree_prim(xbt_graph_t g)
407 int tree_size_max = xbt_dynar_length(g->nodes) - 1;
408 xbt_edge_t *tree = xbt_new0(xbt_edge_t, tree_size_max);
410 xbt_node_t node = NULL;
411 xbt_dynar_t edge_list = NULL;
412 xbt_heap_t heap = xbt_heap_new(10, NULL);
415 xbt_assert0(!(g->directed),
416 "Spanning trees do not make sense on directed graphs");
418 xbt_dynar_foreach(g->nodes, cursor, node) {
419 node->xbtdata = NULL;
422 node = xbt_dynar_getfirst_as(g->nodes, xbt_node_t);
423 node->xbtdata = (void *) 1;
424 edge_list = node->out;
425 xbt_dynar_foreach(edge_list, cursor, e)
426 xbt_heap_push(heap, e, -(e->length));
428 while ((edge = xbt_heap_pop(heap))) {
429 if ((edge->src->xbtdata) && (edge->dst->xbtdata))
431 tree[tree_size++] = edge;
432 if (!(edge->src->xbtdata)) {
433 edge->src->xbtdata = (void *) 1;
434 edge_list = edge->src->out;
435 xbt_dynar_foreach(edge_list, cursor, e) {
436 xbt_heap_push(heap, e, -(e->length));
439 edge->dst->xbtdata = (void *) 1;
440 edge_list = edge->dst->out;
441 xbt_dynar_foreach(edge_list, cursor, e) {
442 xbt_heap_push(heap, e, -(e->length));
445 if (tree_size == tree_size_max)
454 /** @brief Topological sort on the given graph
458 * In graph theory, a topological sort of a directed acyclic graph (DAG) is
459 * a linear ordering of its nodes which is compatible with the partial
460 * order R induced on the nodes where x comes before y (xRy) if there's a
461 * directed path from x to y in the DAG. An equivalent definition is that
462 * each node comes before all nodes to which it has edges. Every DAG has at
463 * least one topological sort, and may have many.
465 xbt_node_t *xbt_graph_topo_sort(xbt_graph_t g)
473 n = xbt_dynar_length(g->nodes);
476 sorted = xbt_malloc(n * sizeof(xbt_node_t));
478 xbt_dynar_foreach(g->nodes, cursor, node)
479 node->xbtdata = xbt_new0(int, 1);
481 xbt_dynar_foreach(g->nodes, cursor, node)
482 xbt_graph_depth_visit(g, node, sorted, &idx);
484 xbt_dynar_foreach(g->nodes, cursor, node) {
486 node->xbtdata = NULL;
492 /** @brief First-depth graph traversal */
493 void xbt_graph_depth_visit(xbt_graph_t g, xbt_node_t n,
494 xbt_node_t * sorted, int *idx)
499 if (*((int *) (n->xbtdata)) == ALREADY_EXPLORED)
501 else if (*((int *) (n->xbtdata)) == CURRENTLY_EXPLORING)
502 THROW0(0, 0, "There is a cycle");
504 *((int *) (n->xbtdata)) = CURRENTLY_EXPLORING;
506 xbt_dynar_foreach(n->out, cursor, edge) {
507 xbt_graph_depth_visit(g, edge->dst, sorted, idx);
510 *((int *) (n->xbtdata)) = ALREADY_EXPLORED;
511 sorted[(*idx)--] = n;
515 /********************* Import and Export ******************/
516 static xbt_graph_t parsed_graph = NULL;
517 static xbt_dict_t parsed_nodes = NULL;
519 static void *(*__parse_node_label_and_data) (xbt_node_t, const char *,
520 const char *) = NULL;
521 static void *(*__parse_edge_label_and_data) (xbt_edge_t, const char *,
522 const char *) = NULL;
524 static void __parse_graph_begin(void)
527 if (A_graphxml_graph_isDirected == A_graphxml_graph_isDirected_true)
528 parsed_graph = xbt_graph_new_graph(1, NULL);
530 parsed_graph = xbt_graph_new_graph(0, NULL);
532 parsed_nodes = xbt_dict_new();
535 static void __parse_graph_end(void)
537 xbt_dict_free(&parsed_nodes);
541 static void __parse_node(void)
543 xbt_node_t node = xbt_graph_new_node(parsed_graph, NULL);
545 DEBUG1("<node name=\"%s\"/>", A_graphxml_node_name);
546 if (__parse_node_label_and_data)
547 node->data = __parse_node_label_and_data(node, A_graphxml_node_label,
548 A_graphxml_node_data);
549 xbt_graph_parse_get_double(&(node->position_x),
550 A_graphxml_node_position_x);
551 xbt_graph_parse_get_double(&(node->position_y),
552 A_graphxml_node_position_y);
554 xbt_dict_set(parsed_nodes, A_graphxml_node_name, (void *) node, NULL);
557 static void __parse_edge(void)
559 xbt_edge_t edge = xbt_graph_new_edge(parsed_graph,
560 xbt_dict_get(parsed_nodes,
561 A_graphxml_edge_source),
562 xbt_dict_get(parsed_nodes,
563 A_graphxml_edge_target),
566 if (__parse_edge_label_and_data)
567 edge->data = __parse_edge_label_and_data(edge, A_graphxml_edge_label,
568 A_graphxml_edge_data);
570 xbt_graph_parse_get_double(&(edge->length), A_graphxml_edge_length);
572 DEBUG3("<edge source=\"%s\" target=\"%s\" length=\"%f\"/>",
573 (char *) (edge->src)->data,
574 (char *) (edge->dst)->data, xbt_graph_edge_get_length(edge));
577 /** @brief Import a graph from a file following the GraphXML format */
578 xbt_graph_t xbt_graph_read(const char *filename,
579 void *(node_label_and_data) (xbt_node_t,
582 void *(edge_label_and_data) (xbt_edge_t,
587 xbt_graph_t graph = NULL;
589 __parse_node_label_and_data = node_label_and_data;
590 __parse_edge_label_and_data = edge_label_and_data;
592 xbt_graph_parse_reset_parser();
594 STag_graphxml_graph_fun = __parse_graph_begin;
595 ETag_graphxml_graph_fun = __parse_graph_end;
596 ETag_graphxml_node_fun = __parse_node;
597 ETag_graphxml_edge_fun = __parse_edge;
599 xbt_graph_parse_open(filename);
600 xbt_assert1((!xbt_graph_parse()), "Parse error in %s", filename);
601 xbt_graph_parse_close();
603 graph = parsed_graph;
609 /** @brief Export the given graph in the GraphViz formatting for visualization */
610 void xbt_graph_export_graphviz(xbt_graph_t g, const char *filename,
611 const char *(node_name) (xbt_node_t),
612 const char *(edge_name) (xbt_edge_t))
615 xbt_node_t node = NULL;
616 xbt_edge_t edge = NULL;
618 const char *name = NULL;
620 file = fopen(filename, "w");
621 xbt_assert1(file, "Failed to open %s \n", filename);
624 fprintf(file, "digraph test {\n");
626 fprintf(file, "graph test {\n");
628 fprintf(file, " graph [overlap=scale]\n");
630 fprintf(file, " node [shape=box, style=filled]\n");
632 " node [width=.3, height=.3, style=filled, color=skyblue]\n\n");
634 xbt_dynar_foreach(g->nodes, cursor, node) {
635 fprintf(file, " \"%p\" ", node);
636 if ((node_name) && ((name = node_name(node))))
637 fprintf(file, "[label=\"%s\"]", name);
638 fprintf(file, ";\n");
640 xbt_dynar_foreach(g->edges, cursor, edge) {
642 fprintf(file, " \"%p\" -> \"%p\"", edge->src, edge->dst);
644 fprintf(file, " \"%p\" -- \"%p\"", edge->src, edge->dst);
645 if ((edge_name) && ((name = edge_name(edge))))
646 fprintf(file, "[label=\"%s\"]", name);
647 fprintf(file, ";\n");
649 fprintf(file, "}\n");
653 /** @brief Export the given graph in the GraphXML format */
654 void xbt_graph_export_graphxml(xbt_graph_t g, const char *filename,
655 const char *(node_name) (xbt_node_t),
656 const char *(edge_name) (xbt_edge_t),
657 const char *(node_data_print) (void *),
658 const char *(edge_data_print) (void *))
661 xbt_node_t node = NULL;
662 xbt_edge_t edge = NULL;
664 const char *name = NULL;
666 file = fopen(filename, "w");
667 xbt_assert1(file, "Failed to open %s \n", filename);
669 fprintf(file, "<?xml version='1.0'?>\n");
670 fprintf(file, "<!DOCTYPE graph SYSTEM \"graphxml.dtd\">\n");
672 fprintf(file, "<graph isDirected=\"true\">\n");
674 fprintf(file, "<graph isDirected=\"false\">\n");
675 xbt_dynar_foreach(g->nodes, cursor, node) {
676 fprintf(file, " <node name=\"%p\" ", node);
677 if ((node_name) && ((name = node_name(node))))
678 fprintf(file, "label=\"%s\" ", name);
679 if ((node_data_print) && ((name = node_data_print(node->data))))
680 fprintf(file, "data=\"%s\" ", name);
681 fprintf(file, ">\n");
683 xbt_dynar_foreach(g->edges, cursor, edge) {
684 fprintf(file, " <edge source=\"%p\" target =\"%p\" ",
685 edge->src, edge->dst);
686 if ((edge_name) && ((name = edge_name(edge))))
687 fprintf(file, "label=\"%s\" ", name);
688 if (edge->length >= 0.0)
689 fprintf(file, "length=\"%g\" ", edge->length);
690 if ((edge_data_print) && ((name = edge_data_print(edge->data))))
691 fprintf(file, "data=\"%s\" ", name);
692 fprintf(file, ">\n");
694 fprintf(file, "</graph>\n");