1 /* a generic graph library. */
3 /* Copyright (c) 2006 Darina Dimitrova, Arnaud Legrand. */
4 /* All rights reserved. */
6 /* This program is free software; you can redistribute it and/or modify it
7 * under the terms of the license (GNU LGPL) which comes with this package. */
10 #include "xbt/sysdep.h"
12 #include "xbt/graph.h"
13 #include "graph_private.h"
14 #include "xbt/graphxml_parse.h"
21 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(xbt_graph, xbt, "Graph");
25 /** @brief Constructor
28 xbt_graph_t xbt_graph_new_graph(unsigned short int directed, void *data)
30 xbt_graph_t graph = NULL;
31 graph = xbt_new0(struct xbt_graph, 1);
32 graph->directed = directed;
34 graph->nodes = xbt_dynar_new(sizeof(xbt_node_t), NULL);
35 graph->edges = xbt_dynar_new(sizeof(xbt_edge_t), NULL);
40 /** @brief add a node to the given graph */
41 xbt_node_t xbt_graph_new_node(xbt_graph_t g, void *data)
43 xbt_node_t node = NULL;
44 node = xbt_new0(struct xbt_node, 1);
47 /* only the "out" field is used */
48 node->in = xbt_dynar_new(sizeof(xbt_edge_t), NULL);
50 node->out = xbt_dynar_new(sizeof(xbt_edge_t), NULL);
51 node->position_x = -1.0;
52 node->position_y = -1.0;
54 xbt_dynar_push(g->nodes, &node);
59 /** @brief add an edge to the given graph */
60 xbt_edge_t xbt_graph_new_edge(xbt_graph_t g,
61 xbt_node_t src, xbt_node_t dst, void *data)
63 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(g->edges, &edge);
81 xbt_edge_t xbt_graph_get_edge(xbt_graph_t g, xbt_node_t src, xbt_node_t dst)
86 xbt_dynar_foreach(src->out, cursor, edge) {
87 DEBUG3("%p = %p--%p", edge, edge->src, edge->dst);
88 if ((edge->src == src) && (edge->dst == dst))
92 xbt_dynar_foreach(src->out, cursor, edge) {
93 DEBUG3("%p = %p--%p", edge, edge->src, edge->dst);
94 if ((edge->dst == src) && (edge->src == dst))
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)
134 unsigned int cursor = 0;
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)
159 (*graph_free_function) (g->data);
166 /** @brief remove the given node from the given graph */
167 void xbt_graph_free_node(xbt_graph_t g, xbt_node_t n,
168 void_f_pvoid_t node_free_function,
169 void_f_pvoid_t edge_free_function)
173 unsigned int cursor = 0;
174 xbt_node_t node = NULL;
175 xbt_edge_t edge = NULL;
177 nbr = xbt_dynar_length(g->edges);
179 for (i = 0; i < nbr; i++) {
180 xbt_dynar_get_cpy(g->edges, cursor, &edge);
182 if ((edge->dst == n) || (edge->src == n)) {
183 xbt_graph_free_edge(g, edge, edge_free_function);
188 if ((node_free_function) && (n->data))
189 (*node_free_function) (n->data);
192 xbt_dynar_foreach(g->nodes, cursor, node)
194 xbt_dynar_cursor_rm(g->nodes, &cursor);
196 xbt_dynar_free(&(n->in));
197 xbt_dynar_free(&(n->out));
204 /** @brief remove the given edge from the given graph */
205 void xbt_graph_free_edge(xbt_graph_t g, xbt_edge_t e,
206 void_f_pvoid_t free_function)
209 unsigned int cursor = 0;
210 xbt_edge_t edge = NULL;
212 if ((free_function) && (e->data))
213 (*free_function) (e->data);
215 xbt_dynar_foreach(g->edges, cursor, edge) {
218 idx = __xbt_find_in_dynar(edge->dst->in, edge);
219 xbt_dynar_remove_at(edge->dst->in, idx, NULL);
220 } else { /* only the out field is used */
221 idx = __xbt_find_in_dynar(edge->dst->out, edge);
222 xbt_dynar_remove_at(edge->dst->out, idx, NULL);
225 idx = __xbt_find_in_dynar(edge->src->out, edge);
226 xbt_dynar_remove_at(edge->src->out, idx, NULL);
228 xbt_dynar_cursor_rm(g->edges, &cursor);
235 int __xbt_find_in_dynar(xbt_dynar_t dynar, void *p)
238 unsigned int cursor = 0;
241 xbt_dynar_foreach(dynar, cursor, tmp) {
248 /** @brief Retrieve the graph's nodes as a dynar */
249 xbt_dynar_t xbt_graph_get_nodes(xbt_graph_t g)
254 /** @brief Retrieve the graph's edges as a dynar */
255 xbt_dynar_t xbt_graph_get_edges(xbt_graph_t g)
260 /** @brief Retrieve the node at the source of the given edge */
261 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)
272 /** @brief Retrieve the outgoing edges of the given node */
273 xbt_dynar_t xbt_graph_node_get_outedges(xbt_node_t n)
278 /** @brief Set the weight of the given edge */
279 void xbt_graph_edge_set_length(xbt_edge_t e, double length)
285 double xbt_graph_edge_get_length(xbt_edge_t e)
291 /** @brief construct the adjacency matrix corresponding to the given graph
293 * The weights are the distances between nodes
295 double *xbt_graph_get_length_matrix(xbt_graph_t g)
297 unsigned int cursor = 0;
298 unsigned int in_cursor = 0;
299 unsigned long idx, i;
301 xbt_edge_t edge = NULL;
302 xbt_node_t node = NULL;
305 # define D(u,v) d[(u)*n+(v)]
306 n = xbt_dynar_length(g->nodes);
308 d = (double *) xbt_new0(double, n * n);
310 for (i = 0; i < n * n; i++) {
314 xbt_dynar_foreach(g->nodes, cursor, node) {
316 D(cursor, cursor) = 0;
318 xbt_dynar_foreach(node->out, in_cursor, edge) {
319 if (edge->dst == node)
320 idx = __xbt_find_in_dynar(g->nodes, edge->src);
321 else /*case of undirected graphs */
322 idx = __xbt_find_in_dynar(g->nodes, edge->dst);
323 D(cursor, idx) = edge->length;
332 /** @brief Floyd-Warshall algorithm for shortest path finding
336 * The Floyd–Warshall algorithm takes as input an adjacency matrix
337 * representation of a weighted, directed graph (V, E). The weight of a
338 * path between two vertices is the sum of the weights of the edges along
339 * that path. The edges E of the graph may have negative weights, but the
340 * graph must not have any negative weight cycles. The algorithm computes,
341 * for each pair of vertices, the minimum weight among all paths between
342 * the two vertices. The running time complexity is Θ(|V|3).
344 void xbt_floyd_algorithm(xbt_graph_t g, double *adj, double *d,
347 unsigned long i, j, k;
349 n = xbt_dynar_length(g->nodes);
351 # define D(u,v) d[(u)*n+(v)]
352 # define P(u,v) p[(u)*n+(v)]
354 for (i = 0; i < n * n; i++) {
359 for (i = 0; i < n; i++) {
360 for (j = 0; j < n; j++) {
362 P(i, j) = *((xbt_node_t *) xbt_dynar_get_ptr(g->nodes, i));
367 for (k = 0; k < n; k++) {
368 for (i = 0; i < n; i++) {
369 for (j = 0; j < n; j++) {
370 if ((D(i, k) != -1) && (D(k, j) != -1)) {
371 if ((D(i, j) == -1) || (D(i, j) > D(i, k) + D(k, j))) {
372 D(i, j) = D(i, k) + D(k, j);
386 /** @brief computes all-pairs shortest paths */
387 xbt_node_t *xbt_graph_shortest_paths(xbt_graph_t g)
391 unsigned long i, j, k;
397 # define P(u,v) p[(u)*n+(v)]
398 # define R(u,v) r[(u)*n+(v)]
400 n = xbt_dynar_length(g->nodes);
401 adj = xbt_graph_get_length_matrix(g);
402 d = xbt_new0(double, n * n);
403 p = xbt_new0(xbt_node_t, n * n);
404 r = xbt_new0(xbt_node_t, n * n);
406 xbt_floyd_algorithm(g, adj, d, p);
408 for (i = 0; i < n; i++) {
409 for (j = 0; j < n; j++) {
412 while ((P(i, k)) && (__xbt_find_in_dynar(g->nodes, P(i, k)) != i)) {
413 k = __xbt_find_in_dynar(g->nodes, P(i, k));
417 R(i, j) = *((xbt_node_t *) xbt_dynar_get_ptr(g->nodes, k));
430 /** @brief Extract a spanning tree of the given graph */
431 xbt_edge_t *xbt_graph_spanning_tree_prim(xbt_graph_t g)
434 int tree_size_max = xbt_dynar_length(g->nodes) - 1;
435 xbt_edge_t *tree = xbt_new0(xbt_edge_t, tree_size_max);
437 xbt_node_t node = NULL;
438 xbt_dynar_t edge_list = NULL;
439 xbt_heap_t heap = xbt_heap_new(10, NULL);
442 xbt_assert0(!(g->directed),
443 "Spanning trees do not make sense on directed graphs");
445 xbt_dynar_foreach(g->nodes, cursor, node) {
446 node->xbtdata = NULL;
449 node = xbt_dynar_getfirst_as(g->nodes, xbt_node_t);
450 node->xbtdata = (void *) 1;
451 edge_list = node->out;
452 xbt_dynar_foreach(edge_list, cursor, e)
453 xbt_heap_push(heap, e, -(e->length));
455 while ((edge = xbt_heap_pop(heap))) {
456 if ((edge->src->xbtdata) && (edge->dst->xbtdata))
458 tree[tree_size++] = edge;
459 if (!(edge->src->xbtdata)) {
460 edge->src->xbtdata = (void *) 1;
461 edge_list = edge->src->out;
462 xbt_dynar_foreach(edge_list, cursor, e) {
463 xbt_heap_push(heap, e, -(e->length));
466 edge->dst->xbtdata = (void *) 1;
467 edge_list = edge->dst->out;
468 xbt_dynar_foreach(edge_list, cursor, e) {
469 xbt_heap_push(heap, e, -(e->length));
472 if (tree_size == tree_size_max)
481 /** @brief Topological sort on the given graph
485 * In graph theory, a topological sort of a directed acyclic graph (DAG) is
486 * a linear ordering of its nodes which is compatible with the partial
487 * order R induced on the nodes where x comes before y (xRy) if there's a
488 * directed path from x to y in the DAG. An equivalent definition is that
489 * each node comes before all nodes to which it has edges. Every DAG has at
490 * least one topological sort, and may have many.
492 xbt_node_t *xbt_graph_topo_sort(xbt_graph_t g)
501 n = xbt_dynar_length(g->nodes);
504 sorted = xbt_malloc(n * sizeof(xbt_node_t));
506 xbt_dynar_foreach(g->nodes, cursor, node)
507 node->xbtdata = xbt_new0(int, 1);
509 xbt_dynar_foreach(g->nodes, cursor, node)
510 xbt_graph_depth_visit(g, node, sorted, &idx);
512 xbt_dynar_foreach(g->nodes, cursor, node) {
514 node->xbtdata = NULL;
520 /** @brief First-depth graph traversal */
521 void xbt_graph_depth_visit(xbt_graph_t g, xbt_node_t n,
522 xbt_node_t * sorted, int *idx)
527 if (*((int *) (n->xbtdata)) == ALREADY_EXPLORED)
529 else if (*((int *) (n->xbtdata)) == CURRENTLY_EXPLORING)
530 THROW0(0, 0, "There is a cycle");
532 *((int *) (n->xbtdata)) = CURRENTLY_EXPLORING;
534 xbt_dynar_foreach(n->out, cursor, edge) {
535 xbt_graph_depth_visit(g, edge->dst, sorted, idx);
538 *((int *) (n->xbtdata)) = ALREADY_EXPLORED;
539 sorted[(*idx)--] = n;
543 /********************* Import and Export ******************/
544 static xbt_graph_t parsed_graph = NULL;
545 static xbt_dict_t parsed_nodes = NULL;
547 static void *(*__parse_node_label_and_data) (xbt_node_t, const char *,
548 const char *) = NULL;
549 static void *(*__parse_edge_label_and_data) (xbt_edge_t, const char *,
550 const char *) = NULL;
552 static void __parse_graph_begin(void)
555 if (A_graphxml_graph_isDirected == A_graphxml_graph_isDirected_true)
556 parsed_graph = xbt_graph_new_graph(1, NULL);
558 parsed_graph = xbt_graph_new_graph(0, NULL);
560 parsed_nodes = xbt_dict_new();
563 static void __parse_graph_end(void)
565 xbt_dict_free(&parsed_nodes);
569 static void __parse_node(void)
571 xbt_node_t node = xbt_graph_new_node(parsed_graph, NULL);
573 DEBUG1("<node name=\"%s\"/>", A_graphxml_node_name);
574 if (__parse_node_label_and_data)
575 node->data = __parse_node_label_and_data(node, A_graphxml_node_label,
576 A_graphxml_node_data);
577 xbt_graph_parse_get_double(&(node->position_x), A_graphxml_node_position_x);
578 xbt_graph_parse_get_double(&(node->position_y), A_graphxml_node_position_y);
580 xbt_dict_set(parsed_nodes, A_graphxml_node_name, (void *) node, NULL);
583 static void __parse_edge(void)
585 xbt_edge_t edge = xbt_graph_new_edge(parsed_graph,
586 xbt_dict_get(parsed_nodes,
587 A_graphxml_edge_source),
588 xbt_dict_get(parsed_nodes,
589 A_graphxml_edge_target),
592 if (__parse_edge_label_and_data)
593 edge->data = __parse_edge_label_and_data(edge, A_graphxml_edge_label,
594 A_graphxml_edge_data);
596 xbt_graph_parse_get_double(&(edge->length), A_graphxml_edge_length);
598 DEBUG3("<edge source=\"%s\" target=\"%s\" length=\"%f\"/>",
599 (char *) (edge->src)->data,
600 (char *) (edge->dst)->data, xbt_graph_edge_get_length(edge));
603 /** @brief Import a graph from a file following the GraphXML format */
604 xbt_graph_t xbt_graph_read(const char *filename,
605 void *(*node_label_and_data) (xbt_node_t,
608 void *(*edge_label_and_data) (xbt_edge_t,
613 xbt_graph_t graph = NULL;
615 __parse_node_label_and_data = node_label_and_data;
616 __parse_edge_label_and_data = edge_label_and_data;
618 xbt_graph_parse_reset_parser();
620 STag_graphxml_graph_fun = __parse_graph_begin;
621 ETag_graphxml_graph_fun = __parse_graph_end;
622 ETag_graphxml_node_fun = __parse_node;
623 ETag_graphxml_edge_fun = __parse_edge;
625 xbt_graph_parse_open(filename);
626 xbt_assert1((!(*xbt_graph_parse) ()), "Parse error in %s", filename);
627 xbt_graph_parse_close();
629 graph = parsed_graph;
635 /** @brief Export the given graph in the GraphViz formatting for visualization */
636 void xbt_graph_export_graphviz(xbt_graph_t g, const char *filename,
637 const char *(node_name) (xbt_node_t),
638 const char *(edge_name) (xbt_edge_t))
640 unsigned int cursor = 0;
641 xbt_node_t node = NULL;
642 xbt_edge_t edge = NULL;
644 const char *name = NULL;
646 file = fopen(filename, "w");
647 xbt_assert1(file, "Failed to open %s \n", filename);
650 fprintf(file, "digraph test {\n");
652 fprintf(file, "graph test {\n");
654 fprintf(file, " graph [overlap=scale]\n");
656 fprintf(file, " node [shape=box, style=filled]\n");
658 " node [width=.3, height=.3, style=filled, color=skyblue]\n\n");
660 xbt_dynar_foreach(g->nodes, cursor, node) {
661 fprintf(file, " \"%p\" ", node);
662 if ((node_name) && ((name = node_name(node))))
663 fprintf(file, "[label=\"%s\"]", name);
664 fprintf(file, ";\n");
666 xbt_dynar_foreach(g->edges, cursor, edge) {
668 fprintf(file, " \"%p\" -> \"%p\"", edge->src, edge->dst);
670 fprintf(file, " \"%p\" -- \"%p\"", edge->src, edge->dst);
671 if ((edge_name) && ((name = edge_name(edge))))
672 fprintf(file, "[label=\"%s\"]", name);
673 fprintf(file, ";\n");
675 fprintf(file, "}\n");
679 /** @brief Export the given graph in the GraphXML format */
680 void xbt_graph_export_graphxml(xbt_graph_t g, const char *filename,
681 const char *(node_name) (xbt_node_t),
682 const char *(edge_name) (xbt_edge_t),
683 const char *(node_data_print) (void *),
684 const char *(edge_data_print) (void *))
686 unsigned int cursor = 0;
687 xbt_node_t node = NULL;
688 xbt_edge_t edge = NULL;
690 const char *name = NULL;
692 file = fopen(filename, "w");
693 xbt_assert1(file, "Failed to open %s \n", filename);
695 fprintf(file, "<?xml version='1.0'?>\n");
696 fprintf(file, "<!DOCTYPE graph SYSTEM \"graphxml.dtd\">\n");
698 fprintf(file, "<graph isDirected=\"true\">\n");
700 fprintf(file, "<graph isDirected=\"false\">\n");
701 xbt_dynar_foreach(g->nodes, cursor, node) {
702 fprintf(file, " <node name=\"%p\" ", node);
703 if ((node_name) && ((name = node_name(node))))
704 fprintf(file, "label=\"%s\" ", name);
705 if ((node_data_print) && ((name = node_data_print(node->data))))
706 fprintf(file, "data=\"%s\" ", name);
707 fprintf(file, ">\n");
709 xbt_dynar_foreach(g->edges, cursor, edge) {
710 fprintf(file, " <edge source=\"%p\" target =\"%p\" ",
711 edge->src, edge->dst);
712 if ((edge_name) && ((name = edge_name(edge))))
713 fprintf(file, "label=\"%s\" ", name);
714 if (edge->length >= 0.0)
715 fprintf(file, "length=\"%g\" ", edge->length);
716 if ((edge_data_print) && ((name = edge_data_print(edge->data))))
717 fprintf(file, "data=\"%s\" ", name);
718 fprintf(file, ">\n");
720 fprintf(file, "</graph>\n");