1 /* a generic graph library. */
3 /* Copyright (c) 2006, 2007, 2008, 2009, 2010. The SimGrid Team.
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. */
9 #include "simgrid_config.h" /* getline */
12 #include "xbt/sysdep.h"
14 #include "xbt/graph.h"
15 #include "graph_private.h"
16 #include "xbt/graphxml_parse.h"
24 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(xbt_graph, xbt, "Graph");
28 /** @brief Constructor
31 xbt_graph_t xbt_graph_new_graph(unsigned short int directed, void *data)
33 xbt_graph_t graph = NULL;
34 graph = xbt_new0(struct xbt_graph, 1);
35 graph->directed = directed;
37 graph->nodes = xbt_dynar_new(sizeof(xbt_node_t), NULL);
38 graph->edges = xbt_dynar_new(sizeof(xbt_edge_t), NULL);
43 /** @brief add a node to the given graph */
44 xbt_node_t xbt_graph_new_node(xbt_graph_t g, void *data)
46 xbt_node_t node = NULL;
47 node = xbt_new0(struct xbt_node, 1);
50 /* only the "out" field is used */
51 node->in = xbt_dynar_new(sizeof(xbt_edge_t), NULL);
53 node->out = xbt_dynar_new(sizeof(xbt_edge_t), NULL);
54 node->position_x = -1.0;
55 node->position_y = -1.0;
57 xbt_dynar_push(g->nodes, &node);
62 /** @brief add an edge to the given graph */
63 xbt_edge_t xbt_graph_new_edge(xbt_graph_t g,
64 xbt_node_t src, xbt_node_t dst, void *data)
66 xbt_edge_t edge = NULL;
68 edge = xbt_new0(struct xbt_edge, 1);
69 xbt_dynar_push(src->out, &edge);
71 xbt_dynar_push(dst->in, &edge);
72 else /* only the "out" field is used */
73 xbt_dynar_push(dst->out, &edge);
79 xbt_dynar_push(g->edges, &edge);
84 /** @brief Get the edge connecting src and dst */
85 xbt_edge_t xbt_graph_get_edge(xbt_graph_t g, xbt_node_t src,
91 xbt_dynar_foreach(src->out, cursor, edge) {
92 XBT_DEBUG("%p = %p--%p", edge, edge->src, edge->dst);
93 if ((edge->src == src) && (edge->dst == dst))
97 xbt_dynar_foreach(src->out, cursor, edge) {
98 XBT_DEBUG("%p = %p--%p", edge, edge->src, edge->dst);
99 if ((edge->dst == src) && (edge->src == dst))
106 /** @brief Get the user data associated to a node */
107 void *xbt_graph_node_get_data(xbt_node_t node)
112 /** @brief Set the user data associated to a node */
113 void xbt_graph_node_set_data(xbt_node_t node, void *data)
118 /** @brief Get the user data associated to a edge */
119 void *xbt_graph_edge_get_data(xbt_edge_t edge)
124 /** @brief Set the user data associated to a edge */
125 void xbt_graph_edge_set_data(xbt_edge_t edge, void *data)
130 /** @brief Destructor
131 * @param g: poor victim
132 * @param node_free_function: function to use to free data associated to each node
133 * @param edge_free_function: function to use to free data associated to each edge
134 * @param graph_free_function: function to use to free data associated to g
136 * Free the graph structure.
138 void xbt_graph_free_graph(xbt_graph_t g,
139 void_f_pvoid_t node_free_function,
140 void_f_pvoid_t edge_free_function,
141 void_f_pvoid_t graph_free_function)
147 xbt_dynar_foreach(g->edges, cursor, edge) {
148 if (edge_free_function)
149 edge_free_function(edge->data);
152 xbt_dynar_free(&(g->edges));
154 xbt_dynar_foreach(g->nodes, cursor, node) {
155 xbt_dynar_free(&(node->out));
156 xbt_dynar_free(&(node->in));
157 if (node_free_function)
158 node_free_function(node->data);
161 xbt_dynar_free(&(g->nodes));
163 if (graph_free_function)
164 graph_free_function(g->data);
166 xbt_graph_parse_lex_destroy();
170 /** @brief remove the given node from the given graph */
171 void xbt_graph_free_node(xbt_graph_t g, xbt_node_t n,
172 void_f_pvoid_t node_free_function,
173 void_f_pvoid_t edge_free_function)
177 unsigned int cursor = 0;
178 xbt_node_t node = NULL;
179 xbt_edge_t edge = NULL;
181 nbr = xbt_dynar_length(g->edges);
183 for (i = 0; i < nbr; i++) {
184 xbt_dynar_get_cpy(g->edges, cursor, &edge);
186 if ((edge->dst == n) || (edge->src == n)) {
187 xbt_graph_free_edge(g, edge, edge_free_function);
192 if ((node_free_function) && (n->data))
193 node_free_function(n->data);
196 xbt_dynar_foreach(g->nodes, cursor, node)
198 xbt_dynar_cursor_rm(g->nodes, &cursor);
200 xbt_dynar_free(&(n->in));
201 xbt_dynar_free(&(n->out));
208 /** @brief remove the given edge from the given graph */
209 void xbt_graph_free_edge(xbt_graph_t g, xbt_edge_t e,
210 void_f_pvoid_t free_function)
213 unsigned int cursor = 0;
214 xbt_edge_t edge = NULL;
216 if ((free_function) && (e->data))
217 free_function(e->data);
219 xbt_dynar_foreach(g->edges, cursor, edge) {
222 idx = __xbt_find_in_dynar(edge->dst->in, edge);
223 xbt_dynar_remove_at(edge->dst->in, idx, NULL);
224 } else { /* only the out field is used */
225 idx = __xbt_find_in_dynar(edge->dst->out, edge);
226 xbt_dynar_remove_at(edge->dst->out, idx, NULL);
229 idx = __xbt_find_in_dynar(edge->src->out, edge);
230 xbt_dynar_remove_at(edge->src->out, idx, NULL);
232 xbt_dynar_cursor_rm(g->edges, &cursor);
239 int __xbt_find_in_dynar(xbt_dynar_t dynar, void *p)
242 unsigned int cursor = 0;
245 xbt_dynar_foreach(dynar, cursor, tmp) {
252 /** @brief Retrieve the graph's nodes as a dynar */
253 xbt_dynar_t xbt_graph_get_nodes(xbt_graph_t g)
258 /** @brief Retrieve the graph's edges as a dynar */
259 xbt_dynar_t xbt_graph_get_edges(xbt_graph_t g)
264 /** @brief Retrieve the node at the source of the given edge */
265 xbt_node_t xbt_graph_edge_get_source(xbt_edge_t e)
270 /** @brief Retrieve the node being the target of the given edge */
271 xbt_node_t xbt_graph_edge_get_target(xbt_edge_t e)
276 /** @brief Retrieve the outgoing edges of the given node */
277 xbt_dynar_t xbt_graph_node_get_outedges(xbt_node_t n)
282 /** @brief Set the weight of the given edge */
283 void xbt_graph_edge_set_length(xbt_edge_t e, double length)
289 /** @brief Get the length of a edge */
290 double xbt_graph_edge_get_length(xbt_edge_t edge)
296 /** @brief construct the adjacency matrix corresponding to the given graph
298 * The weights are the distances between nodes
300 double *xbt_graph_get_length_matrix(xbt_graph_t g)
302 unsigned int cursor = 0;
303 unsigned int in_cursor = 0;
304 unsigned long idx, i;
306 xbt_edge_t edge = NULL;
307 xbt_node_t node = NULL;
310 # define D(u,v) d[(u)*n+(v)]
311 n = xbt_dynar_length(g->nodes);
313 d = (double *) xbt_new0(double, n * n);
315 for (i = 0; i < n * n; i++) {
319 xbt_dynar_foreach(g->nodes, cursor, node) {
321 D(cursor, cursor) = 0;
323 xbt_dynar_foreach(node->out, in_cursor, edge) {
324 if (edge->dst == node)
325 idx = __xbt_find_in_dynar(g->nodes, edge->src);
326 else /*case of undirected graphs */
327 idx = __xbt_find_in_dynar(g->nodes, edge->dst);
328 D(cursor, idx) = edge->length;
337 /** @brief Floyd-Warshall algorithm for shortest path finding
341 * The Floyd–Warshall algorithm takes as input an adjacency matrix
342 * representation of a weighted, directed graph (V, E). The weight of a
343 * path between two vertices is the sum of the weights of the edges along
344 * that path. The edges E of the graph may have negative weights, but the
345 * graph must not have any negative weight cycles. The algorithm computes,
346 * for each pair of vertices, the minimum weight among all paths between
347 * the two vertices. The running time complexity is Θ(|V|3).
349 void xbt_floyd_algorithm(xbt_graph_t g, double *adj, double *d,
352 unsigned long i, j, k;
354 n = xbt_dynar_length(g->nodes);
356 # define D(u,v) d[(u)*n+(v)]
357 # define P(u,v) p[(u)*n+(v)]
359 for (i = 0; i < n * n; i++) {
364 for (i = 0; i < n; i++) {
365 for (j = 0; j < n; j++) {
367 P(i, j) = *((xbt_node_t *) xbt_dynar_get_ptr(g->nodes, i));
372 for (k = 0; k < n; k++) {
373 for (i = 0; i < n; i++) {
374 for (j = 0; j < n; j++) {
375 if ((D(i, k) != -1) && (D(k, j) != -1)) {
376 if ((D(i, j) == -1) || (D(i, j) > D(i, k) + D(k, j))) {
377 D(i, j) = D(i, k) + D(k, j);
391 /** @brief computes all-pairs shortest paths */
392 xbt_node_t *xbt_graph_shortest_paths(xbt_graph_t g)
396 unsigned long i, j, k;
402 # define P(u,v) p[(u)*n+(v)]
403 # define R(u,v) r[(u)*n+(v)]
405 n = xbt_dynar_length(g->nodes);
406 adj = xbt_graph_get_length_matrix(g);
407 d = xbt_new0(double, n * n);
408 p = xbt_new0(xbt_node_t, n * n);
409 r = xbt_new0(xbt_node_t, n * n);
411 xbt_floyd_algorithm(g, adj, d, p);
413 for (i = 0; i < n; i++) {
414 for (j = 0; j < n; j++) {
417 while ((P(i, k)) && (__xbt_find_in_dynar(g->nodes, P(i, k)) != i)) {
418 k = __xbt_find_in_dynar(g->nodes, P(i, k));
422 R(i, j) = *((xbt_node_t *) xbt_dynar_get_ptr(g->nodes, k));
435 /** @brief Extract a spanning tree of the given graph */
436 xbt_edge_t *xbt_graph_spanning_tree_prim(xbt_graph_t g)
439 int tree_size_max = xbt_dynar_length(g->nodes) - 1;
440 xbt_edge_t *tree = xbt_new0(xbt_edge_t, tree_size_max);
442 xbt_node_t node = NULL;
443 xbt_dynar_t edge_list = NULL;
444 xbt_heap_t heap = xbt_heap_new(10, NULL);
447 xbt_assert(!(g->directed),
448 "Spanning trees do not make sense on directed graphs");
450 xbt_dynar_foreach(g->nodes, cursor, node) {
451 node->xbtdata = NULL;
454 node = xbt_dynar_getfirst_as(g->nodes, xbt_node_t);
455 node->xbtdata = (void *) 1;
456 edge_list = node->out;
457 xbt_dynar_foreach(edge_list, cursor, e)
458 xbt_heap_push(heap, e, -(e->length));
460 while ((edge = xbt_heap_pop(heap))) {
461 if ((edge->src->xbtdata) && (edge->dst->xbtdata))
463 tree[tree_size++] = edge;
464 if (!(edge->src->xbtdata)) {
465 edge->src->xbtdata = (void *) 1;
466 edge_list = edge->src->out;
467 xbt_dynar_foreach(edge_list, cursor, e) {
468 xbt_heap_push(heap, e, -(e->length));
471 edge->dst->xbtdata = (void *) 1;
472 edge_list = edge->dst->out;
473 xbt_dynar_foreach(edge_list, cursor, e) {
474 xbt_heap_push(heap, e, -(e->length));
477 if (tree_size == tree_size_max)
486 /** @brief Topological sort on the given graph
490 * In graph theory, a topological sort of a directed acyclic graph (DAG) is
491 * a linear ordering of its nodes which is compatible with the partial
492 * order R induced on the nodes where x comes before y (xRy) if there's a
493 * directed path from x to y in the DAG. An equivalent definition is that
494 * each node comes before all nodes to which it has edges. Every DAG has at
495 * least one topological sort, and may have many.
497 xbt_node_t *xbt_graph_topo_sort(xbt_graph_t g)
506 n = xbt_dynar_length(g->nodes);
509 sorted = xbt_malloc(n * sizeof(xbt_node_t));
511 xbt_dynar_foreach(g->nodes, cursor, node)
512 node->xbtdata = xbt_new0(int, 1);
514 xbt_dynar_foreach(g->nodes, cursor, node)
515 xbt_graph_depth_visit(g, node, sorted, &idx);
517 xbt_dynar_foreach(g->nodes, cursor, node) {
519 node->xbtdata = NULL;
525 /** @brief First-depth graph traversal */
526 void xbt_graph_depth_visit(xbt_graph_t g, xbt_node_t n,
527 xbt_node_t * sorted, int *idx)
532 if (*((int *) (n->xbtdata)) == ALREADY_EXPLORED)
534 else if (*((int *) (n->xbtdata)) == CURRENTLY_EXPLORING)
535 THROWF(0, 0, "There is a cycle");
537 *((int *) (n->xbtdata)) = CURRENTLY_EXPLORING;
539 xbt_dynar_foreach(n->out, cursor, edge) {
540 xbt_graph_depth_visit(g, edge->dst, sorted, idx);
543 *((int *) (n->xbtdata)) = ALREADY_EXPLORED;
544 sorted[(*idx)--] = n;
548 /********************* Import and Export ******************/
549 static xbt_graph_t parsed_graph = NULL;
550 static xbt_dict_t parsed_nodes = NULL;
552 static void *(*__parse_node_label_and_data) (xbt_node_t, const char *,
553 const char *) = NULL;
554 static void *(*__parse_edge_label_and_data) (xbt_edge_t, const char *,
555 const char *) = NULL;
557 static void __parse_graph_begin(void)
559 XBT_DEBUG("<graph>");
560 if (A_graphxml_graph_isDirected == A_graphxml_graph_isDirected_true)
561 parsed_graph = xbt_graph_new_graph(1, NULL);
563 parsed_graph = xbt_graph_new_graph(0, NULL);
565 parsed_nodes = xbt_dict_new_homogeneous(NULL);
568 static void __parse_graph_end(void)
570 xbt_dict_free(&parsed_nodes);
571 XBT_DEBUG("</graph>");
574 static void __parse_node(void)
576 xbt_node_t node = xbt_graph_new_node(parsed_graph, NULL);
578 XBT_DEBUG("<node name=\"%s\"/>", A_graphxml_node_name);
579 if (__parse_node_label_and_data)
580 node->data = __parse_node_label_and_data(node, A_graphxml_node_label,
581 A_graphxml_node_data);
582 node->position_x = xbt_graph_parse_get_double(A_graphxml_node_position___x);
583 node->position_y = xbt_graph_parse_get_double(A_graphxml_node_position___y);
585 xbt_dict_set(parsed_nodes, A_graphxml_node_name, (void *) node, NULL);
588 static void __parse_edge(void)
590 xbt_edge_t edge = xbt_graph_new_edge(parsed_graph,
591 xbt_dict_get(parsed_nodes,
592 A_graphxml_edge_source),
593 xbt_dict_get(parsed_nodes,
594 A_graphxml_edge_target),
597 if (__parse_edge_label_and_data)
598 edge->data = __parse_edge_label_and_data(edge, A_graphxml_edge_label,
599 A_graphxml_edge_data);
601 edge->length = xbt_graph_parse_get_double(A_graphxml_edge_length);
603 XBT_DEBUG("<edge source=\"%s\" target=\"%s\" length=\"%f\"/>",
604 (char *) (edge->src)->data,
605 (char *) (edge->dst)->data, xbt_graph_edge_get_length(edge));
608 /** @brief Import a graph from a file following the GraphXML format */
609 xbt_graph_t xbt_graph_read(const char *filename,
610 void *(*node_label_and_data) (xbt_node_t,
613 void *(*edge_label_and_data) (xbt_edge_t,
618 xbt_graph_t graph = NULL;
620 __parse_node_label_and_data = node_label_and_data;
621 __parse_edge_label_and_data = edge_label_and_data;
623 xbt_graph_parse_reset_parser();
625 STag_graphxml_graph_fun = __parse_graph_begin;
626 ETag_graphxml_graph_fun = __parse_graph_end;
627 ETag_graphxml_node_fun = __parse_node;
628 ETag_graphxml_edge_fun = __parse_edge;
630 xbt_graph_parse_open(filename);
631 _XBT_GNUC_UNUSED int res;
632 res = xbt_graph_parse();
633 xbt_assert(!res, "Parse error in %s", filename);
634 xbt_graph_parse_close();
636 graph = parsed_graph;
642 /** @brief Export the given graph in the GraphViz formatting for visualization */
643 void xbt_graph_export_graphviz(xbt_graph_t g, const char *filename,
644 const char *(node_name) (xbt_node_t),
645 const char *(edge_name) (xbt_edge_t))
647 unsigned int cursor = 0;
648 xbt_node_t node = NULL;
649 xbt_edge_t edge = NULL;
651 const char *name = NULL;
653 file = fopen(filename, "w");
654 xbt_assert(file, "Failed to open %s \n", filename);
657 fprintf(file, "digraph test {\n");
659 fprintf(file, "graph test {\n");
661 fprintf(file, " graph [overlap=scale]\n");
663 fprintf(file, " node [shape=box, style=filled]\n");
665 " node [width=.3, height=.3, style=filled, color=skyblue]\n\n");
667 xbt_dynar_foreach(g->nodes, cursor, node) {
669 fprintf(file, " \"%s\";\n", node_name(node));
671 fprintf(file, " \"%p\";\n", node);
674 xbt_dynar_foreach(g->edges, cursor, edge) {
676 const char *c_dir = "->";
677 const char *c_ndir = "--";
683 const char *src_name, *dst_name;
685 src_name = node_name(edge->src);
686 dst_name = node_name(edge->dst);
687 fprintf(file, " \"%s\" %s \"%s\"", src_name, c, dst_name);
689 fprintf(file, " \"%p\" %s \"%p\"", edge->src, c, edge->dst);
692 if ((edge_name) && ((name = edge_name(edge))))
693 fprintf(file, "[label=\"%s\"]", name);
694 fprintf(file, ";\n");
696 fprintf(file, "}\n");
700 /** @brief Export the given graph in the GraphXML format */
701 void xbt_graph_export_graphxml(xbt_graph_t g, const char *filename,
702 const char *(node_name) (xbt_node_t),
703 const char *(edge_name) (xbt_edge_t),
704 const char *(node_data_print) (void *),
705 const char *(edge_data_print) (void *))
707 unsigned int cursor = 0;
708 xbt_node_t node = NULL;
709 xbt_edge_t edge = NULL;
711 const char *name = NULL;
713 file = fopen(filename, "w");
714 xbt_assert(file, "Failed to open %s \n", filename);
716 fprintf(file, "<?xml version='1.0'?>\n");
717 fprintf(file, "<!DOCTYPE graph SYSTEM \"graphxml.dtd\">\n");
719 fprintf(file, "<graph isDirected=\"true\">\n");
721 fprintf(file, "<graph isDirected=\"false\">\n");
722 xbt_dynar_foreach(g->nodes, cursor, node) {
723 fprintf(file, " <node name=\"%p\" ", node);
724 if ((node_name) && ((name = node_name(node))))
725 fprintf(file, "label=\"%s\" ", name);
726 if ((node_data_print) && ((name = node_data_print(node->data))))
727 fprintf(file, "data=\"%s\" ", name);
728 fprintf(file, ">\n");
730 xbt_dynar_foreach(g->edges, cursor, edge) {
731 fprintf(file, " <edge source=\"%p\" target =\"%p\" ",
732 edge->src, edge->dst);
733 if ((edge_name) && ((name = edge_name(edge))))
734 fprintf(file, "label=\"%s\" ", name);
735 if (edge->length >= 0.0)
736 fprintf(file, "length=\"%g\" ", edge->length);
737 if ((edge_data_print) && ((name = edge_data_print(edge->data))))
738 fprintf(file, "data=\"%s\" ", name);
739 fprintf(file, ">\n");
741 fprintf(file, "</graph>\n");
745 /** @brief Load a graph from a file (in the SimGrid Graph format) */
746 xbt_graph_t xbt_graph_load (const char *filename)
750 file = fopen (filename, "r");
751 xbt_assert(file, "Failed to open %s \n", filename);
753 xbt_dict_t nodes_dict = xbt_dict_new_homogeneous(NULL);
754 xbt_graph_t ret = xbt_graph_new_graph (0, NULL);
756 //read the number of nodes
758 char *nnodes_str = NULL;
759 read = getline (&nnodes_str, &size, file);
761 THROWF(system_error, 0, "getline failed to read the number of nodes (errno = %d)", errno);
762 int i, nnodes = atoi (nnodes_str);
766 for (i = 0; i < nnodes; i++){
767 char *node_str = NULL;
768 read = getline (&node_str, &size, file);
770 THROWF(system_error, 0, "getline failed to read all nodes (errno = %d)", errno);
772 char *name = xbt_strdup (node_str);
773 xbt_str_subst (name, '\n', '\0', 0);
774 n = xbt_graph_new_node (ret, name);
775 xbt_dict_set (nodes_dict, name, n, NULL);
779 //read the number of edges
780 char *nedges_str = NULL;
781 read = getline (&nedges_str, &size, file);
783 THROWF(system_error, 0, "getline failed to read the number of edges (errno = %d)", errno);
784 int nedges = atoi (nedges_str);
788 for (i = 0; i < nedges; i++){
789 char *edge_str = NULL, edge_id[200], node_source[200], node_target[200];
790 read = getline (&edge_str, &size, file);
792 THROWF(system_error, 0, "getline failed to read all edges (errno = %d)", errno);
793 sscanf (edge_str, "%s %s %s", edge_id, node_source, node_target);
795 xbt_str_subst (edge_id, '\n', '\0', 0);
796 xbt_str_subst (node_source, '\n', '\0', 0);
797 xbt_str_subst (node_target, '\n', '\0', 0);
799 xbt_node_t source = xbt_dict_get (nodes_dict, node_source);
800 xbt_node_t target = xbt_dict_get (nodes_dict, node_target);
801 xbt_graph_new_edge (ret, source, target, xbt_strdup(edge_id));
803 xbt_dict_free (&nodes_dict);
807 /** @brief Save a graph from a file (in the SimGrid Graph format) */
808 void xbt_graph_save (xbt_graph_t span,
809 const char *filename,
810 const char *(nname) (xbt_node_t),
811 const char *(ename) (xbt_edge_t))
814 file = fopen(filename, "w");
815 xbt_assert(file, "Failed to open %s \n", filename);
817 xbt_dynar_t nodes = xbt_graph_get_nodes (span);
818 xbt_dynar_t edges = xbt_graph_get_edges (span);
821 fprintf (file, "%lu\n", xbt_dynar_length (nodes));
822 xbt_dynar_foreach (nodes, cpt, node) {
824 fprintf (file, "%s\n", nname(node));
826 fprintf (file, "%p\n", node);
829 fprintf (file, "%lu\n", xbt_dynar_length (edges));
831 xbt_dynar_foreach (edges, cpt, edge) {
832 xbt_node_t source = xbt_graph_edge_get_source (edge);
833 xbt_node_t target = xbt_graph_edge_get_target (edge);
836 fprintf (file, "%s %s %s\n", ename(edge), nname(source), nname(target));
838 fprintf (file, "%s %p %p\n", ename(edge), source, target);
842 fprintf (file, "%p %s %s\n", edge, nname(source), nname(target));
844 fprintf (file, "%p %p %p\n", edge, source, target);