-
-
-
-# undef P
-# undef D
-}
-
-/** @brief computes all-pairs shortest paths */
-xbt_node_t *xbt_graph_shortest_paths(xbt_graph_t g)
-{
- xbt_node_t *p;
- xbt_node_t *r;
- unsigned long i, j, k;
- unsigned long n;
-
- double *adj = NULL;
- double *d = NULL;
-
-# define P(u,v) p[(u)*n+(v)]
-# define R(u,v) r[(u)*n+(v)]
-
- n = xbt_dynar_length(g->nodes);
- adj = xbt_graph_get_length_matrix(g);
- d = xbt_new0(double, n * n);
- p = xbt_new0(xbt_node_t, n * n);
- r = xbt_new0(xbt_node_t, n * n);
-
- xbt_floyd_algorithm(g, adj, d, p);
-
- for (i = 0; i < n; i++) {
- for (j = 0; j < n; j++) {
- k = j;
-
- while ((P(i, k)) && (__xbt_find_in_dynar(g->nodes, P(i, k)) != i)) {
- k = __xbt_find_in_dynar(g->nodes, P(i, k));
- }
-
- if (P(i, j)) {
- R(i, j) = *((xbt_node_t *) xbt_dynar_get_ptr(g->nodes, k));
- }
- }
- }
-# undef R
-# undef P
-
- free(d);
- free(p);
- free(adj);
- return r;
-}
-
-/** @brief Extract a spanning tree of the given graph */
-xbt_edge_t *xbt_graph_spanning_tree_prim(xbt_graph_t g)
-{
- int tree_size = 0;
- int tree_size_max = xbt_dynar_length(g->nodes) - 1;
- xbt_edge_t *tree = xbt_new0(xbt_edge_t, tree_size_max);
- xbt_edge_t e, edge;
- xbt_node_t node = NULL;
- xbt_dynar_t edge_list = NULL;
- xbt_heap_t heap = xbt_heap_new(10, NULL);
- unsigned int cursor;
-
- xbt_assert(!(g->directed),
- "Spanning trees do not make sense on directed graphs");
-
- xbt_dynar_foreach(g->nodes, cursor, node) {
- node->xbtdata = NULL;
- }
-
- node = xbt_dynar_getfirst_as(g->nodes, xbt_node_t);
- node->xbtdata = (void *) 1;
- edge_list = node->out;
- xbt_dynar_foreach(edge_list, cursor, e)
- xbt_heap_push(heap, e, -(e->length));
-
- while ((edge = xbt_heap_pop(heap))) {
- if ((edge->src->xbtdata) && (edge->dst->xbtdata))
- continue;
- tree[tree_size++] = edge;
- if (!(edge->src->xbtdata)) {
- edge->src->xbtdata = (void *) 1;
- edge_list = edge->src->out;
- xbt_dynar_foreach(edge_list, cursor, e) {
- xbt_heap_push(heap, e, -(e->length));
- }
- } else {
- edge->dst->xbtdata = (void *) 1;
- edge_list = edge->dst->out;
- xbt_dynar_foreach(edge_list, cursor, e) {
- xbt_heap_push(heap, e, -(e->length));
- }
- }
- if (tree_size == tree_size_max)
- break;
- }
-
- xbt_heap_free(heap);
-
- return tree;
-}
-
-/** @brief Topological sort on the given graph
- *
- * From wikipedia:
- *
- * In graph theory, a topological sort of a directed acyclic graph (DAG) is
- * a linear ordering of its nodes which is compatible with the partial
- * order R induced on the nodes where x comes before y (xRy) if there's a
- * directed path from x to y in the DAG. An equivalent definition is that
- * each node comes before all nodes to which it has edges. Every DAG has at
- * least one topological sort, and may have many.
- */
-xbt_node_t *xbt_graph_topo_sort(xbt_graph_t g)
-{
-
- xbt_node_t *sorted;
- unsigned int cursor;
- int idx;
- xbt_node_t node;
- unsigned long n;
-
- n = xbt_dynar_length(g->nodes);
- idx = n - 1;
-
- sorted = xbt_malloc(n * sizeof(xbt_node_t));
-
- xbt_dynar_foreach(g->nodes, cursor, node)
- node->xbtdata = xbt_new0(int, 1);
-
- xbt_dynar_foreach(g->nodes, cursor, node)
- xbt_graph_depth_visit(g, node, sorted, &idx);
-
- xbt_dynar_foreach(g->nodes, cursor, node) {
- free(node->xbtdata);
- node->xbtdata = NULL;
- }
-
- return sorted;
-}
-
-/** @brief First-depth graph traversal */
-void xbt_graph_depth_visit(xbt_graph_t g, xbt_node_t n,
- xbt_node_t * sorted, int *idx)
-{
- unsigned int cursor;
- xbt_edge_t edge;
-
- if (*((int *) (n->xbtdata)) == ALREADY_EXPLORED)
- return;
- else if (*((int *) (n->xbtdata)) == CURRENTLY_EXPLORING)
- THROWF(0, 0, "There is a cycle");
- else {
- *((int *) (n->xbtdata)) = CURRENTLY_EXPLORING;
-
- xbt_dynar_foreach(n->out, cursor, edge) {
- xbt_graph_depth_visit(g, edge->dst, sorted, idx);
- }
-
- *((int *) (n->xbtdata)) = ALREADY_EXPLORED;
- sorted[(*idx)--] = n;
- }
-}
-
-/********************* Import and Export ******************/
-static xbt_graph_t parsed_graph = NULL;
-static xbt_dict_t parsed_nodes = NULL;
-
-static void *(*__parse_node_label_and_data) (xbt_node_t, const char *,
- const char *) = NULL;
-static void *(*__parse_edge_label_and_data) (xbt_edge_t, const char *,
- const char *) = NULL;
-
-static void __parse_graph_begin(void)
-{
- XBT_DEBUG("<graph>");
- if (A_graphxml_graph_isDirected == A_graphxml_graph_isDirected_true)
- parsed_graph = xbt_graph_new_graph(1, NULL);
- else
- parsed_graph = xbt_graph_new_graph(0, NULL);
-
- parsed_nodes = xbt_dict_new_homogeneous(NULL);
-}
-
-static void __parse_graph_end(void)
-{
- xbt_dict_free(&parsed_nodes);
- XBT_DEBUG("</graph>");
-}
-
-static void __parse_node(void)
-{
- xbt_node_t node = xbt_graph_new_node(parsed_graph, NULL);
-
- XBT_DEBUG("<node name=\"%s\"/>", A_graphxml_node_name);
- if (__parse_node_label_and_data)
- node->data = __parse_node_label_and_data(node, A_graphxml_node_label,
- A_graphxml_node_data);
- node->position_x = xbt_graph_parse_get_double(A_graphxml_node_position___x);
- node->position_y = xbt_graph_parse_get_double(A_graphxml_node_position___y);
-
- xbt_dict_set(parsed_nodes, A_graphxml_node_name, (void *) node, NULL);
-}
-
-static void __parse_edge(void)
-{
- xbt_edge_t edge = xbt_graph_new_edge(parsed_graph,
- xbt_dict_get(parsed_nodes,
- A_graphxml_edge_source),
- xbt_dict_get(parsed_nodes,
- A_graphxml_edge_target),
- NULL);
-
- if (__parse_edge_label_and_data)
- edge->data = __parse_edge_label_and_data(edge, A_graphxml_edge_label,
- A_graphxml_edge_data);
-
- edge->length = xbt_graph_parse_get_double(A_graphxml_edge_length);
-
- XBT_DEBUG("<edge source=\"%s\" target=\"%s\" length=\"%f\"/>",
- (char *) (edge->src)->data,
- (char *) (edge->dst)->data, xbt_graph_edge_get_length(edge));
-}
-
-/** @brief Import a graph from a file following the GraphXML format */
-xbt_graph_t xbt_graph_read(const char *filename,
- void *(*node_label_and_data) (xbt_node_t,
- const char *,
- const char *),
- void *(*edge_label_and_data) (xbt_edge_t,
- const char *,
- const char *))
-{
-
- xbt_graph_t graph = NULL;
-
- __parse_node_label_and_data = node_label_and_data;
- __parse_edge_label_and_data = edge_label_and_data;
-
- xbt_graph_parse_reset_parser();
-
- STag_graphxml_graph_fun = __parse_graph_begin;
- ETag_graphxml_graph_fun = __parse_graph_end;
- ETag_graphxml_node_fun = __parse_node;
- ETag_graphxml_edge_fun = __parse_edge;
-
- xbt_graph_parse_open(filename);
- _XBT_GNUC_UNUSED int res;
- res = xbt_graph_parse();
- xbt_assert(!res, "Parse error in %s", filename);
- xbt_graph_parse_close();
-
- graph = parsed_graph;
- parsed_graph = NULL;
-
- return graph;