-
-double xbt_graph_edge_get_length(xbt_edge_t e)
-{
- return e->length;
-}
-
-
-/** @brief construct the adjacency matrix corresponding to the given graph
- *
- * The weights are the distances between nodes
- */
-double *xbt_graph_get_length_matrix(xbt_graph_t g)
-{
- int cursor = 0;
- int in_cursor = 0;
- int idx,i;
- unsigned long n;
- xbt_edge_t edge = NULL;
- xbt_node_t node=NULL;
- double *d = NULL;
-
-# define D(u,v) d[(u)*n+(v)]
- n = xbt_dynar_length(g->nodes);
-
- d = (double *) xbt_new0(double, n*n);
-
- for (i = 0; i < n * n; i++)
- {
- d[i] = -1.0;
- }
-
- xbt_dynar_foreach(g->nodes, cursor, node)
- {
- in_cursor = 0;
- D(cursor, cursor) = 0;
-
- xbt_dynar_foreach(node->out, in_cursor, edge)
- {
- if (edge->dst==node)
- idx= __xbt_find_in_dynar(g->nodes, edge->src);
- else /*case of undirected graphs*/
- idx = __xbt_find_in_dynar(g->nodes, edge->dst);
- D( cursor,idx) = edge->length;
- }
- }
-
-# undef D
-
- return d;
-}
-
-/** @brief Floyd-Warshall algorithm for shortest path finding
- *
- * From wikipedia:
- *
- * The Floyd–Warshall algorithm takes as input an adjacency matrix
- * representation of a weighted, directed graph (V, E). The weight of a
- * path between two vertices is the sum of the weights of the edges along
- * that path. The edges E of the graph may have negative weights, but the
- * graph must not have any negative weight cycles. The algorithm computes,
- * for each pair of vertices, the minimum weight among all paths between
- * the two vertices. The running time complexity is Θ(|V|3).
- */
-void xbt_floyd_algorithm(xbt_graph_t g, double *adj, double *d,
- xbt_node_t * p)
-{
- int i, j, k;
- unsigned long n;
- n = xbt_dynar_length(g->nodes);
-
-# define D(u,v) d[(u)*n+(v)]
-# define P(u,v) p[(u)*n+(v)]
-
- for (i = 0; i < n * n; i++)
- {
- d[i] = adj[i];
- }
-
-
- for (i = 0; i < n; i++)
- {
- for (j = 0; j < n; j++)
- {
- if (D(i, j) != -1)
- {
- P(i,j) =*((xbt_node_t*) xbt_dynar_get_ptr(g->nodes, i));
- }
- }
- }
-
- for (k = 0; k < n; k++)
- {
- for (i = 0; i < n; i++)
- {
- for (j = 0; j < n; j++)
- {
- if ((D(i, k) != -1) && (D(k, j) != -1))
- {
- if ((D(i, j) == -1) || (D(i, j) > D(i, k) + D(k, j)))
- {
- D(i, j) = D(i, k) + D(k, j);
- P(i, j) = P(k, j);
- }
- }
- }
- }
- }
-
-
-
-# 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;
- int 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);
- int cursor;
-
- xbt_assert0(!(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;
- int cursor,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)
- {
- 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 )
-{
- int cursor;
- xbt_edge_t edge;
-
- if (*((int*)(n->xbtdata))==ALREADY_EXPLORED)
- return;
- else if (*((int*)(n->xbtdata))==CURRENTLY_EXPLORING)
- THROW0(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)
-{
- DEBUG0("<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();
-}
-
-static void __parse_graph_end(void)
-{
- xbt_dict_free(&parsed_nodes);
- DEBUG0("</graph>");
-}
-
-static void __parse_node(void)
-{
- xbt_node_t node =
- xbt_graph_new_node(parsed_graph, NULL);
-
- DEBUG1("<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);
- xbt_graph_parse_get_double(&(node->position_x),A_graphxml_node_position_x);
- xbt_graph_parse_get_double(&(node->position_y),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);
-
- xbt_graph_parse_get_double(&(edge->length),A_graphxml_edge_length);
-
- DEBUG3("<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_assert1((!xbt_graph_parse()), "Parse error in %s", filename);
- xbt_graph_parse_close();
-
- graph = parsed_graph;
- parsed_graph = NULL;
-
- return graph;
-}
-
-/** @brief Export the given graph in the GraphViz formatting for visualization */
-void xbt_graph_export_graphviz(xbt_graph_t g, const char *filename,
- const char *(node_name) (xbt_node_t),
- const char *(edge_name) (xbt_edge_t))
-{
- int cursor = 0;
- xbt_node_t node = NULL;
- xbt_edge_t edge = NULL;
- FILE *file = NULL;
- const char *name=NULL;
-
- file=fopen(filename,"w");
- xbt_assert1(file, "Failed to open %s \n",filename);
-
- if(g->directed) fprintf(file,"digraph test {\n");
- else fprintf(file,"graph test {\n");
-
- fprintf(file," graph [overlap=scale]\n");
-
- fprintf(file," node [shape=box, style=filled]\n");
- fprintf(file," node [width=.3, height=.3, style=filled, color=skyblue]\n\n");
-
- xbt_dynar_foreach(g->nodes, cursor, node) {
- fprintf(file," \"%p\" ", node);
- if((node_name)&&((name=node_name(node)))) fprintf(file,"[label=\"%s\"]",name);
- fprintf(file,";\n");
- }
- xbt_dynar_foreach(g->edges, cursor, edge) {
- if(g->directed)
- fprintf(file," \"%p\" -> \"%p\"",edge->src, edge->dst);
- else
- fprintf(file," \"%p\" -- \"%p\"",edge->src, edge->dst);
- if((edge_name)&&((name=edge_name(edge)))) fprintf(file,"[label=\"%s\"]",name);
- fprintf(file,";\n");
- }
- fprintf(file,"}\n");
- fclose(file);
-}
-
-/** @brief Export the given graph in the GraphXML format */
-void xbt_graph_export_graphxml(xbt_graph_t g, const char *filename,
- const char *(node_name)(xbt_node_t),
- const char *(edge_name)(xbt_edge_t),
- const char *(node_data_print)(void *),
- const char *(edge_data_print)(void *))
-{
- int cursor = 0;
- xbt_node_t node = NULL;
- xbt_edge_t edge = NULL;
- FILE *file = NULL;
- const char *name = NULL;
-
- file=fopen(filename,"w");
- xbt_assert1(file, "Failed to open %s \n",filename);
-
- fprintf(file,"<?xml version='1.0'?>\n");
- fprintf(file,"<!DOCTYPE graph SYSTEM \"graphxml.dtd\">\n");
- if(g->directed) fprintf(file,"<graph isDirected=\"true\">\n");
- else fprintf(file,"<graph isDirected=\"false\">\n");
- xbt_dynar_foreach(g->nodes, cursor, node) {
- fprintf(file," <node name=\"%p\" ", node);
- if((node_name)&&((name=node_name(node)))) fprintf(file,"label=\"%s\" ",name);
- if((node_data_print)&&((name=node_data_print(node->data))))
- fprintf(file,"data=\"%s\" ",name);
- fprintf(file,">\n");
- }
- xbt_dynar_foreach(g->edges, cursor, edge) {
- fprintf(file," <edge source=\"%p\" target =\"%p\" ",
- edge->src, edge->dst );
- if((edge_name)&&((name=edge_name(edge)))) fprintf(file,"label=\"%s\" ",name);
- if(edge->length>=0.0) fprintf(file,"length=\"%g\" ",edge->length);
- if((edge_data_print)&&((name=edge_data_print(edge->data))))
- fprintf(file,"data=\"%s\" ",name);
- fprintf(file,">\n");
- }
- fprintf(file,"</graph>\n");
- fclose(file);
-}
-