+/* a generic graph library. */
+
+/* Copyright (c) 2006-2017. The SimGrid Team.
+ * All rights reserved. */
+
+/* This program is free software; you can redistribute it and/or modify it
+ * under the terms of the license (GNU LGPL) which comes with this package. */
+
+#include "xbt/sysdep.h"
+#include "xbt/log.h"
+#include "xbt/graph.h"
#include "graph_private.h"
+#include "xbt/dict.h"
+#include "xbt/heap.h"
+#include "xbt/file.h"
+
+#include <errno.h>
+#include <stdlib.h>
+
+XBT_LOG_NEW_DEFAULT_SUBCATEGORY(xbt_graph, xbt, "Graph");
+
+/** @brief Constructor
+ * @return a new graph
+ */
+xbt_graph_t xbt_graph_new_graph(unsigned short int directed, void *data)
+{
+ xbt_graph_t graph = xbt_new0(struct xbt_graph, 1);
+ graph->directed = directed;
+ graph->data = data;
+ graph->nodes = xbt_dynar_new(sizeof(xbt_node_t), NULL);
+ graph->edges = xbt_dynar_new(sizeof(xbt_edge_t), NULL);
+
+ return graph;
+}
+
+/** @brief add a node to the given graph */
+xbt_node_t xbt_graph_new_node(xbt_graph_t g, void *data)
+{
+ xbt_node_t node= xbt_new0(struct xbt_node, 1);
+ node->data = data;
+ if (g->directed)
+ /* only the "out" field is used */
+ node->in = xbt_dynar_new(sizeof(xbt_edge_t), NULL);
+
+ node->out = xbt_dynar_new(sizeof(xbt_edge_t), NULL);
+ node->position_x = -1.0;
+ node->position_y = -1.0;
+
+ xbt_dynar_push(g->nodes, &node);
+
+ return node;
+}
+
+/** @brief add an edge to the given graph */
+xbt_edge_t xbt_graph_new_edge(xbt_graph_t g, xbt_node_t src, xbt_node_t dst, void *data)
+{
+ xbt_edge_t edge = xbt_new0(struct xbt_edge, 1);
+ xbt_dynar_push(src->out, &edge);
+ if (g->directed)
+ xbt_dynar_push(dst->in, &edge);
+ else /* only the "out" field is used */
+ xbt_dynar_push(dst->out, &edge);
+
+ edge->data = data;
+ edge->src = src;
+ edge->dst = dst;
+
+ xbt_dynar_push(g->edges, &edge);
+
+ return edge;
+}
+
+/** @brief Get the edge connecting src and dst */
+xbt_edge_t xbt_graph_get_edge(xbt_graph_t g, xbt_node_t src, xbt_node_t dst)
+{
+ xbt_edge_t edge;
+ unsigned int cursor;
+
+ xbt_dynar_foreach(src->out, cursor, edge) {
+ XBT_DEBUG("%p = %p--%p", edge, edge->src, edge->dst);
+ if ((edge->src == src) && (edge->dst == dst))
+ return edge;
+ }
+ if (!g->directed) {
+ xbt_dynar_foreach(src->out, cursor, edge) {
+ XBT_DEBUG("%p = %p--%p", edge, edge->src, edge->dst);
+ if ((edge->dst == src) && (edge->src == dst))
+ return edge;
+ }
+ }
+ return NULL;
+}
+
+/** @brief Get the user data associated to a node */
+void *xbt_graph_node_get_data(xbt_node_t node)
+{
+ return node->data;
+}
+
+/** @brief Set the user data associated to a node */
+void xbt_graph_node_set_data(xbt_node_t node, void *data)
+{
+ node->data = data;
+}
+
+/** @brief Get the user data associated to a edge */
+void *xbt_graph_edge_get_data(xbt_edge_t edge)
+{
+ return edge->data;
+}
+
+/** @brief Set the user data associated to a edge */
+void xbt_graph_edge_set_data(xbt_edge_t edge, void *data)
+{
+ edge->data = data;
+}
+
+/** @brief Destructor
+ * @param g: poor victim
+ * @param node_free_function: function to use to free data associated to each node
+ * @param edge_free_function: function to use to free data associated to each edge
+ * @param graph_free_function: function to use to free data associated to g
+ *
+ * Free the graph structure.
+ */
+void xbt_graph_free_graph(xbt_graph_t g, void_f_pvoid_t node_free_function, void_f_pvoid_t edge_free_function,
+ void_f_pvoid_t graph_free_function)
+{
+ unsigned int cursor;
+ xbt_node_t node;
+ xbt_edge_t edge;
+
+ xbt_dynar_foreach(g->edges, cursor, edge) {
+ if (edge_free_function)
+ edge_free_function(edge->data);
+ free(edge);
+ }
+ xbt_dynar_free(&(g->edges));
+
+ xbt_dynar_foreach(g->nodes, cursor, node) {
+ xbt_dynar_free(&(node->out));
+ xbt_dynar_free(&(node->in));
+ if (node_free_function)
+ node_free_function(node->data);
+ free(node);
+ }
+ xbt_dynar_free(&(g->nodes));
+
+ if (graph_free_function)
+ graph_free_function(g->data);
+ free(g);
+}
+
+/** @brief Retrieve the graph's nodes as a dynar */
+xbt_dynar_t xbt_graph_get_nodes(xbt_graph_t g)
+{
+ return g->nodes;
+}
+
+/** @brief Retrieve the graph's edges as a dynar */
+xbt_dynar_t xbt_graph_get_edges(xbt_graph_t g)
+{
+ return g->edges;
+}
+
+/** @brief Retrieve the node at the source of the given edge */
+xbt_node_t xbt_graph_edge_get_source(xbt_edge_t e)
+{
+ return e->src;
+}
+
+/** @brief Retrieve the node being the target of the given edge */
+xbt_node_t xbt_graph_edge_get_target(xbt_edge_t e)
+{
+ return e->dst;
+}
+
+/** @brief Retrieve the outgoing edges of the given node */
+xbt_dynar_t xbt_graph_node_get_outedges(xbt_node_t n)
+{
+ return n->out;
+}
+
+/** @brief Set the weight of the given edge */
+void xbt_graph_edge_set_length(xbt_edge_t e, double length)
+{
+ e->length = length;
+
+}
+
+/** @brief Get the length of a edge */
+double xbt_graph_edge_get_length(xbt_edge_t edge)
+{
+ return edge->length;
+}
+
+/** @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)
+{
+ unsigned long i;
+ unsigned long j;
+ unsigned long k;
+ unsigned long n = xbt_dynar_length(g->nodes);
+
+ 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*n+j] > -1) {
+ p[i*n+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*n+k] > -1) && (d[k*n+j] > -1)) {
+ if ((d[i*n+j] < 0) || (d[i*n+j] > d[i*n+k] + d[k*n+j])) {
+ d[i*n+j] = d[i*n+k] + d[k*n+j];
+ p[i*n+j] = p[k*n+j];
+ }
+ }
+ }
+ }
+ }
+}
+
+/** @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))
+{
+ unsigned int cursor = 0;
+ xbt_node_t node = NULL;
+ xbt_edge_t edge = NULL;
+ const char *name = NULL;
+
+ FILE *file = fopen(filename, "w");
+ xbt_assert(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) {
+ if (node_name){
+ fprintf(file, " \"%s\";\n", node_name(node));
+ }else{
+ fprintf(file, " \"%p\";\n", node);
+ }
+ }
+ xbt_dynar_foreach(g->edges, cursor, edge) {
+ const char *c;
+ const char *c_dir = "->";
+ const char *c_ndir = "--";
+ if (g->directed){
+ c = c_dir;
+ }else{
+ c = c_ndir;
+ }
+ if (node_name){
+ const char *src_name = node_name(edge->src);
+ const char *dst_name = node_name(edge->dst);
+ fprintf(file, " \"%s\" %s \"%s\"", src_name, c, dst_name);
+ }else{
+ fprintf(file, " \"%p\" %s \"%p\"", edge->src, c, edge->dst);
+ }
+
+ if (edge_name){
+ name = edge_name(edge);
+ if (name)
+ fprintf(file, "[label=\"%s\"]", name);
+ }
+ fprintf(file, ";\n");
+ }
+ fprintf(file, "}\n");
+ fclose(file);
+}
