markus/lifo-dijkstraserv
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Fix Dijkstra implementation, add debug prints

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This commit is contained in:
Markus Koch 2020-05-03 12:09:29 +02:00
parent d060afea0d
commit 0b755401b8
4 changed files with 72 additions and 32 deletions
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16
src/dijkstragraph.c
View File

@ -89,18 +89,6 @@ struct dijkstra_node *dijkstra_node_new_to_list(GList **list,
return node;
}
int dijkstra_connect_dangling_node_to_path(struct dijkstra_node **node,
struct dijkstra_path *path)
{
if (!path || !node)
return -1;
(*node)->paths = g_list_append((*node)->paths, (gpointer) path);
path->destination = *node;
return 0;
}
int dijkstra_connect_destination_node_to_path(struct dijkstra_node *destination,
struct dijkstra_path *path)
{
@ -406,6 +394,10 @@ void dijkstra_solver_free(struct dijkstra_solver *solver)
inline struct dijkstra_node *dijkstra_node_get_connection(struct dijkstra_node *node,
struct dijkstra_path *path)
{
if (!node || !path) {
report(LL_CRITICAL, "Called get_connection with NULL node (%p) or path (%p).",
node, path);
}
if (node != path->destination && node != path->source) {
report(LL_WARNING, "get_connection requested for invalid node / path pair: %d with %p (%s).", node->uid, path, path->name);
for (GList *l = node->paths; l != NULL; l = l->next) {

64
src/dijkstrasearch.c
View File

@ -8,6 +8,7 @@ void dijkstra_search_reset(struct dijkstra_search *search)
for (i=0; i < search->node_count; i++) {
search->states[i]->cost = DIJKSTRA_COST_MAX;
search->states[i]->visited = 0;
search->states[i]->cheapest_path = NULL;
}
if (search->start) {
@ -28,6 +29,7 @@ struct dijkstra_search *dijkstra_search_new(struct dijkstra_solver *solver)
search = malloc(sizeof(*search));
if (search) {
search->solver = solver;
search->states = malloc(sizeof(*search->states) * g_list_length(solver->nodes));
search->node_count = g_list_length(solver->nodes);
search->start = NULL;
@ -94,11 +96,16 @@ struct dijkstra_node *dijkstra_search_process_queue(struct dijkstra_search *sear
}
node = cheapest_node;
state = search->states[node->uid];
report(LL_DEBUG, "Current cheapest node is %d", node->uid);
report(LL_NOISY, "Current cheapest node is %d", node->uid);
// 2. Mark the current node as visited and remove it from the actives
state->visited = 1;
search->active_nodes = g_list_remove(search->active_nodes, node);
if (!state->cheapest_path && node != search->start) {
report(LL_CRITICAL, "DEBUG: marked current node as visited, even though it doesn't have a path to it. Cost is %d.",
state->cost);
getchar();
}
// 3. Update connecting nodes
for (l = node->paths; l != NULL; l = l->next) {
@ -106,13 +113,14 @@ struct dijkstra_node *dijkstra_search_process_queue(struct dijkstra_search *sear
cost = state->cost + path->weight;
connection = dijkstra_node_get_connection(node, path);
// 3.1 Update cost if cheaper
if (cost < search->states[connection->uid]->cost) {
search->states[connection->uid]->cost = cost;
search->states[connection->uid]->cheapest_path = path;
report(LL_DEBUG, " Set cost of node %d to %d (backpath from %d to %d)", connection->uid, cost, connection->uid, node->uid);
report(LL_NOISY, " Set cost of node %d to %d (backpath from %d to %d)", connection->uid, cost, connection->uid, node->uid);
if (search->states[connection->uid]->visited) {
report(LL_WARNING, " Reset cost of visited node!"); // TODO: not necessary if algorithm OK
report(LL_CRITICAL, " Reset cost of visited node!"); // TODO: not necessary if algorithm OK
}
}
// 3.2. Add connecting nodes to active nodes if not already visited
@ -120,7 +128,10 @@ struct dijkstra_node *dijkstra_search_process_queue(struct dijkstra_search *sear
if (!g_list_find(search->active_nodes, connection)) {
search->active_nodes = g_list_append(search->active_nodes,
(gpointer) connection);
report(LL_DEBUG, " Append %d as an active node.", connection->uid);
report(LL_NOISY, " Append %d as an active node.", connection->uid);
if (!search->states[connection->uid]->cheapest_path) {
report(LL_CRITICAL, "Appended a node without a path!");
}
}
}
}
@ -151,28 +162,59 @@ int dijkstra_search_find_path(struct dijkstra_search *search,
return -1;
}
int dijkstra_print_path(struct dijkstra_search *search,
void dijkstra_print_path(struct dijkstra_search *search,
struct dijkstra_node *destination)
{
struct dijkstra_node *node = NULL;
GList *l;
int i=500; // TODO: This should not be necessary. Plus the number is arbitrary.
unsigned int i = 0;
if (!destination || !search->states[destination->uid]->visited)
return 0;
return;
node = destination;
while (node != search->start) {
while (1) {
if (node != destination)
printf(",");
printf("[%d,%d]", (int) node->position.x, (int) node->position.y);
// printf("%u [%d]-> ", node->uid, search->states[node->uid]->cost);
if (node == search->start)
break;
node = dijkstra_node_get_connection(node, search->states[node->uid]->cheapest_path);
if (!i--) {
if (i++ > search->node_count) {
report(LL_CRITICAL, "Iteration limit for backsolver. This should never happen.");
break;
}
}
printf("\n");
}
void dijkstra_print_nodes(struct dijkstra_search *search)
{
GList *l;
struct dijkstra_node *node;
printf("[");
for (l = search->solver->nodes; l != NULL; l = l->next) {
node = (struct dijkstra_node*) l->data;
printf("{ \"type\": \"Feature\",\n"
" \"geometry\" : {\n"
" \"type\" : \"Point\", \"coordinates\" : [%f, %f]\n"
" },\n"
" \"properties\" : {\n", node->position.x, node->position.y);
if (search->states[node->uid]->cheapest_path) {
printf(" \"name\" : \"Node %d (cost %d, from %d)\"\n",
node->uid, search->states[node->uid]->cost, dijkstra_node_get_connection(node, search->states[node->uid]->cheapest_path)->uid);
} else if (node == search->start) {
printf(" \"name\" : \"Starting node %d\"\n",
node->uid);
} else {
printf(" \"name\" : \"Unvisited node %d\"\n",
node->uid);
}
printf(" }\n"
"},\n");
}
printf("{}]\n");
}

4
src/dijkstrasearch.h
View File

@ -12,6 +12,7 @@ struct dijkstra_state {
};
struct dijkstra_search {
struct dijkstra_solver *solver;
struct dijkstra_state **states;
unsigned int node_count;
struct dijkstra_node *start;
@ -24,6 +25,7 @@ void dijkstra_search_set_start(struct dijkstra_search *search,
struct dijkstra_node *start);
int dijkstra_search_find_path(struct dijkstra_search *search,
struct dijkstra_node *destination);
int dijkstra_print_path(struct dijkstra_search *search,
void dijkstra_print_path(struct dijkstra_search *search,
struct dijkstra_node *destination);
void dijkstra_print_nodes(struct dijkstra_search *search);
#endif // DIJKSTRASEARCH_H

12
src/main.c
View File

@ -92,21 +92,24 @@ int main(int argc, char *argv[])
// add_test_map(solver);
// TODO: This start / end coordinates are only for testing
start = dijkstra_node_new_to_list(&solver->nodes, -1213, -305);
start = dijkstra_node_new_to_list(&solver->nodes, -856, -393);
dest = dijkstra_node_new_to_list(&solver->nodes, 388, 99);
//start = dijkstra_node_new_to_list(&solver->nodes, -957, -467);
//dest = dijkstra_node_new_to_list(&solver->nodes, -712, -467);
if (should_report(LL_NOISY)) {
for (l = solver->nodes; l != NULL; l = l->next) {
node = (struct dijkstra_node*) l->data;
printf("Node %5d @%p: %f,\t%f [%d paths]\n", node->uid, node, node->position.x, node->position.y, g_list_length(node->paths));
fprintf(stderr, "Node %5d @%p: %f,\t%f [%d paths]\n", node->uid, node, node->position.x, node->position.y, g_list_length(node->paths));
}
printf("\n");
for (l = solver->paths; l != NULL; l = l->next) {
path = (struct dijkstra_path*) l->data;
printf("Path %p: %5d (%f,%f) -> %5d (%f,%f) \t\"%s\"\n", path,
fprintf(stderr, "Path %p: %5d (%f,%f) -> %5d (%f,%f) cost %d \t\"%s\"\n", path,
path->source->uid, path->source->position.x, path->source->position.y,
path->destination->uid, path->destination->position.x, path->destination->position.y,
path->weight,
path->name);
}
printf("\n");
@ -125,8 +128,9 @@ int main(int argc, char *argv[])
}
dijkstra_search_set_start(search, start);
if ((iterations = dijkstra_search_find_path(search, dest)) > 0) {
report(LL_INFO, "Found path after %d iterations.", iterations);
report(LL_INFO, "Found path from %d to %d after %d iterations.", start->uid, dest->uid, iterations);
dijkstra_print_path(search, dest);
// dijkstra_print_nodes(search);
} else {
report(LL_WARNING, "Couldn't find path.");
}