radare2/libr/util/graph.c

270 lines
6.4 KiB
C

/* radare - LGPL - Copyright 2007-2019 - pancake, ret2libc */
#include <r_util.h>
enum {
WHITE_COLOR = 0,
GRAY_COLOR,
BLACK_COLOR
};
static RGraphNode *r_graph_node_new (void *data) {
RGraphNode *p = R_NEW0 (RGraphNode);
if (p) {
p->data = data;
p->free = NULL;
p->out_nodes = r_list_new ();
p->in_nodes = r_list_new ();
p->all_neighbours = r_list_new ();
}
return p;
}
static void r_graph_node_free (RGraphNode *n) {
if (!n) {
return;
}
if (n->free) {
n->free (n->data);
}
r_list_free (n->out_nodes);
r_list_free (n->in_nodes);
r_list_free (n->all_neighbours);
free (n);
}
static int node_cmp (unsigned int idx, RGraphNode *b) {
return idx == b->idx ? 0 : -1;
}
static void dfs_node (RGraph *g, RGraphNode *n, RGraphVisitor *vis, int color[]) {
RStack *s = r_stack_new (2 * g->n_edges + 1);
if (!s) {
return;
}
RGraphEdge *edg = R_NEW0 (RGraphEdge);
if (!edg) {
r_stack_free (s);
return;
}
edg->from = NULL;
edg->to = n;
r_stack_push (s, edg);
while (!r_stack_is_empty (s)) {
RGraphEdge *cur_edge = (RGraphEdge *)r_stack_pop (s);
RGraphNode *v, *cur = cur_edge->to, *from = cur_edge->from;
RListIter *it;
int i;
if (from && cur) {
if (color[cur->idx] == WHITE_COLOR && vis->tree_edge) {
vis->tree_edge (cur_edge, vis);
} else if (color[cur->idx] == GRAY_COLOR && vis->back_edge) {
vis->back_edge (cur_edge, vis);
} else if (color[cur->idx] == BLACK_COLOR && vis->fcross_edge) {
vis->fcross_edge (cur_edge, vis);
}
} else if (!cur && from) {
if (color[from->idx] != BLACK_COLOR && vis->finish_node) {
vis->finish_node (from, vis);
}
color[from->idx] = BLACK_COLOR;
}
free (cur_edge);
if (!cur || color[cur->idx] != WHITE_COLOR) {
continue;
}
if (color[cur->idx] == WHITE_COLOR && vis->discover_node) {
vis->discover_node (cur, vis);
}
color[cur->idx] = GRAY_COLOR;
edg = R_NEW0 (RGraphEdge);
if (!edg) {
break;
}
edg->from = cur;
r_stack_push (s, edg);
i = 0;
const RList *neighbours = r_graph_get_neighbours (g, cur);
r_list_foreach (neighbours, it, v) {
edg = R_NEW (RGraphEdge);
edg->from = cur;
edg->to = v;
edg->nth = i++;
r_stack_push (s, edg);
}
}
r_stack_free (s);
}
R_API RGraph *r_graph_new () {
RGraph *t = R_NEW0 (RGraph);
if (!t) {
return NULL;
}
t->nodes = r_list_new ();
if (!t->nodes) {
r_graph_free(t);
return NULL;
}
t->nodes->free = (RListFree)r_graph_node_free;
t->n_nodes = 0;
t->last_index = 0;
return t;
}
R_API void r_graph_free (RGraph* t) {
r_list_free (t->nodes);
free (t);
}
R_API RGraphNode *r_graph_get_node (const RGraph *t, unsigned int idx) {
RListIter *it = r_list_find (t->nodes, (void *)(size_t)idx, (RListComparator)node_cmp);
if (!it) {
return NULL;
}
return (RGraphNode *)it->data;
}
R_API RListIter *r_graph_node_iter (const RGraph *t, unsigned int idx) {
return r_list_find (t->nodes, (void *)(size_t)idx, (RListComparator)node_cmp);
}
R_API void r_graph_reset (RGraph *t) {
r_list_free (t->nodes);
t->nodes = r_list_new ();
if (!t->nodes) {
return;
}
t->nodes->free = (RListFree)r_graph_node_free;
t->n_nodes = 0;
t->n_edges = 0;
t->last_index = 0;
}
R_API RGraphNode *r_graph_add_node (RGraph *t, void *data) {
if (!t) {
return NULL;
}
RGraphNode *n = r_graph_node_new (data);
if (!n) {
return NULL;
}
n->idx = t->last_index++;
r_list_append (t->nodes, n);
t->n_nodes++;
return n;
}
/* remove the node from the graph and free the node */
/* users of this function should be aware they can't access n anymore */
R_API void r_graph_del_node(RGraph *t, RGraphNode *n) {
RGraphNode *gn;
RListIter *it;
if (!n) {
return;
}
r_list_foreach (n->in_nodes, it, gn) {
r_list_delete_data (gn->out_nodes, n);
r_list_delete_data (gn->all_neighbours, n);
t->n_edges--;
}
r_list_foreach (n->out_nodes, it, gn) {
r_list_delete_data (gn->in_nodes, n);
r_list_delete_data (gn->all_neighbours, n);
t->n_edges--;
}
r_list_delete_data (t->nodes, n);
t->n_nodes--;
}
R_API void r_graph_add_edge (RGraph *t, RGraphNode *from, RGraphNode *to) {
r_graph_add_edge_at (t, from, to, -1);
}
R_API void r_graph_add_edge_at (RGraph *t, RGraphNode *from, RGraphNode *to, int nth) {
if (from && to) {
r_list_insert (from->out_nodes, nth, to);
r_list_append (from->all_neighbours, to);
r_list_append (to->in_nodes, from);
r_list_append (to->all_neighbours, from);
t->n_edges++;
}
}
R_API void r_graph_del_edge (RGraph *t, RGraphNode *from, RGraphNode *to) {
if (!from || !to || !r_graph_adjacent (t, from, to)) {
return;
}
r_list_delete_data (from->out_nodes, to);
r_list_delete_data (from->all_neighbours, to);
r_list_delete_data (to->in_nodes, from);
r_list_delete_data (to->all_neighbours, from);
t->n_edges--;
}
// XXX remove comments and static inline all this crap
/* returns the list of nodes reachable from `n` */
R_API const RList *r_graph_get_neighbours (const RGraph *g, const RGraphNode *n) {
return n? n->out_nodes: NULL;
}
/* returns the n-th nodes reachable from the give node `n`.
* This, of course, depends on the order of the nodes. */
R_API RGraphNode *r_graph_nth_neighbour (const RGraph *g, const RGraphNode *n, int nth) {
return n? (RGraphNode *)r_list_get_n (n->out_nodes, nth): NULL;
}
/* returns the list of nodes that can reach `n` */
R_API const RList *r_graph_innodes (const RGraph *g, const RGraphNode *n) {
return n? n->in_nodes: NULL;
}
/* returns the list of nodes reachable from `n` and that can reach `n`. */
R_API const RList *r_graph_all_neighbours (const RGraph *g, const RGraphNode *n) {
return n? n->all_neighbours: NULL;
}
R_API const RList *r_graph_get_nodes (const RGraph *g) {
return g? g->nodes: NULL;
}
/* true if there is an edge from the node `from` to the node `to` */
R_API int r_graph_adjacent (const RGraph *g, const RGraphNode *from, const RGraphNode *to) {
if (!g || !from) {
return false;
}
return r_list_contains (from->out_nodes, to) ? true : false;
}
R_API void r_graph_dfs_node (RGraph *g, RGraphNode *n, RGraphVisitor *vis) {
if (!g || !n || !vis) {
return;
}
int *color = R_NEWS0 (int, g->last_index);
if (color) {
dfs_node (g, n, vis, color);
free (color);
}
}
R_API void r_graph_dfs (RGraph *g, RGraphVisitor *vis) {
r_return_if_fail (g && vis);
RGraphNode *n;
RListIter *it;
int *color = R_NEWS0 (int, g->last_index);
if (color) {
r_list_foreach (g->nodes, it, n) {
if (color[n->idx] == WHITE_COLOR) {
dfs_node (g, n, vis, color);
}
}
free (color);
}
}