static void set_data(Agobj_t * obj, Agrec_t * data, int mtflock)
{
Agedge_t *e;
obj->data = data;
obj->tag.mtflock = mtflock;
if ((AGTYPE(obj) == AGINEDGE) || (AGTYPE(obj) == AGOUTEDGE)) {
e = agopp((Agedge_t *) obj);
AGDATA(e) = data;
e->base.tag.mtflock = mtflock;
}
}
static int
label(Agnode_t *n, int nodecnt, int* edgecnt)
{
Agedge_t *e;
setval(n,1);
nodecnt++;
for (e = agfstedge(n); e; e = agnxtedge(e,n)) {
(*edgecnt) += 1;
if (e->node == n) e = agopp(e);
if (!getval(e->node))
nodecnt = label(e->node,nodecnt,edgecnt);
}
return nodecnt;
}
static int visit(Agnode_t * n, Agraph_t * map, Stack * sp, sccstate * st)
{
unsigned int m, min;
Agnode_t *t;
Agraph_t *subg;
Agedge_t *e;
min = ++(st->ID);
setval(n, min);
push(sp, n);
#ifdef USE_CGRAPH
for (e = agfstout(n->root, n); e; e = agnxtout(n->root, e)) {
#else
for (e = agfstout(n); e; e = agnxtout(e)) {
#endif
t = aghead(e);
if (getval(t) == 0)
m = visit(t, map, sp, st);
else
m = getval(t);
if (m < min)
min = m;
}
if (getval(n) == min) {
if (!wantDegenerateComp && (top(sp) == n)) {
setval(n, INF);
pop(sp);
} else {
char name[32];
Agraph_t *G = agraphof(n);;
sprintf(name, "cluster_%d", (st->Comp)++);
subg = agsubg(G, name, TRUE);
agbindrec(subg, "scc_graph", sizeof(Agraphinfo_t), TRUE);
setrep(subg, agnode(map, name, TRUE));
do {
t = pop(sp);
agsubnode(subg, t, TRUE);
setval(t, INF);
setscc(t, subg);
st->N_nodes_in_nontriv_SCC++;
} while (t != n);
#ifdef USE_CGRAPH
nodeInduce(subg, map);
#else
nodeInduce(subg);
#endif
if (!Silent)
agwrite(subg, stdout);
}
}
return min;
}
static int label(Agnode_t * n, int nodecnt, int *edgecnt)
{
Agedge_t *e;
setval(n, 1);
nodecnt++;
#ifdef USE_CGRAPH
for (e = agfstedge(n->root, n); e; e = agnxtedge(n->root, e, n)) {
#else
for (e = agfstedge(n); e; e = agnxtedge(e, n)) {
#endif
(*edgecnt) += 1;
if (e->node == n)
e = agopp(e);
if (!getval(e->node))
nodecnt = label(e->node, nodecnt, edgecnt);
}
return nodecnt;
}
static int
countComponents(Agraph_t * g, int *max_degree, float *nontree_frac)
{
int nc = 0;
int sum_edges = 0;
int sum_nontree = 0;
int deg;
int n_edges;
int n_nodes;
Agnode_t *n;
#ifdef USE_CGRAPH
for (n = agfstnode(g); n; n = agnxtnode(g, n)) {
#else
for (n = agfstnode(g); n; n = agnxtnode(n)) {
#endif
if (!getval(n)) {
nc++;
n_edges = 0;
n_nodes = label(n, 0, &n_edges);
sum_edges += n_edges;
sum_nontree += (n_edges - n_nodes + 1);
}
}
if (max_degree) {
int maxd = 0;
#ifdef USE_CGRAPH
for (n = agfstnode(g); n; n = agnxtnode(g, n)) {
deg = agdegree(g, n, TRUE, TRUE);
#else
for (n = agfstnode(g); n; n = agnxtnode(n)) {
deg = agdegree(n, TRUE, TRUE);
#endif
if (maxd < deg)
maxd = deg;
setval(n, 0);
}
*max_degree = maxd;
}
if (nontree_frac) {
if (sum_edges > 0)
*nontree_frac = (float) sum_nontree / (float) sum_edges;
else
*nontree_frac = 0.0;
}
return nc;
}
static void process(Agraph_t * G)
{
Agnode_t *n;
Agraph_t *map;
int nc = 0;
float nontree_frac = 0;
int Maxdegree = 0;
Stack stack;
sccstate state;
aginit(G, AGRAPH, "scc_graph", sizeof(Agraphinfo_t), TRUE);
aginit(G, AGNODE, "scc_node", sizeof(Agnodeinfo_t), TRUE);
state.Comp = state.ID = 0;
state.N_nodes_in_nontriv_SCC = 0;
if (Verbose)
nc = countComponents(G, &Maxdegree, &nontree_frac);
initStack(&stack, agnnodes(G) + 1);
map = agopen("scc_map", Agdirected, (Agdisc_t *) 0);
#ifdef USE_CGRAPH
for (n = agfstnode(G); n; n = agnxtnode(G, n))
#else
for (n = agfstnode(G); n; n = agnxtnode(n))
#endif
if (getval(n) == 0)
visit(n, map, &stack, &state);
freeStack(&stack);
if (!Silent)
agwrite(map, stdout);
agclose(map);
if (Verbose)
fprintf(stderr, "%d %d %d %d %.4f %d %.4f\n",
agnnodes(G), agnedges(G), nc, state.Comp,
state.N_nodes_in_nontriv_SCC / (double) agnnodes(G),
Maxdegree, nontree_frac);
else
fprintf(stderr, "%d nodes, %d edges, %d strong components\n",
agnnodes(G), agnedges(G), state.Comp);
}
static char *useString = "Usage: %s [-sdv?] <files>\n\
-s - silent\n\
-d - allow degenerate components\n\
-v - verbose\n\
-? - print usage\n\
If no files are specified, stdin is used\n";
static void usage(int v)
{
printf(useString, CmdName);
exit(v);
}
