/* Merge the nodes of a min, max, or same rank set. */
void collapse_rankset(graph_t *g, graph_t *subg, int kind)
{
node_t *u,*v;
u = v = agfstnode(subg);
if (u) {
ND_ranktype(u) = kind;
while ((v = agnxtnode(subg,v))) {
UF_union(u,v);
ND_ranktype(v) = ND_ranktype(u);
}
switch (kind) {
case MINRANK: case SOURCERANK:
if (GD_minset(g) == NULL) GD_minset(g) = u;
else GD_minset(g) = UF_union(GD_minset(g),u);
break;
case MAXRANK: case SINKRANK:
if (GD_maxset(g) == NULL) GD_maxset(g) = u;
else GD_maxset(g) = UF_union(GD_maxset(g),u);
break;
}
switch (kind) {
case SOURCERANK: GD_minset(g)->u.ranktype = kind; break;
case SINKRANK: GD_maxset(g)->u.ranktype = kind; break;
}
}
}
/* To ensure that min and max rank nodes always have the intended rank
* assignment, reverse any incompatible edges.
*/
static point
minmax_edges(graph_t * g)
{
node_t *n;
edge_t *e;
point slen;
slen.x = slen.y = 0;
if ((GD_maxset(g) == NULL) && (GD_minset(g) == NULL))
return slen;
if (GD_minset(g) != NULL)
GD_minset(g) = UF_find(GD_minset(g));
if (GD_maxset(g) != NULL)
GD_maxset(g) = UF_find(GD_maxset(g));
if ((n = GD_maxset(g))) {
slen.y = (ND_ranktype(GD_maxset(g)) == SINKRANK);
while ((e = ND_out(n).list[0])) {
assert(aghead(e) == UF_find(aghead(e)));
reverse_edge(e);
}
}
if ((n = GD_minset(g))) {
slen.x = (ND_ranktype(GD_minset(g)) == SOURCERANK);
while ((e = ND_in(n).list[0])) {
assert(agtail(e) == UF_find(agtail(e)));
reverse_edge(e);
}
}
return slen;
}
static void
node_induce(graph_t * par, graph_t * g)
{
node_t *n, *nn;
edge_t *e;
int i;
/* enforce that a node is in at most one cluster at this level */
for (n = agfstnode(g); n; n = nn) {
nn = agnxtnode(g, n);
if (ND_ranktype(n)) {
agdelete(g, n);
continue;
}
for (i = 1; i < GD_n_cluster(par); i++)
if (agcontains(GD_clust(par)[i], n))
break;
if (i < GD_n_cluster(par))
agdelete(g, n);
ND_clust(n) = NULL;
}
for (n = agfstnode(g); n; n = agnxtnode(g, n)) {
for (e = agfstout(dot_root(g), n); e; e = agnxtout(dot_root(g), e)) {
if (agcontains(g, aghead(e)))
agsubedge(g,e,1);
}
}
}
/*
* Assigns ranks of non-leader nodes.
* Expands same, min, max rank sets.
* Leaf sets and clusters remain merged.
* Sets minrank and maxrank appropriately.
*/
static void expand_ranksets(graph_t * g, aspect_t* asp)
{
int c;
node_t *n, *leader;
if ((n = agfstnode(g))) {
GD_minrank(g) = MAXSHORT;
GD_maxrank(g) = -1;
while (n) {
leader = UF_find(n);
/* The following works because ND_rank(n) == 0 if n is not in a
* cluster, and ND_rank(n) = the local rank offset if n is in
* a cluster. */
if ((leader != n) && (!asp || (ND_rank(n) == 0)))
ND_rank(n) += ND_rank(leader);
if (GD_maxrank(g) < ND_rank(n))
GD_maxrank(g) = ND_rank(n);
if (GD_minrank(g) > ND_rank(n))
GD_minrank(g) = ND_rank(n);
if (ND_ranktype(n) && (ND_ranktype(n) != LEAFSET))
UF_singleton(n);
n = agnxtnode(g, n);
}
if (g == dot_root(g)) {
if (CL_type == LOCAL) {
for (c = 1; c <= GD_n_cluster(g); c++)
set_minmax(GD_clust(g)[c]);
} else {
find_clusters(g);
}
}
} else {
GD_minrank(g) = GD_maxrank(g) = 0;
}
}
static void
cluster_leader(graph_t * clust)
{
node_t *leader, *n;
int maxrank = 0;
/* find number of ranks and select a leader */
leader = NULL;
for (n = GD_nlist(clust); n; n = ND_next(n)) {
if ((ND_rank(n) == 0) && (ND_node_type(n) == NORMAL))
leader = n;
if (maxrank < ND_rank(n))
maxrank = ND_rank(n);
}
assert(leader != NULL);
GD_leader(clust) = leader;
for (n = agfstnode(clust); n; n = agnxtnode(clust, n)) {
assert((ND_UF_size(n) <= 1) || (n == leader));
UF_union(n, leader);
ND_ranktype(n) = CLUSTER;
}
}
/* this function marks every node in <g> with its top-level cluster under <g> */
void mark_clusters(graph_t * g)
{
int c;
node_t *n, *nn, *vn;
edge_t *orig, *e;
graph_t *clust;
/* remove sub-clusters below this level */
for (n = agfstnode(g); n; n = agnxtnode(g, n)) {
if (ND_ranktype(n) == CLUSTER)
UF_singleton(n);
ND_clust(n) = NULL;
}
for (c = 1; c <= GD_n_cluster(g); c++) {
clust = GD_clust(g)[c];
for (n = agfstnode(clust); n; n = nn) {
nn = agnxtnode(clust,n);
if (ND_ranktype(n) != NORMAL) {
agerr(AGWARN,
"%s was already in a rankset, deleted from cluster %s\n",
agnameof(n), agnameof(g));
agdelete(clust,n);
continue;
}
UF_setname(n, GD_leader(clust));
ND_clust(n) = clust;
ND_ranktype(n) = CLUSTER;
/* here we mark the vnodes of edges in the cluster */
for (orig = agfstout(clust, n); orig;
orig = agnxtout(clust, orig)) {
if ((e = ED_to_virt(orig))) {
#ifndef WITH_CGRAPH
while (e && (vn = e->head)->u.node_type == VIRTUAL) {
#else /* WITH_CGRAPH */
while (e && ND_node_type(vn =aghead(e)) == VIRTUAL) {
#endif /* WITH_CGRAPH */
ND_clust(vn) = clust;
e = ND_out(aghead(e)).list[0];
/* trouble if concentrators and clusters are mixed */
}
}
}
}
}
}
void build_skeleton(graph_t * g, graph_t * subg)
{
int r;
node_t *v, *prev, *rl;
edge_t *e;
prev = NULL;
GD_rankleader(subg) = N_NEW(GD_maxrank(subg) + 2, node_t *);
for (r = GD_minrank(subg); r <= GD_maxrank(subg); r++) {
v = GD_rankleader(subg)[r] = virtual_node(g);
ND_rank(v) = r;
ND_ranktype(v) = CLUSTER;
ND_clust(v) = subg;
if (prev) {
e = virtual_edge(prev, v, NULL);
ED_xpenalty(e) *= CL_CROSS;
}
prev = v;
}
/* set the counts on virtual edges of the cluster skeleton */
for (v = agfstnode(subg); v; v = agnxtnode(subg, v)) {
rl = GD_rankleader(subg)[ND_rank(v)];
ND_UF_size(rl)++;
for (e = agfstout(subg, v); e; e = agnxtout(subg, e)) {
for (r = ND_rank(agtail(e)); r < ND_rank(aghead(e)); r++) {
ED_count(ND_out(rl).list[0])++;
}
}
}
for (r = GD_minrank(subg); r <= GD_maxrank(subg); r++) {
rl = GD_rankleader(subg)[r];
if (ND_UF_size(rl) > 1)
ND_UF_size(rl)--;
}
}
void UF_singleton(node_t * u)
{
ND_UF_size(u) = 1;
ND_UF_parent(u) = NULL;
ND_ranktype(u) = NORMAL;
}