/* find_longest_path:
* Find and return longest path in tree.
*/
static nodelist_t*
find_longest_path(Agraph_t* tree)
{
Agnode_t* n;
Agedge_t* e;
Agnode_t* common = 0;
nodelist_t* path;
nodelist_t* endPath;
int maxlength = 0;
int length;
if (agnnodes(tree) == 1) {
path = mkNodelist();
n = agfstnode(tree);
appendNodelist(path, NULL, n);
SET_ONPATH(n);
return path;
}
for(n = agfstnode(tree); n; n = agnxtnode(tree, n)) {
int count = 0;
for(e = agfstedge(tree, n); e; e = agnxtedge(tree, e, n)) {
count++;
}
if(count == 1)
measure_distance(n, n, 0, NULL);
}
/* find the branch node rooted at the longest path */
for(n = agfstnode(tree); n; n = agnxtnode(tree, n)) {
length = DISTONE(n) + DISTTWO(n);
if(length > maxlength) {
common = n;
maxlength = length;
}
}
path = mkNodelist();
for (n = LEAFONE(common); n != common; n = TPARENT(n)) {
appendNodelist(path, NULL, n);
SET_ONPATH(n);
}
appendNodelist(path, NULL, common);
SET_ONPATH(common);
if (DISTTWO(common)) { /* 2nd path might be empty */
endPath = mkNodelist();
for (n = LEAFTWO(common); n != common; n = TPARENT(n)) {
appendNodelist(endPath, NULL, n);
SET_ONPATH(n);
}
reverseAppend(path, endPath);
}
return path;
}
static void
measure_distance(Agnode_t * n, Agnode_t * ancestor, int dist,
Agnode_t * change)
{
Agnode_t *parent;
parent = TPARENT(ancestor);
if (parent == NULL)
return;
dist++;
/* check parent to see if it has other leaf paths at greater distance
than the context node.
set the path/distance of the leaf at this ancestor node */
if (DISTONE(parent) == 0) {
LEAFONE(parent) = n;
DISTONE(parent) = dist;
} else if (dist > DISTONE(parent)) {
if (LEAFONE(parent) != change) {
if (!DISTTWO(parent) || (LEAFTWO(parent) != change))
change = LEAFONE(parent);
LEAFTWO(parent) = LEAFONE(parent);
DISTTWO(parent) = DISTONE(parent);
}
LEAFONE(parent) = n;
DISTONE(parent) = dist;
} else if (dist > DISTTWO(parent)) {
LEAFTWO(parent) = n;
DISTTWO(parent) = dist;
return;
} else
return;
measure_distance(n, parent, dist, change);
}
void prData(Agnode_t * n, int pass)
{
char *pname;
char *bname;
char *tname;
char *name1;
char *name2;
int dist1, dist2;
if (PARENT(n))
pname = agnameof(PARENT(n));
else
pname = "<P0>";
if (BLOCK(n))
bname = agnameof(BLOCK(n)->sub_graph);
else
pname = "<B0>";
fprintf(stderr, "%s: %x %s %s ", agnameof(n), FLAGS(n), pname, bname);
switch (pass) {
case 0:
fprintf(stderr, "%d %d\n", VAL(n), LOWVAL(n));
break;
case 1:
if (TPARENT(n))
tname = agnameof(TPARENT(n));
else
tname = "<ROOT>";
dist1 = DISTONE(n);
if (dist1 > 0)
name1 = agnameof(LEAFONE(n));
else
name1 = "<null>";
dist2 = DISTTWO(n);
if (dist2 > 0)
name2 = agnameof(LEAFTWO(n));
else
name2 = "<null>";
fprintf(stderr, "%s %s %d %s %d\n", tname, name1, dist1, name2,
dist2);
break;
default:
fprintf(stderr, "%d\n", POSITION(n));
break;
}
}
