/** Propagate the results of creating a new SCC with this node as lead. */
public void propagateSCC() {
Set<GraphNode> visited = new HashSet<>();
visited.add(this);
// Scan predecessors not including ourselves
doVisitPredecessors(
new Visitor<Set<GraphNode>, Object>() {
@Override
public List<GraphNode> visit(
GraphNode node, GraphNode processing, Set<GraphNode> sc, Object ignored) {
// Add closure
node.succClosed.addAll(sc);
// Scan for redundant links
List<GraphNode> kill = null;
for (Iterator<GraphNode> i = node.succ.iterator(); i.hasNext(); ) {
GraphNode s = i.next();
if (sc.contains(s)) {
i.remove();
// s.pred.remove(node);
if (s == processing) {
// Can't remove immediately w/o beaking the visitor loop
if (kill == null) kill = new ArrayList<>();
kill.add(node);
} else {
s.pred.remove(node);
}
}
}
return kill;
}
},
succClosed,
null,
visited);
}
/** Propagate the results of adding a link from this node to the target node. */
public void propagateAdd(GraphNode target) {
Set<GraphNode> sc = new HashSet<>(target.succClosed);
sc.add(target);
visitPredecessors(
new Visitor<Set<GraphNode>, GraphNode>() {
@Override
public List<GraphNode> visit(
GraphNode node, GraphNode processing, Set<GraphNode> sc, GraphNode target) {
// Add closure
node.succClosed.addAll(sc);
// Scan for redundant links
List<GraphNode> kill = null;
for (Iterator<GraphNode> i = node.succ.iterator(); i.hasNext(); ) {
GraphNode s = i.next();
if (sc.contains(s)) {
i.remove();
if (s == processing) {
// Can't remove immediately w/o beaking the visitor loop
if (kill == null) kill = new ArrayList<>();
kill.add(node);
} else {
s.pred.remove(node);
}
}
}
return kill;
}
},
sc,
target);
}
/** Visit each predecessor of this node applying the given visitor. Breadth first. */
private <Alpha, Beta> void doVisitPredecessors(
Visitor<Alpha, Beta> visitor, Alpha arg1, Beta arg2, Set<GraphNode> seen) {
if (seen.add(this)) {
Collection<GraphNode> allKill = null;
for (Iterator<GraphNode> i = pred.iterator(); i.hasNext(); ) {
GraphNode pred = i.next();
List<GraphNode> kill = visitor.visit(pred, this, arg1, arg2);
if (kill != null) {
if (allKill == null) allKill = new ArrayList<GraphNode>();
allKill.addAll(kill);
}
}
if (allKill != null) pred.removeAll(allKill);
for (Iterator<GraphNode> i = pred.iterator(); i.hasNext(); ) {
GraphNode pred = i.next();
pred.doVisitPredecessors(visitor, arg1, arg2, seen);
}
}
}
void addInto(Set<GraphNode> nodes, GraphNode m) {
nodes.add(m);
}
/** Assert an inferred indirect link from this node to the given traget */
public void assertIndirectLinkTo(GraphNode target) {
// if (this == target) return;
succClosed.add(target);
clearTripleCache();
}
/**
* Assert a direct link between this node and this given target. Does not update the closed
* successor cache
*/
public void assertLinkTo(GraphNode target) {
if (this == target) return;
succ.add(target);
target.pred.add(this);
clearTripleCache();
}