// Searches for terms that are similar to the given term (Recursive function)
// Searches the children for nodes that their distance is smaller than threshold
// term: The given term we want to search similar to
// threshold: The maximum distance we want to search for
// collected: Stores all the nodes that fit
// ct: Cancellation Token for the Task
public void SearchMatches(T term, int threshold, Dictionary <T, int> matches, object collectionLock, CancellationToken ct)
{
// Calculates the distance of the given term from this node's term
int distanceFromNode = Distance <T> .calculate(this.term, term);
// Checks if the distance is within the given thershold
if (distanceFromNode <= threshold)
{
// Lock the collection to prevent collisions
lock (collectionLock) {
if (!matches.ContainsKey(this.term))
{
matches.Add(this.term, distanceFromNode);
}
}
}
// Search for matches in the children
for (int score = distanceFromNode - threshold; score <= threshold + distanceFromNode; score++)
{
BKNode <T> child = children.GetValueOrDefault(score);
if (child != null)
{
ct.ThrowIfCancellationRequested();
child.SearchMatches(term, threshold, matches, collectionLock, ct);
}
}
}
// Adds a child to this node
// First calculates the distance (D) between this node and the one we want to add
// Then 2 options:
// if no child with D distance exist, add it to this node as a child
// if this node already has a child with D distance, add it to the child with
// the same D distance
public void add(T term)
{
int score = Distance <T> .calculate(term, this.term);
BKNode <T> child = null;
children.TryGetValue(score, out child);
if (child != null)
{
child.add(term);
}
else
{
children.Add(score, new BKNode <T>(term));
}
}