/**
* Evaluates a query.
*
* @param queryTree A query tree that has been already transformed with
* StructuredRetrieval.transformQuery.
* @param requested The number of documents to retrieve, at most.
* @return
* @throws java.lang.Exception
*/
public ScoredDocument[] runQuery(Node queryTree, int requested) throws Exception {
// my addition
queryTree = this.transformQuery(queryTree);
// System.out.println("runQuery: " + queryTree.toString());
// construct the query iterators
ScoreIterator iterator = (ScoreIterator) createIterator(queryTree);
// now there should be an iterator at the root of this tree
PriorityQueue<ScoredDocument> queue = new PriorityQueue<ScoredDocument>();
while (!iterator.isDone()) {
int document = iterator.nextCandidate();
int length = index.getLength(document);
double score = iterator.score(document, length);
if (queue.size() <= requested || queue.peek().score < score) {
ScoredDocument scoredDocument = new ScoredDocument(document, score);
queue.add(scoredDocument);
if (queue.size() > requested) {
queue.poll();
}
}
iterator.movePast(document);
}
return getArrayResults(queue);
}
public void reset() throws IOException {
iterator.reset();
}
public boolean isDone() {
return iterator.isDone();
}
public double score(int document, int length) {
return weight * iterator.score(document, length);
}
public void movePast(int document) throws IOException {
iterator.movePast(document);
}
public boolean hasMatch(int document) {
return iterator.hasMatch(document);
}
public int nextCandidate() {
return iterator.nextCandidate();
}
