}
PriorityQueue<OffsetsEnum> pq = new PriorityQueue<OffsetsEnum>();
float weights[] = new float[terms.length];
// initialize postings
for (int i = 0; i < terms.length; i++) {
DocsAndPositionsEnum de = postings[i];
int pDoc;
if (de == EMPTY) {
continue;
} else if (de == null) {
postings[i] = EMPTY; // initially
if (!termsEnum.seekExact(terms[i], true)) {
continue; // term not found
}
de = postings[i] = termsEnum.docsAndPositions(null, null, DocsAndPositionsEnum.FLAG_OFFSETS);
if (de == null) {
// no positions available
throw new IllegalArgumentException("field '" + field + "' was indexed without offsets, cannot highlight");
}
pDoc = de.advance(doc);
} else {
pDoc = de.docID();
if (pDoc < doc) {
pDoc = de.advance(doc);
}
}
if (doc == pDoc) {
weights[i] = scorer.weight(contentLength, de.freq());
de.nextPosition();
pq.add(new OffsetsEnum(de, i));
}
}
pq.add(new OffsetsEnum(EMPTY, Integer.MAX_VALUE)); // a sentinel for termination
PriorityQueue<Passage> passageQueue = new PriorityQueue<Passage>(n, new Comparator<Passage>() {
@Override
public int compare(Passage left, Passage right) {
if (left.score < right.score) {
return -1;
} else if (left.score > right.score) {
return 1;
} else {
return left.startOffset - right.startOffset;
}
}
});
Passage current = new Passage();
OffsetsEnum off;
while ((off = pq.poll()) != null) {
final DocsAndPositionsEnum dp = off.dp;
int start = dp.startOffset();
if (start == -1) {
throw new IllegalArgumentException("field '" + field + "' was indexed without offsets, cannot highlight");
}
int end = dp.endOffset();
if (start >= current.endOffset) {
if (current.startOffset >= 0) {
// finalize current
current.score *= scorer.norm(current.startOffset);
// new sentence: first add 'current' to queue
if (passageQueue.size() == n && current.score < passageQueue.peek().score) {
current.reset(); // can't compete, just reset it
} else {
passageQueue.offer(current);
if (passageQueue.size() > n) {
current = passageQueue.poll();
current.reset();
} else {
current = new Passage();
}
}
}
// if we exceed limit, we are done
if (start >= contentLength) {
Passage passages[] = new Passage[passageQueue.size()];
passageQueue.toArray(passages);
for (Passage p : passages) {
p.sort();
}
// sort in ascending order
Arrays.sort(passages, new Comparator<Passage>() {
@Override
public int compare(Passage left, Passage right) {
return left.startOffset - right.startOffset;
}
});
return passages;
}
// advance breakiterator
assert BreakIterator.DONE < 0;
current.startOffset = Math.max(bi.preceding(start+1), 0);
current.endOffset = Math.min(bi.next(), contentLength);
}
int tf = 0;
while (true) {
tf++;
current.addMatch(start, end, terms[off.id]);
if (off.pos == dp.freq()) {
break; // removed from pq
} else {
off.pos++;
dp.nextPosition();
start = dp.startOffset();
end = dp.endOffset();
}
if (start >= current.endOffset) {
pq.offer(off);
break;
}