private int doNext(int doc) throws IOException {
for (; ; ) {
// doc may already be NO_MORE_DOCS here, but we don't check explicitly
// since all scorers should advance to NO_MORE_DOCS, match, then
// return that value.
advanceHead:
for (; ; ) {
for (int i = 1; i < docsAndFreqs.length; i++) {
// invariant: docsAndFreqs[i].doc <= doc at this point.
// docsAndFreqs[i].doc may already be equal to doc if we "broke advanceHead"
// on the previous iteration and the advance on the lead scorer exactly matched.
if (docsAndFreqs[i].doc < doc) {
docsAndFreqs[i].doc = docsAndFreqs[i].scorer.advance(doc);
if (docsAndFreqs[i].doc > doc) {
// DocsEnum beyond the current doc - break and advance lead to the new highest doc.
doc = docsAndFreqs[i].doc;
break advanceHead;
}
}
}
// success - all DocsEnums are on the same doc
return doc;
}
// advance head for next iteration
doc = lead.doc = lead.scorer.advance(doc);
}
}
@Override
public int nextDoc() throws IOException {
lead.doc = lead.scorer.nextDoc();
return lastDoc = doNext(lead.doc);
}
@Override
public int advance(int target) throws IOException {
lead.doc = lead.scorer.advance(target);
return lastDoc = doNext(lead.doc);
}
