/** Called initially, and whenever {@link #visit(org.apache.lucene.spatial.prefix.tree.Node)}
* returns true. */
private void addIntersectingChildren() throws IOException {
assert thisTerm != null;
Node cell = curVNode.cell;
if (cell.getLevel() >= detailLevel)
throw new IllegalStateException("Spatial logic error");
//Check for adjacent leaf (happens for indexed non-point shapes)
assert !cell.isLeaf();
if (hasIndexedLeaves && cell.getLevel() != 0) {
//If the next indexed term just adds a leaf marker ('+') to cell,
// then add all of those docs
assert StringHelper.startsWith(thisTerm, curVNodeTerm);
scanCell = grid.getNode(thisTerm.bytes, thisTerm.offset, thisTerm.length, scanCell);
if (scanCell.getLevel() == cell.getLevel() && scanCell.isLeaf()) {
visitLeaf(scanCell);
//advance
if ((thisTerm = termsEnum.next()) == null)
return; // all done
}
}
//Decide whether to continue to divide & conquer, or whether it's time to
// scan through terms beneath this cell.
// Scanning is a performance optimization trade-off.
//TODO use termsEnum.docFreq() as heuristic
boolean scan = cell.getLevel() >= prefixGridScanLevel;//simple heuristic
if (!scan) {
//Divide & conquer (ultimately termsEnum.seek())
Iterator<Node> subCellsIter = findSubCellsToVisit(cell);