// Entry point for a search.
virtual shared_ptr<Cursor> newCursor(const BSONObj& query, const BSONObj& order,
int numWanted) const {
vector<QueryGeometry> regions;
double maxDistance = DBL_MAX;
bool isNear = false;
bool isIntersect = false;
// Go through the fields that we index, and for each geo one, make a QueryGeometry
// object for the S2Cursor class to do intersection testing/cover generating with.
for (size_t i = 0; i < _fields.size(); ++i) {
const IndexedField &field = _fields[i];
if (IndexedField::GEO != field.type) { continue; }
BSONElement e = query.getFieldDotted(field.name);
if (e.eoo()) { continue; }
if (!e.isABSONObj()) { continue; }
BSONObj obj = e.Obj();
QueryGeometry geoQueryField(field.name);
if (parseLegacy(obj, &geoQueryField, &isNear, &isIntersect, &maxDistance)) {
regions.push_back(geoQueryField);
} else if (parseQuery(obj, &geoQueryField, &isNear, &isIntersect, &maxDistance)) {
regions.push_back(geoQueryField);
} else {
uasserted(16535, "can't parse query for *2d geo search: " + obj.toString());
}
}
if (isNear && isIntersect ) {
uasserted(16474, "Can't do both near and intersect, query: " + query.toString());
}
// I copied this from 2d.cpp. Guard against perversion.
if (numWanted < 0) numWanted *= -1;
if (0 == numWanted) numWanted = INT_MAX;
BSONObjBuilder geoFieldsToNuke;
for (size_t i = 0; i < _fields.size(); ++i) {
const IndexedField &field = _fields[i];
if (IndexedField::GEO != field.type) { continue; }
geoFieldsToNuke.append(field.name, "");
}
// false means we want to filter OUT geoFieldsToNuke, not filter to include only that.
BSONObj filteredQuery = query.filterFieldsUndotted(geoFieldsToNuke.obj(), false);
if (isNear) {
S2NearCursor *cursor = new S2NearCursor(keyPattern(), getDetails(), filteredQuery, regions,
_params, numWanted, maxDistance);
return shared_ptr<Cursor>(cursor);
} else {
// Default to intersect.
S2Cursor *cursor = new S2Cursor(keyPattern(), getDetails(), filteredQuery, regions, _params,
numWanted);
return shared_ptr<Cursor>(cursor);
}
}
Status S2IndexCursor::seek(const BSONObj &position) {
vector<GeoQuery> regions;
bool isNearQuery = false;
NearQuery nearQuery;
// Go through the fields that we index, and for each geo one, make
// a GeoQuery object for the S2*Cursor class to do intersection
// testing/cover generating with.
BSONObjIterator keyIt(_descriptor->keyPattern());
while (keyIt.more()) {
BSONElement keyElt = keyIt.next();
if (keyElt.type() != String || IndexNames::GEO_2DSPHERE != keyElt.valuestr()) {
continue;
}
BSONElement e = position.getFieldDotted(keyElt.fieldName());
if (e.eoo()) { continue; }
if (!e.isABSONObj()) { continue; }
BSONObj obj = e.Obj();
if (nearQuery.parseFrom(obj, _params.radius)) {
if (isNearQuery) {
return Status(ErrorCodes::BadValue, "Only one $near clause allowed: " +
position.toString(), 16685);
}
isNearQuery = true;
nearQuery.field = keyElt.fieldName();
continue;
}
GeoQuery geoQueryField(keyElt.fieldName());
if (!geoQueryField.parseFrom(obj)) {
return Status(ErrorCodes::BadValue, "can't parse query (2dsphere): "
+ obj.toString(), 16535);
}
if (!geoQueryField.hasS2Region()) {
return Status(ErrorCodes::BadValue, "Geometry unsupported: " + obj.toString(),
16684);
}
regions.push_back(geoQueryField);
}
// Remove all the indexed geo regions from the query. The s2*cursor will
// instead create a covering for that key to speed up the search.
//
// One thing to note is that we create coverings for indexed geo keys during
// a near search to speed it up further.
BSONObjBuilder geoFieldsToNuke;
if (isNearQuery) {
geoFieldsToNuke.append(nearQuery.field, "");
}
for (size_t i = 0; i < regions.size(); ++i) {
geoFieldsToNuke.append(regions[i].getField(), "");
}
// false means we want to filter OUT geoFieldsToNuke, not filter to include only that.
BSONObj filteredQuery = position.filterFieldsUndotted(geoFieldsToNuke.obj(), false);
if (isNearQuery) {
S2NearIndexCursor* nearCursor = new S2NearIndexCursor(_descriptor, _params);
_underlyingCursor.reset(nearCursor);
nearCursor->seek(filteredQuery, nearQuery, regions);
} else {
S2SimpleCursor* simpleCursor = new S2SimpleCursor(_descriptor, _params);
_underlyingCursor.reset(simpleCursor);
simpleCursor->seek(filteredQuery, regions);
}
return Status::OK();
}
