BSONObj S2NearCursor::makeFRSObject() {
BSONObjBuilder frsObjBuilder;
frsObjBuilder.appendElements(_filteredQuery);
S2RegionCoverer coverer;
_params.configureCoverer(&coverer);
// Step 1: Make the monstrous BSONObj that describes what keys we want.
for (size_t i = 0; i < _fields.size(); ++i) {
const GeoQueryField &field = _fields[i];
S2Point center = field.getCentroid();
BSONObj inExpr;
// Caps are inclusive and inverting a cap includes the border. This means that our
// initial _innerRadius of 0 is OK -- we'll still find a point that is exactly at
// the start of our search.
S2Cap innerCap = S2Cap::FromAxisAngle(center, S1Angle::Radians(_innerRadius / _params.radius));
S2Cap invInnerCap = innerCap.Complement();
S2Cap outerCap = S2Cap::FromAxisAngle(center, S1Angle::Radians(_outerRadius / _params.radius));
vector<S2Region*> regions;
regions.push_back(&invInnerCap);
regions.push_back(&outerCap);
S2RegionIntersection shell(®ions);
inExpr = S2SearchUtil::coverAsBSON(&coverer, shell, field.field);
// Shell takes ownership of the regions we push in, but they're local variables and
// deleting them would be bad.
shell.Release(NULL);
frsObjBuilder.appendElements(inExpr);
}
return frsObjBuilder.obj();
}
BSONObj S2NearCursor::makeFRSObject() {
BSONObjBuilder frsObjBuilder;
frsObjBuilder.appendElements(_filteredQuery);
S2RegionCoverer coverer;
// Step 1: Make the BSON'd covering for our search annulus.
BSONObj inExpr;
// Caps are inclusive and inverting a cap includes the border. This means that our
// initial _innerRadius of 0 is OK -- we'll still find a point that is exactly at
// the start of our search.
S2Cap innerCap = S2Cap::FromAxisAngle(_nearQuery.centroid,
S1Angle::Radians(_innerRadius / _params.radius));
S2Cap invInnerCap = innerCap.Complement();
S2Cap outerCap = S2Cap::FromAxisAngle(_nearQuery.centroid,
S1Angle::Radians(_outerRadius / _params.radius));
vector<S2Region*> regions;
regions.push_back(&invInnerCap);
regions.push_back(&outerCap);
S2RegionIntersection shell(®ions);
vector<S2CellId> cover;
double area = outerCap.area() - innerCap.area();
S2SearchUtil::setCoverLimitsBasedOnArea(area, &coverer, _params.coarsestIndexedLevel);
coverer.GetCovering(shell, &cover);
LOG(2) << "annulus cover size is " << cover.size()
<< ", params (" << coverer.min_level() << ", " << coverer.max_level() << ")"
<< endl;
inExpr = S2SearchUtil::coverAsBSON(cover, _nearQuery.field,
_params.coarsestIndexedLevel);
// Shell takes ownership of the regions we push in, but they're local variables and
// deleting them would be bad.
shell.Release(NULL);
frsObjBuilder.appendElements(inExpr);
_params.configureCoverer(&coverer);
// Cover the indexed geo components of the query.
for (size_t i = 0; i < _indexedGeoFields.size(); ++i) {
vector<S2CellId> cover;
coverer.GetCovering(_indexedGeoFields[i].getRegion(), &cover);
uassert(16682, "Couldn't generate index keys for geo field "
+ _indexedGeoFields[i].getField(),
cover.size() > 0);
BSONObj fieldRange = S2SearchUtil::coverAsBSON(cover, _indexedGeoFields[i].getField(),
_params.coarsestIndexedLevel);
frsObjBuilder.appendElements(fieldRange);
}
return frsObjBuilder.obj();
}
