// Get the index keys for elements that are GeoJSON.
void S2AccessMethod::getGeoKeys(const BSONElementSet& elements, BSONObjSet* out) const {
S2RegionCoverer coverer;
_params.configureCoverer(&coverer);
// See here for GeoJSON format: geojson.org/geojson-spec.html
for (BSONElementSet::iterator i = elements.begin(); i != elements.end(); ++i) {
uassert(16754, "Can't parse geometry from element: " + i->toString(),
i->isABSONObj());
const BSONObj &obj = i->Obj();
vector<string> cells;
S2Polyline line;
S2Cell point;
// We only support GeoJSON polygons. Why?:
// 1. we don't automagically do WGS84/flat -> WGS84, and
// 2. the old polygon format must die.
if (GeoParser::isGeoJSONPolygon(obj)) {
S2Polygon polygon;
GeoParser::parseGeoJSONPolygon(obj, &polygon);
keysFromRegion(&coverer, polygon, &cells);
} else if (GeoParser::parseLineString(obj, &line)) {
keysFromRegion(&coverer, line, &cells);
} else if (GeoParser::parsePoint(obj, &point)) {
S2CellId parent(point.id().parent(_params.finestIndexedLevel));
cells.push_back(parent.toString());
} else {
uasserted(16755, "Can't extract geo keys from object, malformed geometry?:"
+ obj.toString());
}
uassert(16756, "Unable to generate keys for (likely malformed) geometry: "
+ obj.toString(),
cells.size() > 0);
for (vector<string>::const_iterator it = cells.begin(); it != cells.end(); ++it) {
BSONObjBuilder b;
b.append("", *it);
out->insert(b.obj());
}
}
if (0 == out->size()) {
BSONObjBuilder b;
b.appendNull("");
out->insert(b.obj());
}
}
double S2NearCursor::distanceBetween(const QueryGeometry &field, const BSONObj &obj) {
S2Point us = field.getCentroid();
S2Point them;
S2Polygon polygon;
S2Polyline line;
S2Cell point;
if (GeoJSONParser::parsePolygon(obj, &polygon)) {
them = polygon.Project(us);
} else if (GeoJSONParser::parseLineString(obj, &line)) {
int tmp;
them = line.Project(us, &tmp);
} else if (GeoJSONParser::parsePoint(obj, &point)) {
them = point.GetCenter();
} else {
warning() << "unknown geometry: " << obj.toString();
}
S1Angle angle(us, them);
return angle.radians() * _params.radius;
}
double S2NearIndexCursor::distanceTo(const BSONObj& obj) {
const S2Point &us = _nearQuery.centroid;
S2Point them;
S2Polygon polygon;
S2Polyline line;
S2Cell point;
if (GeoParser::parsePolygon(obj, &polygon)) {
them = polygon.Project(us);
} else if (GeoParser::parseLineString(obj, &line)) {
int tmp;
them = line.Project(us, &tmp);
} else if (GeoParser::parsePoint(obj, &point)) {
them = point.GetCenter();
} else {
warning() << "unknown geometry: " << obj.toString();
return numeric_limits<double>::max();
}
S1Angle angle(us, them);
return angle.radians() * _params.radius;
}
// Fill _results with the next shell of results. We may have to search several times to do
// this. If _results.empty() after calling fillResults, there are no more possible results.
void S2NearCursor::fillResults() {
verify(_results.empty());
if (_innerRadius >= _outerRadius) { return; }
if (_innerRadius > _maxDistance) { return; }
// We iterate until 1. our search radius is too big or 2. we find results.
do {
// Some of these arguments are opaque, look at the definitions of the involved classes.
FieldRangeSet frs(_details->parentNS().c_str(), makeFRSObject(), false, false);
shared_ptr<FieldRangeVector> frv(new FieldRangeVector(frs, _specForFRV, 1));
scoped_ptr<BtreeCursor> cursor(BtreeCursor::make(nsdetails(_details->parentNS().c_str()),
*_details, frv, 0, 1));
// Do the actual search through this annulus.
size_t considered = 0;
for (; cursor->ok(); cursor->advance()) {
++_nscanned;
++considered;
MatchDetails details;
bool matched = _matcher->matchesCurrent(cursor.get(), &details);
if (!matched) { continue; }
const BSONObj& indexedObj = cursor->currLoc().obj();
size_t geoFieldsInRange = 0;
double minMatchingDistance = 1e20;
// Calculate the distance from our query point(s) to the geo field(s).
for (size_t i = 0; i < _fields.size(); ++i) {
const GeoQueryField& field = _fields[i];
BSONElementSet geoFieldElements;
indexedObj.getFieldsDotted(field.field, geoFieldElements);
if (geoFieldElements.empty()) { continue; }
S2Point us = field.getCentroid();
for (BSONElementSet::iterator oi = geoFieldElements.begin();
oi != geoFieldElements.end(); ++oi) {
const BSONObj &geoObj = oi->Obj();
double dist = -1;
S2Point them;
if (GeoJSONParser::isPolygon(geoObj)) {
S2Polygon shape;
GeoJSONParser::parsePolygon(geoObj, &shape);
them = shape.Project(us);
} else if (GeoJSONParser::isLineString(geoObj)) {
S2Polyline shape;
GeoJSONParser::parseLineString(geoObj, &shape);
int tmp;
them = shape.Project(us, &tmp);
} else if (GeoJSONParser::isPoint(geoObj)) {
S2Cell point;
GeoJSONParser::parsePoint(geoObj, &point);
them = point.GetCenter();
}
S1Angle angle(us, them);
dist = angle.radians() * _params.radius;
if (dist >= _innerRadius && dist <= _outerRadius) {
++geoFieldsInRange;
minMatchingDistance = min(dist, minMatchingDistance);
}
}
}
if (_fields.size() == geoFieldsInRange) {
if (_returned.end() == _returned.find(cursor->currLoc())) {
_results.push(Result(cursor->currLoc(), cursor->currKey(), minMatchingDistance));
}
}
}
if (_results.empty()) {
_radiusIncrement *= 2;
nextAnnulus();
}
} while (_results.empty() && _innerRadius < M_PI * _params.radius);
// TODO: consider shrinking _radiusIncrement if _results.size() meets some criteria.
}
