bool applyProjectionToOneField(StringData field) const {
MutableDocument doc;
const FieldPath f{field};
doc.setNestedField(f, Value(1.0));
const Document transformedDoc = applyTransformation(doc.freeze());
return !transformedDoc.getNestedField(f).missing();
}
boost::optional<Document> DocumentSourceGeoNear::getNext() {
pExpCtx->checkForInterrupt();
if (!resultsIterator)
runCommand();
if (!resultsIterator->more())
return boost::none;
// each result from the geoNear command is wrapped in a wrapper object with "obj",
// "dis" and maybe "loc" fields. We want to take the object from "obj" and inject the
// other fields into it.
Document result (resultsIterator->next().embeddedObject());
MutableDocument output (result["obj"].getDocument());
output.setNestedField(*distanceField, result["dis"]);
if (includeLocs)
output.setNestedField(*includeLocs, result["loc"]);
return output.freeze();
}
// Taken as a whole, these three functions should produce the same output document given the
// same deps set as mongo::Projection::transform would on the output of depsToProjection. The
// only exceptions are that we correctly handle the case where no fields are needed and we don't
// need to work around the above mentioned bug with subfields of _id (SERVER-7502). This is
// tested in a DEV block in DocumentSourceCursor::findNext().
//
// Output from this function is input for the next two
//
// ParsedDeps is a simple recursive look-up table. For each field in a ParsedDeps:
// If the value has type==Bool, the whole field is needed
// If the value has type==Object, the fields in the subobject are needed
// All other fields should be missing which means not needed
DocumentSource::ParsedDeps DocumentSource::parseDeps(const set<string>& deps) {
MutableDocument md;
string last;
for (set<string>::const_iterator it(deps.begin()), end(deps.end()); it!=end; ++it) {
if (!last.empty() && str::startsWith(*it, last)) {
// we are including a parent of *it so we don't need to include this field
// explicitly. In fact, if we included this field, the parent wouldn't be fully
// included. This logic relies on on set iterators going in lexicographic order so
// that a string is always directly before of all fields it prefixes.
continue;
}
last = *it + '.';
md.setNestedField(*it, Value(true));
}
return md.freeze();
}
// ParsedDeps::_fields is a simple recursive look-up table. For each field:
// If the value has type==Bool, the whole field is needed
// If the value has type==Object, the fields in the subobject are needed
// All other fields should be missing which means not needed
boost::optional<ParsedDeps> DepsTracker::toParsedDeps() const {
MutableDocument md;
if (needWholeDocument || _needTextScore) {
// can't use ParsedDeps in this case
return boost::none;
}
string last;
for (set<string>::const_iterator it(fields.begin()), end(fields.end()); it != end; ++it) {
if (!last.empty() && str::startsWith(*it, last)) {
// we are including a parent of *it so we don't need to include this field
// explicitly. In fact, if we included this field, the parent wouldn't be fully
// included. This logic relies on on set iterators going in lexicographic order so
// that a string is always directly before of all fields it prefixes.
continue;
}
last = *it + '.';
md.setNestedField(*it, Value(true));
}
return ParsedDeps(md.freeze());
}