Value DocumentSourceCursor::serialize(bool explain) const {
// we never parse a documentSourceCursor, so we only serialize for explain
if (!explain)
return Value();
Status explainStatus(ErrorCodes::InternalError, "");
scoped_ptr<TypeExplain> plan;
{
Lock::DBRead lk(_ns);
Client::Context ctx(_ns, storageGlobalParams.dbpath, /*doVersion=*/false);
ClientCursorPin pin(_cursorId);
ClientCursor* cursor = pin.c();
uassert(17135, "Cursor deleted. Was the collection or database dropped?",
cursor);
Runner* runner = cursor->getRunner();
runner->restoreState();
TypeExplain* explainRaw;
explainStatus = runner->getExplainPlan(&explainRaw);
if (explainStatus.isOK())
plan.reset(explainRaw);
runner->saveState();
}
MutableDocument out;
out["query"] = Value(_query);
if (!_sort.isEmpty())
out["sort"] = Value(_sort);
if (_limit)
out["limit"] = Value(_limit->getLimit());
if (!_projection.isEmpty())
out["fields"] = Value(_projection);
if (explainStatus.isOK()) {
out["plan"] = Value(extractInfo(plan));
} else {
out["planError"] = Value(explainStatus.toString());
}
return out.freezeToValue();
}
