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/**
* Copyright (C) 2013 10gen Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License, version 3,
* as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "mongo/db/query/query_projection.h"
#include "mongo/db/exec/working_set.h"
#include "mongo/db/jsobj.h"
#include "mongo/util/mongoutils/str.h"
namespace mongo {
//
// .find() syntax incl/excl projection
// TODO: Test.
//
class InclExclProjection : public QueryProjection {
public:
virtual ~InclExclProjection() { }
Status project(const WorkingSetMember& wsm, BSONObj* out) {
BSONObjBuilder bob;
if (_includeID) {
BSONElement elt;
if (!wsm.getFieldDotted("_id", &elt)) {
return Status(ErrorCodes::BadValue, "Couldn't get _id field in proj");
}
bob.append(elt);
}
if (_fieldsInclusive) {
// We only want stuff in _fields.
for (unordered_set<string>::const_iterator it = _fields.begin();
it != _fields.end(); ++it) {
BSONElement elt;
if (!wsm.getFieldDotted(*it, &elt)) {
return Status(ErrorCodes::BadValue, "no field " + *it + " in wsm to proj");
}
bob.append(elt);
}
}
else {
// We want stuff NOT in _fields. This can't be covered, so we expect an obj.
if (!wsm.hasObj()) {
return Status(ErrorCodes::BadValue,
"exclusion specified for projection but no obj to iter over");
}
BSONObjIterator it(wsm.obj);
while (it.more()) {
BSONElement elt = it.next();
if (_fields.end() == _fields.find(elt.fieldName())) {
bob.append(elt);
}
}
}
*out = bob.obj();
return Status::OK();
}
private:
friend class QueryProjection;
// _id can be included/excluded separately and is by default included.
bool _includeID;
// Either we include all of _fields or we exclude all of _fields.
bool _fieldsInclusive;
unordered_set<string> _fields;
};
// static
Status QueryProjection::newInclusionExclusion(const BSONObj& obj, QueryProjection** out) {
auto_ptr<InclExclProjection> qp(new InclExclProjection());
// Include _id by default.
qp->_includeID = true;
// By default include everything.
bool lastNonIDValue = false;
BSONObjIterator it(obj);
while (it.more()) {
BSONElement elt = it.next();
if (mongoutils::str::equals("_id", elt.fieldName())) {
qp->_includeID = elt.trueValue();
}
else {
bool newFieldValue = elt.trueValue();
if (qp->_fields.size() > 0) {
// make sure we're all true or all false otherwise error
if (newFieldValue != lastNonIDValue) {
return Status(ErrorCodes::BadValue, "Inconsistent projection specs");
}
}
lastNonIDValue = newFieldValue;
qp->_fields.insert(elt.fieldName());
}
}
qp->_fieldsInclusive = lastNonIDValue;
*out = qp.release();
return Status::OK();
}
} // namespace mongo
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