void Projection::validateQuery( const BSONObj query ) const {
// this function only validates positional operator ($) projections
if ( getArrayOpType() != ARRAY_OP_POSITIONAL &&
getArrayOpType() != ARRAY_OP_POSITIONAL_KEYED )
return;
BSONObjIterator querySpecIter( query );
while ( querySpecIter.more() ) {
// for each query element
BSONElement queryElement = querySpecIter.next();
if ( mongoutils::str::equals( queryElement.fieldName(), "$and" ) )
// don't check $and to avoid deep comparison of the arguments.
// TODO: can be replaced with Matcher::FieldSink when complete (SERVER-4644)
return;
BSONObjIterator projectionSpecIter( getSpec() );
while ( projectionSpecIter.more() ) {
// for each projection element
BSONElement projectionElement = projectionSpecIter.next();
if ( mongoutils::str::contains( projectionElement.fieldName(), ".$" ) &&
mongoutils::str::before( queryElement.fieldName(), '.' ) ==
mongoutils::str::before( projectionElement.fieldName(), "." ) ) {
// found query spec that matches positional array projection spec
LOG(4) << "Query specifies field named for positional operator: "
<< queryElement.fieldName() << endl;
return;
}
}
}
uasserted( 16354, "Positional operator does not match the query specifier." );
}
void Projection::transform( const BSONObj& in , BSONObjBuilder& b, const MatchDetails* details ) const {
const ArrayOpType& arrayOpType = getArrayOpType();
BSONObjIterator i(in);
while ( i.more() ) {
BSONElement e = i.next();
if ( mongoutils::str::equals( "_id" , e.fieldName() ) ) {
if ( _includeID )
b.append( e );
}
else {
Matchers::const_iterator matcher = _matchers.find( e.fieldName() );
if ( matcher == _matchers.end() ) {
// no array projection matchers for this field
append( b, e, details, arrayOpType );
} else {
// field has array projection with $elemMatch specified.
massert( 16348, "matchers are only supported for $elemMatch",
arrayOpType == ARRAY_OP_ELEM_MATCH );
MatchDetails arrayDetails;
arrayDetails.requestElemMatchKey();
if ( matcher->second->matches( in, &arrayDetails ) ) {
LOG(4) << "Matched array on field: " << matcher->first << endl
<< " from array: " << in.getField( matcher->first ) << endl
<< " in object: " << in << endl
<< " at position: " << arrayDetails.elemMatchKey() << endl;
FieldMap::const_iterator field = _fields.find( e.fieldName() );
massert( 16349, "$elemMatch specified, but projection field not found.",
field != _fields.end() );
BSONArrayBuilder a;
BSONObjBuilder o;
massert( 16350, "$elemMatch called on document element with eoo",
! in.getField( e.fieldName() ).eoo() );
massert( 16351, "$elemMatch called on array element with eoo",
! in.getField( e.fieldName() ).Obj().getField(
arrayDetails.elemMatchKey() ).eoo() );
a.append( in.getField( e.fieldName() ).Obj()
.getField( arrayDetails.elemMatchKey() ) );
o.appendArray( matcher->first, a.arr() );
append( b, o.done().firstElement(), details, arrayOpType );
}
}
}
}
}
