void IndexSpec::getKeys( const BSONObj &obj, BSONObjSetDefaultOrder &keys ) const {
if ( _indexType.get() ){
_indexType->getKeys( obj , keys );
return;
}
vector<const char*> fieldNames( _fieldNames );
vector<BSONElement> fixed( _fixed );
_getKeys( fieldNames , fixed , obj, keys );
if ( keys.empty() )
keys.insert( _nullKey );
}
void IndexSpec::_getKeys( vector<const char*> fieldNames , vector<BSONElement> fixed , const BSONObj &obj, BSONObjSetDefaultOrder &keys ) const {
BSONElement arrElt;
unsigned arrIdx = ~0;
for( unsigned i = 0; i < fieldNames.size(); ++i ) {
if ( *fieldNames[ i ] == '\0' )
continue;
BSONElement e = obj.getFieldDottedOrArray( fieldNames[ i ] );
if ( e.eoo() )
e = _nullElt; // no matching field
if ( e.type() != Array )
fieldNames[ i ] = ""; // no matching field or non-array match
if ( *fieldNames[ i ] == '\0' )
fixed[ i ] = e; // no need for further object expansion (though array expansion still possible)
if ( e.type() == Array && arrElt.eoo() ) { // we only expand arrays on a single path -- track the path here
arrIdx = i;
arrElt = e;
}
// enforce single array path here
uassert( 10088 , "cannot index parallel arrays", e.type() != Array || e.rawdata() == arrElt.rawdata() );
}
bool allFound = true; // have we found elements for all field names in the key spec?
for( vector<const char*>::const_iterator i = fieldNames.begin(); i != fieldNames.end(); ++i ){
if ( **i != '\0' ){
allFound = false;
break;
}
}
bool insertArrayNull = false;
if ( allFound ) {
if ( arrElt.eoo() ) {
// no terminal array element to expand
BSONObjBuilder b(_sizeTracker);
for( vector< BSONElement >::iterator i = fixed.begin(); i != fixed.end(); ++i )
b.appendAs( *i, "" );
keys.insert( b.obj() );
}
else {
// terminal array element to expand, so generate all keys
BSONObjIterator i( arrElt.embeddedObject() );
if ( i.more() ){
while( i.more() ) {
BSONObjBuilder b(_sizeTracker);
for( unsigned j = 0; j < fixed.size(); ++j ) {
if ( j == arrIdx )
b.appendAs( i.next(), "" );
else
b.appendAs( fixed[ j ], "" );
}
keys.insert( b.obj() );
}
}
else if ( fixed.size() > 1 ){
insertArrayNull = true;
}
}
} else {
// nonterminal array element to expand, so recurse
assert( !arrElt.eoo() );
BSONObjIterator i( arrElt.embeddedObject() );
if ( i.more() ){
while( i.more() ) {
BSONElement e = i.next();
if ( e.type() == Object ){
_getKeys( fieldNames, fixed, e.embeddedObject(), keys );
}
}
}
else {
insertArrayNull = true;
}
}
if ( insertArrayNull ) {
// x : [] - need to insert undefined
BSONObjBuilder b(_sizeTracker);
for( unsigned j = 0; j < fixed.size(); ++j ) {
if ( j == arrIdx ){
b.appendUndefined( "" );
}
else {
BSONElement e = fixed[j];
if ( e.eoo() )
b.appendNull( "" );
else
b.appendAs( e , "" );
}
}
keys.insert( b.obj() );
}
}