virtual bool advance() {
if ( _takeover ) {
return _takeover->advance();
}
// Ok to advance if currOp in an error state due to failed yield recovery.
// This may be the case when advance() is called by recoverFromYield().
if ( !( _currOp && _currOp->error() ) && !ok() ) {
return false;
}
_currOp = 0;
shared_ptr<QueryOp> op = _mps->nextOp();
rethrowOnError( op );
QueryOptimizerCursorOp *qocop = dynamic_cast<QueryOptimizerCursorOp*>( op.get() );
if ( !op->complete() ) {
// 'qocop' will be valid until we call _mps->nextOp() again.
_currOp = qocop;
}
else if ( op->stopRequested() ) {
if ( qocop->cursor() ) {
_takeover.reset( new MultiCursor( _mps,
qocop->cursor(),
op->matcher( qocop->cursor() ),
*op,
_nscanned - qocop->cursor()->nscanned() ) );
}
}
return ok();
}
void QueryOptimizerCursorImpl::init( bool explain ) {
_mps->initialRunner( _originalRunner );
if ( explain ) {
_explainQueryInfo = _mps->generateExplainInfo();
}
shared_ptr<QueryPlanRunner> runner = _mps->nextRunner();
rethrowOnError( runner );
if ( !runner->complete() ) {
_currRunner = runner.get();
}
}
QueryOptimizerCursor( auto_ptr<MultiPlanScanner> &mps ) :
_mps( mps ),
_originalOp( new QueryOptimizerCursorOp( _nscanned ) ),
_currOp(),
_nscanned() {
_mps->initialOp( _originalOp );
shared_ptr<QueryOp> op = _mps->nextOp();
rethrowOnError( op );
if ( !op->complete() ) {
_currOp = dynamic_cast<QueryOptimizerCursorOp*>( op.get() );
}
}
bool QueryOptimizerCursorImpl::_advance( bool force ) {
if ( _takeover ) {
return _takeover->advance();
}
if ( !force && !ok() ) {
return false;
}
_currRunner = 0;
shared_ptr<QueryPlanRunner> runner = _mps->nextRunner();
rethrowOnError( runner );
if ( !runner->complete() ) {
// The 'runner' will be valid until we call _mps->nextOp() again. We return 'current'
// values from this op.
_currRunner = runner.get();
}
else if ( runner->stopRequested() ) {
if ( runner->cursor() ) {
_takeover.reset( new MultiCursor( _mps,
runner->cursor(),
runner->queryPlan().matcher(),
runner->explainInfo(),
*runner,
_nscanned - runner->cursor()->nscanned() ) );
}
}
else {
if ( _initialCandidatePlans.hybridPlanSet() ) {
_completePlanOfHybridSetScanAndOrderRequired =
runner->queryPlan().scanAndOrderRequired();
}
}
return ok();
}
