shared_ptr<QueryOp> QueryPlanSet::Runner::next() {
mayYield();
OpHolder holder = _queue.top();
_queue.pop();
QueryOp &op = *holder._op;
nextOp( op );
if ( op.complete() ) {
if ( _plans._mayRecordPlan && op.mayRecordPlan() ) {
op.qp().registerSelf( op.nscanned() );
}
return holder._op;
}
if ( op.error() ) {
return holder._op;
}
_queue.push( holder );
if ( !_plans._bestGuessOnly && _plans._usingPrerecordedPlan && op.nscanned() > _plans._oldNScanned * 10 && _plans._special.empty() ) {
holder._offset = -op.nscanned();
_plans.addOtherPlans( /* avoid duplicating the initial plan */ true );
PlanSet::iterator i = _plans._plans.begin();
++i;
for( ; i != _plans._plans.end(); ++i ) {
shared_ptr<QueryOp> op( _op.createChild() );
op->setQueryPlan( i->get() );
_ops.push_back( op );
initOp( *op );
if ( op->complete() )
return op;
_queue.push( op );
}
_plans._mayRecordPlan = true;
_plans._usingPrerecordedPlan = false;
}
return holder._op;
}
shared_ptr<QueryOp> QueryPlanSet::Runner::run() {
massert( 10369 , "no plans", _plans._plans.size() > 0 );
vector<shared_ptr<QueryOp> > ops;
if ( _plans._bestGuessOnly ) {
shared_ptr<QueryOp> op( _op.createChild() );
op->setQueryPlan( _plans.getBestGuess().get() );
ops.push_back( op );
}
else {
if ( _plans._plans.size() > 1 )
log(1) << " running multiple plans" << endl;
for( PlanSet::iterator i = _plans._plans.begin(); i != _plans._plans.end(); ++i ) {
shared_ptr<QueryOp> op( _op.createChild() );
op->setQueryPlan( i->get() );
ops.push_back( op );
}
}
for( vector<shared_ptr<QueryOp> >::iterator i = ops.begin(); i != ops.end(); ++i ) {
initOp( **i );
if ( (*i)->complete() )
return *i;
}
std::priority_queue<OpHolder> queue;
for( vector<shared_ptr<QueryOp> >::iterator i = ops.begin(); i != ops.end(); ++i ) {
if ( !(*i)->error() ) {
queue.push( *i );
}
}
while( !queue.empty() ) {
mayYield( ops );
OpHolder holder = queue.top();
queue.pop();
QueryOp &op = *holder._op;
nextOp( op );
if ( op.complete() ) {
if ( _plans._mayRecordPlan && op.mayRecordPlan() ) {
op.qp().registerSelf( op.nscanned() );
}
return holder._op;
}
if ( op.error() ) {
continue;
}
queue.push( holder );
if ( !_plans._bestGuessOnly && _plans._usingPrerecordedPlan && op.nscanned() > _plans._oldNScanned * 10 && _plans._special.empty() ) {
holder._offset = -op.nscanned();
_plans.addOtherPlans( /* avoid duplicating the initial plan */ true );
PlanSet::iterator i = _plans._plans.begin();
++i;
for( ; i != _plans._plans.end(); ++i ) {
shared_ptr<QueryOp> op( _op.createChild() );
op->setQueryPlan( i->get() );
ops.push_back( op );
initOp( *op );
if ( op->complete() )
return op;
queue.push( op );
}
_plans._mayRecordPlan = true;
_plans._usingPrerecordedPlan = false;
}
}
return ops[ 0 ];
}
