PlanStage::StageState OplogStart::work(WorkingSetID* out) {
// We do our (heavy) init in a work(), where work is expected.
if (_needInit) {
CollectionScanParams params;
params.collection = _collection;
params.direction = CollectionScanParams::BACKWARD;
_cs.reset(new CollectionScan(_txn, params, _workingSet, NULL));
_needInit = false;
_backwardsScanning = true;
_timer.reset();
}
// If we're still reading backwards, keep trying until timing out.
if (_backwardsScanning) {
verify(!_extentHopping);
// Still have time to succeed with reading backwards.
if (_timer.seconds() < _backwardsScanTime) {
return workBackwardsScan(out);
}
switchToExtentHopping();
}
// Don't find it in time? Swing from extent to extent like tarzan.com.
verify(_extentHopping);
return workExtentHopping(out);
}
PlanStage::StageState OplogStart::work(WorkingSetID* out) {
// We do our (heavy) init in a work(), where work is expected.
if (_needInit) {
CollectionScanParams params;
params.collection = _collection;
params.direction = CollectionScanParams::BACKWARD;
_cs.reset(new CollectionScan(params, _workingSet, NULL));
_nsd = _collection->details();
_needInit = false;
_backwardsScanning = true;
_timer.reset();
}
// If we don't have a _curloc yet, then we'll have
// to backwards scan this time in order to initialize it.
if (_curloc.isNull() && !_extentHopping) {
return workBackwardsScan(out);
}
// If we're reading backwards, try again.
if (_backwardsScanning) {
// Still have time to succeed with reading backwards.
if (_timer.seconds() < _backwardsScanTime) {
return workBackwardsScan(out);
}
switchToExtentHopping();
}
// Don't find it in time? Swing from extent to extent like tarzan.com.
verify(_extentHopping);
return workExtentHopping(out);
}
