PlanStage::StageState Count::work(WorkingSetID* out) {
if (NULL == _btreeCursor.get()) {
// First call to work(). Perform cursor init.
initIndexCursor();
checkEnd();
return PlanStage::NEED_TIME;
}
if (isEOF()) { return PlanStage::IS_EOF; }
DiskLoc loc = _btreeCursor->getValue();
_btreeCursor->next();
checkEnd();
if (_shouldDedup) {
if (_returned.end() != _returned.find(loc)) {
return PlanStage::NEED_TIME;
}
else {
_returned.insert(loc);
}
}
*out = WorkingSet::INVALID_ID;
return PlanStage::ADVANCED;
}
PlanStage::StageState DistinctScan::work(WorkingSetID* out) {
++_commonStats.works;
if (NULL == _btreeCursor.get()) {
// First call to work(). Perform cursor init.
initIndexCursor();
checkEnd();
}
if (isEOF()) { return PlanStage::IS_EOF; }
// Grab the next (key, value) from the index.
BSONObj ownedKeyObj = _btreeCursor->getKey().getOwned();
DiskLoc loc = _btreeCursor->getValue();
// The underlying IndexCursor points at the *next* thing we want to return. We do this so
// that if we're scanning an index looking for docs to delete we don't continually clobber
// the thing we're pointing at.
// We skip to the next value of the _params.fieldNo-th field in the index key pattern.
// This is the field we're distinct-ing over.
_btreeCursor->skip(_btreeCursor->getKey(),
_params.fieldNo + 1,
true,
_keyElts,
_keyEltsInc);
// And make sure we're within the bounds.
checkEnd();
// Package up the result for the caller.
WorkingSetID id = _workingSet->allocate();
WorkingSetMember* member = _workingSet->get(id);
member->loc = loc;
member->keyData.push_back(IndexKeyDatum(_descriptor->keyPattern(), ownedKeyObj));
member->state = WorkingSetMember::LOC_AND_IDX;
*out = id;
++_commonStats.advanced;
return PlanStage::ADVANCED;
}
PlanStage::StageState Count::work(WorkingSetID* out) {
++_commonStats.works;
// Adds the amount of time taken by work() to executionTimeMillis.
ScopedTimer timer(&_commonStats.executionTimeMillis);
if (NULL == _btreeCursor.get()) {
// First call to work(). Perform cursor init.
initIndexCursor();
checkEnd();
++_commonStats.needTime;
return PlanStage::NEED_TIME;
}
if (isEOF()) { return PlanStage::IS_EOF; }
DiskLoc loc = _btreeCursor->getValue();
_btreeCursor->next();
checkEnd();
++_specificStats.keysExamined;
if (_shouldDedup) {
if (_returned.end() != _returned.find(loc)) {
++_commonStats.needTime;
return PlanStage::NEED_TIME;
}
else {
_returned.insert(loc);
}
}
*out = WorkingSet::INVALID_ID;
++_commonStats.advanced;
return PlanStage::ADVANCED;
}
PlanStage::StageState IndexScan::work(WorkingSetID* out) {
++_commonStats.works;
if (NULL == _indexCursor.get()) {
// First call to work(). Perform cursor init.
initIndexCursor();
checkEnd();
}
else if (_yieldMovedCursor) {
_yieldMovedCursor = false;
// Note that we're not calling next() here. We got the next thing when we recovered
// from yielding.
}
if (isEOF()) { return PlanStage::IS_EOF; }
// Grab the next (key, value) from the index.
BSONObj keyObj = _indexCursor->getKey();
DiskLoc loc = _indexCursor->getValue();
// Move to the next result.
// The underlying IndexCursor points at the *next* thing we want to return. We do this so
// that if we're scanning an index looking for docs to delete we don't continually clobber
// the thing we're pointing at.
_indexCursor->next();
checkEnd();
if (_shouldDedup) {
++_specificStats.dupsTested;
if (_returned.end() != _returned.find(loc)) {
++_specificStats.dupsDropped;
++_commonStats.needTime;
return PlanStage::NEED_TIME;
}
else {
_returned.insert(loc);
}
}
if (Filter::passes(keyObj, _keyPattern, _filter)) {
if (NULL != _filter) {
++_specificStats.matchTested;
}
// We must make a copy of the on-disk data since it can mutate during the execution of
// this query.
BSONObj ownedKeyObj = keyObj.getOwned();
// Fill out the WSM.
WorkingSetID id = _workingSet->allocate();
WorkingSetMember* member = _workingSet->get(id);
member->loc = loc;
member->keyData.push_back(IndexKeyDatum(_keyPattern, ownedKeyObj));
member->state = WorkingSetMember::LOC_AND_IDX;
if (_params.addKeyMetadata) {
BSONObjBuilder bob;
bob.appendKeys(_keyPattern, ownedKeyObj);
member->addComputed(new IndexKeyComputedData(bob.obj()));
}
*out = id;
++_commonStats.advanced;
return PlanStage::ADVANCED;
}
++_commonStats.needTime;
return PlanStage::NEED_TIME;
}