void DocumentSourceGroup::populate() {
for(bool hasNext = !pSource->eof(); hasNext;
hasNext = pSource->advance()) {
intrusive_ptr<Document> pDocument(pSource->getCurrent());
/* get the _id document */
intrusive_ptr<const Value> pId(pIdExpression->evaluate(pDocument));
/* treat Undefined the same as NULL SERVER-4674 */
if (pId->getType() == Undefined)
pId = Value::getNull();
/*
Look for the _id value in the map; if it's not there, add a
new entry with a blank accumulator.
*/
vector<intrusive_ptr<Accumulator> > *pGroup;
GroupsType::iterator it(groups.find(pId));
if (it != groups.end()) {
/* point at the existing accumulators */
pGroup = &it->second;
}
else {
/* insert a new group into the map */
groups.insert(it,
pair<intrusive_ptr<const Value>,
vector<intrusive_ptr<Accumulator> > >(
pId, vector<intrusive_ptr<Accumulator> >()));
/* find the accumulator vector (the map value) */
it = groups.find(pId);
pGroup = &it->second;
/* add the accumulators */
const size_t n = vpAccumulatorFactory.size();
pGroup->reserve(n);
for(size_t i = 0; i < n; ++i) {
intrusive_ptr<Accumulator> pAccumulator(
(*vpAccumulatorFactory[i])(pExpCtx));
pAccumulator->addOperand(vpExpression[i]);
pGroup->push_back(pAccumulator);
}
}
/* point at the existing key */
// unneeded atm // pId = it.first;
/* tickle all the accumulators for the group we found */
const size_t n = pGroup->size();
for(size_t i = 0; i < n; ++i)
(*pGroup)[i]->evaluate(pDocument);
}
/* start the group iterator */
groupsIterator = groups.begin();
if (groupsIterator != groups.end())
pCurrent = makeDocument(groupsIterator);
populated = true;
}
intrusive_ptr<Accumulator> AccumulatorFirst::create(
const intrusive_ptr<ExpressionContext> &pCtx) {
intrusive_ptr<AccumulatorFirst> pAccumulator(
new AccumulatorFirst());
return pAccumulator;
}
intrusive_ptr<Accumulator> AccumulatorPush::create(
const intrusive_ptr<ExpressionContext> &pCtx) {
intrusive_ptr<AccumulatorPush> pAccumulator(
new AccumulatorPush(pCtx));
return pAccumulator;
}
intrusive_ptr<Accumulator> AccumulatorMinMax::createMax(
const intrusive_ptr<ExpressionContext> &pCtx) {
intrusive_ptr<AccumulatorMinMax> pAccumulator(
new AccumulatorMinMax(-1));
return pAccumulator;
}
intrusive_ptr<Accumulator> AccumulatorAddToSet::create(
const intrusive_ptr<ExpressionContext> &pCtx) {
intrusive_ptr<AccumulatorAddToSet> pAccumulator(
new AccumulatorAddToSet(pCtx));
return pAccumulator;
}
