protected internal virtual Expression VisitCorrelatedGroupBy(CorrelatedGroupByExpression node)
{
return(node.Update(
Visit(node.Source),
Visit(node.Id),
Visit(node.Accumulators)));
}
protected internal virtual Expression VisitCorrelatedGroupBy(CorrelatedGroupByExpression node)
{
return node.Update(
Visit(node.Source),
Visit(node.Id),
Visit(node.Accumulators));
}
protected internal override Expression VisitCorrelatedGroupBy(CorrelatedGroupByExpression node)
{
if (_lookup != null && _lookup.Contains(node.CorrelationId))
{
var source = Visit(node.Source);
var accumulators = new List<SerializationExpression>();
var comparer = new ExpressionComparer();
foreach (var correlatedAccumulator in _lookup[node.CorrelationId])
{
var index = accumulators.FindIndex(x => comparer.Compare(x.Expression, correlatedAccumulator.Accumulator));
if (index == -1)
{
var serializer = _serializerRegistry.GetSerializer(correlatedAccumulator.Type);
var info = new BsonSerializationInfo(
"__agg" + accumulators.Count,
serializer,
serializer.ValueType);
var serializationExpression = new SerializationExpression(correlatedAccumulator.Accumulator, info);
accumulators.Add(serializationExpression);
_map[correlatedAccumulator] = serializationExpression;
}
else
{
_map[correlatedAccumulator] = accumulators[index];
}
}
node = node.Update(
source,
node.Id,
accumulators.OfType<Expression>());
}
return base.VisitCorrelatedGroupBy(node);
}
private void VisitCorrelatedGroupBy(CorrelatedGroupByExpression node)
{
Visit(node.Source);
var group = new BsonDocument();
group.Add("_id", AggregateLanguageTranslator.Translate(node.Id));
foreach (var accumulator in node.Accumulators)
{
var serializationExpression = (SerializationExpression)accumulator;
group.Add(
serializationExpression.SerializationInfo.ElementName,
AggregateLanguageTranslator.Translate(serializationExpression.Expression));
}
_stages.Add(new BsonDocument("$group", group));
}
