/// <summary>
/// Sets aggregation mode.
/// </summary>
/// <param name="mode">New aggregation mode.</param>
public void SetCollectorMode(QueryCollectionState mode)
{
_states.Push(_currentState);
switch (mode)
{
case QueryCollectionState.Where:
_currentState = new QueryCollectorStateWhere(_aggregator);
return;
case QueryCollectionState.OrderBy:
_currentState = new QueryCollectorStateOrderBy(_aggregator);
return;
case QueryCollectionState.Select:
_currentState = new QueryCollectorStateSelect(_aggregator);
return;
case QueryCollectionState.GroupBy:
_currentState = new QueryCollectorStateGroupBy(_aggregator);
return;
case QueryCollectionState.Aggregate:
_currentState = new QueryCollectorStateAggregation(_aggregator);
return;
default:
throw new InvalidOperationException($"Aggregation mode {mode} is not yet supported by QueryPartCollector.");
}
}
/// <summary>
/// Restores previous aggregation mode.
/// </summary>
public void PopCollectorMode()
{
LogWriter.WriteLine($"<- PopCollectorMode");
if (null == _currentState)
{
throw new InvalidOperationException($"Unable to restore previous aggregation mode, history is empty.");
}
_currentState.Dispose();
_currentState = _states.Pop();
}