private DataNode <string, Cell> BuildTree(Set <int> groupbySet, string leafColumn)
{
EnumeratorMgr em = new EnumeratorMgr();
foreach (int colOrdinal in groupbySet)
{
em.AddEnumerable(_indexes[colOrdinal]);
}
int leafColOrdinal = _colMap.FindT2(leafColumn);
DataNode <string, Cell> root = new DataNode <string, Cell>("root");
while (em.MoveNext())
{
// Get current leaf set
// All the leaves share the same parent / parents
Set <int> leafSet = ProduceLeafSet(em, leafColOrdinal);
if (leafSet == null || leafSet.Count < 1)
{
continue;
}
// Build parent nodes for these leaves
DataRow row = _dataTbl.Rows[leafSet[0]];
DataNode <string, Cell> currentParent = root;
foreach (int colOrdinal in groupbySet)
{
string nodeName = row[colOrdinal].ToString();
DataNode <string, Cell> nodeTmp = null;
if (!currentParent.Children.TryGetValue(nodeName, out nodeTmp))
{
nodeTmp = AddChild(currentParent, nodeName);
nodeTmp.Data = new Cell(leafSet[0], colOrdinal);
}
System.Diagnostics.Debug.Assert(nodeTmp.Data != null);
currentParent = nodeTmp; // Move one level down
}
// Add these leaves
DataRowCollection rows = _dataTbl.Rows;
foreach (int rowIndex in leafSet)
{
row = _dataTbl.Rows[rowIndex];
DataNode <string, Cell> leafNode = AddChild(currentParent, rowIndex.ToString());
leafNode.Data = new Cell(rowIndex, -1);
}
}
return(root);
}
/// <summary> All the leaves share the same parent / parents </summary>
private Set <int> ProduceLeafSet(EnumeratorMgr em, int leafColOrdinal)
{
// Get current leaf set
Set <int> leafSet = null;
foreach (IEnumerator <KeyValuePair <string, Set <int> > > colEnum in em.Current)
{
if (leafSet == null)
{
leafSet = colEnum.Current.Value;
}
else
{
leafSet = leafSet.Intersect(colEnum.Current.Value);
}
}
// To do: sort the leafSet by leaf column
return(leafSet);
}
