/// <summary>
/// Creates new instance of BPlusTreeEnumerator type
/// </summary>
/// <param name="nodes">Node provider which contains tree nodes</param>
/// <param name="rootNodeId">Root item ID</param>
/// <param name="edgeType">Edge type to use as a filter for enumeration</param>
public BPlusTreeEnumerator(INodeProvider <Guid, object, EdgeData> nodes, Guid rootNodeId, EdgeType edgeType)
{
this.nodes = nodes;
this.rootNodeId = rootNodeId;
this.edgeType = edgeType;
var currentLeaf = BPlusTreeOperations.LeftLeaf(nodes, nodes.GetNode(rootNodeId, NodeAccess.Read));
this.currentLeafEnumerator = currentLeaf.Edges.Values.GetEnumerator();
}
/// <summary>
/// Resets the enumerator
/// </summary>
public void Reset()
{
if (currentLeafEnumerator != null)
{
currentLeafEnumerator.Dispose();
}
var currentLeaf = BPlusTreeOperations.LeftLeaf(nodes, nodes.GetNode(rootNodeId, NodeAccess.Read));
this.currentLeafEnumerator = currentLeaf.Edges.Values.GetEnumerator();
}
/// <summary>
/// Moves to next item without regards to edge type
/// </summary>
/// <returns>True if next item was found</returns>
private bool MoveNextInternal()
{
if (currentLeafEnumerator == null)
{
return(false);
}
var current = Current;
EdgeData sampleData = null;
if (current != null)
{
sampleData = current.Data;
}
bool res = currentLeafEnumerator.MoveNext();
if (res)
{
return(true);
}
else
{
this.currentLeafEnumerator.Dispose();
this.currentLeafEnumerator = null;
var currentLeaf = BPlusTreeOperations.NextLeaf(nodes, rootNodeId, sampleData);
if (currentLeaf == null)
{
return(false);
}
else
{
this.currentLeafEnumerator = currentLeaf.Edges.Values.GetEnumerator();
return(currentLeafEnumerator.MoveNext());
}
}
}
