/// <summary>
/// Insert a edge at given parent.
/// </summary>
/// <param name="parentEdge">Parent edge.</param>
/// <param name="startIndex">Start index of edge</param>
/// <param name="endIndex">End index of edge</param>
/// <returns>New edge created</returns>
public override IEdge Insert(IEdge parentEdge, int startIndex, int endIndex)
{
// This is a leaf node with both start and end indices pointing to
// terminating symbol. Don't insert this.
if (startIndex >= Sequence.Count)
{
return(null);
}
if (PersisntThreshold > Count)
{
return(base.Insert(parentEdge, startIndex, endIndex));
}
PersistentMultiWaySuffixEdge edge = new PersistentMultiWaySuffixEdge(
startIndex,
endIndex,
MaximumChildrenCount);
edge.Key = EdgeStore.Write(edge);
// Parent edge of type PersistentMultiWaySuffixEdge
PersistentMultiWaySuffixEdge pmwParentEdge = parentEdge as PersistentMultiWaySuffixEdge;
if (pmwParentEdge != null)
{
pmwParentEdge.AddChild(edge.Key);
Count++;
return(edge);
}
// Parent edge of type MultiWaySuffixEdge
MultiWaySuffixEdge mwParentEdge = parentEdge as MultiWaySuffixEdge;
if (mwParentEdge != null)
{
if (mwParentEdge.GetChildren() == null)
{
mwParentEdge.AddChild(edge);
Count++;
return(edge);
}
if (mwParentEdge.GetChildren().Length < MaximumChildrenCount)
{
mwParentEdge.AddChild(edge);
Count++;
return(edge);
}
// No more children edge can be added.
throw new InvalidOperationException(string.Format(
CultureInfo.CurrentCulture,
"Cannot add more than {0} child nodes to edge.",
MaximumChildrenCount));
}
return(edge);
}
public override IEdge Split(IEdge edge, int splitAt)
{
// This is a leaf node with both start and end indices pointing to
// terminating symbol. Don't insert this.
if (splitAt == Sequence.Count)
{
return(edge);
}
PersistentMultiWaySuffixEdge pmwCurrentEdge = edge as PersistentMultiWaySuffixEdge;
if (pmwCurrentEdge == null)
{
return(base.Split(edge, splitAt));
}
// Create the new edge
PersistentMultiWaySuffixEdge newEdge =
new PersistentMultiWaySuffixEdge(splitAt + 1, pmwCurrentEdge.EndIndex, MaximumChildrenCount);
// Copy the children of old edge to new edge
newEdge.ReplaceChildren(pmwCurrentEdge.GetChildren());
// Write the edge to storage
newEdge.Key = EdgeStore.Write(newEdge);
// Update the old edge
pmwCurrentEdge.EndIndex = splitAt;
// Set new edge as child edge to old edge
pmwCurrentEdge.ClearChildren();
pmwCurrentEdge.AddChild(newEdge.Key);
Count++;
// Update the edge in storage
EdgeStore.Write(pmwCurrentEdge);
return(pmwCurrentEdge);
}
