/// <summary>
/// Removes nodes that are part of redundant paths.
/// </summary>
/// <param name="graph">De Bruijn graph</param>
/// <param name="nodesList">Path nodes to be deleted</param>
public void RemoveErroneousNodes(DeBruijnGraph graph, DeBruijnPathList nodesList)
{
DeBruijnGraph.ValidateGraph(graph);
if (nodesList == null)
{
throw new ArgumentNullException("nodesList");
}
_graph = graph;
// Neighbors of all nodes have to be updated.
HashSet <DeBruijnNode> deleteNodes = new HashSet <DeBruijnNode>(
nodesList.Paths.AsParallel().SelectMany(nl => nl.PathNodes));
// Update extensions for deletion
// No need for read-write lock as deleteNode's dictionary is being read,
// and only other graph node's dictionaries are updated
Parallel.ForEach(deleteNodes, node =>
{
foreach (DeBruijnNode extension in
node.LeftExtensionNodes.Keys.Union(node.RightExtensionNodes.Keys))
{
// If the neighbor is also to be deleted, there is no use of updation in that case
if (!deleteNodes.Contains(extension))
{
extension.RemoveExtensionThreadSafe(node);
}
}
});
// Delete nodes from graph
_graph.RemoveNodes(deleteNodes);
}
/// <summary>
/// Removes nodes that are part of dangling links.
/// </summary>
/// <param name="deBruijnGraph">Input graph.</param>
/// <param name="nodesList">List of dangling link nodes.</param>
public void RemoveErroneousNodes(DeBruijnGraph deBruijnGraph, DeBruijnPathList nodesList)
{
// Argument Validation
if (deBruijnGraph == null)
{
throw new ArgumentNullException("deBruijnGraph");
}
if (nodesList == null)
{
throw new ArgumentNullException("nodesList");
}
HashSet <DeBruijnNode> lastNodes = new HashSet <DeBruijnNode>(nodesList.Paths.Select(nl => nl.PathNodes.Last()));
// Update extensions and Delete nodes from graph.
deBruijnGraph.RemoveNodes(
nodesList.Paths.AsParallel().SelectMany(nodes =>
{
RemoveLinkNodes(nodes, lastNodes);
return(nodes.PathNodes);
}));
}
