com.sparsity.dex.algorithms
Class TraversalBFS

java.lang.Object
  extended by com.sparsity.dex.algorithms.Traversal
      extended by com.sparsity.dex.algorithms.TraversalBFS
All Implemented Interfaces:
java.io.Closeable

public class TraversalBFS
extends Traversal

Breadth-First Search implementation of Traversal.

Starting from a source node, it visits all its neighbors at distance 1, then all its neighbors at distance 2, and so on.

Check out the 'Algorithms' section in the DEX User Manual for more details on this.

Author:
Sparsity Technologies http://www.sparsity-technologies.com

Constructor Summary
TraversalBFS(Session s, long node)
          Creates a new instance.
 
Method Summary
 void addAllEdgeTypes(EdgesDirection d)
          Allows for traversing all edge types of the graph.
 void addAllNodeTypes()
          Allows for traversing all node types of the graph.
 void addEdgeType(int t, EdgesDirection d)
          Allows for traversing edges of the given type.
 void addNodeType(int t)
          Allows for traversing nodes of the given type.
 void excludeEdges(Objects edges)
          Set which edges can't be used.
 void excludeNodes(Objects nodes)
          Set which nodes can't be used.
 int getCurrentDepth()
          Returns the depth of the current node.
 boolean hasNext()
          Gets if there are more objects to be traversed.
 long next()
          Gets the next object of the traversal.
 void setMaximumHops(int maxhops)
          Sets the maximum hops restriction.
 
Methods inherited from class com.sparsity.dex.algorithms.Traversal
close, isClosed
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

TraversalBFS

public TraversalBFS(Session s,
                    long node)
Creates a new instance.

Parameters:
s - [in] Session to get the graph from and perform traversal.
node - [in] Node to start traversal from.
Method Detail

addAllNodeTypes

public void addAllNodeTypes()
Allows for traversing all node types of the graph.

Overrides:
addAllNodeTypes in class Traversal

addAllEdgeTypes

public void addAllEdgeTypes(EdgesDirection d)
Allows for traversing all edge types of the graph.

Overrides:
addAllEdgeTypes in class Traversal
Parameters:
d - [in] Edge direction.

hasNext

public boolean hasNext()
Gets if there are more objects to be traversed.

Overrides:
hasNext in class Traversal
Returns:
TRUE if there are more objects, FALSE otherwise.

excludeNodes

public void excludeNodes(Objects nodes)
Set which nodes can't be used.

This will replace any previously specified set of excluded nodes. Should only be used to exclude the usage of specific nodes from allowed node types because it's less efficient than not allowing a node type.

Overrides:
excludeNodes in class Traversal
Parameters:
nodes - [in] A set of node identifiers that must be kept intact until the destruction of the class.

next

public long next()
Gets the next object of the traversal.

Overrides:
next in class Traversal
Returns:
A node or edge identifier.

addEdgeType

public void addEdgeType(int t,
                        EdgesDirection d)
Allows for traversing edges of the given type.

Overrides:
addEdgeType in class Traversal
Parameters:
t - [in] Edge type.
d - [in] Edge direction.

addNodeType

public void addNodeType(int t)
Allows for traversing nodes of the given type.

Overrides:
addNodeType in class Traversal
Parameters:
t - null

getCurrentDepth

public int getCurrentDepth()
Returns the depth of the current node.

That is, it returns the depth of the node returned in the last call to Next().

Overrides:
getCurrentDepth in class Traversal
Returns:
The depth of the current node.

setMaximumHops

public void setMaximumHops(int maxhops)
Sets the maximum hops restriction.

All paths longer than the maximum hops restriction will be ignored.

Overrides:
setMaximumHops in class Traversal
Parameters:
maxhops - [in] The maximum hops restriction. It must be positive or zero. Zero, the default value, means unlimited.

excludeEdges

public void excludeEdges(Objects edges)
Set which edges can't be used.

This will replace any previously specified set of excluded edges. Should only be used to exclude the usage of specific edges from allowed edge types because it's less efficient than not allowing an edge type.

Overrides:
excludeEdges in class Traversal
Parameters:
edges - [in] A set of edge identifiers that must be kept intact until the destruction of the class.