uk.gov.gchq.gaffer.data.graph

Class Walk

java.lang.Object

uk.gov.gchq.gaffer.data.graph.Walk

All Implemented Interfaces:

Iterable<Set<Edge>>

public class Walk
extends Object
implements Iterable<Set<Edge>>

A Walk describes a graph traversal which begins at a vertex and comprises of:

• a sequence of Edge objects, where the source of one edge must follow on from the destination of the previous
• an optional sequence of Entity objects which are associated to each of the vertices visited on the Walk. Vertices with no associated entities are still represented, but only as empty collections.

For example, a Walk through a simple graph could look like:

 
 A --> B --> C
       \     \
       \     (Entity2, Entity3)
       \
       (Entity1)

 Edges:       A -> B, B -> C
 Entities:    [], [Entity1], [Entity2, Entity3]
 
 

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	Walk.Builder

Constructor Summary

Constructors

Constructor and Description
Walk(List<Set<Edge>> edges, List<Map.Entry<Object,Set<Entity>>> entities) Constructor used by Jackson.

Method Summary

Modifier and Type	Method and Description
boolean	equals(Object obj)
Object	getDestinationVertex()
List<Set<Edge>>	getEdges()
List<Set<Entity>>	getEntities()
List<Map.Entry<Object,Set<Entity>>>	getEntitiesAsEntries()
Set<Entity>	getEntitiesAtDistance(int n) Get all of the entities at some distance from the start of the walk.
Set<Entity>	getEntitiesForVertex(Object vertex) Retrieve all of the entities associated with a particular vertex on the walk.
Object	getSourceVertex()
Set<Object>	getVertexSet() Get the Set of vertices on the walk.
List<Object>	getVerticesOrdered() Get an ordered List of the vertices on the walk.
int	hashCode()
boolean	isPath() A walk is also a path if it contains no repeated vertices (i.e.
boolean	isTrail() A walk is also a trail if it contains no repeated edges.
Iterator<Set<Edge>>	iterator()
int	length()
String	toString()

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Constructor Detail

Walk

public Walk(List<Set<Edge>> edges,
            List<Map.Entry<Object,Set<Entity>>> entities)

Constructor used by Jackson.

Parameters:

edges - the edges to add to the walk

entities - the entities to add to the walk

Method Detail

getEntitiesForVertex

public Set<Entity> getEntitiesForVertex(Object vertex)

Retrieve all of the entities associated with a particular vertex on the walk.

Parameters:

vertex - the vertex of interest

Returns:

a Set of all of the entities associated with the vertex

getEntitiesAtDistance

public Set<Entity> getEntitiesAtDistance(int n)

Get all of the entities at some distance from the start of the walk.

Parameters:

n - the distance from the start of the walk (in terms of the number of edges that would have to be traversed)

Returns:

the entities at the specified distance

getEdges

public List<Set<Edge>> getEdges()

getEntitiesAsEntries

public List<Map.Entry<Object,Set<Entity>>> getEntitiesAsEntries()

getEntities

public List<Set<Entity>> getEntities()

getVerticesOrdered

public List<Object> getVerticesOrdered()

Get an ordered List of the vertices on the walk.

This will include any repeated vertices.

Returns:

a list of the vertices on the walk

getVertexSet

public Set<Object> getVertexSet()

Get the Set of vertices on the walk.

Returns:

a set of the vertices on the walk.

length

public int length()

isTrail

public boolean isTrail()

A walk is also a trail if it contains no repeated edges.

Returns:

true if the walk does not contain any repeated edges, otherwise false

isPath

public boolean isPath()

A walk is also a path if it contains no repeated vertices (i.e. does not contain any loops).

Returns:

true if the walk does not contain any repeated vertices, otherwise false

getSourceVertex

public Object getSourceVertex()

getDestinationVertex

public Object getDestinationVertex()

equals

public boolean equals(Object obj)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

toString

public String toString()

Overrides:

toString in class Object

iterator

public Iterator<Set<Edge>> iterator()

Specified by:

iterator in interface Iterable<Set<Edge>>