com.google.common.graph

Class AbstractValueGraph<N,V>

java.lang.Object

com.google.common.graph.AbstractValueGraph<N,V>

Type Parameters:

N - Node parameter type

V - Value parameter type

All Implemented Interfaces:

ValueGraph<N,V>

Direct Known Subclasses:

ImmutableValueGraph

@Beta
public abstract class AbstractValueGraph<N,V>
extends Object
implements ValueGraph<N,V>

This class provides a skeletal implementation of ValueGraph. It is recommended to extend this class rather than implement ValueGraph directly.

The methods implemented in this class should not be overridden unless the subclass admits a more efficient implementation.

Since:

20.0

Author:

James Sexton

Constructor Summary

Constructors

Constructor and Description
AbstractValueGraph()

Method Summary

Modifier and Type	Method and Description
Graph<N>	asGraph() Returns a live view of this graph as a Graph.
int	degree(N node) Returns the count of node's incident edges, counting self-loops twice (equivalently, the number of times an edge touches node).
protected long	edgeCount() Returns the number of edges in this graph; used to calculate the size of edges().
Set<EndpointPair<N>>	edges() An implementation of BaseGraph.edges() defined in terms of nodes() and successors(Object).
boolean	equals(Object obj) Returns true iff object is a ValueGraph that has the same elements and the same structural relationships as those in this graph.
boolean	hasEdgeConnecting(N nodeU, N nodeV) Returns true if there is an edge directly connecting nodeU to nodeV.
int	hashCode() Returns the hash code for this graph.
int	inDegree(N node) Returns the count of node's incoming edges (equal to predecessors(node).size()) in a directed graph.
int	outDegree(N node) Returns the count of node's outgoing edges (equal to successors(node).size()) in a directed graph.
String	toString() Returns a string representation of this graph.

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface com.google.common.graph.ValueGraph

adjacentNodes, allowsSelfLoops, degree, edges, edgeValueOrDefault, hasEdgeConnecting, inDegree, isDirected, nodeOrder, nodes, outDegree, predecessors, successors

Constructor Detail

AbstractValueGraph

public AbstractValueGraph()

Method Detail

asGraph

public Graph<N> asGraph()

Description copied from interface: ValueGraph

Returns a live view of this graph as a Graph. The resulting Graph will have an edge connecting node A to node B if this ValueGraph has an edge connecting A to B.

Specified by:

asGraph in interface ValueGraph<N,V>

equals

public final boolean equals(@Nullable
                            Object obj)

Description copied from interface: ValueGraph

Returns true iff object is a ValueGraph that has the same elements and the same structural relationships as those in this graph.

Thus, two value graphs A and B are equal if all of the following are true:

• A and B have equal directedness.
• A and B have equal node sets.
• A and B have equal edge sets.
• The value of a given edge is the same in both A and B.

Graph properties besides directedness do not affect equality. For example, two graphs may be considered equal even if one allows self-loops and the other doesn't. Additionally, the order in which nodes or edges are added to the graph, and the order in which they are iterated over, are irrelevant.

A reference implementation of this is provided by equals(Object).

Specified by:

equals in interface ValueGraph<N,V>

Overrides:

equals in class Object

hashCode

public final int hashCode()

Description copied from interface: ValueGraph

Returns the hash code for this graph. The hash code of a graph is defined as the hash code of a map from each of its edges to the associated edge value.

A reference implementation of this is provided by hashCode().

Specified by:

hashCode in interface ValueGraph<N,V>

Overrides:

hashCode in class Object

toString

public String toString()

Returns a string representation of this graph.

Overrides:

toString in class Object

edgeCount

protected long edgeCount()

Returns the number of edges in this graph; used to calculate the size of edges(). This implementation requires O(|N|) time. Classes extending this one may manually keep track of the number of edges as the graph is updated, and override this method for better performance.

edges

public Set<EndpointPair<N>> edges()

An implementation of BaseGraph.edges() defined in terms of nodes() and successors(Object).

degree

public int degree(N node)

Returns the count of node's incident edges, counting self-loops twice (equivalently, the number of times an edge touches node).

For directed graphs, this is equal to inDegree(node) + outDegree(node).

For undirected graphs, this is equal to adjacentNodes(node).size() + (1 if node has an incident self-loop, 0 otherwise).

If the count is greater than Integer.MAX_VALUE, returns Integer.MAX_VALUE.

inDegree

public int inDegree(N node)

Returns the count of node's incoming edges (equal to predecessors(node).size()) in a directed graph. In an undirected graph, returns the degree(Object).

If the count is greater than Integer.MAX_VALUE, returns Integer.MAX_VALUE.

outDegree

public int outDegree(N node)

Returns the count of node's outgoing edges (equal to successors(node).size()) in a directed graph. In an undirected graph, returns the degree(Object).

If the count is greater than Integer.MAX_VALUE, returns Integer.MAX_VALUE.

hasEdgeConnecting

public boolean hasEdgeConnecting(N nodeU,
                                 N nodeV)

Returns true if there is an edge directly connecting nodeU to nodeV. This is equivalent to nodes().contains(nodeU) && successors(nodeU).contains(nodeV).

In an undirected graph, this is equal to hasEdgeConnecting(nodeV, nodeU).