com.google.javascript.jscomp.graph

Class GraphColoring<N,E>

java.lang.Object

com.google.javascript.jscomp.graph.GraphColoring<N,E>

Type Parameters:

N - Value type that the graph node stores.

E - Value type that the graph edge stores.

Direct Known Subclasses:

GraphColoring.GreedyGraphColoring

public abstract class GraphColoring<N,E>
extends java.lang.Object

Annotates the graph with a color in a way that no connected node will have the same color. Nodes of the same color can then be partitioned together and be represented by a super node. This class will merely annotate the nodes with a color using Annotatable.setAnnotation(Annotation) and provide a node to super node mapping with getPartitionSuperNode(Object). The given graph itself will not be modified.

This algorithm is NOT deterministic by default. Passes that requires deterministic output should provide a Comparator in the constructor as a tie-breaker. This tie-break will be used when deciding which node should be colored first when multiple nodes have the same degree.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	GraphColoring.Color The color of a node
static class	GraphColoring.GreedyGraphColoring<N,E> Greedily assign nodes with high degree unique colors.

Field Summary

Fields

Modifier and Type	Field and Description
protected N[]	colorToNodeMap
protected AdjacencyGraph<N,E>	graph

Constructor Summary

Constructors

Constructor and Description
GraphColoring(AdjacencyGraph<N,E> graph)

Method Summary

Modifier and Type	Method and Description
abstract int	color() Annotates the graph with GraphColoring.Color objects using Annotatable.setAnnotation(Annotation).
AdjacencyGraph<N,E>	getGraph()
N	getPartitionSuperNode(N node) Using the coloring as partitions, finds the node that represents that partition as the super node.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

colorToNodeMap

protected N[] colorToNodeMap

graph

protected final AdjacencyGraph<N,E> graph

Constructor Detail

GraphColoring

public GraphColoring(AdjacencyGraph<N,E> graph)

Method Detail

color

public abstract int color()

Annotates the graph with GraphColoring.Color objects using Annotatable.setAnnotation(Annotation).

Returns:

The number of unique colors need.

getPartitionSuperNode

public N getPartitionSuperNode(N node)

Using the coloring as partitions, finds the node that represents that partition as the super node. The first to retrieve its partition will become the super node.

getGraph

public AdjacencyGraph<N,E> getGraph()