net.xqhs.graphs.graph
Class SimpleGraph

java.lang.Object
  net.xqhs.util.config.Config
      net.xqhs.util.logging.Unit
          net.xqhs.graphs.graph.SimpleGraph

All Implemented Interfaces:

Graph, net.xqhs.util.config.Configurable

Direct Known Subclasses:

GraphPattern, HyperGraph, TrackingGraph

public class SimpleGraph
extends net.xqhs.util.logging.Unit
implements Graph

Represents a directed graph, using Node and Edge elements.

Functions that modify the graph return the graph itself, so that chained calls are possible.

This class should only be used as a data structure. Visualization should happen elsewhere (for instance, in LinearGraphRepresentation.

Currently only supports adding of new nodes and edges, as well as reading from / writing to simple formats.

Warning: if a graph contains the edge, it does not necessarily contain any of the nodes of the edge. It may be that the nodes have not been added to the graph. This is because this graph may be a subgraph of a larger graph.

Author:

Andrei Olaru

Nested Class Summary

protected static class

SimpleGraph.NodeData Protected structure holding two sets of edges -- incoming and outgoing.

Nested classes/interfaces inherited from class net.xqhs.util.config.Config

net.xqhs.util.config.Config.ConfigLockedException

Field Summary

static char	EDGE_LINE Character that marks the beginning and end of an edge.
static char	EDGE_SEPARATOR Separator between edges.
static char	EDGE_TARGET Character that marks the destination end of an oriented edge.
protected java.util.Set<Edge>	edges The edges
protected java.util.Map<Node,SimpleGraph.NodeData>	nodes The nodes

Fields inherited from class net.xqhs.util.logging.Unit

DEFAULT_LEVEL, DEFAULT_UNIT_NAME

Constructor Summary

SimpleGraph()
Creates an empty graph.

Method Summary

SimpleGraph	add(GraphComponent component) This is the only method that actually adds a component to the graph.
SimpleGraph	addAll(java.util.Collection<? extends GraphComponent> components)
SimpleGraph	addEdge(Edge edge) Warning: the function will not add the nodes to the graph, only the edge between them.
SimpleGraph	addNode(Node node)
java.util.Map<Node,java.lang.Integer>	computeDistancesFromUndirected(Node node) Simple Dijkstra algorithm to compute the distance between one node and all others.
boolean	contains(GraphComponent component)
java.util.Collection<GraphComponent>	getComponents()
java.util.Collection<Edge>	getEdges()
java.util.Collection<Edge>	getInEdges(Node node) Retrieves the edges going into the specified node.
java.util.Collection<Node>	getNodes()
java.util.Collection<Node>	getNodesNamed(java.lang.String name)
java.util.Collection<Edge>	getOutEdges(Node node) Retrieves the edges outgoing from the specified node.
java.lang.String	getUnitName()
int	m()
int	n()
SimpleGraph	readFrom(java.io.InputStream input) Reads the structure of the graph as list of edges, adding all nodes appearing in the definition of edges.
SimpleGraph	remove(GraphComponent component) This is the only method that actually removes a component from the graph.
Graph	removeAll(java.util.Collection<? extends GraphComponent> components)
SimpleGraph	removeEdge(Edge edge)
SimpleGraph	removeNode(Node node)
int	size()
java.lang.String	toDot() Creates a representation of the Graph in DOT format.
java.lang.String	toString() Returns a display of the graph that shows the number of nodes and edges, the list of nodes and the list of edges.

Methods inherited from class net.xqhs.util.logging.Unit

compose, dbg, doExit, getDefaultUnitName, l, le, lf, li, lock, lockedR, lr, lr, lw, setLink, setLink, setLogDisplay, setLogEnsureNew, setLoggerClass, setLoggerType, setLoggerTypeClass, setLogLevel, setLogReporter, setUnitName, setUnitName

Methods inherited from class net.xqhs.util.config.Config

build, ensureLocked, locked, lockedEx, makeDefaults

Methods inherited from class java.lang.Object

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

Field Detail

EDGE_SEPARATOR

public static char EDGE_SEPARATOR

Separator between edges.

EDGE_LINE

public static char EDGE_LINE

Character that marks the beginning and end of an edge. Edge labels may contain this character, but node labels may not. At the destination end of the edge it may be replaced by EDGE_TARGET. In case of bi-directional unlabeled edges, the representation of an edge may contain only one character.

EDGE_TARGET

public static char EDGE_TARGET

Character that marks the destination end of an oriented edge.

nodes

protected java.util.Map<Node,SimpleGraph.NodeData> nodes

The nodes

edges

protected java.util.Set<Edge> edges

The edges

Constructor Detail

SimpleGraph

public SimpleGraph()

Creates an empty graph.

Method Detail

getUnitName

public java.lang.String getUnitName()

Overrides:

getUnitName in class net.xqhs.util.logging.Unit

addNode

public SimpleGraph addNode(Node node)

Specified by:

addNode in interface Graph

Parameters:

node - - the Node to add.

Returns:

the graph itself, for chaining calls.

addEdge

public SimpleGraph addEdge(Edge edge)

Warning: the function will not add the nodes to the graph, only the edge between them. Nodes must be added separately.

Specified by:

addEdge in interface Graph

Parameters:

edge - : the edge to add

Returns:

the updated graph

add

public SimpleGraph add(GraphComponent component)

This is the only method that actually adds a component to the graph. Any other methods call (should call) this method.

Specified by:

add in interface Graph

Parameters:

component - - the component to add. Must be an implementation of GraphComponent that the implementing class can recognize.

Returns:

the graph itself, for chained calls.

addAll

public SimpleGraph addAll(java.util.Collection<? extends GraphComponent> components)

Specified by:

addAll in interface Graph

Parameters:

components - - the components to add. Each must be an implementation of GraphComponent that the implementing class can recognize.

Returns:

the graph itself, for chained calls.

removeNode

public SimpleGraph removeNode(Node node)

Specified by:

removeNode in interface Graph

Parameters:

node - - the Node to remove.

Returns:

the graph itself, for chained calls.

removeEdge

public SimpleGraph removeEdge(Edge edge)

Specified by:

removeEdge in interface Graph

Parameters:

edge - - the Edge to remove.

Returns:

the graph itself, for chained calls.

remove

public SimpleGraph remove(GraphComponent component)

This is the only method that actually removes a component from the graph. Any other methods call (should call) this method.

Specified by:

remove in interface Graph

Parameters:

component - - the component to remove. Must be an implementation of GraphComponent that the implementing class can recognize.

Returns:

the graph itself, for chained calls.

removeAll

public Graph removeAll(java.util.Collection<? extends GraphComponent> components)

Specified by:

removeAll in interface Graph

Parameters:

components - - the components to remove. Each must be an implementation of GraphComponent that the implementing class can recognize.

Returns:

the graph itself, for chained calls.

n

public int n()

Specified by:

n in interface Graph

Returns:

the number of nodes in the graph

m

public int m()

Specified by:

m in interface Graph

Returns:

the number of edges in the graph

size

public int size()

Specified by:

size in interface Graph

Returns:

the size of the graph, in number of nodes

getNodes

public java.util.Collection<Node> getNodes()

Specified by:

getNodes in interface Graph

Returns:

the list of Node instances in the graph. May be an immutable collection.

getEdges

public java.util.Collection<Edge> getEdges()

Specified by:

getEdges in interface Graph

Returns:

the list of Edge instances in the graph. May be an immutable collection.

getComponents

public java.util.Collection<GraphComponent> getComponents()

Specified by:

getComponents in interface Graph

Returns:

the list of GraphComponent instances in the graph. May be an immutable collection.

getOutEdges

public java.util.Collection<Edge> getOutEdges(Node node)

Description copied from interface: Graph

Retrieves the edges outgoing from the specified node.

Specified by:

getOutEdges in interface Graph

Parameters:

node - - the node.

Returns:

the edges outgoing from the node.

getInEdges

public java.util.Collection<Edge> getInEdges(Node node)

Description copied from interface: Graph

Retrieves the edges going into the specified node.

Specified by:

getInEdges in interface Graph

Parameters:

node - - the node.

Returns:

the edges going into the node.

contains

public boolean contains(GraphComponent component)

Specified by:

contains in interface Graph

Parameters:

component - - the component search for. Must be an implementation of GraphComponent that the implementing class can recognize.

Returns:

true if the component is contained; false otherwise.

getNodesNamed

public java.util.Collection<Node> getNodesNamed(java.lang.String name)

Specified by:

getNodesNamed in interface Graph

Parameters:

name - - the name to search for.

Returns:

a Collection of Node instances with the required label.

computeDistancesFromUndirected

public java.util.Map<Node,java.lang.Integer> computeDistancesFromUndirected(Node node)

Simple Dijkstra algorithm to compute the distance between one node and all others.

Parameters:

node - : the source node.

Returns:

the distances to the other nodes.

toString

public java.lang.String toString()

Returns a display of the graph that shows the number of nodes and edges, the list of nodes and the list of edges.

Overrides:

toString in class java.lang.Object

toDot

public java.lang.String toDot()

Creates a representation of the Graph in DOT format.

See http://en.wikipedia.org/wiki/DOT_language

Returns:

the DOT representation

readFrom

public SimpleGraph readFrom(java.io.InputStream input)

Reads the structure of the graph as list of edges, adding all nodes appearing in the definition of edges.

• lines will always be read separately
• multiple edges are read from the same line, if they are separated by a semi-column (;)
• node names cannot have dashes or 'greater' (>)
• edge names cannot have 'greater' (>)
• a labeled edge begins with a dash (-)
• a unidirectional edge ends with dash-greater or just greater (-> or >)
• an unlabeled unidirectional edge is either dash-greater or just greater (-> or >)
• all unidirectional edges are to the right (source -> destination)
• bi-directional edges with no label should be one or two dashes (- or --)
• labeled bi-directional edges should begin and end with a dash ( - label here - )
• all spaces between elements are accepted and ignored

The newly read edges and nodes are added on the existing structure, if any.

Parameters:

input - - a stream to read from

Returns:

the enriched SimpleGraph instance