com.tinkerpop.blueprints.util.wrappers.event

Class EventGraph<T extends Graph>

java.lang.Object

com.tinkerpop.blueprints.util.wrappers.event.EventGraph<T>

All Implemented Interfaces:

Graph, WrapperGraph<T>

Direct Known Subclasses:

EventIndexableGraph, EventTransactionalGraph

public class EventGraph<T extends Graph>
extends Object
implements Graph, WrapperGraph<T>

An EventGraph is a wrapper to existing Graph implementations and provides for graph events to be raised to one or more listeners on changes to the Graph. Notifications to the listeners occur for the following events: new vertex/edge, vertex/edge property changed, vertex/edge property removed, vertex/edge removed. The limiting factor to events being raised is related to out-of-process functions changing graph elements. To gather events from EventGraph, simply provide an implementation of the GraphChangedListener to the EventGraph by utilizing the addListener method. EventGraph allows the addition of multiple GraphChangedListener implementations. Each listener will be notified in the order that it was added.

Author:

Stephen Mallette

Field Summary

Fields

Modifier and Type	Field and Description
protected T	baseGraph
protected List<GraphChangedListener>	graphChangedListeners
protected EventTrigger	trigger

Constructor Summary

Constructors

Constructor and Description
EventGraph(T baseGraph)

Method Summary

Methods

Modifier and Type	Method and Description
Edge	addEdge(Object id, Vertex outVertex, Vertex inVertex, String label) Raises an edgeAdded event.
void	addListener(GraphChangedListener listener)
Vertex	addVertex(Object id) Raises a vertexAdded event.
T	getBaseGraph() Get the graph this wrapper delegates to.
Edge	getEdge(Object id) Return the edge referenced by the provided object identifier.
Iterable<Edge>	getEdges() Return an iterable to all the edges in the graph.
Iterable<Edge>	getEdges(String key, Object value) Return an iterable to all the edges in the graph that have a particular key/value property.
Features	getFeatures() Get the particular features of the graph implementation.
Iterator<GraphChangedListener>	getListenerIterator()
EventTrigger	getTrigger()
Vertex	getVertex(Object id) Return the vertex referenced by the provided object identifier.
Iterable<Vertex>	getVertices() Return an iterable to all the vertices in the graph.
Iterable<Vertex>	getVertices(String key, Object value) Return an iterable to all the vertices in the graph that have a particular key/value property.
protected void	onEdgeAdded(Edge edge)
protected void	onEdgeRemoved(Edge edge, Map<String,Object> props)
protected void	onVertexAdded(Vertex vertex)
protected void	onVertexRemoved(Vertex vertex, Map<String,Object> props)
GraphQuery	query() Generate a query object that can be used to fine tune which edges/vertices are retrieved from the graph.
void	removeAllListeners()
void	removeEdge(Edge edge) Raises an edgeRemoved event.
void	removeListener(GraphChangedListener listener)
void	removeVertex(Vertex vertex) Raises a vertexRemoved event.
void	shutdown() A shutdown function is required to properly close the graph.
String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

trigger

protected EventTrigger trigger

baseGraph

protected final T extends Graph baseGraph

graphChangedListeners

protected final List<GraphChangedListener> graphChangedListeners

Constructor Detail

EventGraph

public EventGraph(T baseGraph)

Method Detail

removeAllListeners

public void removeAllListeners()

addListener

public void addListener(GraphChangedListener listener)

getListenerIterator

public Iterator<GraphChangedListener> getListenerIterator()

getTrigger

public EventTrigger getTrigger()

removeListener

public void removeListener(GraphChangedListener listener)

onVertexAdded

protected void onVertexAdded(Vertex vertex)

onVertexRemoved

protected void onVertexRemoved(Vertex vertex,
                   Map<String,Object> props)

onEdgeAdded

protected void onEdgeAdded(Edge edge)

onEdgeRemoved

protected void onEdgeRemoved(Edge edge,
                 Map<String,Object> props)

addVertex

public Vertex addVertex(Object id)

Raises a vertexAdded event.

Specified by:

addVertex in interface Graph

Parameters:

id - the recommended object identifier

Returns:

the newly created vertex

getVertex

public Vertex getVertex(Object id)

Description copied from interface: Graph

Return the vertex referenced by the provided object identifier. If no vertex is referenced by that identifier, then return null.

Specified by:

getVertex in interface Graph

Parameters:

id - the identifier of the vertex to retrieved from the graph

Returns:

the vertex referenced by the provided identifier or null when no such vertex exists

removeVertex

public void removeVertex(Vertex vertex)

Raises a vertexRemoved event.

Specified by:

removeVertex in interface Graph

Parameters:

vertex - the vertex to remove from the graph

getVertices

public Iterable<Vertex> getVertices()

Description copied from interface: Graph

Return an iterable to all the vertices in the graph. If this is not possible for the implementation, then an UnsupportedOperationException can be thrown.

Specified by:

getVertices in interface Graph

Returns:

an iterable reference to all vertices in the graph

getVertices

public Iterable<Vertex> getVertices(String key,
                           Object value)

Description copied from interface: Graph

Return an iterable to all the vertices in the graph that have a particular key/value property. If this is not possible for the implementation, then an UnsupportedOperationException can be thrown. The graph implementation should use indexing structures to make this efficient else a full vertex-filter scan is required.

Specified by:

getVertices in interface Graph

Parameters:

key - the key of vertex

value - the value of the vertex

Returns:

an iterable of vertices with provided key and value

addEdge

public Edge addEdge(Object id,
           Vertex outVertex,
           Vertex inVertex,
           String label)

Raises an edgeAdded event.

Specified by:

addEdge in interface Graph

Parameters:

id - the recommended object identifier

outVertex - the vertex on the tail of the edge

inVertex - the vertex on the head of the edge

label - the label associated with the edge

Returns:

the newly created edge

getEdge

public Edge getEdge(Object id)

Description copied from interface: Graph

Return the edge referenced by the provided object identifier. If no edge is referenced by that identifier, then return null.

Specified by:

getEdge in interface Graph

Parameters:

id - the identifier of the edge to retrieved from the graph

Returns:

the edge referenced by the provided identifier or null when no such edge exists

removeEdge

public void removeEdge(Edge edge)

Raises an edgeRemoved event.

Specified by:

removeEdge in interface Graph

Parameters:

edge - the edge to remove from the graph

getEdges

public Iterable<Edge> getEdges()

Description copied from interface: Graph

Return an iterable to all the edges in the graph. If this is not possible for the implementation, then an UnsupportedOperationException can be thrown.

Specified by:

getEdges in interface Graph

Returns:

an iterable reference to all edges in the graph

getEdges

public Iterable<Edge> getEdges(String key,
                      Object value)

Description copied from interface: Graph

Return an iterable to all the edges in the graph that have a particular key/value property. If this is not possible for the implementation, then an UnsupportedOperationException can be thrown. The graph implementation should use indexing structures to make this efficient else a full edge-filter scan is required.

Specified by:

getEdges in interface Graph

Parameters:

key - the key of the edge

value - the value of the edge

Returns:

an iterable of edges with provided key and value

query

public GraphQuery query()

Description copied from interface: Graph

Generate a query object that can be used to fine tune which edges/vertices are retrieved from the graph.

Specified by:

query in interface Graph

Returns:

a graph query object with methods for constraining which data is pulled from the underlying graph

shutdown

public void shutdown()

Description copied from interface: Graph

A shutdown function is required to properly close the graph. This is important for implementations that utilize disk-based serializations.

Specified by:

shutdown in interface Graph

toString

public String toString()

Overrides:

toString in class Object

getBaseGraph

public T getBaseGraph()

Description copied from interface: WrapperGraph

Get the graph this wrapper delegates to.

Specified by:

getBaseGraph in interface WrapperGraph<T extends Graph>

Returns:

the underlying graph that this WrapperGraph delegates its operations to.

getFeatures

public Features getFeatures()

Description copied from interface: Graph

Get the particular features of the graph implementation. Not all graph implementations are identical nor perfectly implement the Blueprints API. The Features object returned contains meta-data about numerous potential divergences between implementations.

Specified by:

getFeatures in interface Graph

Returns:

the features of this particular Graph implementation