org.chronos.chronosphere.internal.ogm.impl

Class GremlinUtils

java.lang.Object

org.chronos.chronosphere.internal.ogm.impl.GremlinUtils

public class GremlinUtils
extends java.lang.Object

Constructor Summary

Constructors

Constructor and Description
GremlinUtils()

Method Summary

Modifier and Type	Method and Description
static org.apache.tinkerpop.gremlin.structure.Edge	ensureEdgeExists(org.apache.tinkerpop.gremlin.structure.Vertex source, java.lang.String label, org.apache.tinkerpop.gremlin.structure.Vertex target) Searches for an Edge between the given source and target vertices and returns it, creating a new one if it does not exist.
static org.apache.tinkerpop.gremlin.structure.Edge	getEdge(org.apache.tinkerpop.gremlin.structure.Vertex source, java.lang.String label, org.apache.tinkerpop.gremlin.structure.Vertex target) Finds and returns the single Edge that connects the given source Vertex with the given target Vertex.
static java.util.Set<org.apache.tinkerpop.gremlin.structure.Edge>	getEdges(org.apache.tinkerpop.gremlin.structure.Vertex source, java.lang.String label, org.apache.tinkerpop.gremlin.structure.Vertex target) Finds and returns the Edges that connects the given source Vertex with the given target Vertex.
static org.apache.tinkerpop.gremlin.structure.Edge	setEdgeTarget(org.apache.tinkerpop.gremlin.structure.Vertex source, java.lang.String label, org.apache.tinkerpop.gremlin.structure.Vertex target) Makes sure that only a single outgoing Edge with the given label exists in the source Vertex and that edge connects to the target Vertex.
static java.util.List<org.apache.tinkerpop.gremlin.structure.Edge>	setEdgeTargets(org.apache.tinkerpop.gremlin.structure.Vertex source, java.lang.String label, java.util.List<org.apache.tinkerpop.gremlin.structure.Vertex> targets) A variant of setEdgeTargets(Vertex, String, Set) that respects target ordering and non-uniqueness of targets.
static java.util.Set<org.apache.tinkerpop.gremlin.structure.Edge>	setEdgeTargets(org.apache.tinkerpop.gremlin.structure.Vertex source, java.lang.String label, java.util.Set<org.apache.tinkerpop.gremlin.structure.Vertex> targets) Makes sure that every edge with the given label that is outgoing from the given source vertex leads to one of the given targets, and that there is one edge for each target.

Methods inherited from class java.lang.Object

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

Constructor Detail

GremlinUtils

public GremlinUtils()

Method Detail

setEdgeTarget

public static org.apache.tinkerpop.gremlin.structure.Edge setEdgeTarget(org.apache.tinkerpop.gremlin.structure.Vertex source,
                                                                        java.lang.String label,
                                                                        org.apache.tinkerpop.gremlin.structure.Vertex target)

Makes sure that only a single outgoing Edge with the given label exists in the source Vertex and that edge connects to the target Vertex.

There are several cases:

1. There is no outgoing edge at the source vertex with the given label. In this case, a new edge will be added from source to target vertex with the given label.
2. There is an outgoing edge at the source vertex with the given label, and that edge connects to the given target vertex. In this case, this method is a no-op and simply returns that edge.
3. There is an outgoing edge at the source vertex with the given label, and that edge connects to a vertex other than the given target vertex. In this case, this old edge is removed, a new edge is added from the given source vertex to the given target vertex with the given label, and the new edge is returned.

Parameters:

source - The source vertex that owns the edge to override. Must not be null.

label - The label of the single edge. Must not be null.

target - The target vertex to which the single edge should connect. Must not be null.

Returns:

The single outgoing edge in the source vertex with the given label that connects to the given target vertex. The edge may have been created, may have already existed, or may have been redirected from a previous target (see specification above).

setEdgeTargets

public static java.util.Set<org.apache.tinkerpop.gremlin.structure.Edge> setEdgeTargets(org.apache.tinkerpop.gremlin.structure.Vertex source,
                                                                                        java.lang.String label,
                                                                                        java.util.Set<org.apache.tinkerpop.gremlin.structure.Vertex> targets)

Makes sure that every edge with the given label that is outgoing from the given source vertex leads to one of the given targets, and that there is one edge for each target.

This method is a two-step process.

1. In the source vertex, iterate over the outgoing edges that have the given label.
   1. If the current edge leads to a vertex that is in our targets set, keep the edge and add it to the result set.
   2. if the current edge leads to a vertex that is not in our targets set, delete it.
2. For each vertex in our targets that we did not find in the previous step, create a new edge from the source vertex with the given label, and add it to the result set.

Parameters:

source - The source vertex that owns the edge to override. Must not be null.

label - The edge label in question. Must not be null.

targets - The desired set of target vertices. May be empty (in which case all outgoing edges from the source vertex will be deleted and the result set will be empty), but must not be null.

Returns:

The set of edges that lead from the source vertex to one of the target vertices via the given label. The edges may have already existed, or were generated by this method. May be empty in case that the targets set was empty, but will never be null.

setEdgeTargets

public static java.util.List<org.apache.tinkerpop.gremlin.structure.Edge> setEdgeTargets(org.apache.tinkerpop.gremlin.structure.Vertex source,
                                                                                         java.lang.String label,
                                                                                         java.util.List<org.apache.tinkerpop.gremlin.structure.Vertex> targets)

A variant of setEdgeTargets(Vertex, String, Set) that respects target ordering and non-uniqueness of targets.

This method will check if there is an Edge from the given source Vertex to each of the given target vertices. If the list of targets contains one vertex several times, this method will ensure that there are as many edges to that target. Any outgoing edge from the given source with the given label that is not reused by this process will be deleted. Additional edges will be created only if necessary. The returned list of edges will be ordered by target vertex, and have the same ordering as the given list of targets.

Parameters:

source - The source vertex that owns the edge to override. Must not be null.

label - The edge label in question. Must not be null.

targets - The desired list of target vertices. May be empty (in which case all outgoing edges from the source vertex will be deleted and the result set will be empty), but must not be null. Multiple occurrences of the same vertex will be respected, as well as the ordering of vertices in the list.

Returns:

The list of edges that lead from the source vertex to one of the target vertices via the given label. The edges may have already existed, or were generated by this method. May be empty in case that the targets set was empty, but will never be null.

getEdge

public static org.apache.tinkerpop.gremlin.structure.Edge getEdge(org.apache.tinkerpop.gremlin.structure.Vertex source,
                                                                  java.lang.String label,
                                                                  org.apache.tinkerpop.gremlin.structure.Vertex target)

Finds and returns the single Edge that connects the given source Vertex with the given target Vertex.

Parameters:

source - The source vertex of the edge to look for. Must not be null.

label - The label of the edge to look for. Must not be null.

target - The target vertex of the edge to look for. Must not be null.

Returns:

The single egde that connects the given source and target vertices with the given label, or null if no such edge exists.

Throws:

java.lang.IllegalArgumentException - Thrown if there is more than one edge with the given label from the given source to the given target vertex.

getEdges

public static java.util.Set<org.apache.tinkerpop.gremlin.structure.Edge> getEdges(org.apache.tinkerpop.gremlin.structure.Vertex source,
                                                                                  java.lang.String label,
                                                                                  org.apache.tinkerpop.gremlin.structure.Vertex target)

Finds and returns the Edges that connects the given source Vertex with the given target Vertex.

Parameters:

source - The source vertex of the edge to look for. Must not be null.

label - The label of the edge to look for. Must not be null.

target - The target vertex of the edge to look for. Must not be null.

Returns:

The edges that connects the given source and target vertices with the given label. May be empty if no edge is found, but never null.

ensureEdgeExists

public static org.apache.tinkerpop.gremlin.structure.Edge ensureEdgeExists(org.apache.tinkerpop.gremlin.structure.Vertex source,
                                                                           java.lang.String label,
                                                                           org.apache.tinkerpop.gremlin.structure.Vertex target)

Searches for an Edge between the given source and target vertices and returns it, creating a new one if it does not exist.

Parameters:

source - The source vertex. Must not be null.

label - The edge label. Must not be null.

target - The target vertex. Must not be null.

Returns:

The edge. If it already existed, it will be returned untouched, otherwise a new edge was created and will be returned.