org.neo4j.graphdb.traversal

Enum Uniqueness

java.lang.Object

java.lang.Enum<Uniqueness>

org.neo4j.graphdb.traversal.Uniqueness

All Implemented Interfaces:

Serializable, Comparable<Uniqueness>, UniquenessFactory

public enum Uniqueness
extends Enum<Uniqueness>
implements UniquenessFactory

A catalogue of convenient uniqueness factories. Copied from kernel package so that we can hide kernel from the public API.

Enum Constant Summary

Enum Constants

Enum Constant and Description
NODE_GLOBAL A node cannot be traversed more than once.
NODE_LEVEL Entities on the same level are guaranteed to be unique.
NODE_PATH For each returned node there's a unique path from the start node to it.
NODE_RECENT This is like NODE_GLOBAL, but only guarantees uniqueness among the most recent visited nodes, with a configurable count.
NONE No restriction (the user will have to manage it).
RELATIONSHIP_GLOBAL A relationship cannot be traversed more than once, whereas nodes can.
RELATIONSHIP_LEVEL Entities on the same level are guaranteed to be unique.
RELATIONSHIP_PATH For each returned node there's a (relationship wise) unique path from the start node to it.
RELATIONSHIP_RECENT Same as for NODE_RECENT, but for relationships.

Method Summary

Methods

Modifier and Type	Method and Description
static Uniqueness	valueOf(String name) Returns the enum constant of this type with the specified name.
static Uniqueness[]	values() Returns an array containing the constants of this enum type, in the order they are declared.

Methods inherited from class java.lang.Enum

compareTo, equals, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.neo4j.graphdb.traversal.UniquenessFactory

create

Enum Constant Detail

NODE_GLOBAL

public static final Uniqueness NODE_GLOBAL

A node cannot be traversed more than once. This is what the legacy traversal framework does.

NODE_PATH

public static final Uniqueness NODE_PATH

For each returned node there's a unique path from the start node to it.

NODE_RECENT

public static final Uniqueness NODE_RECENT

This is like NODE_GLOBAL, but only guarantees uniqueness among the most recent visited nodes, with a configurable count. Traversing a huge graph is quite memory intensive in that it keeps track of all the nodes it has visited. For huge graphs a traverser can hog all the memory in the JVM, causing OutOfMemoryError. Together with this Uniqueness you can supply a count, which is the number of most recent visited nodes. This can cause a node to be visited more than once, but scales infinitely.

NODE_LEVEL

public static final Uniqueness NODE_LEVEL

Entities on the same level are guaranteed to be unique.

RELATIONSHIP_GLOBAL

public static final Uniqueness RELATIONSHIP_GLOBAL

A relationship cannot be traversed more than once, whereas nodes can.

RELATIONSHIP_PATH

public static final Uniqueness RELATIONSHIP_PATH

For each returned node there's a (relationship wise) unique path from the start node to it.

RELATIONSHIP_RECENT

public static final Uniqueness RELATIONSHIP_RECENT

Same as for NODE_RECENT, but for relationships.

RELATIONSHIP_LEVEL

public static final Uniqueness RELATIONSHIP_LEVEL

Entities on the same level are guaranteed to be unique.

NONE

public static final Uniqueness NONE

No restriction (the user will have to manage it).

Method Detail

values

public static Uniqueness[] values()

Returns an array containing the constants of this enum type, in the order they are declared. This method may be used to iterate over the constants as follows:

for (Uniqueness c : Uniqueness.values())
    System.out.println(c);

Returns:

an array containing the constants of this enum type, in the order they are declared

valueOf

public static Uniqueness valueOf(String name)

Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)

Parameters:

name - the name of the enum constant to be returned.

Returns:

the enum constant with the specified name

Throws:

IllegalArgumentException - if this enum type has no constant with the specified name

NullPointerException - if the argument is null