org.janusgraph.graphdb.query.vertex

Class VertexIdList

java.lang.Object

org.janusgraph.graphdb.query.vertex.VertexIdList

All Implemented Interfaces:

Iterable<JanusGraphVertex>, VertexList, VertexListInternal

public class VertexIdList
extends Object
implements VertexListInternal

An implementation of VertexListInternal that stores only the vertex ids and simply wraps an List and keeps a boolean flag to remember whether this list is in sort order. In addition, we need a transaction reference in order to construct actual vertex references on request.

This is a more efficient way to represent a vertex result set but only applies to loaded vertices that have ids. So, compared to VertexArrayList this is an optimization for the special use case that a vertex is loaded.

Author:

Matthias Broecheler (me@matthiasb.com)

Field Summary

Fields

Modifier and Type	Field and Description
static Comparator<Object>	VERTEX_ID_COMPARATOR

Constructor Summary

Constructors

Constructor and Description
VertexIdList(StandardJanusGraphTx tx)
VertexIdList(StandardJanusGraphTx tx, List<Object> vertices, boolean sorted)

Method Summary

Modifier and Type	Method and Description
void	add(JanusGraphVertex n) Adds the provided vertex to this list.
void	addAll(VertexList vertexlist) Copies all vertices in the given vertex list into this list.
JanusGraphVertex	get(int pos) Returns the vertex at a given position in the list.
Object	getID(int pos) Returns the id of the vertex at the specified position
List<Object>	getIDs() Returns a list of ids of all vertices in this list of vertices in the same order of the original vertex list.
boolean	isSorted() Whether this list of vertices is sorted by id in increasing order.
Iterator<JanusGraphVertex>	iterator()
int	size() Returns the number of vertices in this list.
void	sort() Sorts this list according to vertex ids in increasing order.
VertexList	subList(int fromPosition, int length) Returns a sub list of this list of vertices from the given position with the given number of vertices.
VertexArrayList	toVertexArrayList()

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Field Detail

VERTEX_ID_COMPARATOR

public static final Comparator<Object> VERTEX_ID_COMPARATOR

Constructor Detail

VertexIdList

public VertexIdList(StandardJanusGraphTx tx)

VertexIdList

public VertexIdList(StandardJanusGraphTx tx,
                    List<Object> vertices,
                    boolean sorted)

Method Detail

add

public void add(JanusGraphVertex n)

Description copied from interface: VertexListInternal

Adds the provided vertex to this list.

Specified by:

add in interface VertexListInternal

getID

public Object getID(int pos)

Description copied from interface: VertexList

Returns the id of the vertex at the specified position

Specified by:

getID in interface VertexList

Parameters:

pos - The position of the vertex in the list

Returns:

The id of that vertex

getIDs

public List<Object> getIDs()

Description copied from interface: VertexList

Returns a list of ids of all vertices in this list of vertices in the same order of the original vertex list.

Specified by:

getIDs in interface VertexList

Returns:

A list of idAuthorities of all vertices in this list of vertices in the same order of the original vertex list.

get

public JanusGraphVertex get(int pos)

Description copied from interface: VertexList

Returns the vertex at a given position in the list.

Specified by:

get in interface VertexList

Parameters:

pos - Position for which to retrieve the vertex.

Returns:

JanusGraphVertex at the given position

sort

public void sort()

Description copied from interface: VertexList

Sorts this list according to vertex ids in increasing order. If the list is already sorted, invoking this method incurs no cost.

Specified by:

sort in interface VertexList

isSorted

public boolean isSorted()

Description copied from interface: VertexList

Whether this list of vertices is sorted by id in increasing order.

Specified by:

isSorted in interface VertexList

Returns:

subList

public VertexList subList(int fromPosition,
                          int length)

Description copied from interface: VertexList

Returns a sub list of this list of vertices from the given position with the given number of vertices.

Specified by:

subList in interface VertexList

Returns:

size

public int size()

Description copied from interface: VertexList

Returns the number of vertices in this list.

Specified by:

size in interface VertexList

Returns:

Number of vertices in the list.

addAll

public void addAll(VertexList vertexlist)

Description copied from interface: VertexListInternal

Copies all vertices in the given vertex list into this list.

Specified by:

addAll in interface VertexListInternal

toVertexArrayList

public VertexArrayList toVertexArrayList()

iterator

public Iterator<JanusGraphVertex> iterator()

Specified by:

iterator in interface Iterable<JanusGraphVertex>