overflowdb

Class NodeDb

java.lang.Object

overflowdb.NodeDb

All Implemented Interfaces:

Element, Node

public abstract class NodeDb
extends java.lang.Object
implements Node

Holds node properties and edges to adjacent nodes (including edge properties). Each {NodeRef} refers to exactly one NodeDb instance, and if required can set that instance to `null`, thus freeing up memory, e.g. if heap memory is low. While {NodeRef} instances are very small (they will never be garbage collected), NodeDb instances consume a bit more space. Adjacent nodes and edge properties are stored in a flat array (adjacentNodesWithEdgeProperties). Edges only exist virtually and are created on request. This allows for a small memory footprint, especially given that most graph domains have magnitudes more edges than nodes.

Field Summary

Fields

Modifier and Type	Field and Description
NodeRef	ref

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	NodeDb(NodeRef ref)

Method Summary

Modifier and Type	Method and Description
Edge	addEdge(java.lang.String label, Node inNode, java.util.Map<java.lang.String,java.lang.Object> keyValues) Add an outgoing edge to the node with provided label and edge properties as key/value pairs.
Edge	addEdge(java.lang.String label, Node inNode, java.lang.Object... keyValues) Add an outgoing edge to the node with provided label and edge properties as key/value pairs.
void	addEdgeSilent(java.lang.String label, Node inNode, java.util.Map<java.lang.String,java.lang.Object> keyValues) Add an outgoing edge to the node with provided label and edge properties as key/value pairs.
void	addEdgeSilent(java.lang.String label, Node inNode, java.lang.Object... keyValues) Add an outgoing edge to the node with provided label and edge properties as key/value pairs.
int	blockLength(int offsetPosition) Returns the length of an edge type block in the adjacentNodesWithEdgeProperties array.
protected int	blockOffsetToOccurrence(Direction direction, java.lang.String label, NodeRef otherNode, int blockOffset) If there are multiple edges between the same two nodes with the same label, we use the `occurrence` to differentiate between those edges.
java.util.Iterator<Node>	both()
java.util.Iterator<Node>	both(java.lang.String... edgeLabels)
java.util.Iterator<Edge>	bothE()
java.util.Iterator<Edge>	bothE(java.lang.String... edgeLabels)
java.util.Iterator<Node>	createAdjacentNodeIteratorByOffSet(int offsetPos)
<P> P	edgeProperty(Direction direction, Edge edge, int blockOffset, java.lang.String key)
java.util.Map<java.lang.String,java.lang.Object>	edgePropertyMap(Direction direction, Edge edge, int blockOffset)
<V> java.util.Optional<V>	edgePropertyOption(Direction direction, Edge edge, int blockOffset, java.lang.String key)
boolean	equals(java.lang.Object obj)
java.lang.Object[]	getAdjacentNodesWithEdgeProperties()
int[]	getEdgeOffsets()
PackedIntArray	getEdgeOffsetsPackedArray()
<V> java.util.Iterator<V>	getEdgeProperties(Direction direction, Edge edge, int blockOffset, java.lang.String... keys)
int	getStrideSize(java.lang.String edgeLabel)
Graph	graph()
int	hashCode()
long	id()
java.util.Iterator<Node>	in()
java.util.Iterator<Node>	in(java.lang.String... edgeLabels)
java.util.Iterator<Edge>	inE()
java.util.Iterator<Edge>	inE(java.lang.String... edgeLabels)
Edge	instantiateDummyEdge(java.lang.String label, NodeRef outNode, NodeRef inNode) to follow the tinkerpop api, instantiate and return a dummy edge, which doesn't really exist in the graph
boolean	isDirty()
java.lang.String	label()
abstract NodeLayoutInformation	layoutInformation()
void	markAsClean()
void	markAsDirty()
protected int	occurrenceToBlockOffset(Direction direction, java.lang.String label, NodeRef adjacentNode, int occurrence)
java.util.Iterator<Node>	out()
java.util.Iterator<Node>	out(java.lang.String... edgeLabels)
java.util.Iterator<Edge>	outE()
java.util.Iterator<Edge>	outE(java.lang.String... edgeLabels)
protected int	outEdgeCount()
<A> A	property(PropertyKey<A> key)
java.util.Set<java.lang.String>	propertyKeys()
java.util.Map<java.lang.String,java.lang.Object>	propertyMap() Map with all properties
<A> java.util.Optional<A>	propertyOption(PropertyKey<A> key)
java.util.Optional<java.lang.Object>	propertyOption(java.lang.String key)
void	remove()
protected void	removeEdge(Direction direction, java.lang.String label, int blockOffset) Removes an 'edge', i.e.
void	removeEdgeProperty(Direction direction, java.lang.String edgeLabel, java.lang.String key, int blockOffset)
void	removeProperty(java.lang.String key)
protected abstract void	removeSpecificProperty(java.lang.String key)
void	setAdjacentNodesWithEdgeProperties(java.lang.Object[] adjacentNodesWithEdgeProperties)
void	setEdgeOffsets(int[] edgeOffsets)
<V> void	setEdgeProperty(Direction direction, java.lang.String edgeLabel, java.lang.String key, V value, int blockOffset)
void	setProperty(Property<?> property)
<A> void	setProperty(PropertyKey<A> key, A value)
void	setProperty(java.lang.String key, java.lang.Object value)
int	startIndex(int offsetPosition)
int	storeAdjacentNode(Direction direction, java.lang.String edgeLabel, NodeRef adjacentNode, java.lang.Object... edgeKeyValues)
long	trim() Trims the node to save storage: shrinks overallocations
protected abstract void	updateSpecificProperty(java.lang.String key, java.lang.Object value)
abstract java.util.Map<java.lang.String,java.lang.Object>	valueMap()

Methods inherited from class java.lang.Object

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

Methods inherited from interface overflowdb.Element

property

Field Detail

ref

public final NodeRef ref

Constructor Detail

NodeDb

protected NodeDb(NodeRef ref)

Method Detail

layoutInformation

public abstract NodeLayoutInformation layoutInformation()

getAdjacentNodesWithEdgeProperties

public java.lang.Object[] getAdjacentNodesWithEdgeProperties()

setAdjacentNodesWithEdgeProperties

public void setAdjacentNodesWithEdgeProperties(java.lang.Object[] adjacentNodesWithEdgeProperties)

getEdgeOffsets

public int[] getEdgeOffsets()

getEdgeOffsetsPackedArray

public PackedIntArray getEdgeOffsetsPackedArray()

setEdgeOffsets

public void setEdgeOffsets(int[] edgeOffsets)

valueMap

public abstract java.util.Map<java.lang.String,java.lang.Object> valueMap()

graph

public Graph graph()

Specified by:

graph in interface Element

id

public long id()

Specified by:

id in interface Node

label

public java.lang.String label()

Specified by:

label in interface Element

property

public <A> A property(PropertyKey<A> key)

Specified by:

property in interface Element

propertyOption

public <A> java.util.Optional<A> propertyOption(PropertyKey<A> key)

Specified by:

propertyOption in interface Element

propertyOption

public java.util.Optional<java.lang.Object> propertyOption(java.lang.String key)

Specified by:

propertyOption in interface Element

propertyMap

public java.util.Map<java.lang.String,java.lang.Object> propertyMap()

Description copied from interface: Element

Map with all properties

Specified by:

propertyMap in interface Element

propertyKeys

public java.util.Set<java.lang.String> propertyKeys()

Specified by:

propertyKeys in interface Element

setProperty

public void setProperty(java.lang.String key,
                        java.lang.Object value)

Specified by:

setProperty in interface Element

setProperty

public <A> void setProperty(PropertyKey<A> key,
                            A value)

Specified by:

setProperty in interface Element

setProperty

public void setProperty(Property<?> property)

Specified by:

setProperty in interface Element

removeProperty

public void removeProperty(java.lang.String key)

Specified by:

removeProperty in interface Element

updateSpecificProperty

protected abstract void updateSpecificProperty(java.lang.String key,
                                               java.lang.Object value)

removeSpecificProperty

protected abstract void removeSpecificProperty(java.lang.String key)

remove

public void remove()

Specified by:

remove in interface Element

markAsDirty

public void markAsDirty()

markAsClean

public void markAsClean()

getEdgeProperties

public <V> java.util.Iterator<V> getEdgeProperties(Direction direction,
                                                   Edge edge,
                                                   int blockOffset,
                                                   java.lang.String... keys)

edgePropertyMap

public java.util.Map<java.lang.String,java.lang.Object> edgePropertyMap(Direction direction,
                                                                        Edge edge,
                                                                        int blockOffset)

edgePropertyOption

public <V> java.util.Optional<V> edgePropertyOption(Direction direction,
                                                    Edge edge,
                                                    int blockOffset,
                                                    java.lang.String key)

edgeProperty

public <P> P edgeProperty(Direction direction,
                          Edge edge,
                          int blockOffset,
                          java.lang.String key)

setEdgeProperty

public <V> void setEdgeProperty(Direction direction,
                                java.lang.String edgeLabel,
                                java.lang.String key,
                                V value,
                                int blockOffset)

removeEdgeProperty

public void removeEdgeProperty(Direction direction,
                               java.lang.String edgeLabel,
                               java.lang.String key,
                               int blockOffset)

addEdge

public Edge addEdge(java.lang.String label,
                    Node inNode,
                    java.lang.Object... keyValues)

Description copied from interface: Node

Add an outgoing edge to the node with provided label and edge properties as key/value pairs. These key/values must be provided in an even number where the odd numbered arguments are String property keys and the even numbered arguments are the related property values.

Specified by:

addEdge in interface Node

addEdge

public Edge addEdge(java.lang.String label,
                    Node inNode,
                    java.util.Map<java.lang.String,java.lang.Object> keyValues)

Description copied from interface: Node

Add an outgoing edge to the node with provided label and edge properties as key/value pairs.

Specified by:

addEdge in interface Node

addEdgeSilent

public void addEdgeSilent(java.lang.String label,
                          Node inNode,
                          java.lang.Object... keyValues)

Description copied from interface: Node

Add an outgoing edge to the node with provided label and edge properties as key/value pairs. These key/values must be provided in an even number where the odd numbered arguments are String property keys and the even numbered arguments are the related property values. Just like {{{addEdge2}}, but doesn't instantiate and return a dummy edge

Specified by:

addEdgeSilent in interface Node

addEdgeSilent

public void addEdgeSilent(java.lang.String label,
                          Node inNode,
                          java.util.Map<java.lang.String,java.lang.Object> keyValues)

Description copied from interface: Node

Add an outgoing edge to the node with provided label and edge properties as key/value pairs. Just like {{{addEdge2}}, but doesn't instantiate and return a dummy edge

Specified by:

addEdgeSilent in interface Node

out

public java.util.Iterator<Node> out()

Specified by:

out in interface Node

out

public java.util.Iterator<Node> out(java.lang.String... edgeLabels)

Specified by:

out in interface Node

in

public java.util.Iterator<Node> in()

Specified by:

in in interface Node

in

public java.util.Iterator<Node> in(java.lang.String... edgeLabels)

Specified by:

in in interface Node

both

public java.util.Iterator<Node> both()

Specified by:

both in interface Node

both

public java.util.Iterator<Node> both(java.lang.String... edgeLabels)

Specified by:

both in interface Node

outE

public java.util.Iterator<Edge> outE()

Specified by:

outE in interface Node

outE

public java.util.Iterator<Edge> outE(java.lang.String... edgeLabels)

Specified by:

outE in interface Node

inE

public java.util.Iterator<Edge> inE()

Specified by:

inE in interface Node

inE

public java.util.Iterator<Edge> inE(java.lang.String... edgeLabels)

Specified by:

inE in interface Node

bothE

public java.util.Iterator<Edge> bothE()

Specified by:

bothE in interface Node

bothE

public java.util.Iterator<Edge> bothE(java.lang.String... edgeLabels)

Specified by:

bothE in interface Node

outEdgeCount

protected int outEdgeCount()

blockOffsetToOccurrence

protected final int blockOffsetToOccurrence(Direction direction,
                                            java.lang.String label,
                                            NodeRef otherNode,
                                            int blockOffset)

If there are multiple edges between the same two nodes with the same label, we use the `occurrence` to differentiate between those edges. Both nodes use the same occurrence index for the same edge.

Returns:

the occurrence for a given edge, calculated by counting the number times the given adjacent node occurred between the start of the edge-specific block and the blockOffset

occurrenceToBlockOffset

protected final int occurrenceToBlockOffset(Direction direction,
                                            java.lang.String label,
                                            NodeRef adjacentNode,
                                            int occurrence)

Parameters:

direction - OUT or IN

label - the edge label

occurrence - if there are multiple edges between the same two nodes with the same label, this is used to differentiate between those edges. Both nodes use the same occurrence index in their `adjacentNodesWithEdgeProperties` array for the same edge.

Returns:

the index into `adjacentNodesWithEdgeProperties`

removeEdge

protected final void removeEdge(Direction direction,
                                java.lang.String label,
                                int blockOffset)

Removes an 'edge', i.e. in reality it removes the information about the adjacent node from `adjacentNodesWithEdgeProperties`. The corresponding elements will be set to `null`, i.e. we'll have holes. Note: this decrements the `offset` of the following edges in the same block by one, but that's ok because the only thing that matters is that the offset is identical for both connected nodes (assuming thread safety).

Parameters:

blockOffset - must have been initialized

createAdjacentNodeIteratorByOffSet

public final java.util.Iterator<Node> createAdjacentNodeIteratorByOffSet(int offsetPos)

storeAdjacentNode

public int storeAdjacentNode(Direction direction,
                             java.lang.String edgeLabel,
                             NodeRef adjacentNode,
                             java.lang.Object... edgeKeyValues)

startIndex

public int startIndex(int offsetPosition)

getStrideSize

public final int getStrideSize(java.lang.String edgeLabel)

Returns:

number of elements reserved in `adjacentNodesWithEdgeProperties` for a given edge label includes space for the node ref and all properties

blockLength

public final int blockLength(int offsetPosition)

Returns the length of an edge type block in the adjacentNodesWithEdgeProperties array. Length means number of index positions.

instantiateDummyEdge

public final Edge instantiateDummyEdge(java.lang.String label,
                                       NodeRef outNode,
                                       NodeRef inNode)

to follow the tinkerpop api, instantiate and return a dummy edge, which doesn't really exist in the graph

trim

public long trim()

Trims the node to save storage: shrinks overallocations

isDirty

public final boolean isDirty()

hashCode

public int hashCode()

Overrides:

hashCode in class java.lang.Object

equals

public boolean equals(java.lang.Object obj)

Overrides:

equals in class java.lang.Object