com.hazelcast.jet.core

Class DAG

java.lang.Object

com.hazelcast.jet.core.DAG

All Implemented Interfaces:

com.hazelcast.nio.serialization.DataSerializable, com.hazelcast.nio.serialization.IdentifiedDataSerializable, Iterable<Vertex>

public class DAG
extends Object
implements com.hazelcast.nio.serialization.IdentifiedDataSerializable, Iterable<Vertex>

Describes a computation to be performed by the Jet computation engine. A vertex represents a unit of data processing and an edge represents the path along which the data travels to the next vertex.

The work of a single vertex is parallelized and distributed, so that there are several instances of the Processor type on each member corresponding to it. Whenever possible, each instance should be tasked with only a slice of the total data and a partitioning strategy can be employed to ensure that the data sent to each vertex is collated by a partitioning key.

There are three basic kinds of vertices:

1. source with just outbound edges;
2. processor with both inbound and outbound edges;
3. sink with just inbound edges.

Data travels from sources to sinks and is transformed and reshaped as it passes through the processors.

Constructor Summary

Constructors

Constructor and Description
DAG()

Method Summary

Modifier and Type	Method and Description
DAG	edge(Edge edge) Adds an edge to this DAG.
int	getFactoryId()
int	getId()
List<Edge>	getInboundEdges(String vertexName) Returns the inbound edges connected to the vertex with the given name.
List<Edge>	getOutboundEdges(String vertexName) Returns the outbound edges connected to the vertex with the given name.
Vertex	getVertex(String vertexName) Returns the vertex with the given name.
Iterator<Vertex>	iterator() Returns an iterator over the DAG's vertices in topological order.
Vertex	newVertex(String name, DistributedSupplier<? extends Processor> simpleSupplier) Creates a vertex from a Supplier<Processor> and adds it to this DAG.
Vertex	newVertex(String name, ProcessorMetaSupplier metaSupplier) Creates a vertex from a ProcessorMetaSupplier and adds it to this DAG.
Vertex	newVertex(String name, ProcessorSupplier processorSupplier) Creates a vertex from a ProcessorSupplier and adds it to this DAG.
void	readData(com.hazelcast.nio.ObjectDataInput in)
String	toString()
DAG	vertex(Vertex vertex) Adds a vertex to this DAG.
void	writeData(com.hazelcast.nio.ObjectDataOutput out)

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Constructor Detail

DAG

public DAG()

Method Detail

newVertex

public Vertex newVertex(String name,
                        DistributedSupplier<? extends Processor> simpleSupplier)

Creates a vertex from a Supplier<Processor> and adds it to this DAG.

Parameters:

name - the unique name of the vertex

simpleSupplier - the simple, parameterless supplier of Processor instances

See Also:

Vertex.Vertex(String, DistributedSupplier)

newVertex

public Vertex newVertex(String name,
                        ProcessorSupplier processorSupplier)

Creates a vertex from a ProcessorSupplier and adds it to this DAG.

Parameters:

name - the unique name of the vertex

processorSupplier - the supplier of Processor instances which will be used on all members

See Also:

Vertex.Vertex(String, ProcessorSupplier)

newVertex

public Vertex newVertex(String name,
                        ProcessorMetaSupplier metaSupplier)

Creates a vertex from a ProcessorMetaSupplier and adds it to this DAG.

Parameters:

name - the unique name of the vertex

metaSupplier - the meta-supplier of ProcessorSuppliers for each member

See Also:

Vertex.Vertex(String, ProcessorMetaSupplier)

vertex

public DAG vertex(Vertex vertex)

Adds a vertex to this DAG. The vertex name must be unique.

edge

public DAG edge(Edge edge)

Adds an edge to this DAG. The vertices it connects must already be present in the DAG. It is an error to add an edge that connects the same two vertices as another existing edge. It is an error to connect an edge to a vertex at the same ordinal as another existing edge. However, inbound and outbound ordinals are independent, so there can be two edges at the same ordinal, one inbound and one outbound.

getInboundEdges

public List<Edge> getInboundEdges(String vertexName)

Returns the inbound edges connected to the vertex with the given name.

getOutboundEdges

public List<Edge> getOutboundEdges(String vertexName)

Returns the outbound edges connected to the vertex with the given name.

getVertex

public Vertex getVertex(String vertexName)

Returns the vertex with the given name.

iterator

public Iterator<Vertex> iterator()

Returns an iterator over the DAG's vertices in topological order.

Specified by:

iterator in interface Iterable<Vertex>

toString

public String toString()

Overrides:

toString in class Object

writeData

public void writeData(com.hazelcast.nio.ObjectDataOutput out)
               throws IOException

Specified by:

writeData in interface com.hazelcast.nio.serialization.DataSerializable

Throws:

IOException

readData

public void readData(com.hazelcast.nio.ObjectDataInput in)
              throws IOException

Specified by:

readData in interface com.hazelcast.nio.serialization.DataSerializable

Throws:

IOException

getFactoryId

public int getFactoryId()

Specified by:

getFactoryId in interface com.hazelcast.nio.serialization.IdentifiedDataSerializable

getId

public int getId()

Specified by:

getId in interface com.hazelcast.nio.serialization.IdentifiedDataSerializable