org.apache.giraph.io

Class VertexReader<I extends org.apache.hadoop.io.WritableComparable,V extends org.apache.hadoop.io.Writable,E extends org.apache.hadoop.io.Writable>

java.lang.Object

org.apache.giraph.conf.DefaultImmutableClassesGiraphConfigurable<I,V,E>

org.apache.giraph.worker.WorkerAggregatorDelegator<I,V,E>

org.apache.giraph.io.VertexReader<I,V,E>

Type Parameters:

I - Vertex id

V - Vertex data

E - Edge data

All Implemented Interfaces:

AggregatorUsage, GiraphConfigurationSettable<I,V,E>, ImmutableClassesGiraphConfigurable<I,V,E>, WorkerAggregatorUsage, WorkerBroadcastUsage, WorkerGlobalCommUsage, WorkerReduceUsage

Direct Known Subclasses:

BasicVertexValueReader, GeneratedVertexReader, SequenceFileVertexInputFormat.SequenceFileVertexReader, TextVertexInputFormat.TextVertexReader, VertexReaderWrapper, WrappedVertexReader

public abstract class VertexReader<I extends org.apache.hadoop.io.WritableComparable,V extends org.apache.hadoop.io.Writable,E extends org.apache.hadoop.io.Writable>
extends WorkerAggregatorDelegator<I,V,E>

Analogous to Hadoop's RecordReader for vertices. Will read the vertices from an input split.

Constructor Summary

Constructors

Constructor and Description
VertexReader()

Method Summary

Modifier and Type	Method and Description
abstract void	close() Close this VertexReader to future operations.
abstract Vertex<I,V,E>	getCurrentVertex() Get the current vertex.
abstract float	getProgress() How much of the input has the VertexReader consumed i.e.
abstract void	initialize(org.apache.hadoop.mapreduce.InputSplit inputSplit, org.apache.hadoop.mapreduce.TaskAttemptContext context) Use the input split and context to setup reading the vertices.
abstract boolean	nextVertex()

Methods inherited from class org.apache.giraph.worker.WorkerAggregatorDelegator

aggregate, getAggregatedValue, getBroadcast, reduce, reduceMerge, setWorkerGlobalCommUsage

Methods inherited from class org.apache.giraph.conf.DefaultImmutableClassesGiraphConfigurable

getConf, setConf

Methods inherited from class java.lang.Object

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

Constructor Detail

VertexReader

public VertexReader()

Method Detail

initialize

public abstract void initialize(org.apache.hadoop.mapreduce.InputSplit inputSplit,
                                org.apache.hadoop.mapreduce.TaskAttemptContext context)
                         throws IOException,
                                InterruptedException

Use the input split and context to setup reading the vertices. Guaranteed to be called prior to any other function.

Parameters:

inputSplit - Input split to be used for reading vertices.

context - Context from the task.

Throws:

IOException

InterruptedException

nextVertex

public abstract boolean nextVertex()
                            throws IOException,
                                   InterruptedException

Returns:

false iff there are no more vertices

Throws:

IOException

InterruptedException

getCurrentVertex

public abstract Vertex<I,V,E> getCurrentVertex()
                                        throws IOException,
                                               InterruptedException

Get the current vertex.

Returns:

the current vertex which has been read. nextVertex() should be called first.

Throws:

IOException

InterruptedException

close

public abstract void close()
                    throws IOException

Close this VertexReader to future operations.

Throws:

IOException

getProgress

public abstract float getProgress()
                           throws IOException,
                                  InterruptedException

How much of the input has the VertexReader consumed i.e. has been processed by?

Returns:

Progress from 0.0 to 1.0.

Throws:

IOException

InterruptedException