org.apache.giraph.io

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

java.lang.Object

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

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

org.apache.giraph.io.MappingInputFormat<I,V,E,B>

Type Parameters:

I - vertexId type

V - vertexValue type

E - edgeValue type

B - mappingTarget type

All Implemented Interfaces:

GiraphConfigurationSettable<I,V,E>, ImmutableClassesGiraphConfigurable<I,V,E>

Direct Known Subclasses:

MultiMappingInputFormat, WrappedMappingInputFormat

public abstract class MappingInputFormat<I extends org.apache.hadoop.io.WritableComparable,V extends org.apache.hadoop.io.Writable,E extends org.apache.hadoop.io.Writable,B extends org.apache.hadoop.io.Writable>
extends GiraphInputFormat<I,V,E>

Use this to load data for a BSP application. Note that the InputSplit must also implement Writable. It's guaranteed that whatever parameters are set in the configuration are also going to be available in all method arguments related to this input format (context in getSplits and createVertexReader; methods invoked on MappingReader). So if backing input format relies on some parameters from configuration, you can safely set them for example in DefaultImmutableClassesGiraphConfigurable.setConf(org.apache.giraph.conf.ImmutableClassesGiraphConfiguration).

Constructor Summary

Constructors

Constructor and Description
MappingInputFormat()

Method Summary

Modifier and Type	Method and Description
abstract MappingReader<I,V,E,B>	createMappingReader(org.apache.hadoop.mapreduce.InputSplit split, org.apache.hadoop.mapreduce.TaskAttemptContext context) Create a vertex reader for a given split.

Methods inherited from class org.apache.giraph.io.GiraphInputFormat

checkInputSpecs, getSplits, readInputSplit, writeInputSplit

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

MappingInputFormat

public MappingInputFormat()

Method Detail

createMappingReader

public abstract MappingReader<I,V,E,B> createMappingReader(org.apache.hadoop.mapreduce.InputSplit split,
                                                           org.apache.hadoop.mapreduce.TaskAttemptContext context)
                                                    throws IOException

Create a vertex reader for a given split. Guaranteed to have been configured with setConf() prior to use. The framework will also call VertexReader.initialize(InputSplit, org.apache.hadoop.mapreduce.TaskAttemptContext) before the split is used.

Parameters:

split - the split to be read

context - the information about the task

Returns:

a new record reader

Throws:

IOException