com.thinkaurelius.titan.hadoop.compat.h1

Class MemoryMapper<A,B,C,D>

java.lang.Object

org.apache.hadoop.mapreduce.Mapper<A,B,C,D>

com.thinkaurelius.titan.hadoop.compat.h1.MemoryMapper<A,B,C,D>

Direct Known Subclasses:

MapSequence.Map

public class MemoryMapper<A,B,C,D>
extends org.apache.hadoop.mapreduce.Mapper<A,B,C,D>

MemoryMapper supports in-memory mapping for a chain of consecutive mappers. This provides significant performance improvements as each map need not write its results to disk. Note that MemoryMapper is not general-purpose and is specific to Titan/Hadoop's current MapReduce library. In particular, it assumes that the chain of mappers emits 0 or 1 key/value pairs for each input.

Author:

Marko A. Rodriguez (http://markorodriguez.com)

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
class	MemoryMapper.MemoryMapContext

Nested classes/interfaces inherited from class org.apache.hadoop.mapreduce.Mapper

org.apache.hadoop.mapreduce.Mapper.Context

Constructor Summary

Constructors

Constructor and Description
MemoryMapper()

Method Summary

Methods inherited from class org.apache.hadoop.mapreduce.Mapper

cleanup, map, run, setup

Methods inherited from class java.lang.Object

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

Constructor Detail

MemoryMapper

public MemoryMapper()