org.apache.hadoop.mapred
Interface MapRunnable<K1,V1,K2,V2>

All Superinterfaces:
JobConfigurable
All Known Implementing Classes:
MapRunner, MultithreadedMapRunner, PipeMapRunner

public interface MapRunnable<K1,V1,K2,V2>
extends JobConfigurable

Expert: Generic interface for Mappers.

Custom implementations of MapRunnable can exert greater control on map processing e.g. multi-threaded, asynchronous mappers etc.

See Also:
Mapper

Method Summary
 void run(RecordReader<K1,V1> input, OutputCollector<K2,V2> output, Reporter reporter)
          Start mapping input <key, value> pairs.
 
Methods inherited from interface org.apache.hadoop.mapred.JobConfigurable
configure
 

Method Detail

run

void run(RecordReader<K1,V1> input,
         OutputCollector<K2,V2> output,
         Reporter reporter)
         throws IOException
Start mapping input <key, value> pairs.

Mapping of input records to output records is complete when this method returns.

Parameters:
input - the RecordReader to read the input records.
output - the OutputCollector to collect the outputrecords.
reporter - Reporter to report progress, status-updates etc.
Throws:
IOException


Copyright © 2009 The Apache Software Foundation