org.apache.hadoop.contrib.index.mapred
Class IndexUpdateMapper<K extends WritableComparable,V extends Writable>

java.lang.Object
  extended by org.apache.hadoop.mapred.MapReduceBase
      extended by org.apache.hadoop.contrib.index.mapred.IndexUpdateMapper<K,V>
All Implemented Interfaces:
Closeable, JobConfigurable, Mapper<K,V,Shard,IntermediateForm>

public class IndexUpdateMapper<K extends WritableComparable,V extends Writable>
extends MapReduceBase
implements Mapper<K,V,Shard,IntermediateForm>

This class applies local analysis on a key-value pair and then convert the result docid-operation pair to a shard-and-intermediate form pair.


Constructor Summary
IndexUpdateMapper()
           
 
Method Summary
 void close()
          Default implementation that does nothing.
 void configure(JobConf job)
          Default implementation that does nothing.
static Class<? extends WritableComparable> getMapOutputKeyClass()
          Get the map output key class.
static Class<? extends Writable> getMapOutputValueClass()
          Get the map output value class.
 void map(K key, V value, OutputCollector<Shard,IntermediateForm> output, Reporter reporter)
          Map a key-value pair to a shard-and-intermediate form pair.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

IndexUpdateMapper

public IndexUpdateMapper()
Method Detail

getMapOutputKeyClass

public static Class<? extends WritableComparable> getMapOutputKeyClass()
Get the map output key class.

Returns:
the map output key class

getMapOutputValueClass

public static Class<? extends Writable> getMapOutputValueClass()
Get the map output value class.

Returns:
the map output value class

map

public void map(K key,
                V value,
                OutputCollector<Shard,IntermediateForm> output,
                Reporter reporter)
         throws IOException
Map a key-value pair to a shard-and-intermediate form pair. Internally, the local analysis is first applied to map the key-value pair to a document id-and-operation pair, then the docid-and-operation pair is mapped to a shard-intermediate form pair. The intermediate form is of the form of a single-document ram index and/or a single delete term.

Specified by:
map in interface Mapper<K extends WritableComparable,V extends Writable,Shard,IntermediateForm>
Parameters:
key - the input key.
value - the input value.
output - collects mapped keys and values.
reporter - facility to report progress.
Throws:
IOException

configure

public void configure(JobConf job)
Description copied from class: MapReduceBase
Default implementation that does nothing.

Specified by:
configure in interface JobConfigurable
Overrides:
configure in class MapReduceBase
Parameters:
job - the configuration

close

public void close()
           throws IOException
Description copied from class: MapReduceBase
Default implementation that does nothing.

Specified by:
close in interface Closeable
Overrides:
close in class MapReduceBase
Throws:
IOException


Copyright © 2009 The Apache Software Foundation