org.apache.nutch.scoring.webgraph
Class Loops.Looper

java.lang.Object
  org.apache.hadoop.conf.Configured
      org.apache.nutch.scoring.webgraph.Loops.Looper

All Implemented Interfaces:

Closeable, Configurable, JobConfigurable, Mapper<Text,Writable,Text,ObjectWritable>, Reducer<Text,ObjectWritable,Text,Loops.Route>

Enclosing class:

Loops

public static class Loops.Looper
extends Configured
implements Mapper<Text,Writable,Text,ObjectWritable>, Reducer<Text,ObjectWritable,Text,Loops.Route>

Follows a route path looking for the start url of the route. If the start url is found then the route is a cyclical path.

Constructor Summary

Loops.Looper()
Default constructor.

Loops.Looper(Configuration conf)
Configurable constructor.

Method Summary

void	close()
void	configure(JobConf conf) Configure the job.
void	map(Text key, Writable value, OutputCollector<Text,ObjectWritable> output, Reporter reporter) Wrap values in ObjectWritable.
void	reduce(Text key, Iterator<ObjectWritable> values, OutputCollector<Text,Loops.Route> output, Reporter reporter) Performs a single loop pass looking for loop cycles within routes.

Methods inherited from class org.apache.hadoop.conf.Configured

getConf, setConf

Methods inherited from class java.lang.Object

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

Constructor Detail

Loops.Looper

public Loops.Looper()

Default constructor.

Loops.Looper

public Loops.Looper(Configuration conf)

Configurable constructor.

Method Detail

configure

public void configure(JobConf conf)

Configure the job.

Specified by:

configure in interface JobConfigurable

map

public void map(Text key,
                Writable value,
                OutputCollector<Text,ObjectWritable> output,
                Reporter reporter)
         throws IOException

Wrap values in ObjectWritable.

Specified by:

map in interface Mapper<Text,Writable,Text,ObjectWritable>

Throws:

IOException

reduce

public void reduce(Text key,
                   Iterator<ObjectWritable> values,
                   OutputCollector<Text,Loops.Route> output,
                   Reporter reporter)
            throws IOException

Performs a single loop pass looking for loop cycles within routes. If This is not the last loop cycle then url will be mapped for further passes.

Specified by:

reduce in interface Reducer<Text,ObjectWritable,Text,Loops.Route>

Throws:

IOException

close

public void close()

Specified by:

close in interface Closeable