com.google.appengine.tools.mapreduce.impl

Class BaseShardContext<O>

java.lang.Object

com.google.appengine.tools.mapreduce.impl.BaseContext

com.google.appengine.tools.mapreduce.impl.BaseShardContext<O>

Type Parameters:

O - type of emitted values

All Implemented Interfaces:

Context, ShardContext, WorkerContext<O>

Direct Known Subclasses:

MergeContext, SortContext

public abstract class BaseShardContext<O>
extends BaseContext
implements WorkerContext<O>

Base class for all ShardContext implementations.

Constructor Summary

Constructors

Constructor and Description
BaseShardContext(IncrementalTaskContext taskContext, OutputWriter<O> outputWriter)

Method Summary

Methods

Modifier and Type	Method and Description
void	emit(O value) Emits a value to the output.
Counter	getCounter(String name) Returns the Counter with the given name.
Counters	getCounters() Returns a Counters object for doing simple aggregate calculations.
int	getShardCount() Returns the total number of shards.
int	getShardNumber() Returns the number of this mapper or reducer shard (zero-based).
void	incrementCounter(String name) Increments the Counter with the given name by 1.
void	incrementCounter(String name, long delta) Increments the Counter with the given name by delta.

Methods inherited from class com.google.appengine.tools.mapreduce.impl.BaseContext

getJobId

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.google.appengine.tools.mapreduce.Context

getJobId

Constructor Detail

BaseShardContext

public BaseShardContext(IncrementalTaskContext taskContext,
                OutputWriter<O> outputWriter)

Method Detail

getShardCount

public int getShardCount()

Description copied from interface: ShardContext

Returns the total number of shards.

Specified by:

getShardCount in interface ShardContext

getShardNumber

public int getShardNumber()

Description copied from interface: ShardContext

Returns the number of this mapper or reducer shard (zero-based).

Specified by:

getShardNumber in interface ShardContext

getCounters

public Counters getCounters()

Description copied from interface: ShardContext

Returns a Counters object for doing simple aggregate calculations.

Specified by:

getCounters in interface ShardContext

getCounter

public Counter getCounter(String name)

Description copied from interface: ShardContext

Returns the Counter with the given name.

Specified by:

getCounter in interface ShardContext

incrementCounter

public final void incrementCounter(String name,
                    long delta)

Description copied from interface: ShardContext

Increments the Counter with the given name by delta.

Specified by:

incrementCounter in interface ShardContext

incrementCounter

public final void incrementCounter(String name)

Description copied from interface: ShardContext

Increments the Counter with the given name by 1.

Specified by:

incrementCounter in interface ShardContext

emit

public void emit(O value)

Description copied from interface: WorkerContext

Emits a value to the output.

Specified by:

emit in interface WorkerContext<O>