water
Class MRTask<T extends MRTask>

java.lang.Object
  jsr166y.ForkJoinTask<java.lang.Void>
      jsr166y.CountedCompleter
          water.H2O.H2OCountedCompleter
              water.DTask<T>
                  water.DRemoteTask<T>
                      water.MRTask<T>

All Implemented Interfaces:

java.io.Serializable, java.lang.Cloneable, java.util.concurrent.Future<java.lang.Void>, Freezable

Direct Known Subclasses:

BaseStatsTask, BitsCmpTask, BooleanVectorFilter, ConfusionTask, Covariance.COV_Task, DatasetCompare, DParseTask, Helpers.ScallarCollector, Histogram.BinningTask, Histogram.OutlineTask, KMeans.Lloyds, KMeans.Sampler, KMeans.Sqr, KMeansModel.KMeansApply, KMeansModel.KMeansScore, LinearRegression.CalcRegressionTask, LinearRegression.CalcSquareErrorsTasks, LinearRegression.CalcSumsTask, MinorityClasses.ClassExtractTask, MinorityClasses.CountMClassRowsTask, MinorityClasses.HistogramTask, MinorityClasses.ReplicationTask, MRColumnProducer, NewRowVecTask, NOPTask, ParseDataset.GuessSetupTsk, ParseDataset2.EnumFetchTask, ParseDataset2.MultiFileParseTask, ParseDataset2.SVFTask, PersistS3Task, RowTask, RowVecTask, ScoreTask, SliceFilter

public abstract class MRTask<T extends MRTask>
extends DRemoteTask<T>

Map/Reduce style distributed computation.

See Also:

Serialized Form

Field Summary

protected int	_hi
protected int	_lo

Fields inherited from class water.DRemoteTask

_fs, _is_local, _keys

Fields inherited from class water.DTask

_cls, _eFromNode, _exception, _fname, _lineNum, _msg, _mth

Constructor Summary

MRTask()

Method Summary

int	hi()
void	init()
void	lcompute() Do all the keys in the list associated with this Node.
int	lo()
void	lonCompletion(jsr166y.CountedCompleter caller)
abstract void	map(Key key) Run some useful function over this local key, and record the results in the this MRTask.
long	memOverheadPerChunk()
boolean	onExceptionalCompletion(java.lang.Throwable ex, jsr166y.CountedCompleter caller) Performs an action when method ForkJoinTask.completeExceptionally(java.lang.Throwable) is invoked or method CountedCompleter.compute() throws an exception, and this task has not otherwise already completed normally.

Methods inherited from class water.DRemoteTask

alsoBlockFor, alsoBlockFor, clone, compute2, dfork, getFutures, invoke, invokeOnAllNodes, keys, merge, merge, merge, onCompletion, reduce, reduceAlsoBlock

Methods inherited from class water.DTask

copyOver, dinvoke, frozenType, getDException, hasException, logVerbose, newInstance, onAck, onAckAck, read, setException, toDocField, write, writeJSONFields

Methods inherited from class water.H2O.H2OCountedCompleter

compute, priority

Methods inherited from class jsr166y.CountedCompleter

addToPendingCount, compareAndSetPendingCount, complete, exec, getCompleter, getPendingCount, getRawResult, setCompleter, setPendingCount, setRawResult, tryComplete

Methods inherited from class jsr166y.ForkJoinTask

adapt, adapt, adapt, cancel, compareAndSetForkJoinTaskTag, completeExceptionally, fork, get, get, getException, getForkJoinTaskTag, getPool, getQueuedTaskCount, getSurplusQueuedTaskCount, helpQuiesce, inForkJoinPool, invoke, invokeAll, invokeAll, invokeAll, isCancelled, isCompletedAbnormally, isCompletedNormally, isDone, join, peekNextLocalTask, pollNextLocalTask, pollTask, quietlyComplete, quietlyInvoke, quietlyJoin, reinitialize, setForkJoinTaskTag, tryUnfork

Methods inherited from class java.lang.Object

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

Field Detail

_lo

protected transient int _lo

_hi

protected transient int _hi

Constructor Detail

MRTask

public MRTask()

Method Detail

memOverheadPerChunk

public long memOverheadPerChunk()

init

public void init()

Overrides:

init in class DRemoteTask<T extends MRTask>

map

public abstract void map(Key key)

Run some useful function over this local key, and record the results in the this MRTask.

lcompute

public final void lcompute()

Do all the keys in the list associated with this Node. Roll up the results into this MRTask.

Specified by:

lcompute in class DRemoteTask<T extends MRTask>

lonCompletion

public final void lonCompletion(jsr166y.CountedCompleter caller)

Overrides:

lonCompletion in class DRemoteTask<T extends MRTask>

onExceptionalCompletion

public final boolean onExceptionalCompletion(java.lang.Throwable ex,
                                             jsr166y.CountedCompleter caller)

Description copied from class: jsr166y.CountedCompleter

Performs an action when method ForkJoinTask.completeExceptionally(java.lang.Throwable) is invoked or method CountedCompleter.compute() throws an exception, and this task has not otherwise already completed normally. On entry to this method, this task ForkJoinTask.isCompletedAbnormally(). The return value of this method controls further propagation: If true and this task has a completer, then this completer is also completed exceptionally. The default implementation of this method does nothing except return true.

Overrides:

onExceptionalCompletion in class DTask<T extends MRTask>

Parameters:

ex - the exception

caller - the task invoking this method (which may be this task itself).

Returns:

true if this exception should be propagated to this tasks completer, if one exists.

lo

public final int lo()

hi

public final int hi()