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>, jsr166y.ForkJoinPool.ManagedBlocker, Freezable

Direct Known Subclasses:

BaseStatsTask, BitsCmpTask, ConfusionTask, Covariance.COV_Task, DatasetCompare, DGLM.GLMModel.GLMValidationTask, DParseTask, 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, NewRowVecTask, NOPTask, ParseDataset.GuessSetupTsk, ParseDataset2.EnumFetchTask, ParseDataset2.MultiFileParseTask, ParseDataset2.SVFTask, PersistS3Task, RowTask, RowVecTask, ScoreTask, ToEnum.CollectIntDomain, ToEnum.EnumIntSwapTask

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

Map/Reduce style distributed computation.

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
protected int	_hi
protected int	_lo
protected boolean	_runSingleThreaded

Fields inherited from class water.DRemoteTask

_fs, _is_local, _keys, _top_level

Fields inherited from class water.DTask

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

Constructor Summary

Constructors

Constructor and Description
MRTask()

Method Summary

Methods

Modifier and Type	Method and Description
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, block, clone, compute2, dfork, getFutures, invoke, invokeOnAllNodes, isReleasable, keys, onCompletion, postGlobal, 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

_runSingleThreaded

protected boolean _runSingleThreaded

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 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()