org.imemex.operators
Class AbstractPullOperator<E>

java.lang.Object
  org.imemex.operators.AbstractPullOperator<E>

Type Parameters:

E - type of elements

All Implemented Interfaces:

java.util.Iterator<E>, Operator, PullOperator<E>

Direct Known Subclasses:

AbstractFilterPullOperator, AbstractMapperPullOperator, AddLineageInfoOperator, AntiHashJoinPullOperator, BinaryOIDPullOperator, CachePullOperator, ComponentExtractingPullOperator, ComponentFromMappingListPullOperator, DeepUnnestPullOperator, DistinctOperator, EqualsOperator, EquiJoinOperator, ExternalMemorySorter, ExternalQueue, Filter, GetParentsOperator, IMAPFolderPullOperator, IndexViewFromComponentPullOperator, IndexViewFromOIDPullOperator, IndexViewToRVPullOperator, InMemoryGeneratedOIDOnlyPullOperator, IntersectOperator, KeywordOperator, LeftPreservingUnionPullOperator, LimitOperator, LineageDematerializePullOperator, LineageMaterializePullOperator, LineageSortOperator, ListPullOperator, ListQueue, LuceneScanPullOperator, MainMemorySorter, Merger, MinusPullOperator, MVReading, OIDPullOperator, OIDResourceViewToIndexViewPullOperator, ParallelPullOperator, PhysicalChoosePullOperator, PluginIdentifiableToOIDResourceViewPullOperator, PQTopKOperator, PrefixContentConvertedIdPullOperator, QueueWrapperPullOperator, RandomInteger, RankBoosterOperator, RankingOperator, RegexOperator, ResultSetPullOperator, RVGroupingOperator, ShallowUnnestPullOperator, SingletonPullOperator, SortPullOperator, ThetaJoinOperator, TopKSnapshotOperator, TupleFilter, UnionAllPullOperator, VersionMergeOperator

public abstract class AbstractPullOperator<E>
extends java.lang.Object
implements PullOperator<E>

Abstract implementation of a pull operator which has a single element buffer.

Since the size of the buffer is only one, we can keep track of whether there is a next element in the buffer using a boolean status flag (hasElementInBuffer).

Author:

Lukas Blunschi (blukas@student.ethz.ch)

Nested Class Summary

Nested classes/interfaces inherited from interface org.imemex.operators.Operator

Operator.ExecTimeType

Field Summary

static boolean

measureNext Set to true to measure timing on calls to next.

Constructor Summary

AbstractPullOperator()

Method Summary

void	addExecTime(long nanos, Operator.ExecTimeType type) If an operator implementor wants - and it would if everyone did, he may collect execution times using this method.
void	close() Does nothing.
java.lang.String	getDesc() Get description.
long	getExecTime(Operator.ExecTimeType type) Get collected execution times.
java.util.List<PullOperator>	getInputOperators() Get input operators of this operator.
OperatorMetaData	getMetaData() Returns the meta data of this operator.
long	getNumberOfElementsPassed() Get the number of results produced so far.
boolean	hasNext()
E	next()
void	open() Does nothing.
E	peek() Shows the next element without removing it from the iterator
void	remove() Throws an UnsupportedOperationException.
void	setDesc(java.lang.String description) Set description.
static PullOperator<java.lang.Object>	toObjectPullOperator(PullOperator<?> inputOp) transforms PullOperator of any type to Object-PullOperator
java.lang.String	toString()
java.lang.String	toXML() Get an XML representation of this pull operator.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

measureNext

public static boolean measureNext

Set to true to measure timing on calls to next. SHOULD BE FALSE ON DEFAULT.

Constructor Detail

AbstractPullOperator

public AbstractPullOperator()

Method Detail

open

public void open()

Does nothing.

Specified by:

open in interface Operator

hasNext

public boolean hasNext()

Specified by:

hasNext in interface java.util.Iterator<E>

next

public final E next()

Specified by:

next in interface java.util.Iterator<E>

remove

public void remove()

Throws an UnsupportedOperationException.

Specified by:

remove in interface java.util.Iterator<E>

close

public void close()

Does nothing.

Specified by:

close in interface Operator

peek

public E peek()

Description copied from interface: PullOperator

Shows the next element without removing it from the iterator

Specified by:

peek in interface PullOperator<E>

Returns:

getMetaData

public OperatorMetaData getMetaData()

Returns the meta data of this operator.

Specified by:

getMetaData in interface Operator

Returns:

meta data

toXML

public final java.lang.String toXML()

Description copied from interface: Operator

Get an XML representation of this pull operator.

Specified by:

toXML in interface Operator

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

Returns:

description of this pull operator. This may span several lines, but if so, the last one should be ended with a newline.

getDesc

public final java.lang.String getDesc()

Description copied from interface: Operator

Get description.

Specified by:

getDesc in interface Operator

setDesc

public final void setDesc(java.lang.String description)

Description copied from interface: Operator

Set description.

Specified by:

setDesc in interface Operator

getNumberOfElementsPassed

public final long getNumberOfElementsPassed()

Description copied from interface: Operator

Get the number of results produced so far.

Specified by:

getNumberOfElementsPassed in interface Operator

Returns:

number of results

addExecTime

public final void addExecTime(long nanos,
                              Operator.ExecTimeType type)

Description copied from interface: Operator

If an operator implementor wants - and it would if everyone did, he may collect execution times using this method.

Specified by:

addExecTime in interface Operator

Parameters:

nanos - number of nanoseconds to add to given time type.

type - type of execution time.

getExecTime

public final long getExecTime(Operator.ExecTimeType type)

Description copied from interface: Operator

Get collected execution times.

Specified by:

getExecTime in interface Operator

Parameters:

type - type of execution time.

Returns:

number of nanoseconds

getInputOperators

public java.util.List<PullOperator> getInputOperators()

Description copied from interface: PullOperator

Get input operators of this operator. This is mainly used to recursively generate an XML representation of an operator tree.

Specified by:

getInputOperators in interface PullOperator<E>

Returns:

list of operators

toObjectPullOperator

public static PullOperator<java.lang.Object> toObjectPullOperator(PullOperator<?> inputOp)

transforms PullOperator of any type to Object-PullOperator

Parameters:

inputOp -

Returns: