org.apache.hadoop.hive.ql.udf.ptf

Class ValueBoundaryScanner

java.lang.Object

org.apache.hadoop.hive.ql.udf.ptf.ValueBoundaryScanner

public abstract class ValueBoundaryScanner
extends Object

Field Summary

Fields

Modifier and Type	Field and Description
protected boolean	nullsLast

Constructor Summary

Constructors

Constructor and Description
ValueBoundaryScanner(BoundaryDef start, BoundaryDef end, boolean nullsLast)

Method Summary

Modifier and Type	Method and Description
abstract int	computeEnd(int rowIdx, PTFPartition p)
abstract int	computeStart(int rowIdx, PTFPartition p)
abstract Object	computeValue(Object row)
protected Object	computeValueUseCache(int r, PTFPartition p) Uses cache to lookup row value.
static ValueBoundaryScanner	getScanner(WindowFrameDef winFrameDef, boolean nullsLast)
void	handleCache(int rowIdx, PTFPartition p) Checks and maintains cache content - optimizes cache window to always be around current row thereby makes it follow the current progress.
abstract boolean	isDistanceGreater(Object v1, Object v2, int amt) Checks if the distance of v2 to v1 is greater than the given amt.
abstract boolean	isEqual(Object v1, Object v2) Checks if the values of v1 or v2 are the same.
protected org.apache.commons.lang3.tuple.Pair<Integer,Object>	skipOrStepBack(int r, PTFPartition p) Uses cache content to jump backwards if possible.
protected org.apache.commons.lang3.tuple.Pair<Integer,Object>	skipOrStepForward(int r, PTFPartition p) Uses cache content to jump forward if possible.

Methods inherited from class java.lang.Object

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

Field Detail

nullsLast

protected final boolean nullsLast

Constructor Detail

ValueBoundaryScanner

public ValueBoundaryScanner(BoundaryDef start,
                            BoundaryDef end,
                            boolean nullsLast)

Method Detail

computeValue

public abstract Object computeValue(Object row)
                             throws HiveException

Throws:

HiveException

isDistanceGreater

public abstract boolean isDistanceGreater(Object v1,
                                          Object v2,
                                          int amt)

Checks if the distance of v2 to v1 is greater than the given amt.

Returns:

True if the value of v1 - v2 is greater than amt or either value is null.

isEqual

public abstract boolean isEqual(Object v1,
                                Object v2)

Checks if the values of v1 or v2 are the same.

Returns:

True if both values are the same or both are nulls.

computeStart

public abstract int computeStart(int rowIdx,
                                 PTFPartition p)
                          throws HiveException

Throws:

HiveException

computeEnd

public abstract int computeEnd(int rowIdx,
                               PTFPartition p)
                        throws HiveException

Throws:

HiveException

handleCache

public void handleCache(int rowIdx,
                        PTFPartition p)
                 throws HiveException

Checks and maintains cache content - optimizes cache window to always be around current row thereby makes it follow the current progress.

Parameters:

rowIdx - current row

p - current partition for the PTF operator

Throws:

HiveException

skipOrStepBack

protected org.apache.commons.lang3.tuple.Pair<Integer,Object> skipOrStepBack(int r,
                                                                             PTFPartition p)
                                                                      throws HiveException

Uses cache content to jump backwards if possible. If not, it steps one back.

Parameters:

r -

p -

Returns:

pair of (row we stepped/jumped onto ; row value at this position)

Throws:

HiveException

skipOrStepForward

protected org.apache.commons.lang3.tuple.Pair<Integer,Object> skipOrStepForward(int r,
                                                                                PTFPartition p)
                                                                         throws HiveException

Uses cache content to jump forward if possible. If not, it steps one forward.

Parameters:

r -

p -

Returns:

pair of (row we stepped/jumped onto ; row value at this position)

Throws:

HiveException

computeValueUseCache

protected Object computeValueUseCache(int r,
                                      PTFPartition p)
                               throws HiveException

Uses cache to lookup row value. Computes it on the fly on cache miss.

Parameters:

r -

p -

Returns:

row value.

Throws:

HiveException

getScanner

public static ValueBoundaryScanner getScanner(WindowFrameDef winFrameDef,
                                              boolean nullsLast)
                                       throws HiveException

Throws:

HiveException