org.apache.hadoop.hbase.filter

Class PrefixFilter

java.lang.Object

org.apache.hadoop.hbase.filter.Filter

org.apache.hadoop.hbase.filter.FilterBase

org.apache.hadoop.hbase.filter.PrefixFilter

All Implemented Interfaces:

HintingFilter

@InterfaceAudience.Public
public class PrefixFilter
extends org.apache.hadoop.hbase.filter.FilterBase
implements HintingFilter

Pass results that have same row prefix.

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.hadoop.hbase.filter.Filter

Filter.ReturnCode

Field Summary

Fields

Modifier and Type	Field and Description
protected boolean	filterRow
protected Cell	forwardNextCellHint
protected boolean	passedPrefix
protected byte[]	prefix
protected boolean	provideHint
protected Cell	reversedNextCellHint

Fields inherited from class org.apache.hadoop.hbase.filter.Filter

reversed

Constructor Summary

Constructors

Constructor and Description
PrefixFilter(byte[] prefix)

Method Summary

Modifier and Type	Method and Description
static Filter	createFilterFromArguments(ArrayList<byte[]> filterArguments)
boolean	equals(Object obj)
boolean	filterAllRemaining() Filters that never filter all remaining can inherit this implementation that never stops the filter early.
Filter.ReturnCode	filterCell(Cell c) A way to filter based on the column family, column qualifier and/or the column value.
Filter.ReturnCode	filterKeyValue(Cell c) Deprecated.
boolean	filterRow() Filters that never filter by rows based on previously gathered state from Filter.filterCell(Cell) can inherit this implementation that never filters a row.
boolean	filterRowKey(Cell firstRowCell) Filters a row based on the row key.
Cell	getNextCellHint(Cell cell) Filters that are not sure which key must be next seeked to, can inherit this implementation that, by default, returns a null Cell.
byte[]	getPrefix()
int	hashCode()
static PrefixFilter	parseFrom(byte[] pbBytes) Parse a serialized representation of PrefixFilter
void	reset() Filters that are purely stateless and do nothing in their reset() methods can inherit this null/empty implementation.
byte[]	toByteArray() Returns The filter serialized using pb
String	toString() Return filter's info for debugging and logging purpose.

Methods inherited from class org.apache.hadoop.hbase.filter.FilterBase

filterRowCells, filterRowKey, hasFilterRow, isFamilyEssential, transformCell

Methods inherited from class org.apache.hadoop.hbase.filter.Filter

isReversed, setReversed

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

prefix

protected byte[] prefix

passedPrefix

protected boolean passedPrefix

filterRow

protected boolean filterRow

provideHint

protected boolean provideHint

reversedNextCellHint

protected Cell reversedNextCellHint

forwardNextCellHint

protected Cell forwardNextCellHint

Constructor Detail

PrefixFilter

public PrefixFilter(byte[] prefix)

Method Detail

getPrefix

public byte[] getPrefix()

filterRowKey

public boolean filterRowKey(Cell firstRowCell)

Description copied from class: Filter

Filters a row based on the row key. If this returns true, the entire row will be excluded. If false, each KeyValue in the row will be passed to Filter.filterCell(Cell) below. If Filter.filterAllRemaining() returns true, then Filter.filterRowKey(Cell) should also return true. Concrete implementers can signal a failure condition in their code by throwing an IOException.

Overrides:

filterRowKey in class org.apache.hadoop.hbase.filter.FilterBase

Parameters:

firstRowCell - The first cell coming in the new row

Returns:

true, remove entire row, false, include the row (maybe).

filterKeyValue

@Deprecated
public Filter.ReturnCode filterKeyValue(Cell c)

Deprecated.

Description copied from class: Filter

A way to filter based on the column family, column qualifier and/or the column value. Return code is described below. This allows filters to filter only certain number of columns, then terminate without matching ever column. If filterRowKey returns true, filterKeyValue needs to be consistent with it. filterKeyValue can assume that filterRowKey has already been called for the row. If your filter returns ReturnCode.NEXT_ROW, it should return ReturnCode.NEXT_ROW until Filter.reset() is called just in case the caller calls for the next row. Concrete implementers can signal a failure condition in their code by throwing an IOException.

Overrides:

filterKeyValue in class Filter

Parameters:

c - the Cell in question

Returns:

code as described below, Filter.ReturnCode.INCLUDE by default

See Also:

Filter.ReturnCode

filterCell

public Filter.ReturnCode filterCell(Cell c)

Description copied from class: Filter

A way to filter based on the column family, column qualifier and/or the column value. Return code is described below. This allows filters to filter only certain number of columns, then terminate without matching ever column. If filterRowKey returns true, filterCell needs to be consistent with it. filterCell can assume that filterRowKey has already been called for the row. If your filter returns ReturnCode.NEXT_ROW, it should return ReturnCode.NEXT_ROW until Filter.reset() is called just in case the caller calls for the next row. Concrete implementers can signal a failure condition in their code by throwing an IOException.

Overrides:

filterCell in class Filter

Parameters:

c - the Cell in question

Returns:

code as described below

See Also:

Filter.ReturnCode

filterRow

public boolean filterRow()

Description copied from class: org.apache.hadoop.hbase.filter.FilterBase

Filters that never filter by rows based on previously gathered state from Filter.filterCell(Cell) can inherit this implementation that never filters a row. Last chance to veto row based on previous Filter.filterCell(Cell) calls. The filter needs to retain state then return a particular value for this call if they wish to exclude a row if a certain column is missing (for example). Concrete implementers can signal a failure condition in their code by throwing an IOException.

Overrides:

filterRow in class org.apache.hadoop.hbase.filter.FilterBase

Returns:

true to exclude row, false to include row.

reset

public void reset()

Description copied from class: org.apache.hadoop.hbase.filter.FilterBase

Filters that are purely stateless and do nothing in their reset() methods can inherit this null/empty implementation. Reset the state of the filter between rows. Concrete implementers can signal a failure condition in their code by throwing an IOException.

Overrides:

reset in class org.apache.hadoop.hbase.filter.FilterBase

filterAllRemaining

public boolean filterAllRemaining()

Description copied from class: org.apache.hadoop.hbase.filter.FilterBase

Filters that never filter all remaining can inherit this implementation that never stops the filter early. If this returns true, the scan will terminate. Concrete implementers can signal a failure condition in their code by throwing an IOException.

Overrides:

filterAllRemaining in class org.apache.hadoop.hbase.filter.FilterBase

Returns:

true to end scan, false to continue.

getNextCellHint

public Cell getNextCellHint(Cell cell)

Description copied from class: org.apache.hadoop.hbase.filter.FilterBase

Filters that are not sure which key must be next seeked to, can inherit this implementation that, by default, returns a null Cell. If the filter returns the match code SEEK_NEXT_USING_HINT, then it should also tell which is the next key it must seek to. After receiving the match code SEEK_NEXT_USING_HINT, the QueryMatcher would call this function to find out which key it must next seek to. Concrete implementers can signal a failure condition in their code by throwing an IOException.

Overrides:

getNextCellHint in class org.apache.hadoop.hbase.filter.FilterBase

Returns:

KeyValue which must be next seeked. return null if the filter is not sure which key to seek to next.

createFilterFromArguments

public static Filter createFilterFromArguments(ArrayList<byte[]> filterArguments)

toByteArray

public byte[] toByteArray()

Returns The filter serialized using pb

Overrides:

toByteArray in class org.apache.hadoop.hbase.filter.FilterBase

Returns:

The filter serialized using pb

parseFrom

public static PrefixFilter parseFrom(byte[] pbBytes)
                              throws org.apache.hadoop.hbase.exceptions.DeserializationException

Parse a serialized representation of PrefixFilter

Parameters:

pbBytes - A pb serialized PrefixFilter instance

Returns:

An instance of PrefixFilter made from bytes

Throws:

org.apache.hadoop.hbase.exceptions.DeserializationException - if an error occurred

See Also:

toByteArray()

toString

public String toString()

Description copied from class: org.apache.hadoop.hbase.filter.FilterBase

Return filter's info for debugging and logging purpose.

Overrides:

toString in class org.apache.hadoop.hbase.filter.FilterBase

equals

public boolean equals(Object obj)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object