org.apache.hadoop.hbase.filter

Class ColumnCountGetFilter

java.lang.Object

org.apache.hadoop.hbase.filter.Filter

org.apache.hadoop.hbase.filter.FilterBase

org.apache.hadoop.hbase.filter.ColumnCountGetFilter

@InterfaceAudience.Public
public class ColumnCountGetFilter
extends FilterBase

Simple filter that returns first N columns on row only. This filter was written to test filters in Get and as soon as it gets its quota of columns, filterAllRemaining() returns true. This makes this filter unsuitable as a Scan filter.

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
private int	count
private int	limit

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

reversed

Constructor Summary

Constructors

Constructor and Description
ColumnCountGetFilter(int n)

Method Summary

Modifier and Type	Method and Description
(package private) boolean	areSerializedFieldsEqual(Filter o) Returns true if and only if the fields of the filter that are serialized are equal to the corresponding fields in other.
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	filterRowKey(Cell cell) Filters a row based on the row key.
int	getLimit()
int	hashCode()
static ColumnCountGetFilter	parseFrom(byte[] pbBytes) Parse a serialized representation of ColumnCountGetFilter
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

filterRow, filterRowCells, filterRowKey, getNextCellHint, 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

limit

private int limit

count

private int count

Constructor Detail

ColumnCountGetFilter

public ColumnCountGetFilter(int n)

Method Detail

getLimit

public int getLimit()

filterRowKey

public boolean filterRowKey(Cell cell)
                     throws IOException

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 FilterBase

Parameters:

cell - The first cell coming in the new row

Returns:

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

Throws:

IOException - in case an I/O or an filter specific failure needs to be signaled.

filterAllRemaining

public boolean filterAllRemaining()

Description copied from class: 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 FilterBase

Returns:

true to end scan, false to continue.

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

reset

public void reset()

Description copied from class: 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 FilterBase

createFilterFromArguments

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

toByteArray

public byte[] toByteArray()

Returns The filter serialized using pb

Overrides:

toByteArray in class FilterBase

Returns:

The filter serialized using pb

parseFrom

public static ColumnCountGetFilter parseFrom(byte[] pbBytes)
                                      throws DeserializationException

Parse a serialized representation of ColumnCountGetFilter

Parameters:

pbBytes - A pb serialized ColumnCountGetFilter instance

Returns:

An instance of ColumnCountGetFilter made from bytes

Throws:

DeserializationException - if an error occurred

See Also:

toByteArray()

areSerializedFieldsEqual

boolean areSerializedFieldsEqual(Filter o)

Returns true if and only if the fields of the filter that are serialized are equal to the corresponding fields in other. Used for testing.

Overrides:

areSerializedFieldsEqual in class FilterBase

toString

public String toString()

Description copied from class: FilterBase

Return filter's info for debugging and logging purpose.

Overrides:

toString in class FilterBase

equals

public boolean equals(Object obj)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object