org.apache.hadoop.hbase.filter

Class ColumnPrefixFilter

java.lang.Object

org.apache.hadoop.hbase.filter.Filter

org.apache.hadoop.hbase.filter.FilterBase

org.apache.hadoop.hbase.filter.ColumnPrefixFilter

@InterfaceAudience.Public
@InterfaceStability.Stable
public class ColumnPrefixFilter
extends FilterBase

This filter is used for selecting only those keys with columns that matches a particular prefix. For example, if prefix is 'an', it will pass keys with columns like 'and', 'anti' but not keys with columns like 'ball', 'act'.

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 byte[]	prefix

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

reversed

Constructor Summary

Constructors

Constructor and Description
ColumnPrefixFilter(byte[] prefix)

Method Summary

Methods

Modifier and Type	Method and Description
static Filter	createFilterFromArguments(ArrayList<byte[]> filterArguments)
Filter.ReturnCode	filterColumn(byte[] buffer, int qualifierOffset, int qualifierLength)
Filter.ReturnCode	filterKeyValue(Cell kv) A way to filter based on the column family, column qualifier and/or the column value.
Cell	getNextCellHint(Cell kv) 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()
static ColumnPrefixFilter	parseFrom(byte[] pbBytes)
byte[]	toByteArray() Return length 0 byte array for Filters that don't require special serialization
String	toString() Return filter's info for debugging and logging purpose.
Cell	transformCell(Cell v) By default no transformation takes place

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

filterAllRemaining, filterRow, filterRowCells, filterRowKey, getNextKeyHint, hasFilterRow, isFamilyEssential, reset, transform

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

isReversed, setReversed

Methods inherited from class java.lang.Object

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

Field Detail

prefix

protected byte[] prefix

Constructor Detail

ColumnPrefixFilter

public ColumnPrefixFilter(byte[] prefix)

Method Detail

getPrefix

public byte[] getPrefix()

filterKeyValue

public Filter.ReturnCode filterKeyValue(Cell kv)

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.

Specified by:

filterKeyValue in class Filter

Parameters:

kv - the Cell in question

Returns:

code as described below

See Also:

Filter.ReturnCode

transformCell

public Cell transformCell(Cell v)

Description copied from class: FilterBase

By default no transformation takes place

Overrides:

transformCell in class FilterBase

Parameters:

v - the KeyValue in question

Returns:

the changed KeyValue

See Also:

The transformed KeyValue is what is eventually returned to the client. Most filters will return the passed KeyValue unchanged., for an example of a transformation. Concrete implementers can signal a failure condition in their code by throwing an {@link IOException}.

filterColumn

public Filter.ReturnCode filterColumn(byte[] buffer,
                             int qualifierOffset,
                             int qualifierLength)

createFilterFromArguments

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

toByteArray

public byte[] toByteArray()

Description copied from class: FilterBase

Return length 0 byte array for Filters that don't require special serialization

Overrides:

toByteArray in class FilterBase

Returns:

The filter serialized using pb

parseFrom

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

Parameters:

pbBytes - A pb serialized ColumnPrefixFilter instance

Returns:

An instance of ColumnPrefixFilter made from bytes

Throws:

DeserializationException

See Also:

toByteArray()

getNextCellHint

public Cell getNextCellHint(Cell kv)

Description copied from class: FilterBase

Filters that are not sure which key must be next seeked to, can inherit this implementation that, by default, returns a null Cell.

Overrides:

getNextCellHint in class FilterBase

Returns:

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

toString

public String toString()

Description copied from class: FilterBase

Return filter's info for debugging and logging purpose.

Overrides:

toString in class FilterBase