org.apache.hadoop.hbase.filter

Class ColumnValueFilter

java.lang.Object

org.apache.hadoop.hbase.filter.Filter

org.apache.hadoop.hbase.filter.FilterBase

org.apache.hadoop.hbase.filter.ColumnValueFilter

@InterfaceAudience.Public
public class ColumnValueFilter
extends FilterBase

Different from SingleColumnValueFilter which returns an entire row when specified condition is matched, ColumnValueFilter return the matched cell only.

This filter is used to filter cells based on column and value. It takes a CompareOperator operator (<, <=, =, !=, >, >=), and and a ByteArrayComparable comparator.

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 boolean	columnFound
private ByteArrayComparable	comparator
private byte[]	family
private CompareOperator	op
private byte[]	qualifier

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

reversed

Constructor Summary

Constructors

Constructor and Description
ColumnValueFilter(byte[] family, byte[] qualifier, CompareOperator op, byte[] value)
ColumnValueFilter(byte[] family, byte[] qualifier, CompareOperator op, ByteArrayComparable comparator)

Method Summary

Modifier and Type	Method and Description
(package private) boolean	areSerializedFieldsEqual(Filter o) Default implementation so that writers of custom filters aren't forced to implement.
private boolean	compareValue(CompareOperator op, ByteArrayComparable comparator, Cell cell) This method is used to determine a cell should be included or filtered out.
(package private) org.apache.hadoop.hbase.shaded.protobuf.generated.FilterProtos.ColumnValueFilter	convert()
static Filter	createFilterFromArguments(ArrayList<byte[]> filterArguments) Creating this filter by reflection, it is used by ParseFilter,
boolean	equals(Object obj)
Filter.ReturnCode	filterCell(Cell c) A way to filter based on the column family, column qualifier and/or the column value.
boolean	filterRowKey(Cell cell) Filters a row based on the row key.
ByteArrayComparable	getComparator()
CompareOperator	getCompareOperator()
byte[]	getFamily()
byte[]	getQualifier()
int	hashCode()
boolean	isFamilyEssential(byte[] name) By default, we require all scan's column families to be present.
static ColumnValueFilter	parseFrom(byte[] pbBytes) Parse protobuf bytes to a ColumnValueFilter
void	reset() Filters that are purely stateless and do nothing in their reset() methods can inherit this null/empty implementation.
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.

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

filterAllRemaining, filterRow, filterRowCells, filterRowKey, getNextCellHint, hasFilterRow, transformCell

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

filterKeyValue, isReversed, setReversed

Methods inherited from class java.lang.Object

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

Field Detail

family

private final byte[] family

qualifier

private final byte[] qualifier

op

private final CompareOperator op

comparator

private final ByteArrayComparable comparator

columnFound

private boolean columnFound

Constructor Detail

ColumnValueFilter

public ColumnValueFilter(byte[] family,
                         byte[] qualifier,
                         CompareOperator op,
                         byte[] value)

ColumnValueFilter

public ColumnValueFilter(byte[] family,
                         byte[] qualifier,
                         CompareOperator op,
                         ByteArrayComparable comparator)

Method Detail

getCompareOperator

public CompareOperator getCompareOperator()

Returns:

operator

getComparator

public ByteArrayComparable getComparator()

Returns:

the comparator

getFamily

public byte[] getFamily()

Returns:

the column family

getQualifier

public byte[] getQualifier()

Returns:

the qualifier

reset

public void reset()
           throws IOException

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

Throws:

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

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.

filterCell

public Filter.ReturnCode filterCell(Cell c)
                             throws IOException

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

Throws:

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

See Also:

Filter.ReturnCode

compareValue

private boolean compareValue(CompareOperator op,
                             ByteArrayComparable comparator,
                             Cell cell)

This method is used to determine a cell should be included or filtered out.

Parameters:

op - one of operators CompareOperator

comparator - comparator used to compare cells.

cell - cell to be compared.

Returns:

true means cell should be filtered out, included otherwise.

createFilterFromArguments

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

Creating this filter by reflection, it is used by ParseFilter,

Parameters:

filterArguments - arguments for creating a ColumnValueFilter

Returns:

a ColumnValueFilter

convert

org.apache.hadoop.hbase.shaded.protobuf.generated.FilterProtos.ColumnValueFilter convert()

Returns:

A pb instance to represent this instance.

parseFrom

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

Parse protobuf bytes to a ColumnValueFilter

Parameters:

pbBytes - pbBytes

Returns:

a ColumnValueFilter

Throws:

DeserializationException - deserialization exception

toByteArray

public byte[] toByteArray()
                   throws IOException

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

Throws:

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

areSerializedFieldsEqual

boolean areSerializedFieldsEqual(Filter o)

Description copied from class: FilterBase

Default implementation so that writers of custom filters aren't forced to implement.

Overrides:

areSerializedFieldsEqual in class FilterBase

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.

isFamilyEssential

public boolean isFamilyEssential(byte[] name)
                          throws IOException

Description copied from class: FilterBase

By default, we require all scan's column families to be present. Our subclasses may be more precise. Check that given column family is essential for filter to check row. Most filters always return true here. But some could have more sophisticated logic which could significantly reduce scanning process by not even touching columns until we are 100% sure that it's data is needed in result. Concrete implementers can signal a failure condition in their code by throwing an IOException.

Overrides:

isFamilyEssential in class FilterBase

Throws:

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

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