org.apache.hadoop.hbase.filter

Class PageFilter

java.lang.Object

org.apache.hadoop.hbase.filter.Filter

org.apache.hadoop.hbase.filter.FilterBase

org.apache.hadoop.hbase.filter.PageFilter

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

Implementation of Filter interface that limits results to a specific page size. It terminates scanning once the number of filter-passed rows is > the given page size.

Note that this filter cannot guarantee that the number of results returned to a client are <= page size. This is because the filter is applied separately on different region servers. It does however optimize the scan of individual HRegions by making sure that the page size is never exceeded locally.

Nested Class Summary

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

Filter.ReturnCode

Constructor Summary

Constructors

Constructor and Description
PageFilter(long pageSize) Constructor that takes a maximum page size.

Method Summary

Methods

Modifier and Type	Method and Description
static Filter	createFilterFromArguments(ArrayList<byte[]> filterArguments)
boolean	filterAllRemaining() Filters that never filter all remaining can inherit this implementation that never stops the filter early.
boolean	filterRow() Filters that never filter by rows based on previously gathered state from FilterBase.filterKeyValue(Cell) can inherit this implementation that never filters a row.
long	getPageSize()
boolean	hasFilterRow() Fitlers that never filter by modifying the returned List of Cells can inherit this implementation that does nothing.
static PageFilter	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.

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

filterKeyValue, filterRow, filterRowCells, filterRowKey, getNextCellHint, getNextKeyHint, isFamilyEssential, reset, transform, transformCell

Methods inherited from class java.lang.Object

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

Constructor Detail

PageFilter

public PageFilter(long pageSize)

Constructor that takes a maximum page size.

Parameters:

pageSize - Maximum result size.

Method Detail

getPageSize

public long getPageSize()

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.

Overrides:

filterAllRemaining in class FilterBase

Returns:

true to end scan, false to continue.

filterRow

public boolean filterRow()

Description copied from class: FilterBase

Filters that never filter by rows based on previously gathered state from FilterBase.filterKeyValue(Cell) can inherit this implementation that never filters a row.

Overrides:

filterRow in class FilterBase

Returns:

true to exclude row, false to include row.

hasFilterRow

public boolean hasFilterRow()

Description copied from class: FilterBase

Fitlers that never filter by modifying the returned List of Cells can inherit this implementation that does nothing.

Overrides:

hasFilterRow in class FilterBase

Returns:

True if this filter actively uses filterRow(List) or filterRow().

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 PageFilter parseFrom(byte[] pbBytes)
                            throws DeserializationException

Parameters:

pbBytes - A pb serialized PageFilter instance

Returns:

An instance of PageFilter made from bytes

Throws:

DeserializationException

See Also:

toByteArray()

toString

public String toString()

Description copied from class: FilterBase

Return filter's info for debugging and logging purpose.

Overrides:

toString in class FilterBase