org.apache.hadoop.hbase.filter

类 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.

嵌套类概要

从类继承的嵌套类/接口 org.apache.hadoop.hbase.filter.Filter

Filter.ReturnCode

字段概要

从类继承的字段 org.apache.hadoop.hbase.filter.Filter

reversed

构造器概要

构造器

构造器和说明
PageFilter(long pageSize) Constructor that takes a maximum page size.

方法概要

方法

限定符和类型	方法和说明
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	filterKeyValue(Cell ignored) A way to filter based on the column family, column qualifier and/or the column value.
boolean	filterRow() Filters that never filter by rows based on previously gathered state from Filter.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.
int	hashCode()
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.
Cell	transformCell(Cell v) By default no transformation takes place Give the filter a chance to transform the passed KeyValue.

从类继承的方法 org.apache.hadoop.hbase.filter.FilterBase

filterRowCells, filterRowKey, getNextCellHint, getNextKeyHint, isFamilyEssential, reset, transform

从类继承的方法 org.apache.hadoop.hbase.filter.Filter

isReversed, setReversed

从类继承的方法 java.lang.Object

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

构造器详细资料

PageFilter

public PageFilter(long pageSize)

Constructor that takes a maximum page size.

参数:

pageSize - Maximum result size.

方法详细资料

getPageSize

public long getPageSize()

filterKeyValue

public Filter.ReturnCode filterKeyValue(Cell ignored)
                                 throws IOException

从类复制的说明: 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.

指定者:

filterKeyValue 在类中 Filter

参数:

ignored - the Cell in question

返回:

code as described below

抛出:

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

另请参阅:

Filter.ReturnCode

transformCell

public Cell transformCell(Cell v)

从类复制的说明: FilterBase

By default no transformation takes place Give the filter a chance to transform the passed KeyValue. If the Cell is changed a new Cell object must be returned.

覆盖:

transformCell 在类中 FilterBase

参数:

v - the KeyValue in question

返回:

the changed KeyValue

另请参阅:

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}.

filterAllRemaining

public boolean filterAllRemaining()

从类复制的说明: 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.

覆盖:

filterAllRemaining 在类中 FilterBase

返回:

true to end scan, false to continue.

filterRow

public boolean filterRow()

从类复制的说明: FilterBase

Filters that never filter by rows based on previously gathered state from Filter.filterKeyValue(Cell) can inherit this implementation that never filters a row. Last chance to veto row based on previous Filter.filterKeyValue(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.

覆盖:

filterRow 在类中 FilterBase

返回:

true to exclude row, false to include row.

hasFilterRow

public boolean hasFilterRow()

从类复制的说明: FilterBase

Fitlers that never filter by modifying the returned List of Cells can inherit this implementation that does nothing. Primarily used to check for conflicts with scans(such as scans that do not read a full row at a time).

覆盖:

hasFilterRow 在类中 FilterBase

返回:

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

createFilterFromArguments

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

toByteArray

public byte[] toByteArray()

从类复制的说明: FilterBase

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

覆盖:

toByteArray 在类中 FilterBase

返回:

The filter serialized using pb

parseFrom

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

参数:

pbBytes - A pb serialized PageFilter instance

返回:

An instance of PageFilter made from bytes

抛出:

DeserializationException

另请参阅:

toByteArray()

toString

public String toString()

从类复制的说明: FilterBase

Return filter's info for debugging and logging purpose.

覆盖:

toString 在类中 FilterBase

equals

public boolean equals(Object obj)

覆盖:

equals 在类中 Object

hashCode

public int hashCode()

覆盖:

hashCode 在类中 Object