org.apache.hadoop.hbase.filter.FilterWrapper

@Private public final class FilterWrapper extends Filter

This is a Filter wrapper class which is used in the server side. Some filter related hooks can be defined in this wrapper. The only way to create a FilterWrapper instance is passing a client side Filter instance through Scan.getFilter().

Nested Class Summary

Nested Classes

Modifier and Type

Class

Description

static enum

FilterWrapper.FilterRowRetCode

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

Fields

Modifier and Type

Field

Description

(package private) Filter

filter

Fields inherited from class org.apache.hadoop.hbase.filter.Filter
reversed
Constructor Summary

Constructors

Constructor

Description

FilterWrapper(Filter filter)

Constructor.
Method Summary

Modifier and Type

Method

Description

(package private) boolean

areSerializedFieldsEqual(Filter o)

Concrete implementers can signal a failure condition in their code by throwing an IOException.

boolean

filterAllRemaining()

If this returns true, the scan will terminate.

Filter.ReturnCode

filterCell(Cell c)

A way to filter based on the column family, column qualifier and/or the column value.

boolean

filterRow()

Last chance to veto row based on previous Filter.filterCell(Cell) calls.

void

filterRowCells(List<Cell> kvs)

Chance to alter the list of Cells to be submitted.

FilterWrapper.FilterRowRetCode

filterRowCellsWithRet(List<Cell> kvs)

boolean

filterRowKey(Cell cell)

Filters a row based on the row key.

Cell

getNextCellHint(Cell currentCell)

If the filter returns the match code SEEK_NEXT_USING_HINT, then it should also tell which is the next key it must seek to.

boolean

hasFilterRow()

Primarily used to check for conflicts with scans(such as scans that do not read a full row at a time).

boolean

isFamilyEssential(byte[] name)

Check that given column family is essential for filter to check row.

static FilterWrapper

parseFrom(byte[] pbBytes)

void

reset()

Reset the state of the filter between rows.

byte[]

toByteArray()

Returns The filter serialized using pb

Cell

transformCell(Cell v)

Give the filter a chance to transform the passed Cell.

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, toString, wait, wait, wait

Field Details
- filter
  
  Filter filter
Constructor Details
- FilterWrapper
  
  public FilterWrapper(Filter filter)
  
  Constructor.
  
  Parameters:
  
  filter - filter to wrap
  
  Throws:
  
  NullPointerException - if filter is null
Method Details
- toByteArray
  
  public byte[] toByteArray() throws IOException
  
  Returns The filter serialized using pb
  
  Specified by:
  
  toByteArray in class Filter
  
  Returns:
  
  The filter serialized using pb
  
  Throws:
  
  IOException - in case an I/O or an filter specific failure needs to be signaled.
- parseFrom
  
  public static FilterWrapper parseFrom(byte[] pbBytes) throws DeserializationException
  Parameters:
  
  pbBytes - A pb serialized FilterWrapper instance
  
  Returns:
  
  An instance of FilterWrapper made from bytes
  
  Throws:
  
  DeserializationException
  
  See Also:
  
  toByteArray()
- reset
  
  public void reset() throws IOException
  
  Description copied from class: Filter
  
  Reset the state of the filter between rows. Concrete implementers can signal a failure condition in their code by throwing an IOException.
  
  Specified by:
  
  reset in class Filter
  
  Throws:
  
  IOException - in case an I/O or an filter specific failure needs to be signaled.
- filterAllRemaining
  
  public boolean filterAllRemaining() throws IOException
  
  Description copied from class: Filter
  
  If this returns true, the scan will terminate. Concrete implementers can signal a failure condition in their code by throwing an IOException.
  
  Specified by:
  
  filterAllRemaining in class Filter
  
  Returns:
  
  true to end scan, false to continue.
  
  Throws:
  
  IOException - in case an I/O or an filter specific failure needs to be signaled.
- filterRow
  
  public boolean filterRow() throws IOException
  
  Description copied from class: Filter
  
  Last chance to veto row based on previous Filter.filterCell(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.
  
  Specified by:
  
  filterRow in class Filter
  
  Returns:
  
  true to exclude row, false to include row.
  
  Throws:
  
  IOException - in case an I/O or an filter specific failure needs to be signaled.
- getNextCellHint
  
  public Cell getNextCellHint(Cell currentCell) throws IOException
  
  Description copied from class: Filter
  
  If the filter returns the match code SEEK_NEXT_USING_HINT, then it should also tell which is the next key it must seek to. After receiving the match code SEEK_NEXT_USING_HINT, the QueryMatcher would call this function to find out which key it must next seek to. Concrete implementers can signal a failure condition in their code by throwing an IOException. NOTICE: Filter will be evaluate at server side so the returned Cell must be an ExtendedCell, although it is marked as IA.Private.
  
  Specified by:
  
  getNextCellHint in class Filter
  
  Returns:
  
  KeyValue which must be next seeked. return null if the filter is not sure which key to seek to next.
  
  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.
  
  Specified by:
  
  filterRowKey in class Filter
  
  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
- transformCell
  
  public Cell transformCell(Cell v) throws IOException
  
  Description copied from class: Filter
  
  Give the filter a chance to transform the passed Cell. If the Cell is changed a new Cell object must be returned.
  NOTICE: Filter will be evaluate at server side so the returned Cell must be an ExtendedCell, although it is marked as IA.Private.
  Specified by:
  
  transformCell in class Filter
  
  Parameters:
  
  v - the Cell in question
  
  Returns:
  
  the changed Cell
  
  Throws:
  
  IOException - in case an I/O or an filter specific failure needs to be signaled.
  
  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 IOException.
- hasFilterRow
  
  public boolean hasFilterRow()
  
  Description copied from class: Filter
  
  Primarily used to check for conflicts with scans(such as scans that do not read a full row at a time).
  
  Specified by:
  
  hasFilterRow in class Filter
  
  Returns:
  
  True if this filter actively uses filterRowCells(List) or filterRow().
- filterRowCells
  
  public void filterRowCells(List<Cell> kvs) throws IOException
  
  Description copied from class: Filter
  
  Chance to alter the list of Cells to be submitted. Modifications to the list will carry on Concrete implementers can signal a failure condition in their code by throwing an IOException.
  
  Specified by:
  
  filterRowCells in class Filter
  
  Parameters:
  
  kvs - the list of Cells to be filtered
  
  Throws:
  
  IOException - in case an I/O or an filter specific failure needs to be signaled.
- filterRowCellsWithRet
  
  public FilterWrapper.FilterRowRetCode filterRowCellsWithRet(List<Cell> kvs) throws IOException
  
  Throws:
  
  IOException
- isFamilyEssential
  
  public boolean isFamilyEssential(byte[] name) throws IOException
  
  Description copied from class: Filter
  
  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.
  
  Specified by:
  
  isFamilyEssential in class Filter
  
  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: Filter
  
  Concrete implementers can signal a failure condition in their code by throwing an IOException.
  
  Specified by:
  
  areSerializedFieldsEqual in class Filter
  
  Parameters:
  
  o - the other filter to compare with
  
  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.

Class FilterWrapper

Nested Class Summary

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

Field Summary

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

Constructor Summary

Method Summary

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

Methods inherited from class java.lang.Object

Field Details

filter

Constructor Details

FilterWrapper

Method Details

toByteArray

parseFrom

reset

filterAllRemaining

filterRow

getNextCellHint

filterRowKey

filterCell

transformCell

hasFilterRow

filterRowCells

filterRowCellsWithRet

isFamilyEssential

areSerializedFieldsEqual