WhileMatchFilter (Apache HBase 1.4.11 API)

java.lang.Object
- org.apache.hadoop.hbase.filter.Filter
- - org.apache.hadoop.hbase.filter.FilterBase
  - - org.apache.hadoop.hbase.filter.WhileMatchFilter

```
@InterfaceAudience.Public
@InterfaceStability.Stable
public class WhileMatchFilter
extends FilterBase
```
A wrapper filter that returns true from filterAllRemaining() as soon as the wrapped filters Filter.filterRowKey(byte[], int, int), Filter.filterKeyValue(org.apache.hadoop.hbase.Cell), Filter.filterRow() or Filter.filterAllRemaining() methods returns true.

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

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

Constructor Summary

Constructors
Constructor and Description

WhileMatchFilter(Filter filter)

Constructors
Constructor and Description
`WhileMatchFilter(Filter filter)`

Method Summary

Methods
Modifier and Type	Method and Description
`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 v)` 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.
`boolean`	`filterRowKey(byte[] buffer, int offset, int length)` Filters that do not filter by row key can inherit this implementation that never filters anything.
`Filter`	`getFilter()`
`boolean`	`hasFilterRow()` Fitlers that never filter by modifying the returned List of Cells can inherit this implementation that does nothing.
`int`	`hashCode()`
`boolean`	`isFamilyEssential(byte[] name)` By default, we require all scan's column families to be present.
`static WhileMatchFilter`	`parseFrom(byte[] pbBytes)`
`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.
`Cell`	`transformCell(Cell v)` By default no transformation takes place Give the filter a chance to transform the passed KeyValue.

Methods inherited from class org.apache.hadoop.hbase.filter.FilterBase
createFilterFromArguments, filterRowCells, getNextCellHint, getNextKeyHint, transform

Methods inherited from class org.apache.hadoop.hbase.filter.Filter
isReversed, setReversed

Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait

- Constructor Detail
  - WhileMatchFilter
```
public WhileMatchFilter(Filter filter)
```
- Method Detail
  - getFilter
```
public Filter getFilter()
```
  - 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.
  - filterAllRemaining
```
public boolean filterAllRemaining()
                           throws IOException
```
    Description copied from class: 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.
    
    Overrides:
    
    filterAllRemaining in class FilterBase
    
    Returns:
    true to end scan, false to continue.
    
    Throws:
    
    IOException - in case an I/O or an filter specific failure needs to be signaled.
  - filterRowKey
```
public boolean filterRowKey(byte[] buffer,
                   int offset,
                   int length)
                     throws IOException
```
    Description copied from class: FilterBase
    
    Filters that do not filter by row key can inherit this implementation that never filters anything. (ie: returns false). 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.filterKeyValue(Cell) below. Concrete implementers can signal a failure condition in their code by throwing an IOException.
    
    Overrides:
    
    filterRowKey in class FilterBase
    
    Parameters:
    buffer - buffer containing row key
    offset - offset into buffer where row key starts
    length - length of the row key
    
    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.
  - filterKeyValue
```
public Filter.ReturnCode filterKeyValue(Cell v)
                                 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, 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:
    v - 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: 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.
    
    Overrides:
    
    transformCell in class FilterBase
    
    Parameters:
    v - the KeyValue in question
    
    Returns:
    the changed KeyValue
    
    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 {@link IOException}.
  - filterRow
```
public boolean filterRow()
                  throws IOException
```
    Description copied from class: 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.
    
    Overrides:
    
    filterRow in class FilterBase
    
    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.
  - 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. Primarily used to check for conflicts with scans(such as scans that do not read a full row at a time).
    
    Overrides:
    
    hasFilterRow in class FilterBase
    
    Returns:
    True if this filter actively uses filterRowCells(List) or filterRow().
  - 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.
  - parseFrom
```
public static WhileMatchFilter parseFrom(byte[] pbBytes)
                                  throws DeserializationException
```
    Parameters:
    pbBytes - A pb serialized WhileMatchFilter instance
    
    Returns:
    An instance of WhileMatchFilter made from bytes
    
    Throws:
    
    DeserializationException
    See Also:
    toByteArray()
  - 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

Class WhileMatchFilter

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.FilterBase

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

Methods inherited from class java.lang.Object

Constructor Detail

WhileMatchFilter

Method Detail

getFilter

reset

filterAllRemaining

filterRowKey

filterKeyValue

transformCell

filterRow

hasFilterRow

toByteArray

parseFrom

isFamilyEssential

toString

equals

hashCode