@InterfaceAudience.Public @InterfaceStability.Stable public class FirstKeyOnlyFilter extends FilterBase
This filter can be used to more efficiently perform row count operations.
Filter.ReturnCode
Constructor and Description |
---|
FirstKeyOnlyFilter() |
Modifier and Type | Method and Description |
---|---|
static Filter |
createFilterFromArguments(java.util.ArrayList<byte[]> filterArguments) |
Filter.ReturnCode |
filterKeyValue(Cell v)
A way to filter based on the column family, column qualifier and/or the column value.
|
protected boolean |
hasFoundKV() |
static FirstKeyOnlyFilter |
parseFrom(byte[] pbBytes) |
void |
reset()
Filters that are purely stateless and do nothing in their reset() methods can inherit
this null/empty implementation.
|
protected void |
setFoundKV(boolean value) |
byte[] |
toByteArray()
Return length 0 byte array for Filters that don't require special serialization
|
Cell |
transformCell(Cell v)
By default no transformation takes place
|
filterAllRemaining, filterRow, filterRowCells, filterRowKey, getNextCellHint, getNextKeyHint, hasFilterRow, isFamilyEssential, toString, transform
isReversed, setReversed
public void reset()
FilterBase
reset
in class FilterBase
public Filter.ReturnCode filterKeyValue(Cell v)
Filter
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
.filterKeyValue
in class Filter
v
- the Cell in questionFilter.ReturnCode
public Cell transformCell(Cell v)
FilterBase
transformCell
in class FilterBase
v
- the KeyValue in questionThe 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}.
public static Filter createFilterFromArguments(java.util.ArrayList<byte[]> filterArguments)
protected boolean hasFoundKV()
protected void setFoundKV(boolean value)
value
- update foundKV
flag with value.public byte[] toByteArray()
FilterBase
toByteArray
in class FilterBase
public static FirstKeyOnlyFilter parseFrom(byte[] pbBytes) throws DeserializationException
pbBytes
- A pb serialized FirstKeyOnlyFilter
instanceFirstKeyOnlyFilter
made from bytes
DeserializationException
toByteArray()