org.apache.hadoop.hbase.filter
Class FirstKeyOnlyFilter
java.lang.Object
org.apache.hadoop.hbase.filter.Filter
org.apache.hadoop.hbase.filter.FilterBase
org.apache.hadoop.hbase.filter.FirstKeyOnlyFilter
- Direct Known Subclasses:
- FirstKeyValueMatchingQualifiersFilter
@InterfaceAudience.Public
@InterfaceStability.Stable
public class FirstKeyOnlyFilter
- extends FilterBase
A filter that will only return the first KV from each row.
This filter can be used to more efficiently perform row count operations.
Fields inherited from class org.apache.hadoop.hbase.filter.Filter |
reversed |
Methods inherited from class org.apache.hadoop.hbase.filter.FilterBase |
filterAllRemaining, filterRow, filterRow, filterRowCells, filterRowKey, getNextCellHint, getNextKeyHint, hasFilterRow, isFamilyEssential, toString, transform, transformCell |
FirstKeyOnlyFilter
public FirstKeyOnlyFilter()
reset
public void reset()
- Description copied from class:
FilterBase
- Filters that are purely stateless and do nothing in their reset() methods can inherit
this null/empty implementation.
- Overrides:
reset
in class FilterBase
filterKeyValue
public Filter.ReturnCode filterKeyValue(Cell v)
- Description copied from class:
FilterBase
- Filters that dont filter by key value can inherit this implementation that
includes all Cells.
- Overrides:
filterKeyValue
in class FilterBase
- Parameters:
v
- the Cell in question
- Returns:
- code as described below
- See Also:
Filter.ReturnCode
createFilterFromArguments
public static Filter createFilterFromArguments(ArrayList<byte[]> filterArguments)
hasFoundKV
protected boolean hasFoundKV()
- Returns:
- true if first KV has been found.
setFoundKV
protected void setFoundKV(boolean value)
- Parameters:
value
- update foundKV
flag with value.
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 FirstKeyOnlyFilter parseFrom(byte[] pbBytes)
throws DeserializationException
- Parameters:
pbBytes
- A pb serialized FirstKeyOnlyFilter
instance
- Returns:
- An instance of
FirstKeyOnlyFilter
made from bytes
- Throws:
DeserializationException
- See Also:
toByteArray()
Copyright © 2007–2016 The Apache Software Foundation. All rights reserved.