@InterfaceAudience.Public public class SkipFilter extends org.apache.hadoop.hbase.filter.FilterBase
For example, if all columns in a row represent weights of different things, with the values being
the actual weights, and we want to filter out the entire row if any of its weights are zero. In
this case, we want to prevent rows from being emitted if a single key is filtered. Combine this
filter with a ValueFilter
:
scan.setFilter(new SkipFilter(new ValueFilter(CompareOp.NOT_EQUAL,
new BinaryComparator(Bytes.toBytes(0))));
Any row which contained a column whose value was 0 will be filtered out (since
ValueFilter will not pass that Cell). Without this filter, the other non-zero valued columns in
the row would still be emitted.
Filter.ReturnCode
Constructor and Description |
---|
SkipFilter(Filter filter) |
Modifier and Type | Method and Description |
---|---|
boolean |
equals(Object obj) |
Filter.ReturnCode |
filterCell(Cell c)
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.filterCell(Cell) can inherit this implementation that never filters a row. |
boolean |
filterRowKey(Cell cell)
Filters a row based on the row key.
|
Filter |
getFilter() |
boolean |
hasFilterRow()
Filters 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 SkipFilter |
parseFrom(byte[] pbBytes)
Parse a serialized representation of
SkipFilter |
void |
reset()
Filters that are purely stateless and do nothing in their reset() methods can inherit this
null/empty implementation.
|
byte[] |
toByteArray()
Returns The filter serialized using pb
|
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.
|
createFilterFromArguments, filterAllRemaining, filterRowCells, getNextCellHint
isReversed, setReversed
public SkipFilter(Filter filter)
public void reset() throws IOException
org.apache.hadoop.hbase.filter.FilterBase
IOException
.reset
in class org.apache.hadoop.hbase.filter.FilterBase
IOException
- in case an I/O or an filter specific failure needs to be signaled.public boolean filterRowKey(Cell cell) throws IOException
Filter
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
.filterRowKey
in class org.apache.hadoop.hbase.filter.FilterBase
cell
- The first cell coming in the new rowIOException
- in case an I/O or an filter specific failure needs to be signaled.public Filter.ReturnCode filterCell(Cell c) throws IOException
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
.filterCell
in class Filter
c
- the Cell in questionIOException
- in case an I/O or an filter specific failure needs to be signaled.Filter.ReturnCode
public Cell transformCell(Cell v) throws IOException
org.apache.hadoop.hbase.filter.FilterBase
transformCell
in class org.apache.hadoop.hbase.filter.FilterBase
v
- the KeyValue in questionIOException
- in case an I/O or an filter specific failure needs to be signaled.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}.
public boolean filterRow()
org.apache.hadoop.hbase.filter.FilterBase
Filter.filterCell(Cell)
can inherit this implementation that never filters a row.
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
.filterRow
in class org.apache.hadoop.hbase.filter.FilterBase
public boolean hasFilterRow()
org.apache.hadoop.hbase.filter.FilterBase
hasFilterRow
in class org.apache.hadoop.hbase.filter.FilterBase
public byte[] toByteArray() throws IOException
toByteArray
in class org.apache.hadoop.hbase.filter.FilterBase
IOException
- in case an I/O or an filter specific failure needs to be signaled.public static SkipFilter parseFrom(byte[] pbBytes) throws org.apache.hadoop.hbase.exceptions.DeserializationException
SkipFilter
pbBytes
- A pb serialized SkipFilter
instanceSkipFilter
made from bytes
org.apache.hadoop.hbase.exceptions.DeserializationException
- if an error occurredtoByteArray()
public boolean isFamilyEssential(byte[] name) throws IOException
org.apache.hadoop.hbase.filter.FilterBase
IOException
.isFamilyEssential
in class org.apache.hadoop.hbase.filter.FilterBase
IOException
- in case an I/O or an filter specific failure needs to be signaled.public String toString()
org.apache.hadoop.hbase.filter.FilterBase
toString
in class org.apache.hadoop.hbase.filter.FilterBase
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