@InterfaceAudience.Public @InterfaceStability.Stable public abstract class Filter extends java.lang.Object
reset()
: reset the filter state before filtering a new row. filterAllRemaining()
: true means row scan is over; false means keep going. filterRowKey(byte[],int,int)
: true means drop this row; false means include.filterKeyValue(Cell)
: decides whether to include or exclude this KeyValue.
See Filter.ReturnCode
. transform(KeyValue)
: if the KeyValue is included, let the filter transform the
KeyValue. filterRowCells(List)
: allows direct modification of the final list to be submitted
filterRow()
: last chance to drop entire row based on the sequence of
filter calls. Eg: filter a row if it doesn't contain a specified column. FilterBase
to help
you reduce boilerplate.FilterBase
Modifier and Type | Class and Description |
---|---|
static class |
Filter.ReturnCode
Return codes for filterValue().
|
Modifier and Type | Field and Description |
---|---|
protected boolean |
reversed |
Constructor and Description |
---|
Filter() |
Modifier and Type | Method and Description |
---|---|
abstract boolean |
filterAllRemaining()
If this returns true, the scan will terminate.
|
abstract Filter.ReturnCode |
filterKeyValue(Cell v)
A way to filter based on the column family, column qualifier and/or the column value.
|
abstract boolean |
filterRow()
Last chance to veto row based on previous
filterKeyValue(Cell) calls. |
abstract void |
filterRowCells(java.util.List<Cell> kvs)
Chance to alter the list of Cells to be submitted.
|
abstract boolean |
filterRowKey(byte[] buffer,
int offset,
int length)
Filters a row based on the row key.
|
abstract Cell |
getNextCellHint(Cell currentKV)
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.
|
abstract KeyValue |
getNextKeyHint(KeyValue currentKV)
Deprecated.
|
abstract boolean |
hasFilterRow()
Primarily used to check for conflicts with scans(such as scans that do not read a full row at a
time).
|
abstract boolean |
isFamilyEssential(byte[] name)
Check that given column family is essential for filter to check row.
|
boolean |
isReversed() |
static Filter |
parseFrom(byte[] pbBytes)
Concrete implementers can signal a failure condition in their code by throwing an
IOException . |
abstract void |
reset()
Reset the state of the filter between rows.
|
void |
setReversed(boolean reversed)
alter the reversed scan flag
|
abstract byte[] |
toByteArray()
TODO: JAVADOC
Concrete implementers can signal a failure condition in their code by throwing an
IOException . |
abstract KeyValue |
transform(KeyValue currentKV)
Deprecated.
|
abstract Cell |
transformCell(Cell v)
Give the filter a chance to transform the passed KeyValue.
|
public abstract void reset() throws java.io.IOException
IOException
.java.io.IOException
- in case an I/O or an filter specific failure needs to be signaled.public abstract boolean filterRowKey(byte[] buffer, int offset, int length) throws java.io.IOException
filterKeyValue(Cell)
below.
Concrete implementers can signal a failure condition in their code by throwing an
IOException
.buffer
- buffer containing row keyoffset
- offset into buffer where row key startslength
- length of the row keyjava.io.IOException
- in case an I/O or an filter specific failure needs to be signaled.public abstract boolean filterAllRemaining() throws java.io.IOException
IOException
.java.io.IOException
- in case an I/O or an filter specific failure needs to be signaled.public abstract Filter.ReturnCode filterKeyValue(Cell v) throws java.io.IOException
ReturnCode.NEXT_ROW
, it should return
ReturnCode.NEXT_ROW
until 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
.v
- the Cell in questionjava.io.IOException
- in case an I/O or an filter specific failure needs to be signaled.Filter.ReturnCode
public abstract Cell transformCell(Cell v) throws java.io.IOException
v
- the KeyValue in questionjava.io.IOException
- 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}.
@Deprecated public abstract KeyValue transform(KeyValue currentKV) throws java.io.IOException
transformCell(Cell)
.
This is for transition from 0.94 -> 0.96java.io.IOException
public abstract void filterRowCells(java.util.List<Cell> kvs) throws java.io.IOException
IOException
.kvs
- the list of Cells to be filteredjava.io.IOException
- in case an I/O or an filter specific failure needs to be signaled.public abstract boolean hasFilterRow()
public abstract boolean filterRow() throws java.io.IOException
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
.java.io.IOException
- in case an I/O or an filter specific failure needs to be signaled.@Deprecated public abstract KeyValue getNextKeyHint(KeyValue currentKV) throws java.io.IOException
currentKV
- java.io.IOException
- Function is Deprecated. Use getNextCellHint(Cell)
instead.public abstract Cell getNextCellHint(Cell currentKV) throws java.io.IOException
IOException
.java.io.IOException
- in case an I/O or an filter specific failure needs to be signaled.public abstract boolean isFamilyEssential(byte[] name) throws java.io.IOException
IOException
.java.io.IOException
- in case an I/O or an filter specific failure needs to be signaled.public abstract byte[] toByteArray() throws java.io.IOException
IOException
.java.io.IOException
- in case an I/O or an filter specific failure needs to be signaled.public static Filter parseFrom(byte[] pbBytes) throws DeserializationException
IOException
.pbBytes
- A pb serialized Filter
instanceFilter
made from bytes
DeserializationException
java.io.IOException
- in case an I/O or an filter specific failure needs to be signaled.toByteArray()
public void setReversed(boolean reversed)
reversed
- flagpublic boolean isReversed()