|
||||||||||
PREV CLASS NEXT CLASS | FRAMES NO FRAMES | |||||||||
SUMMARY: NESTED | FIELD | CONSTR | METHOD | DETAIL: FIELD | CONSTR | METHOD |
java.lang.Objectorg.apache.hadoop.hbase.filter.PageFilter
public class PageFilter
Implementation of Filter interface that limits results to a specific page size. It terminates scanning once the number of filter-passed rows is > the given page size.
Note that this filter cannot guarantee that the number of results returned to a client are <= page size. This is because the filter is applied separately on different region servers. It does however optimize the scan of individual HRegions by making sure that the page size is never exceeded locally.
Nested Class Summary |
---|
Nested classes/interfaces inherited from interface org.apache.hadoop.hbase.filter.Filter |
---|
Filter.ReturnCode |
Constructor Summary | |
---|---|
PageFilter()
Default constructor, filters nothing. |
|
PageFilter(long pageSize)
Constructor that takes a maximum page size. |
Method Summary | |
---|---|
boolean |
filterAllRemaining()
If this returns true, the scan will terminate. |
Filter.ReturnCode |
filterKeyValue(KeyValue v)
A way to filter based on the column family, column qualifier and/or the column value. |
boolean |
filterRow()
Last chance to veto row based on previous Filter.filterKeyValue(KeyValue)
calls. |
boolean |
filterRowKey(byte[] rowKey,
int offset,
int length)
Filters a row based on the row key. |
long |
getPageSize()
|
void |
readFields(DataInput in)
|
void |
reset()
Reset the state of the filter between rows. |
void |
write(DataOutput out)
|
Methods inherited from class java.lang.Object |
---|
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
Constructor Detail |
---|
public PageFilter()
public PageFilter(long pageSize)
pageSize
- Maximum result size.Method Detail |
---|
public long getPageSize()
public void reset()
Filter
reset
in interface Filter
public boolean filterAllRemaining()
Filter
filterAllRemaining
in interface Filter
public boolean filterRowKey(byte[] rowKey, int offset, int length)
Filter
Filter.filterKeyValue(KeyValue)
below.
filterRowKey
in interface Filter
rowKey
- buffer containing row keyoffset
- offset into buffer where row key startslength
- length of the row key
public void readFields(DataInput in) throws IOException
readFields
in interface org.apache.hadoop.io.Writable
IOException
public void write(DataOutput out) throws IOException
write
in interface org.apache.hadoop.io.Writable
IOException
public Filter.ReturnCode filterKeyValue(KeyValue 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.
filterKeyValue
in interface Filter
v
- the KeyValue in question
Filter.ReturnCode
public boolean filterRow()
Filter
Filter.filterKeyValue(KeyValue)
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).
filterRow
in interface Filter
|
||||||||||
PREV CLASS NEXT CLASS | FRAMES NO FRAMES | |||||||||
SUMMARY: NESTED | FIELD | CONSTR | METHOD | DETAIL: FIELD | CONSTR | METHOD |