org.apache.hadoop.hbase.filter
Class WhileMatchRowFilter

java.lang.Object
  extended by org.apache.hadoop.hbase.filter.WhileMatchRowFilter
All Implemented Interfaces:
RowFilterInterface, org.apache.hadoop.io.Writable

public class WhileMatchRowFilter
extends Object
implements RowFilterInterface

WhileMatchRowFilter is a wrapper filter that filters everything after the first filtered row. Once the nested filter returns true for either of it's filter(..) methods or filterNotNull(SortedMap), this wrapper's filterAllRemaining() will return true. All filtering methods will thereafter defer to the result of filterAllRemaining().


Constructor Summary
WhileMatchRowFilter()
          Default constructor, filters nothing.
WhileMatchRowFilter(RowFilterInterface filter)
          Constructor
 
Method Summary
 boolean filterAllRemaining()
          Returns true once the nested filter has filtered out a row (returned true on a call to one of it's filtering methods).
 boolean filterColumn(byte[] rowKey, byte[] colKey, byte[] data)
          Filters on row key, column name, and column value.
 boolean filterRow(SortedMap<byte[],Cell> columns)
          Filter on the fully assembled row.
 boolean filterRowKey(byte[] rowKey)
          Filters on just a row key.
 RowFilterInterface getInternalFilter()
          Returns the internal filter being wrapped
 boolean processAlways()
          Returns whether or not the filter should always be processed in any filtering call.
 void readFields(DataInput in)
           
 void reset()
          Resets the state of the filter.
 void rowProcessed(boolean filtered, byte[] rowKey)
          Called to let filter know the final decision (to pass or filter) on a given row.
 void validate(byte[][] columns)
          Validates that this filter applies only to a subset of the given columns.
 void write(DataOutput out)
           
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

WhileMatchRowFilter

public WhileMatchRowFilter()
Default constructor, filters nothing. Required though for RPC deserialization.


WhileMatchRowFilter

public WhileMatchRowFilter(RowFilterInterface filter)
Constructor

Parameters:
filter -
Method Detail

getInternalFilter

public RowFilterInterface getInternalFilter()
Returns the internal filter being wrapped

Returns:
the internal filter

reset

public void reset()
Description copied from interface: RowFilterInterface
Resets the state of the filter. Used prior to the start of a Region scan.

Specified by:
reset in interface RowFilterInterface

processAlways

public boolean processAlways()
Description copied from interface: RowFilterInterface
Returns whether or not the filter should always be processed in any filtering call. This precaution is necessary for filters that maintain state and need to be updated according to their response to filtering calls (see WhileMatchRowFilter for an example). At times, filters nested in RowFilterSets may or may not be called because the RowFilterSet determines a result as fast as possible. Returning true for processAlways() ensures that the filter will always be called.

Specified by:
processAlways in interface RowFilterInterface
Returns:
whether or not to always process the filter

filterAllRemaining

public boolean filterAllRemaining()
Returns true once the nested filter has filtered out a row (returned true on a call to one of it's filtering methods). Until then it returns false.

Specified by:
filterAllRemaining in interface RowFilterInterface
Returns:
true/false whether the nested filter has returned true on a filter call.

filterRowKey

public boolean filterRowKey(byte[] rowKey)
Description copied from interface: RowFilterInterface
Filters on just a row key. This is the first chance to stop a row.

Specified by:
filterRowKey in interface RowFilterInterface
Returns:
true if given row key is filtered and row should not be processed.

filterColumn

public boolean filterColumn(byte[] rowKey,
                            byte[] colKey,
                            byte[] data)
Description copied from interface: RowFilterInterface
Filters on row key, column name, and column value. This will take individual columns out of a row, but the rest of the row will still get through.

Specified by:
filterColumn in interface RowFilterInterface
Parameters:
rowKey - row key to filter on.
colKey - column name to filter on
data - column value to filter on
Returns:
true if row filtered and should not be processed.

filterRow

public boolean filterRow(SortedMap<byte[],Cell> columns)
Description copied from interface: RowFilterInterface
Filter on the fully assembled row. This is the last chance to stop a row.

Specified by:
filterRow in interface RowFilterInterface
Returns:
true if row filtered and should not be processed.

rowProcessed

public void rowProcessed(boolean filtered,
                         byte[] rowKey)
Description copied from interface: RowFilterInterface
Called to let filter know the final decision (to pass or filter) on a given row. With out HScanner calling this, the filter does not know if a row passed filtering even if it passed the row itself because other filters may have failed the row. E.g. when this filter is a member of a RowFilterSet with an OR operator.

Specified by:
rowProcessed in interface RowFilterInterface
See Also:
RowFilterSet

validate

public void validate(byte[][] columns)
Description copied from interface: RowFilterInterface
Validates that this filter applies only to a subset of the given columns. This check is done prior to opening of scanner due to the limitation that filtering of columns is dependent on the retrieval of those columns within the HRegion. Criteria on columns that are not part of a scanner's column list will be ignored. In the case of null value filters, all rows will pass the filter. This behavior should be 'undefined' for the user and therefore not permitted.

Specified by:
validate in interface RowFilterInterface

readFields

public void readFields(DataInput in)
                throws IOException
Specified by:
readFields in interface org.apache.hadoop.io.Writable
Throws:
IOException

write

public void write(DataOutput out)
           throws IOException
Specified by:
write in interface org.apache.hadoop.io.Writable
Throws:
IOException


Copyright © 2008 The Apache Software Foundation