org.apache.hadoop.hbase.filter

Class FilterList

java.lang.Object

org.apache.hadoop.hbase.filter.Filter

org.apache.hadoop.hbase.filter.FilterBase

org.apache.hadoop.hbase.filter.FilterList

@InterfaceAudience.Public
public final class FilterList
extends FilterBase

Implementation of Filter that represents an ordered List of Filters which will be evaluated with a specified boolean operator FilterList.Operator.MUST_PASS_ALL (AND) or FilterList.Operator.MUST_PASS_ONE (OR). Since you can use Filter Lists as children of Filter Lists, you can create a hierarchy of filters to be evaluated.
FilterList.Operator.MUST_PASS_ALL evaluates lazily: evaluation stops as soon as one filter does not include the KeyValue.
FilterList.Operator.MUST_PASS_ONE evaluates non-lazily: all filters are always evaluated.
Defaults to FilterList.Operator.MUST_PASS_ALL.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	FilterList.Operator set operator

Nested classes/interfaces inherited from class org.apache.hadoop.hbase.filter.Filter

Filter.ReturnCode

Field Summary

Fields inherited from class org.apache.hadoop.hbase.filter.Filter

reversed

Constructor Summary

Constructors

Constructor and Description
FilterList(Filter... rowFilters) Constructor that takes a var arg number of Filters.
FilterList(FilterList.Operator operator) Constructor that takes an operator.
FilterList(FilterList.Operator operator, Filter... rowFilters) Constructor that takes a var arg number of Filters and an operator.
FilterList(FilterList.Operator operator, List<Filter> rowFilters) Constructor that takes a set of Filters and an operator.
FilterList(List<Filter> rowFilters) Constructor that takes a set of Filters.

Method Summary

Modifier and Type	Method and Description
void	addFilter(Filter filter) Add a filter.
void	addFilter(List<Filter> filters)
boolean	filterAllRemaining() Filters that never filter all remaining can inherit this implementation that never stops the filter early.
Filter.ReturnCode	filterKeyValue(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.filterKeyValue(Cell) can inherit this implementation that never filters a row.
void	filterRowCells(List<Cell> cells) Filters that never filter by modifying the returned List of Cells can inherit this implementation that does nothing.
boolean	filterRowKey(byte[] rowKey, int offset, int length) Filters that do not filter by row key can inherit this implementation that never filters anything.
boolean	filterRowKey(Cell firstRowCell) Filters a row based on the row key.
List<Filter>	getFilters() Get the filters.
Cell	getNextCellHint(Cell currentCell) Filters that are not sure which key must be next seeked to, can inherit this implementation that, by default, returns a null Cell.
FilterList.Operator	getOperator() Get the operator.
boolean	hasFilterRow() Fitlers that never filter by modifying the returned List of Cells can inherit this implementation that does nothing.
void	initPrevListForMustPassOne(int size)
boolean	isFamilyEssential(byte[] name) By default, we require all scan's column families to be present.
static FilterList	parseFrom(byte[] pbBytes)
void	reset() Filters that are purely stateless and do nothing in their reset() methods can inherit this null/empty implementation.
void	setReversed(boolean reversed) alter the reversed scan flag
int	size()
byte[]	toByteArray() Return length 0 byte array for Filters that don't require special serialization
String	toString() Return filter's info for debugging and logging purpose.
protected String	toString(int maxFilters)
Cell	transformCell(Cell c) By default no transformation takes place Give the filter a chance to transform the passed KeyValue.

Methods inherited from class org.apache.hadoop.hbase.filter.FilterBase

createFilterFromArguments

Methods inherited from class org.apache.hadoop.hbase.filter.Filter

isReversed

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

FilterList

public FilterList(List<Filter> rowFilters)

Constructor that takes a set of Filters. The default operator MUST_PASS_ALL is assumed. All filters are cloned to internal list.

Parameters:

rowFilters - list of filters

FilterList

public FilterList(Filter... rowFilters)

Constructor that takes a var arg number of Filters. The fefault operator MUST_PASS_ALL is assumed.

Parameters:

rowFilters -

FilterList

public FilterList(FilterList.Operator operator)

Constructor that takes an operator.

Parameters:

operator - Operator to process filter set with.

FilterList

public FilterList(FilterList.Operator operator,
                  List<Filter> rowFilters)

Constructor that takes a set of Filters and an operator.

Parameters:

operator - Operator to process filter set with.

rowFilters - Set of row filters.

FilterList

public FilterList(FilterList.Operator operator,
                  Filter... rowFilters)

Constructor that takes a var arg number of Filters and an operator.

Parameters:

operator - Operator to process filter set with.

rowFilters - Filters to use

Method Detail

initPrevListForMustPassOne

public void initPrevListForMustPassOne(int size)

getOperator

public FilterList.Operator getOperator()

Get the operator.

Returns:

operator

getFilters

public List<Filter> getFilters()

Get the filters.

Returns:

filters

size

public int size()

addFilter

public void addFilter(List<Filter> filters)

addFilter

public void addFilter(Filter filter)

Add a filter.

Parameters:

filter - another filter

reset

public void reset()
           throws IOException

Description copied from class: FilterBase

Filters that are purely stateless and do nothing in their reset() methods can inherit this null/empty implementation. Reset the state of the filter between rows. Concrete implementers can signal a failure condition in their code by throwing an IOException.

Overrides:

reset in class FilterBase

Throws:

IOException - in case an I/O or an filter specific failure needs to be signaled.

filterRowKey

public boolean filterRowKey(byte[] rowKey,
                            int offset,
                            int length)
                     throws IOException

Description copied from class: FilterBase

Filters that do not filter by row key can inherit this implementation that never filters anything. (ie: returns false). Filters a row based on the row key. If this returns true, the entire row will be excluded. If false, each KeyValue in the row will be passed to Filter.filterKeyValue(Cell) below. Concrete implementers can signal a failure condition in their code by throwing an IOException.

Overrides:

filterRowKey in class FilterBase

Parameters:

rowKey - buffer containing row key

offset - offset into buffer where row key starts

length - length of the row key

Returns:

true, remove entire row, false, include the row (maybe).

Throws:

IOException - in case an I/O or an filter specific failure needs to be signaled.

filterRowKey

public boolean filterRowKey(Cell firstRowCell)
                     throws IOException

Description copied from class: Filter

Filters a row based on the row key. If this returns true, the entire row will be excluded. If false, each KeyValue in the row will be passed to Filter.filterKeyValue(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.

Overrides:

filterRowKey in class FilterBase

Parameters:

firstRowCell - The first cell coming in the new row

Returns:

true, remove entire row, false, include the row (maybe).

Throws:

IOException - in case an I/O or an filter specific failure needs to be signaled.

filterAllRemaining

public boolean filterAllRemaining()
                           throws IOException

Description copied from class: FilterBase

Filters that never filter all remaining can inherit this implementation that never stops the filter early. If this returns true, the scan will terminate. Concrete implementers can signal a failure condition in their code by throwing an IOException.

Overrides:

filterAllRemaining in class FilterBase

Returns:

true to end scan, false to continue.

Throws:

IOException - in case an I/O or an filter specific failure needs to be signaled.

transformCell

public Cell transformCell(Cell c)
                   throws IOException

Description copied from class: FilterBase

By default no transformation takes place Give the filter a chance to transform the passed KeyValue. If the Cell is changed a new Cell object must be returned.

Overrides:

transformCell in class FilterBase

Parameters:

c - the KeyValue in question

Returns:

the changed KeyValue

Throws:

IOException - in case an I/O or an filter specific failure needs to be signaled.

See Also:

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}.

filterKeyValue

public Filter.ReturnCode filterKeyValue(Cell c)
                                 throws IOException

Description copied from class: Filter

A way to filter based on the column family, column qualifier and/or the column value. Return code is described below. This allows filters to filter only certain number of columns, then terminate without matching ever column. If filterRowKey returns true, filterKeyValue needs to be consistent with it. filterKeyValue can assume that filterRowKey has already been called for the row. If your filter returns 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.

Specified by:

filterKeyValue in class Filter

Parameters:

c - the Cell in question

Returns:

code as described below

Throws:

IOException - in case an I/O or an filter specific failure needs to be signaled.

See Also:

Filter.ReturnCode

filterRowCells

public void filterRowCells(List<Cell> cells)
                    throws IOException

Filters that never filter by modifying the returned List of Cells can inherit this implementation that does nothing. Filters that never filter by modifying the returned List of Cells can inherit this implementation that does nothing. Chance to alter the list of Cells to be submitted. Modifications to the list will carry on Concrete implementers can signal a failure condition in their code by throwing an IOException.

Overrides:

filterRowCells in class FilterBase

Parameters:

cells - the list of Cells to be filtered

Throws:

IOException - in case an I/O or an filter specific failure needs to be signaled.

hasFilterRow

public boolean hasFilterRow()

Description copied from class: FilterBase

Fitlers that never filter by modifying the returned List of Cells can inherit this implementation that does nothing. Primarily used to check for conflicts with scans(such as scans that do not read a full row at a time).

Overrides:

hasFilterRow in class FilterBase

Returns:

True if this filter actively uses filterRowCells(List) or filterRow().

filterRow

public boolean filterRow()
                  throws IOException

Description copied from class: FilterBase

Filters that never filter by rows based on previously gathered state from Filter.filterKeyValue(Cell) can inherit this implementation that never filters a row. Last chance to veto row based on previous Filter.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.

Overrides:

filterRow in class FilterBase

Returns:

true to exclude row, false to include row.

Throws:

IOException - in case an I/O or an filter specific failure needs to be signaled.

toByteArray

public byte[] toByteArray()
                   throws IOException

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

Throws:

IOException - in case an I/O or an filter specific failure needs to be signaled.

parseFrom

public static FilterList parseFrom(byte[] pbBytes)
                            throws DeserializationException

Parameters:

pbBytes - A pb serialized FilterList instance

Returns:

An instance of FilterList made from bytes

Throws:

DeserializationException

See Also:

toByteArray()

getNextCellHint

public Cell getNextCellHint(Cell currentCell)
                     throws IOException

Description copied from class: FilterBase

Filters that are not sure which key must be next seeked to, can inherit this implementation that, by default, returns a null Cell. 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. After receiving the match code SEEK_NEXT_USING_HINT, the QueryMatcher would call this function to find out which key it must next seek to. Concrete implementers can signal a failure condition in their code by throwing an IOException.

Overrides:

getNextCellHint in class FilterBase

Returns:

KeyValue which must be next seeked. return null if the filter is not sure which key to seek to next.

Throws:

IOException - in case an I/O or an filter specific failure needs to be signaled.

isFamilyEssential

public boolean isFamilyEssential(byte[] name)
                          throws IOException

Description copied from class: FilterBase

By default, we require all scan's column families to be present. Our subclasses may be more precise. Check that given column family is essential for filter to check row. Most filters always return true here. But some could have more sophisticated logic which could significantly reduce scanning process by not even touching columns until we are 100% sure that it's data is needed in result. Concrete implementers can signal a failure condition in their code by throwing an IOException.

Overrides:

isFamilyEssential in class FilterBase

Throws:

IOException - in case an I/O or an filter specific failure needs to be signaled.

setReversed

public void setReversed(boolean reversed)

Description copied from class: Filter

alter the reversed scan flag

Overrides:

setReversed in class Filter

Parameters:

reversed - flag

toString

public String toString()

Description copied from class: FilterBase

Return filter's info for debugging and logging purpose.

Overrides:

toString in class FilterBase

toString

protected String toString(int maxFilters)