org.apache.hadoop.hbase.filter

Class FilterListBase

java.lang.Object

org.apache.hadoop.hbase.filter.Filter

org.apache.hadoop.hbase.filter.FilterBase

org.apache.hadoop.hbase.filter.FilterListBase

Direct Known Subclasses:

FilterListWithAND, FilterListWithOR

@InterfaceAudience.Private
public abstract class FilterListBase
extends FilterBase

Base class for FilterList. Currently, we have two sub-classes to extend this class: FilterListWithOR, FilterListWithAND.

Nested Class Summary

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

Filter.ReturnCode

Field Summary

Fields

Modifier and Type	Field and Description
protected ArrayList<Filter>	filters
private static int	MAX_LOG_FILTERS
protected ArrayList<Boolean>	subFiltersIncludedCell For each sub-filter in filter list, we save a boolean flag to indicate that whether the return code of filterCell(c) for sub-filter is INCLUDE* (INCLUDE, INCLUDE_AND_NEXT_COL, INCLUDE_AND_SEEK_NEXT_ROW) case.

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

reversed

Constructor Summary

Constructors

Constructor and Description
FilterListBase(List<Filter> filters)

Method Summary

Modifier and Type	Method and Description
abstract void	addFilterLists(List<Filter> filters)
protected static boolean	checkAndGetReversed(List<Filter> rowFilters, boolean defaultValue)
protected int	compareCell(Cell a, Cell b)
Filter.ReturnCode	filterKeyValue(Cell c) A way to filter based on the column family, column qualifier and/or the column value.
void	filterRowCells(List<Cell> cells) Filters that never filter by modifying the returned List of Cells can inherit this implementation that does nothing.
protected abstract String	formatLogFilters(List<Filter> logFilters)
ArrayList<Filter>	getFilters()
boolean	hasFilterRow() Fitlers that never filter by modifying the returned List of Cells can inherit this implementation that does nothing.
boolean	isEmpty()
boolean	isFamilyEssential(byte[] name) By default, we require all scan's column families to be present.
protected static boolean	isInReturnCodes(Filter.ReturnCode testRC, Filter.ReturnCode... returnCodes)
void	setReversed(boolean reversed) alter the reversed scan flag
int	size()
String	toString() Return filter's info for debugging and logging purpose.
Cell	transformCell(Cell c) For FilterList, we can consider a filter list as a node in a tree.

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

areSerializedFieldsEqual, createFilterFromArguments, filterAllRemaining, filterRow, filterRowKey, filterRowKey, getNextCellHint, reset, toByteArray

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

filterCell, isReversed, parseFrom

Methods inherited from class java.lang.Object

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

Field Detail

MAX_LOG_FILTERS

private static final int MAX_LOG_FILTERS

See Also:

Constant Field Values

filters

protected final ArrayList<Filter> filters

subFiltersIncludedCell

protected ArrayList<Boolean> subFiltersIncludedCell

For each sub-filter in filter list, we save a boolean flag to indicate that whether the return code of filterCell(c) for sub-filter is INCLUDE* (INCLUDE, INCLUDE_AND_NEXT_COL, INCLUDE_AND_SEEK_NEXT_ROW) case. if true, we need to transform cell for the sub-filter.

Constructor Detail

FilterListBase

public FilterListBase(List<Filter> filters)

Method Detail

isInReturnCodes

protected static boolean isInReturnCodes(Filter.ReturnCode testRC,
                                         Filter.ReturnCode... returnCodes)

checkAndGetReversed

protected static boolean checkAndGetReversed(List<Filter> rowFilters,
                                             boolean defaultValue)

addFilterLists

public abstract void addFilterLists(List<Filter> filters)

size

public int size()

isEmpty

public boolean isEmpty()

getFilters

public ArrayList<Filter> getFilters()

compareCell

protected int compareCell(Cell a,
                          Cell b)

transformCell

public Cell transformCell(Cell c)
                   throws IOException

For FilterList, we can consider a filter list as a node in a tree. sub-filters of the filter list are children of the relative node. The logic of transforming cell of a filter list, well, we can consider it as the process of post-order tree traverse. For a node , before we traverse the current child, we should set the traverse result (transformed cell) of previous node(s) as the initial value. (HBASE-18879).

Overrides:

transformCell in class FilterBase

Parameters:

c - The cell in question.

Returns:

the transformed cell.

Throws:

IOException

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.

Overrides:

filterKeyValue in class Filter

Parameters:

c - the Cell in question

Returns:

code as described below, Filter.ReturnCode.INCLUDE by default

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().

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

formatLogFilters

protected abstract String formatLogFilters(List<Filter> logFilters)