Package org.apache.hadoop.hbase.filter
Class FilterBase
java.lang.Object
org.apache.hadoop.hbase.filter.Filter
org.apache.hadoop.hbase.filter.FilterBase
- Direct Known Subclasses:
AccessControlFilter
,ColumnCountGetFilter
,ColumnPaginationFilter
,ColumnPrefixFilter
,ColumnRangeFilter
,ColumnValueFilter
,CompareFilter
,FilterList
,FilterListBase
,FirstKeyOnlyFilter
,FuzzyRowFilter
,InclusiveStopFilter
,KeyOnlyFilter
,MobReferenceOnlyFilter
,MultipleColumnPrefixFilter
,MultiRowRangeFilter
,PageFilter
,PrefixFilter
,RandomRowFilter
,SingleColumnValueFilter
,SkipFilter
,TimestampsFilter
,VisibilityController.DeleteVersionVisibilityExpressionFilter
,VisibilityLabelFilter
,WhileMatchFilter
Abstract base class to help you implement new Filters. Common "ignore" or NOOP type methods can
go here, helping to reduce boiler plate in an ever-expanding filter library. If you could
instantiate FilterBase, it would end up being a "null" filter - that is one that never filters
anything.
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Nested Class Summary
Nested classes/interfaces inherited from class org.apache.hadoop.hbase.filter.Filter
Filter.ReturnCode
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Field Summary
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Constructor Summary
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Method Summary
Modifier and TypeMethodDescription(package private) boolean
areSerializedFieldsEqual
(Filter other) Default implementation so that writers of custom filters aren't forced to implement.static Filter
createFilterFromArguments
(ArrayList<byte[]> filterArguments) Given the filter's arguments it constructs the filterboolean
Filters that never filter all remaining can inherit this implementation that never stops the filter early.boolean
Filters that never filter by rows based on previously gathered state fromFilter.filterCell(Cell)
can inherit this implementation that never filters a row.void
filterRowCells
(List<Cell> ignored) Filters that never filter by modifying the returned List of Cells can inherit this implementation that does nothing.boolean
filterRowKey
(byte[] buffer, int offset, int length) Deprecated.As of release 2.0.0, this will be removed in HBase 3.0.0.boolean
filterRowKey
(Cell cell) Filters a row based on the row key.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.boolean
Filters that never filter by modifying the returned List of Cells can inherit this implementation that does nothing.boolean
isFamilyEssential
(byte[] name) By default, we require all scan's column families to be present.void
reset()
Filters that are purely stateless and do nothing in their reset() methods can inherit this null/empty implementation.byte[]
Return length 0 byte array for Filters that don't require special serializationtoString()
Return filter's info for debugging and logging purpose.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.Filter
filterCell, filterKeyValue, isReversed, parseFrom, setReversed
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Constructor Details
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FilterBase
public FilterBase()
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Method Details
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reset
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 anIOException
.- Specified by:
reset
in classFilter
- Throws:
IOException
- in case an I/O or an filter specific failure needs to be signaled.
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filterRowKey
Deprecated.As of release 2.0.0, this will be removed in HBase 3.0.0. Instead usefilterRowKey(Cell)
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 toFilter.filterCell(Cell)
below. Concrete implementers can signal a failure condition in their code by throwing anIOException
.- Specified by:
filterRowKey
in classFilter
- Parameters:
buffer
- buffer containing row keyoffset
- offset into buffer where row key startslength
- 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.
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filterRowKey
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 toFilter.filterCell(Cell)
below. IfFilter.filterAllRemaining()
returns true, thenFilter.filterRowKey(Cell)
should also return true. Concrete implementers can signal a failure condition in their code by throwing anIOException
.- Specified by:
filterRowKey
in classFilter
- Parameters:
cell
- 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.
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filterAllRemaining
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 anIOException
.- Specified by:
filterAllRemaining
in classFilter
- Returns:
- true to end scan, false to continue.
- Throws:
IOException
- in case an I/O or an filter specific failure needs to be signaled.
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transformCell
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.- Specified by:
transformCell
in classFilter
- Parameters:
v
- 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:
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filterRowCells
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 anIOException
.- Specified by:
filterRowCells
in classFilter
- Parameters:
ignored
- the list of Cells to be filtered- Throws:
IOException
- in case an I/O or an filter specific failure needs to be signaled.
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hasFilterRow
Filters 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).- Specified by:
hasFilterRow
in classFilter
- Returns:
- True if this filter actively uses filterRowCells(List) or filterRow().
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filterRow
Filters that never filter by rows based on previously gathered state fromFilter.filterCell(Cell)
can inherit this implementation that never filters a row. Last chance to veto row based on previousFilter.filterCell(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 anIOException
.- Specified by:
filterRow
in classFilter
- 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.
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getNextCellHint
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 anIOException
.- Specified by:
getNextCellHint
in classFilter
- 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.
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isFamilyEssential
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 anIOException
.- Specified by:
isFamilyEssential
in classFilter
- Throws:
IOException
- in case an I/O or an filter specific failure needs to be signaled.
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createFilterFromArguments
Given the filter's arguments it constructs the filter- Parameters:
filterArguments
- the filter's arguments- Returns:
- constructed filter object
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toString
Return filter's info for debugging and logging purpose. -
toByteArray
Return length 0 byte array for Filters that don't require special serialization- Specified by:
toByteArray
in classFilter
- Returns:
- The filter serialized using pb
- Throws:
IOException
- in case an I/O or an filter specific failure needs to be signaled.
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areSerializedFieldsEqual
Default implementation so that writers of custom filters aren't forced to implement.- Specified by:
areSerializedFieldsEqual
in classFilter
- Returns:
- true if and only if the fields of the filter that are serialized are equal to the corresponding fields in other. Used for testing.
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