Package org.apache.hadoop.hbase.filter
Class PageFilter
java.lang.Object
org.apache.hadoop.hbase.filter.Filter
org.apache.hadoop.hbase.filter.FilterBase
org.apache.hadoop.hbase.filter.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.
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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
Returns true if and only if the fields of the filter that are serialized are equal to the corresponding fields in other.static Filter
createFilterFromArguments
(ArrayList<byte[]> filterArguments) boolean
boolean
Filters that never filter all remaining can inherit this implementation that never stops the filter early.filterCell
(Cell ignored) A way to filter based on the column family, column qualifier and/or the column value.Deprecated.boolean
Filters that never filter by rows based on previously gathered state fromFilter.filterCell(Cell)
can inherit this implementation that never filters a row.boolean
filterRowKey
(Cell cell) Filters a row based on the row key.long
boolean
Filters that never filter by modifying the returned List of Cells can inherit this implementation that does nothing.int
hashCode()
static PageFilter
parseFrom
(byte[] pbBytes) Parse a serialized representation ofPageFilter
byte[]
Returns The filter serialized using pbtoString()
Return filter's info for debugging and logging purpose.Methods inherited from class org.apache.hadoop.hbase.filter.FilterBase
filterRowCells, filterRowKey, getNextCellHint, isFamilyEssential, reset, transformCell
Methods inherited from class org.apache.hadoop.hbase.filter.Filter
isReversed, setReversed
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Field Details
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pageSize
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rowsAccepted
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Constructor Details
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PageFilter
Constructor that takes a maximum page size.- Parameters:
pageSize
- Maximum result size.
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Method Details
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getPageSize
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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
.- Overrides:
filterRowKey
in classFilterBase
- 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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filterKeyValue
Deprecated.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 returnsReturnCode.NEXT_ROW
, it should returnReturnCode.NEXT_ROW
untilFilter.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 anIOException
.- Overrides:
filterKeyValue
in classFilter
- 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:
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filterCell
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, filterCell needs to be consistent with it. filterCell can assume that filterRowKey has already been called for the row. If your filter returnsReturnCode.NEXT_ROW
, it should returnReturnCode.NEXT_ROW
untilFilter.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 anIOException
.- Overrides:
filterCell
in classFilter
- Parameters:
ignored
- 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:
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filterAllRemaining
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 anIOException
.- Overrides:
filterAllRemaining
in classFilterBase
- Returns:
- true to end scan, false to continue.
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filterRow
Description copied from class:FilterBase
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
.- Overrides:
filterRow
in classFilterBase
- Returns:
- true to exclude row, false to include row.
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hasFilterRow
Description copied from class:FilterBase
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).- Overrides:
hasFilterRow
in classFilterBase
- Returns:
- True if this filter actively uses filterRowCells(List) or filterRow().
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createFilterFromArguments
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toByteArray
Returns The filter serialized using pb- Overrides:
toByteArray
in classFilterBase
- Returns:
- The filter serialized using pb
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parseFrom
Parse a serialized representation ofPageFilter
- Parameters:
pbBytes
- A pb serializedPageFilter
instance- Returns:
- An instance of
PageFilter
made frombytes
- Throws:
DeserializationException
- if an error occurred- See Also:
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areSerializedFieldsEqual
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.- Overrides:
areSerializedFieldsEqual
in classFilterBase
- 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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toString
Description copied from class:FilterBase
Return filter's info for debugging and logging purpose.- Overrides:
toString
in classFilterBase
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equals
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hashCode
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