MultiRowRangeFilter (Apache HBase 2.0.6 API)

java.lang.Object
- org.apache.hadoop.hbase.filter.Filter
- - org.apache.hadoop.hbase.filter.FilterBase
  - - org.apache.hadoop.hbase.filter.MultiRowRangeFilter

```
@InterfaceAudience.Public
public class MultiRowRangeFilter
extends org.apache.hadoop.hbase.filter.FilterBase
```
Filter to support scan multiple row key ranges. It can construct the row key ranges from the passed list which can be accessed by each region server. HBase is quite efficient when scanning only one small row key range. If user needs to specify multiple row key ranges in one scan, the typical solutions are: 1. through FilterList which is a list of row key Filters, 2. using the SQL layer over HBase to join with two table, such as hive, phoenix etc. However, both solutions are inefficient. Both of them can't utilize the range info to perform fast forwarding during scan which is quite time consuming. If the number of ranges are quite big (e.g. millions), join is a proper solution though it is slow. However, there are cases that user wants to specify a small number of ranges to scan (e.g. <1000 ranges). Both solutions can't provide satisfactory performance in such case. MultiRowRangeFilter is to support such usec ase (scan multiple row key ranges), which can construct the row key ranges from user specified list and perform fast-forwarding during scan. Thus, the scan will be quite efficient.

Nested Class Summary

Nested Classes
Modifier and Type Class and Description

static class MultiRowRangeFilter.RowRange
- Nested classes/interfaces inherited from class org.apache.hadoop.hbase.filter.Filter
  Filter.ReturnCode

Nested Classes
Modifier and Type	Class and Description
`static class`	`MultiRowRangeFilter.RowRange`

Field Summary
- Fields inherited from class org.apache.hadoop.hbase.filter.Filter
  reversed

Constructor Summary

Constructors
Constructor and Description

MultiRowRangeFilter(List<MultiRowRangeFilter.RowRange> list)

Constructors
Constructor and Description
`MultiRowRangeFilter(List<MultiRowRangeFilter.RowRange> list)`

Method Summary

All Methods Static Methods Instance Methods Concrete Methods Deprecated Methods
Modifier and Type	Method and Description
`boolean`	`equals(Object obj)`
`boolean`	`filterAllRemaining()` Filters that never filter all remaining can inherit this implementation that never stops the filter early.
`Filter.ReturnCode`	`filterCell(Cell ignored)` A way to filter based on the column family, column qualifier and/or the column value.
`Filter.ReturnCode`	`filterKeyValue(Cell ignored)` Deprecated.
`boolean`	`filterRowKey(Cell firstRowCell)` Filters a row based on the row key.
`Cell`	`getNextCellHint(Cell currentKV)` Filters that are not sure which key must be next seeked to, can inherit this implementation that, by default, returns a null Cell.
`List<MultiRowRangeFilter.RowRange>`	`getRowRanges()`
`int`	`hashCode()`
`static MultiRowRangeFilter`	`parseFrom(byte[] pbBytes)`
`static List<MultiRowRangeFilter.RowRange>`	`sortAndMerge(List<MultiRowRangeFilter.RowRange> ranges)` sort the ranges and if the ranges with overlap, then merge them.
`byte[]`	`toByteArray()` Return length 0 byte array for Filters that don't require special serialization

Methods inherited from class org.apache.hadoop.hbase.filter.FilterBase
createFilterFromArguments, filterRow, filterRowCells, filterRowKey, hasFilterRow, isFamilyEssential, reset, toString, transformCell

Methods inherited from class org.apache.hadoop.hbase.filter.Filter
isReversed, setReversed

Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait

- Constructor Detail
  - MultiRowRangeFilter
```
public MultiRowRangeFilter(List<MultiRowRangeFilter.RowRange> list)
```
    Parameters:
    
    list - A list of RowRange
- Method Detail
  - getRowRanges
```
public List<MultiRowRangeFilter.RowRange> getRowRanges()
```
  - filterAllRemaining
```
public boolean filterAllRemaining()
```
    Description copied from class: org.apache.hadoop.hbase.filter.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 org.apache.hadoop.hbase.filter.FilterBase
    
    Returns:
    
    true to end scan, false to continue.
  - filterRowKey
```
public boolean filterRowKey(Cell firstRowCell)
```
    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.filterCell(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 org.apache.hadoop.hbase.filter.FilterBase
    
    Parameters:
    
    firstRowCell - The first cell coming in the new row
    
    Returns:
    
    true, remove entire row, false, include the row (maybe).
  - filterKeyValue
```
@Deprecated
public Filter.ReturnCode filterKeyValue(Cell ignored)
```
    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 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:
    
    ignored - the Cell in question
    
    Returns:
    
    code as described below, Filter.ReturnCode.INCLUDE by default
    
    See Also:
    
    Filter.ReturnCode
  - filterCell
```
public Filter.ReturnCode filterCell(Cell ignored)
```
    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 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:
    
    filterCell in class Filter
    
    Parameters:
    
    ignored - the Cell in question
    
    Returns:
    
    code as described below
    
    See Also:
    
    Filter.ReturnCode
  - getNextCellHint
```
public Cell getNextCellHint(Cell currentKV)
```
    Description copied from class: org.apache.hadoop.hbase.filter.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 org.apache.hadoop.hbase.filter.FilterBase
    
    Returns:
    
    KeyValue which must be next seeked. return null if the filter is not sure which key to seek to next.
  - toByteArray
```
public byte[] toByteArray()
```
    Description copied from class: org.apache.hadoop.hbase.filter.FilterBase
    
    Return length 0 byte array for Filters that don't require special serialization
    
    Overrides:
    
    toByteArray in class org.apache.hadoop.hbase.filter.FilterBase
    
    Returns:
    
    The filter serialized using pb
  - parseFrom
```
public static MultiRowRangeFilter parseFrom(byte[] pbBytes)
                                     throws org.apache.hadoop.hbase.exceptions.DeserializationException
```
    Parameters:
    
    pbBytes - A pb serialized instance
    
    Returns:
    
    An instance of MultiRowRangeFilter
    
    Throws:
    
    org.apache.hadoop.hbase.exceptions.DeserializationException
  - sortAndMerge
```
public static List<MultiRowRangeFilter.RowRange> sortAndMerge(List<MultiRowRangeFilter.RowRange> ranges)
```
    sort the ranges and if the ranges with overlap, then merge them.
    
    Parameters:
    
    ranges - the list of ranges to sort and merge.
    
    Returns:
    
    the ranges after sort and merge.
  - equals
```
public boolean equals(Object obj)
```
    Overrides:
    
    equals in class Object
  - hashCode
```
public int hashCode()
```
    Overrides:
    
    hashCode in class Object

Class MultiRowRangeFilter

Nested Class Summary

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

Field Summary

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

Constructor Summary

Method Summary

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

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

Methods inherited from class java.lang.Object

Constructor Detail

MultiRowRangeFilter

Method Detail

getRowRanges

filterAllRemaining

filterRowKey

filterKeyValue

filterCell

getNextCellHint

toByteArray

parseFrom

sortAndMerge

equals

hashCode