NonReversedNonLazyKeyValueScanner (Apache HBase 1.2.12 API)

java.lang.Object
- org.apache.hadoop.hbase.regionserver.NonLazyKeyValueScanner
- - org.apache.hadoop.hbase.regionserver.NonReversedNonLazyKeyValueScanner

All Implemented Interfaces:

KeyValueScanner

Direct Known Subclasses:

CollectionBackedScanner, KeyValueHeap, StoreScanner
```
@InterfaceAudience.Private
public abstract class NonReversedNonLazyKeyValueScanner
extends NonLazyKeyValueScanner
```
A "non-reversed & non-lazy" scanner which does not support backward scanning and always does a real seek operation. Most scanners are inherited from this class.

Field Summary
- Fields inherited from interface org.apache.hadoop.hbase.regionserver.KeyValueScanner
  NO_NEXT_INDEXED_KEY

Constructor Summary

Constructors
Constructor and Description

NonReversedNonLazyKeyValueScanner()

Constructors
Constructor and Description
`NonReversedNonLazyKeyValueScanner()`

Method Summary

Methods
Modifier and Type	Method and Description
`boolean`	`backwardSeek(Cell key)` Seek the scanner at or before the row of specified Cell, it firstly tries to seek the scanner at or after the specified Cell, return if peek KeyValue of scanner has the same row with specified Cell, otherwise seek the scanner at the first Cell of the row which is the previous row of specified KeyValue
`boolean`	`seekToLastRow()` Seek the scanner at the first KeyValue of last row
`boolean`	`seekToPreviousRow(Cell key)` Seek the scanner at the first Cell of the row which is the previous row of specified key

Methods inherited from class org.apache.hadoop.hbase.regionserver.NonLazyKeyValueScanner
doRealSeek, enforceSeek, getNextIndexedKey, isFileScanner, realSeekDone, requestSeek, shouldUseScanner

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

Methods inherited from interface org.apache.hadoop.hbase.regionserver.KeyValueScanner
close, getSequenceID, next, peek, reseek, seek

- Constructor Detail
  - NonReversedNonLazyKeyValueScanner
```
public NonReversedNonLazyKeyValueScanner()
```
- Method Detail
  - backwardSeek
```
public boolean backwardSeek(Cell key)
                     throws IOException
```
    Description copied from interface: KeyValueScanner
    
    Seek the scanner at or before the row of specified Cell, it firstly tries to seek the scanner at or after the specified Cell, return if peek KeyValue of scanner has the same row with specified Cell, otherwise seek the scanner at the first Cell of the row which is the previous row of specified KeyValue
    
    Parameters:
    key - seek KeyValue
    
    Returns:
    true if the scanner is at the valid KeyValue, false if such KeyValue does not exist
    
    Throws:
    
    IOException
  - seekToPreviousRow
```
public boolean seekToPreviousRow(Cell key)
                          throws IOException
```
    Description copied from interface: KeyValueScanner
    
    Seek the scanner at the first Cell of the row which is the previous row of specified key
    
    Parameters:
    key - seek value
    
    Returns:
    true if the scanner at the first valid Cell of previous row, false if not existing such Cell
    
    Throws:
    
    IOException
  - seekToLastRow
```
public boolean seekToLastRow()
                      throws IOException
```
    Description copied from interface: KeyValueScanner
    
    Seek the scanner at the first KeyValue of last row
    
    Returns:
    true if scanner has values left, false if the underlying data is empty
    
    Throws:
    
    IOException

Class NonReversedNonLazyKeyValueScanner

Field Summary

Fields inherited from interface org.apache.hadoop.hbase.regionserver.KeyValueScanner

Constructor Summary

Method Summary

Methods inherited from class org.apache.hadoop.hbase.regionserver.NonLazyKeyValueScanner

Methods inherited from class java.lang.Object

Methods inherited from interface org.apache.hadoop.hbase.regionserver.KeyValueScanner

Constructor Detail

NonReversedNonLazyKeyValueScanner

Method Detail

backwardSeek

seekToPreviousRow

seekToLastRow