ScanDeleteTracker (Apache HBase 1.4.11 API)

java.lang.Object
- org.apache.hadoop.hbase.regionserver.querymatcher.ScanDeleteTracker

All Implemented Interfaces:

DeleteTracker

Direct Known Subclasses:

VisibilityScanDeleteTracker
```
@InterfaceAudience.Private
public class ScanDeleteTracker
extends Object
implements DeleteTracker
```
This class is responsible for the tracking and enforcement of Deletes during the course of a Scan operation. It only has to enforce Delete and DeleteColumn, since the DeleteFamily is handled at a higher level.
This class is utilized through three methods:
- add(org.apache.hadoop.hbase.Cell) when encountering a Delete or DeleteColumn
- isDeleted(org.apache.hadoop.hbase.Cell) when checking if a Put KeyValue has been deleted
- update() when reaching the end of a StoreFile or row for scans
This class is NOT thread-safe as queries are never multi-threaded

Nested Class Summary
- Nested classes/interfaces inherited from interface org.apache.hadoop.hbase.regionserver.DeleteTracker
  DeleteTracker.DeleteCompare, DeleteTracker.DeleteResult

Field Summary

Fields
Modifier and Type	Field and Description
`protected byte[]`	`deleteBuffer`
`protected int`	`deleteLength`
`protected int`	`deleteOffset`
`protected long`	`deleteTimestamp`
`protected byte`	`deleteType`
`protected long`	`familyStamp`
`protected SortedSet<Long>`	`familyVersionStamps`
`protected boolean`	`hasFamilyStamp`

Constructor Summary

Constructors
Constructor and Description

ScanDeleteTracker()

Constructors
Constructor and Description
`ScanDeleteTracker()`

Method Summary

Methods
Modifier and Type	Method and Description
`void`	`add(Cell cell)` Add the specified KeyValue to the list of deletes to check against for this row operation.
`DeleteTracker.DeleteResult`	`isDeleted(Cell cell)` Check if the specified KeyValue buffer has been deleted by a previously seen delete.
`boolean`	`isEmpty()`
`void`	`reset()` Called between rows.
`void`	`update()` Called at the end of every StoreFile.

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

- Field Detail
  - hasFamilyStamp
```
protected boolean hasFamilyStamp
```
  - familyStamp
```
protected long familyStamp
```
  - familyVersionStamps
```
protected SortedSet<Long> familyVersionStamps
```
  - deleteBuffer
```
protected byte[] deleteBuffer
```
  - deleteOffset
```
protected int deleteOffset
```
  - deleteLength
```
protected int deleteLength
```
  - deleteType
```
protected byte deleteType
```
  - deleteTimestamp
```
protected long deleteTimestamp
```
- Constructor Detail
  - ScanDeleteTracker
```
public ScanDeleteTracker()
```
- Method Detail
  - add
```
public void add(Cell cell)
```
    Add the specified KeyValue to the list of deletes to check against for this row operation.
    This is called when a Delete is encountered.
    
    Specified by:
    
    add in interface DeleteTracker
    
    Parameters:
    cell - - the delete cell
  - isDeleted
```
public DeleteTracker.DeleteResult isDeleted(Cell cell)
```
    Check if the specified KeyValue buffer has been deleted by a previously seen delete.
    
    Specified by:
    
    isDeleted in interface DeleteTracker
    
    Parameters:
    cell - - current cell to check if deleted by a previously seen delete
    
    Returns:
    deleteResult
  - isEmpty
```
public boolean isEmpty()
```
    Specified by:
    
    isEmpty in interface DeleteTracker
    
    Returns:
    true if there are no current delete, false otherwise
  - reset
```
public void reset()
```
    Description copied from interface: DeleteTracker
    
    Called between rows.
    This clears everything as if a new DeleteTracker was instantiated.
    
    Specified by:
    
    reset in interface DeleteTracker
  - update
```
public void update()
```
    Description copied from interface: DeleteTracker
    
    Called at the end of every StoreFile.
    Many optimized implementations of Trackers will require an update at when the end of each StoreFile is reached.
    
    Specified by:
    
    update in interface DeleteTracker

Class ScanDeleteTracker

Nested Class Summary

Nested classes/interfaces inherited from interface org.apache.hadoop.hbase.regionserver.DeleteTracker

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

hasFamilyStamp

familyStamp

familyVersionStamps

deleteBuffer

deleteOffset

deleteLength

deleteType

deleteTimestamp

Constructor Detail

ScanDeleteTracker

Method Detail

add

isDeleted

isEmpty

reset

update