org.apache.hadoop.hbase.regionserver

Class ReversedMobStoreScanner

java.lang.Object

org.apache.hadoop.hbase.regionserver.NonLazyKeyValueScanner

org.apache.hadoop.hbase.regionserver.NonReversedNonLazyKeyValueScanner

org.apache.hadoop.hbase.regionserver.StoreScanner

org.apache.hadoop.hbase.regionserver.ReversedStoreScanner

org.apache.hadoop.hbase.regionserver.ReversedMobStoreScanner

All Implemented Interfaces:

Closeable, AutoCloseable, ChangedReadersObserver, InternalScanner, KeyValueScanner, Shipper

@InterfaceAudience.Private
public class ReversedMobStoreScanner
extends ReversedStoreScanner

ReversedMobStoreScanner extends from ReversedStoreScanner, and is used to support reversed scanning in both the memstore and the MOB store.

Field Summary

Fields inherited from class org.apache.hadoop.hbase.regionserver.StoreScanner

DEFAULT_HBASE_CELLS_SCANNED_PER_HEARTBEAT_CHECK, HBASE_CELLS_SCANNED_PER_HEARTBEAT_CHECK, heap, readPt, store, STORESCANNER_PARALLEL_SEEK_ENABLE, STORESCANNER_PREAD_MAX_BYTES

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

NO_NEXT_INDEXED_KEY

Method Summary

Modifier and Type	Method and Description
void	close() Close the KeyValue scanner.
boolean	next(List<Cell> outResult, ScannerContext ctx) Firstly reads the cells from the HBase.
void	shipped() Called after a batch of rows scanned and set to be returned to client.

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

backwardSeek, checkScanOrder, newKVHeap, reseek, seek, seekAsDirection, seekScanners, seekToNextRow, seekToPreviousRow

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

checkFlushed, getEstimatedNumberOfKvsScanned, getNextIndexedKey, getReadPoint, next, peek, reopenAfterFlush, resetKVHeap, selectScannersFrom, trySkipToNextColumn, trySkipToNextRow, updateReaders

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

seekToLastRow

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

doRealSeek, enforceSeek, getFilePath, 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

enforceSeek, getFilePath, getNextIndexedKey, getScannerOrder, isFileScanner, next, peek, realSeekDone, requestSeek, seekToLastRow, shouldUseScanner

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

next

Method Detail

next

public boolean next(List<Cell> outResult,
                    ScannerContext ctx)
             throws IOException

Firstly reads the cells from the HBase. If the cell is a reference cell (which has the reference tag), the scanner need seek this cell from the mob file, and use the cell found from the mob file as the result.

Specified by:

next in interface InternalScanner

Overrides:

next in class StoreScanner

Parameters:

outResult - return output array

Returns:

true if there are more rows, false if scanner is done

Throws:

IOException - e

shipped

public void shipped()
             throws IOException

Description copied from interface: Shipper

Called after a batch of rows scanned and set to be returned to client. Any in between cleanup can be done here.

Specified by:

shipped in interface Shipper

Overrides:

shipped in class StoreScanner

Throws:

IOException

close

public void close()

Description copied from interface: KeyValueScanner

Close the KeyValue scanner.

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Specified by:

close in interface InternalScanner

Specified by:

close in interface KeyValueScanner

Overrides:

close in class StoreScanner