org.apache.hadoop.hbase.regionserver

Class MobStoreScanner

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.MobStoreScanner

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable, ChangedReadersObserver, InternalScanner, KeyValueScanner

@InterfaceAudience.Private
public class MobStoreScanner
extends StoreScanner

Scanner scans both the memstore and the MOB Store. Coalesce KeyValue stream into List for a single row.

Field Summary

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

cacheBlocks, cellsPerHeartbeatCheck, closing, columns, countPerRow, DEFAULT_HBASE_CELLS_SCANNED_PER_HEARTBEAT_CHECK, executor, explicitColumnQuery, HBASE_CELLS_SCANNED_PER_HEARTBEAT_CHECK, heap, isGet, isParallelSeekEnabled, lastTop, lazySeekEnabledGlobally, lock, matcher, maxRowSize, minVersions, now, oldestUnexpiredTS, readPt, scan, store, storeLimit, storeOffset, STORESCANNER_PARALLEL_SEEK_ENABLE, useRowColBloom

Constructor Summary

Constructors

Constructor and Description
MobStoreScanner(Store store, ScanInfo scanInfo, Scan scan, java.util.NavigableSet<byte[]> columns, long readPt)

Method Summary

Modifier and Type	Method and Description
boolean	next(java.util.List<Cell> outResult, ScannerContext ctx) Firstly reads the cells from the HBase.

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

checkReseek, checkScanOrder, close, getEstimatedNumberOfKvsScanned, getNextIndexedKey, getScannersNoCompaction, getSequenceID, next, next, peek, reseek, resetKVHeap, resetScannerStack, seek, seekAsDirection, seekScanners, seekToNextRow, selectScannersFrom, updateReaders

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

backwardSeek, seekToLastRow, seekToPreviousRow

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

doRealSeek, enforceSeek, 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

backwardSeek, enforceSeek, isFileScanner, realSeekDone, requestSeek, seekToLastRow, seekToPreviousRow, shouldUseScanner

Constructor Detail

MobStoreScanner

public MobStoreScanner(Store store,
                       ScanInfo scanInfo,
                       Scan scan,
                       java.util.NavigableSet<byte[]> columns,
                       long readPt)
                throws java.io.IOException

Throws:

java.io.IOException

Method Detail

next

public boolean next(java.util.List<Cell> outResult,
                    ScannerContext ctx)
             throws java.io.IOException

Firstly reads the cells from the HBase. If the cell are 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:

java.io.IOException - e