org.apache.hadoop.hbase.regionserver

类 ReversedStoreScanner

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

所有已实现的接口:

Closeable, AutoCloseable, ChangedReadersObserver, InternalScanner, KeyValueScanner, Shipper

直接已知子类:

ReversedMobStoreScanner

@InterfaceAudience.Private
public class ReversedStoreScanner
extends StoreScanner
implements KeyValueScanner

ReversedStoreScanner extends from StoreScanner, and is used to support reversed scanning.

字段概要

从类继承的字段 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

从接口继承的字段 org.apache.hadoop.hbase.regionserver.KeyValueScanner

NO_NEXT_INDEXED_KEY

构造器概要

构造器

构造器和说明
ReversedStoreScanner(HStore store, ScanInfo scanInfo, Scan scan, NavigableSet<byte[]> columns, long readPt) Opens a scanner across memstore, snapshot, and all StoreFiles.
ReversedStoreScanner(Scan scan, ScanInfo scanInfo, NavigableSet<byte[]> columns, List<? extends KeyValueScanner> scanners) Constructor for testing.

方法概要

限定符和类型	方法和说明
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
protected void	checkScanOrder(Cell prevKV, Cell kv, CellComparator comparator) Check whether scan as expected order
protected KeyValueHeap	newKVHeap(List<? extends KeyValueScanner> scanners, CellComparator comparator)
boolean	reseek(Cell kv) Reseek the scanner at or after the specified KeyValue.
boolean	seek(Cell key) Seek the scanner at or after the specified KeyValue.
protected boolean	seekAsDirection(Cell kv) Do a backwardSeek in a reversed StoreScanner(scan backward)
protected void	seekScanners(List<? extends KeyValueScanner> scanners, Cell seekKey, boolean isLazy, boolean isParallelSeek) Seek the specified scanners with the given key
protected boolean	seekToNextRow(Cell kv)
boolean	seekToPreviousRow(Cell key) Seek the scanner at the first Cell of the row which is the previous row of specified key

从类继承的方法 org.apache.hadoop.hbase.regionserver.StoreScanner

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

从类继承的方法 org.apache.hadoop.hbase.regionserver.NonReversedNonLazyKeyValueScanner

seekToLastRow

从类继承的方法 org.apache.hadoop.hbase.regionserver.NonLazyKeyValueScanner

doRealSeek, enforceSeek, getFilePath, isFileScanner, realSeekDone, requestSeek, shouldUseScanner

从类继承的方法 java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

从接口继承的方法 org.apache.hadoop.hbase.regionserver.KeyValueScanner

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

从接口继承的方法 org.apache.hadoop.hbase.regionserver.Shipper

shipped

从接口继承的方法 org.apache.hadoop.hbase.regionserver.InternalScanner

next

构造器详细资料

ReversedStoreScanner

public ReversedStoreScanner(HStore store,
                            ScanInfo scanInfo,
                            Scan scan,
                            NavigableSet<byte[]> columns,
                            long readPt)
                     throws IOException

Opens a scanner across memstore, snapshot, and all StoreFiles. Assumes we are not in a compaction.

参数:

store - who we scan

scanInfo -

scan - the spec

columns - which columns we are scanning

抛出:

IOException

ReversedStoreScanner

public ReversedStoreScanner(Scan scan,
                            ScanInfo scanInfo,
                            NavigableSet<byte[]> columns,
                            List<? extends KeyValueScanner> scanners)
                     throws IOException

Constructor for testing.

抛出:

IOException

方法详细资料

newKVHeap

protected KeyValueHeap newKVHeap(List<? extends KeyValueScanner> scanners,
                                 CellComparator comparator)
                          throws IOException

覆盖:

newKVHeap 在类中 StoreScanner

抛出:

IOException

seekScanners

protected void seekScanners(List<? extends KeyValueScanner> scanners,
                            Cell seekKey,
                            boolean isLazy,
                            boolean isParallelSeek)
                     throws IOException

从类复制的说明: StoreScanner

Seek the specified scanners with the given key

覆盖:

seekScanners 在类中 StoreScanner

isLazy - true if using lazy seek

isParallelSeek - true if using parallel seek

抛出:

IOException

seekToNextRow

protected boolean seekToNextRow(Cell kv)
                         throws IOException

覆盖:

seekToNextRow 在类中 StoreScanner

抛出:

IOException

seekAsDirection

protected boolean seekAsDirection(Cell kv)
                           throws IOException

Do a backwardSeek in a reversed StoreScanner(scan backward)

覆盖:

seekAsDirection 在类中 StoreScanner

返回:

true if scanner has values left, false if end of scanner

抛出:

IOException

checkScanOrder

protected void checkScanOrder(Cell prevKV,
                              Cell kv,
                              CellComparator comparator)
                       throws IOException

从类复制的说明: StoreScanner

Check whether scan as expected order

覆盖:

checkScanOrder 在类中 StoreScanner

抛出:

IOException

reseek

public boolean reseek(Cell kv)
               throws IOException

从接口复制的说明: KeyValueScanner

Reseek the scanner at or after the specified KeyValue. This method is guaranteed to seek at or after the required key only if the key comes after the current position of the scanner. Should not be used to seek to a key which may come before the current position.

指定者:

reseek 在接口中 KeyValueScanner

覆盖:

reseek 在类中 StoreScanner

参数:

kv - seek value (should be non-null)

返回:

true if scanner has values left, false if end of scanner

抛出:

IOException

seek

public boolean seek(Cell key)
             throws IOException

从接口复制的说明: KeyValueScanner

Seek the scanner at or after the specified KeyValue.

指定者:

seek 在接口中 KeyValueScanner

覆盖:

seek 在类中 StoreScanner

参数:

key - seek value

返回:

true if scanner has values left, false if end of scanner

抛出:

IOException

seekToPreviousRow

public boolean seekToPreviousRow(Cell key)
                          throws IOException

从接口复制的说明: KeyValueScanner

Seek the scanner at the first Cell of the row which is the previous row of specified key

指定者:

seekToPreviousRow 在接口中 KeyValueScanner

覆盖:

seekToPreviousRow 在类中 NonReversedNonLazyKeyValueScanner

参数:

key - seek value

返回:

true if the scanner at the first valid Cell of previous row, false if not existing such Cell

抛出:

IOException

backwardSeek

public boolean backwardSeek(Cell key)
                     throws IOException

从接口复制的说明: 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

指定者:

backwardSeek 在接口中 KeyValueScanner

覆盖:

backwardSeek 在类中 NonReversedNonLazyKeyValueScanner

参数:

key - seek KeyValue

返回:

true if the scanner is at the valid KeyValue, false if such KeyValue does not exist

抛出:

IOException