org.apache.hadoop.hbase.codec.prefixtree.scanner

接口 ReversibleCellScanner

所有超级接口:

CellScanner

所有已知子接口:

CellSearcher

所有已知实现类:

PrefixTreeArrayReversibleScanner, PrefixTreeArraySearcher

@InterfaceAudience.Private
public interface ReversibleCellScanner
extends CellScanner

An extension of CellScanner indicating the scanner supports iterating backwards through cells.

Note: This was not added to suggest that HBase should support client facing reverse Scanners, but because some CellSearcher implementations, namely PrefixTree, need a method of backing up if the positionAt(..) method goes past the requested cell.

方法概要

方法

限定符和类型	方法和说明
boolean	previous() Try to position the scanner one Cell before the current position.
boolean	previousRow(boolean endOfRow) Try to position the scanner in the row before the current row.

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

advance, current

方法详细资料

previous

boolean previous()

Try to position the scanner one Cell before the current position.

返回:

true if the operation was successful, meaning getCurrentCell() will return a valid Cell.
false if there were no previous cells, meaning getCurrentCell() will return null. Scanner position will be CellScannerPosition.BEFORE_FIRST

previousRow

boolean previousRow(boolean endOfRow)

Try to position the scanner in the row before the current row.

参数:

endOfRow - true for the last cell in the previous row; false for the first cell

返回:

true if the operation was successful, meaning getCurrentCell() will return a valid Cell.
false if there were no previous cells, meaning getCurrentCell() will return null. Scanner position will be CellScannerPosition.BEFORE_FIRST