org.apache.hadoop.hbase.regionserver

Class NonReversedNonLazyKeyValueScanner

java.lang.Object

org.apache.hadoop.hbase.regionserver.NonLazyKeyValueScanner

org.apache.hadoop.hbase.regionserver.NonReversedNonLazyKeyValueScanner

All Implemented Interfaces:

KeyValueScanner

Direct Known Subclasses:

CollectionBackedScanner, KeyValueHeap, StoreScanner

@InterfaceAudience.Private
public abstract class NonReversedNonLazyKeyValueScanner
extends NonLazyKeyValueScanner

A "non-reversed & non-lazy" scanner which does not support backward scanning and always does a real seek operation. Most scanners are inherited from this class.

Constructor Summary

Constructors

Constructor and Description
NonReversedNonLazyKeyValueScanner()

Method Summary

Methods

Modifier and Type	Method and Description
boolean	backwardSeek(KeyValue key) Seek the scanner at or before the row of specified KeyValue, it firstly tries to seek the scanner at or after the specified KeyValue, return if peek KeyValue of scanner has the same row with specified KeyValue, otherwise seek the scanner at the first KeyValue of the row which is the previous row of specified KeyValue
boolean	seekToLastRow() Seek the scanner at the first KeyValue of last row
boolean	seekToPreviousRow(KeyValue key) Seek the scanner at the first KeyValue of the row which is the previous row of specified key

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

close, getSequenceID, next, peek, reseek, seek

Constructor Detail

NonReversedNonLazyKeyValueScanner

public NonReversedNonLazyKeyValueScanner()

Method Detail

backwardSeek

public boolean backwardSeek(KeyValue key)
                     throws IOException

Description copied from interface: KeyValueScanner

Seek the scanner at or before the row of specified KeyValue, it firstly tries to seek the scanner at or after the specified KeyValue, return if peek KeyValue of scanner has the same row with specified KeyValue, otherwise seek the scanner at the first KeyValue of the row which is the previous row of specified KeyValue

Parameters:

key - seek KeyValue

Returns:

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

Throws:

IOException

seekToPreviousRow

public boolean seekToPreviousRow(KeyValue key)
                          throws IOException

Description copied from interface: KeyValueScanner

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

Parameters:

key - seek value

Returns:

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

Throws:

IOException

seekToLastRow

public boolean seekToLastRow()
                      throws IOException

Description copied from interface: KeyValueScanner

Seek the scanner at the first KeyValue of last row

Returns:

true if scanner has values left, false if the underlying data is empty

Throws:

IOException