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:

Closeable, AutoCloseable, KeyValueScanner, Shipper

Direct Known Subclasses:

CollectionBackedScanner, KeyValueHeap, SnapshotSegmentScanner, 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.

Field Summary

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

NO_NEXT_INDEXED_KEY

Constructor Summary

Constructors

Constructor and Description
NonReversedNonLazyKeyValueScanner()

Method Summary

Modifier and Type	Method and Description
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
boolean	seekToLastRow() Seek the scanner at the first KeyValue of last row
boolean	seekToPreviousRow(Cell key) Seek the scanner at the first Cell of the row which is the previous row of specified key

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

doRealSeek, enforceSeek, getFilePath, getNextIndexedKey, isFileScanner, realSeekDone, requestSeek, shipped, 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, getScannerOrder, next, peek, reseek, seek

Constructor Detail

NonReversedNonLazyKeyValueScanner

public NonReversedNonLazyKeyValueScanner()

Method Detail

backwardSeek

public boolean backwardSeek(Cell key)
                     throws IOException

Description copied from interface: 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

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(Cell key)
                          throws IOException

Description copied from interface: KeyValueScanner

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

Parameters:

key - seek value

Returns:

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

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