com.sleepycat.je.recovery
Class RollbackTracker.Scanner

java.lang.Object
  extended by com.sleepycat.je.recovery.RollbackTracker.Scanner
Direct Known Subclasses:
RollbackTracker.BackwardScanner, RollbackTracker.UnderConstructionScanner
Enclosing class:
RollbackTracker

abstract class RollbackTracker.Scanner
extends Object

A Scanner is to process LNs during a recovery pass. It determines whether this log entry is within the rollback period, and should be accordingly undone or ignored. It serves as a sort of cursor or iterator that works with the rollback tracker.


Field Summary
(package private)  RollbackTracker.RollbackPeriod target
           
 
Constructor Summary
RollbackTracker.Scanner()
           
 
Method Summary
(package private)  boolean needsRollback()
           
(package private) abstract  boolean positionAndCheck(long lsn, long txnId)
          Return true if this transactional log entry is something that should be rolled back in this rollback period.
 void rollback(Long txnId, LNFileReader reader, RecoveryUtilizationTracker tracker)
          Rollback the filereader's current LN_TX.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

target

RollbackTracker.RollbackPeriod target
Constructor Detail

RollbackTracker.Scanner

RollbackTracker.Scanner()
Method Detail

positionAndCheck

abstract boolean positionAndCheck(long lsn,
                                  long txnId)
Return true if this transactional log entry is something that should be rolled back in this rollback period. The Scanner's position can be changed by this call. Update the target field if necessary.


rollback

public void rollback(Long txnId,
                     LNFileReader reader,
                     RecoveryUtilizationTracker tracker)
Rollback the filereader's current LN_TX. This assumes that the the caller has ascertained that the LN is contained within this rollback period.


needsRollback

boolean needsRollback()


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