com.arjuna.ats.internal.arjuna.abstractrecords

Class RecoveryRecord

java.lang.Object

com.arjuna.ats.arjuna.StateManager

com.arjuna.ats.arjuna.coordinator.AbstractRecord

com.arjuna.ats.internal.arjuna.abstractrecords.RecoveryRecord

Direct Known Subclasses:

PersistenceRecord

public class RecoveryRecord
extends AbstractRecord

Field Summary

Fields

Modifier and Type	Field and Description
protected StateManager	objectAddr
protected OutputObjectState	state

Fields inherited from class com.arjuna.ats.arjuna.StateManager

modifyingActions, objectModel, objectUid, usingActions

Constructor Summary

Constructors

Constructor and Description
RecoveryRecord()
RecoveryRecord(OutputObjectState os, StateManager sm) This constructor is used to create a new instance of a RecoveryRecord.

Method Summary

Methods

Modifier and Type	Method and Description
void	alter(AbstractRecord a) Alter the current record with the one presented.
boolean	doSave() Should this record be saved in the intentions list? If the record is saved, then it may be recovered later in the event of a failure.
void	finalize()
protected void	forgetAction(boolean commit)
void	merge(AbstractRecord a) Merge the current record with the one presented.
int	nestedAbort() nestedAbort causes the restore_state function of the object to be invoked passing it the saved ObjectState.
int	nestedCommit() nestedCommit does nothing since the passing of the state up to the parent action is handled by the record list merging system.
int	nestedPrepare() A prepare for a nested transaction has occurred.
void	print(PrintWriter strm) Write information about this specific instance to the specified stream.
boolean	restore_state(InputObjectState os, int ot) During recovery, the transaction log is given to the recovery system and it will recreate a transaction instance to perform necessary recovery actions.
boolean	save_state(OutputObjectState os, int ot) When the transaction is required to make the intentions list persistent, it scans the list and asks each record whether or not it requires state to be saved (by calling doSave).
void	setValue(Object newState)
boolean	shouldAdd(AbstractRecord a) Should we add the record presented to the intentions list?
boolean	shouldAlter(AbstractRecord a) Should we alter the current record with the one presented?
boolean	shouldMerge(AbstractRecord a) Should we merge the current record with the one presented?
boolean	shouldReplace(AbstractRecord a) Should we replace the record presented with the current record?
int	topLevelAbort() topLevelAbort for Recovery records implies the object state should be restored to the saved state exactly like a nested abort.
int	topLevelCommit() topLevelCommit has nothing to do for RecoveryRecords as no changes have been made in the object store.
int	topLevelPrepare() topLevelPrepare can return PREPARE_READONLY to avoid topLevelCommit being called in the action commit case
String	type() Re-implementation of abstract methods inherited from base class.
int	typeIs()
Object	value() If this abstract record caused a heuristic then it should return an object which implements HeuristicInformation

Methods inherited from class com.arjuna.ats.arjuna.coordinator.AbstractRecord

create, equals, forgetHeuristic, getNext, getPrevious, getTypeOfObject, greaterThan, lessThan, nestedCleanup, nestedOnePhaseCommit, order, propagateOnAbort, propagateOnCommit, replace, setNext, setPrevious, topLevelCleanup, topLevelOnePhaseCommit

Methods inherited from class com.arjuna.ats.arjuna.StateManager

activate, activate, cleanup, createLists, deactivate, deactivate, deactivate, destroy, disable, forgetAction, get_uid, getMutex, getObjectModel, getStore, getStoreRoot, loadObjectState, lockMutex, modified, objectType, packHeader, persist, rememberAction, setStatus, setupStore, setupStore, setupStore, status, terminate, tryLockMutex, unlockMutex, unpackHeader

Methods inherited from class java.lang.Object

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

Field Detail

objectAddr

protected StateManager objectAddr

state

protected OutputObjectState state

Constructor Detail

RecoveryRecord

public RecoveryRecord(OutputObjectState os,
              StateManager sm)

This constructor is used to create a new instance of a RecoveryRecord.

RecoveryRecord

public RecoveryRecord()

Method Detail

finalize

public void finalize()
              throws Throwable

Overrides:

finalize in class Object

Throws:

Throwable

typeIs

public int typeIs()

Specified by:

typeIs in class AbstractRecord

Returns:

RecordType value.

value

public Object value()

Description copied from class: AbstractRecord

If this abstract record caused a heuristic then it should return an object which implements HeuristicInformation

Specified by:

value in class AbstractRecord

Returns:

Object to be used to order.

setValue

public void setValue(Object newState)

Specified by:

setValue in class AbstractRecord

nestedAbort

public int nestedAbort()

nestedAbort causes the restore_state function of the object to be invoked passing it the saved ObjectState.

Specified by:

nestedAbort in class AbstractRecord

Returns:

TwoPhaseOutcome to indicate success/failure.

See Also:

TwoPhaseOutcome

nestedCommit

public int nestedCommit()

nestedCommit does nothing since the passing of the state up to the parent action is handled by the record list merging system. In fact since nestedPrepare returns PREPARE_READONLY this function should never actually be called

Specified by:

nestedCommit in class AbstractRecord

Returns:

TwoPhaseOutcome to indicate success/failure.

See Also:

TwoPhaseOutcome

nestedPrepare

public int nestedPrepare()

Description copied from class: AbstractRecord

A prepare for a nested transaction has occurred.

Specified by:

nestedPrepare in class AbstractRecord

Returns:

TwoPhaseOutcome to indicate success/failure.

See Also:

TwoPhaseOutcome

topLevelAbort

public int topLevelAbort()

topLevelAbort for Recovery records implies the object state should be restored to the saved state exactly like a nested abort.

Specified by:

topLevelAbort in class AbstractRecord

Returns:

TwoPhaseOutcome to indicate success/failure.

See Also:

TwoPhaseOutcome

topLevelCommit

public int topLevelCommit()

topLevelCommit has nothing to do for RecoveryRecords as no changes have been made in the object store. In fact since topLevelPrepare returns PREPARE_READONLY this function should never actually be called

Specified by:

topLevelCommit in class AbstractRecord

Returns:

TwoPhaseOutcome to indicate success/failure.

See Also:

TwoPhaseOutcome

topLevelPrepare

public int topLevelPrepare()

topLevelPrepare can return PREPARE_READONLY to avoid topLevelCommit being called in the action commit case

Specified by:

topLevelPrepare in class AbstractRecord

Returns:

TwoPhaseOutcome to indicate success/failure.

See Also:

TwoPhaseOutcome

doSave

public boolean doSave()

Description copied from class: AbstractRecord

Should this record be saved in the intentions list? If the record is saved, then it may be recovered later in the event of a failure. Note, however, that the size of the intentions list on disk is critical to the performance of the system (disk I/O is a bottleneck).

Overrides:

doSave in class AbstractRecord

Returns:

true if it should be saved, false otherwise. false is the default.

restore_state

public boolean restore_state(InputObjectState os,
                    int ot)

Description copied from class: AbstractRecord

During recovery, the transaction log is given to the recovery system and it will recreate a transaction instance to perform necessary recovery actions. This transaction will recreate the intentions list and give each recreated AbstractRecord the state that that was saved during transaction persistence. The base class will restore information that it needs from the log. Data items must be unpacked in the same order that they were packed.

Overrides:

restore_state in class AbstractRecord

Returns:

true if successful, false otherwise.

save_state

public boolean save_state(OutputObjectState os,
                 int ot)

Description copied from class: AbstractRecord

When the transaction is required to make the intentions list persistent, it scans the list and asks each record whether or not it requires state to be saved (by calling doSave). If the answer is yes, then save_state is called and the record instance must save enough information to enable it to be restored from that state later. The basic AbstractRecord save_state will save common data that is required by the base class during recovery. If a derived class calls super.save_state then it must be called before packing any other data item.

Overrides:

save_state in class AbstractRecord

Returns:

true if successful, false otherwise.

print

public void print(PrintWriter strm)

Description copied from class: AbstractRecord

Write information about this specific instance to the specified stream.

Overrides:

print in class AbstractRecord

Parameters:

strm - the stream on which to output.

type

public String type()

Description copied from class: AbstractRecord

Re-implementation of abstract methods inherited from base class.

Overrides:

type in class AbstractRecord

merge

public void merge(AbstractRecord a)

Description copied from class: AbstractRecord

Merge the current record with the one presented.

Specified by:

merge in class AbstractRecord

Parameters:

a - the record with which to merge.

alter

public void alter(AbstractRecord a)

Description copied from class: AbstractRecord

Alter the current record with the one presented.

Specified by:

alter in class AbstractRecord

Parameters:

a - the record with which to alter.

shouldAdd

public boolean shouldAdd(AbstractRecord a)

Description copied from class: AbstractRecord

Should we add the record presented to the intentions list?

Specified by:

shouldAdd in class AbstractRecord

Parameters:

a - The record to try to add.

Returns:

true if the record should be added, false otherwise.

shouldAlter

public boolean shouldAlter(AbstractRecord a)

Description copied from class: AbstractRecord

Should we alter the current record with the one presented?

Specified by:

shouldAlter in class AbstractRecord

Parameters:

a - The record to try to alter.

Returns:

true if the record should be altered, false otherwise.

shouldMerge

public boolean shouldMerge(AbstractRecord a)

Description copied from class: AbstractRecord

Should we merge the current record with the one presented?

Specified by:

shouldMerge in class AbstractRecord

Parameters:

a - The record to try to merge.

Returns:

true if the record should be merged, false otherwise.

shouldReplace

public boolean shouldReplace(AbstractRecord a)

Description copied from class: AbstractRecord

Should we replace the record presented with the current record?

Specified by:

shouldReplace in class AbstractRecord

Parameters:

a - The record to try to replace.

Returns:

true if the record should be replaced, false otherwise.

forgetAction

protected final void forgetAction(boolean commit)