org.apache.derby.impl.store.raw.data

Class PhysicalUndoOperation

java.lang.Object

org.apache.derby.impl.store.raw.data.PhysicalUndoOperation

All Implemented Interfaces:

java.io.Externalizable, java.io.Serializable, Formatable, TypedFormat, Compensation, Loggable, RePreparable

public final class PhysicalUndoOperation
extends java.lang.Object
implements Compensation

PhysicalUndoOperation is a compensation operation that rolls back the change of an Undo-able operation. A PhysicalUndoOperation itself is not undo-able, i.e, it is loggable but not undoable.

See Also:

Serialized Form

Field Summary

Fields inherited from interface org.apache.derby.iapi.store.raw.Loggable

ABORT, BI_LOG, CHECKSUM, COMMIT, COMPENSATION, FILE_RESOURCE, FIRST, LAST, PREPARE, RAWSTORE, XA_NEEDLOCK

Constructor Summary

Constructors

Constructor and Description
PhysicalUndoOperation() Return my format identifier.

Method Summary

Modifier and Type	Method and Description
void	doMe(Transaction xact, LogInstant instant, LimitObjectInput in) Apply the undo operation, in this implementation of the RawStore, it can only call the undoMe method of undoOp
org.apache.derby.impl.store.raw.data.BasePage	findpage(Transaction xact) Find the page the operation applies to and latch it, this only uses the segmentId, containerId, and pageId stored in this log record to find the page.
Page	getPage()
long	getPageVersion()
ByteArray	getPreparedLog() the default for optional data is set to null.
int	getTypeFormatId() Get a universally unique identifier for the type of this object.
int	group() A page operation is a RAWSTORE log record
boolean	needsRedo(Transaction xact) Returns true if this op should be redone during recovery redo, if so, get and latched the page.
void	readExternal(java.io.ObjectInput in)
void	reclaimPrepareLocks(Transaction t, LockingPolicy locking_policy) reclaim locks associated with the changes in this log record.
void	releaseResource(Transaction xact) Release latched page and any other resources acquired during a previous findpage, safe to call multiple times.
void	restoreMe(Transaction xact, org.apache.derby.impl.store.raw.data.BasePage undoPage, LogInstant CLRinstant, LimitObjectInput in) Undo the change indicated by this log operation and optional data.
void	setUndoOp(Undoable op) Set up a PageUndoOperation during recovery redo.
java.lang.String	toString() DEBUG: Print self.
void	writeExternal(java.io.ObjectOutput out)

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.apache.derby.iapi.store.raw.Loggable

needsRedo

Methods inherited from interface java.io.Externalizable

readExternal, writeExternal

Constructor Detail

PhysicalUndoOperation

public PhysicalUndoOperation()

Return my format identifier.

Method Detail

getTypeFormatId

public int getTypeFormatId()

Description copied from interface: TypedFormat

Get a universally unique identifier for the type of this object.

Specified by:

getTypeFormatId in interface TypedFormat

Returns:

The identifier. (A UUID stuffed in an array of 16 bytes).

setUndoOp

public void setUndoOp(Undoable op)

Set up a PageUndoOperation during recovery redo.

Specified by:

setUndoOp in interface Compensation

Parameters:

op - the Undoable operation

See Also:

Loggable.needsRedo(org.apache.derby.iapi.store.raw.Transaction)

doMe

public final void doMe(Transaction xact,
                       LogInstant instant,
                       LimitObjectInput in)
                throws StandardException,
                       java.io.IOException

Apply the undo operation, in this implementation of the RawStore, it can only call the undoMe method of undoOp

Specified by:

doMe in interface Loggable

Parameters:

xact - the Transaction that is doing the rollback

instant - the log instant of this undo operation

in - optional data

Throws:

java.io.IOException - Can be thrown by any of the methods of InputStream.

StandardException - Standard Derby policy.

releaseResource

public void releaseResource(Transaction xact)

Release latched page and any other resources acquired during a previous findpage, safe to call multiple times. In this RawStore implementataion, resource is acquired by a log operation in one of two places

during runtime or recovery undo in PageOperation.generateUndo() during recovery redo in PageBasicOperation.needsRedo()

Specified by:

releaseResource in interface Loggable

group

public int group()

A page operation is a RAWSTORE log record

Specified by:

group in interface Loggable

getPreparedLog

public final ByteArray getPreparedLog()

the default for optional data is set to null. If an operation has optional data, the operation need to prepare the optional data for this method. WARNING: If a log operation extends this class, and the operation has optional data, it MUST overwrite this method to return a ByteArray that contains the optional data.

Specified by:

getPreparedLog in interface Loggable

restoreMe

public void restoreMe(Transaction xact,
                      org.apache.derby.impl.store.raw.data.BasePage undoPage,
                      LogInstant CLRinstant,
                      LimitObjectInput in)

Undo the change indicated by this log operation and optional data. The page the undo should apply to is the latched undoPage. The undoPage must be the same page as the doMe page and the undo operation must restore the before image of the row that changed.
this can only be used under special circumstances: namely table level locking, and no internal or nested transaction, and all operations are rollec back with restoreMe instead of undoMe.
This method is here to support BeforeImageLogging

Parameters:

xact - the Transaction doing the rollback

undoPage - the page to rollback changes on

CLRinstant - the log instant of this (PageUndo) operation

in - optional data for the rollback operation

toString

public java.lang.String toString()

DEBUG: Print self.

writeExternal

public void writeExternal(java.io.ObjectOutput out)
                   throws java.io.IOException

Specified by:

writeExternal in interface java.io.Externalizable

Throws:

java.io.IOException

readExternal

public void readExternal(java.io.ObjectInput in)
                  throws java.io.IOException,
                         java.lang.ClassNotFoundException

Specified by:

readExternal in interface java.io.Externalizable

Throws:

java.io.IOException

java.lang.ClassNotFoundException

needsRedo

public final boolean needsRedo(Transaction xact)
                        throws StandardException

Returns true if this op should be redone during recovery redo, if so, get and latched the page.

Specified by:

needsRedo in interface Loggable

Parameters:

xact - The transaction trying to redo this operation

Returns:

true if operation needs redoing, false if not.

Throws:

StandardException - Standard Derby policy.

See Also:

Loggable.releaseResource(org.apache.derby.iapi.store.raw.Transaction)

reclaimPrepareLocks

public void reclaimPrepareLocks(Transaction t,
                                LockingPolicy locking_policy)
                         throws StandardException

reclaim locks associated with the changes in this log record.

Specified by:

reclaimPrepareLocks in interface RePreparable

Throws:

StandardException - Standard exception policy.

findpage

public final org.apache.derby.impl.store.raw.data.BasePage findpage(Transaction xact)
                                                             throws StandardException

Find the page the operation applies to and latch it, this only uses the segmentId, containerId, and pageId stored in this log record to find the page.

Returns:

null if container is dropped and committed (possibly stubbified), else return the latched page

Throws:

StandardException - Standard Derby policy.

getPage

public final Page getPage()

getPageVersion

public final long getPageVersion()