PhysicalUndoOperation (Apache Derby V10.14 Internals)

java.lang.Object
- org.apache.derby.impl.store.raw.data.PageBasicOperation
- - 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 PageBasicOperation
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
Modifier and Type Field Description

private PhysicalPageOperation undoOp
The operation to be rolled back
- 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
- Fields inherited from class org.apache.derby.impl.store.raw.data.PageBasicOperation
  containerHdl, foundHere, page

Fields
Modifier and Type	Field	Description
`private PhysicalPageOperation`	`undoOp`	The operation to be rolled back

Constructor Summary

Constructors
Constructor	Description
`PhysicalUndoOperation()`	Return my format identifier.
`PhysicalUndoOperation(BasePage page)`
`PhysicalUndoOperation(BasePage page, PhysicalPageOperation op)`	Set up a compensation operation during run time rollback

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	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
`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
`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, 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.

Methods inherited from interface java.io.Externalizable
readExternal, writeExternal

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

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from class org.apache.derby.impl.store.raw.data.PageBasicOperation
findpage, getPage, getPageForRedoRecovery, getPageId, getPageVersion, needsRedo, readExternal, reclaimPrepareLocks, resetPageNumber, writeExternal

- Field Detail
  - undoOp
```
private transient PhysicalPageOperation undoOp
```
    The operation to be rolled back
- Constructor Detail
  - PhysicalUndoOperation
```
PhysicalUndoOperation(BasePage page)
```
  - PhysicalUndoOperation
```
PhysicalUndoOperation(BasePage page,
                      PhysicalPageOperation op)
```
    Set up a compensation operation during run time rollback
  - 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)
```
    Description copied from class: PageBasicOperation
    
    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
Overrides:: releaseResource in class PageBasicOperation

group
```
public int group()
```
Description copied from class: PageBasicOperation

A page operation is a RAWSTORE log record

Specified by:

group in interface Loggable

Overrides:

group in class PageBasicOperation

getPreparedLog
```
public final ByteArray getPreparedLog()
```
Description copied from class: PageBasicOperation

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

Overrides:

getPreparedLog in class PageBasicOperation

restoreMe
```
public void restoreMe(Transaction xact,
                      BasePage undoPage,
                      LogInstant CLRinstant,
                      LimitObjectInput in)
```
Description copied from class: PageBasicOperation

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

Specified by:

restoreMe in class PageBasicOperation

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.

Overrides:

toString in class PageBasicOperation

Format ID	LOGOP_PAGE_PHYSICAL_UNDO the formatId is written by FormatIdOutputStream when this object is written out by writeObject
Purpose
update a physical log operation
Upgrade

Disk Layout	PageBasicOperation the super class OptionalData none (compensation operation never have optional data)

Class PhysicalUndoOperation

Field Summary

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

Fields inherited from class org.apache.derby.impl.store.raw.data.PageBasicOperation

Constructor Summary

Method Summary

Methods inherited from interface java.io.Externalizable

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

Methods inherited from class java.lang.Object

Methods inherited from class org.apache.derby.impl.store.raw.data.PageBasicOperation

Field Detail

undoOp

Constructor Detail

PhysicalUndoOperation

PhysicalUndoOperation

PhysicalUndoOperation

Method Detail

getTypeFormatId

setUndoOp

doMe

releaseResource

group

getPreparedLog

restoreMe

toString