Class UpdateFieldOperation

java.lang.Object

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

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

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

All Implemented Interfaces:

Externalizable, Serializable, Formatable, TypedFormat, Loggable, LogicalUndoable, RePreparable, Undoable

public final class UpdateFieldOperation
extends LogicalPageOperation

Represents the update of a particular field of a row on a page.

See Also:

• Serialized Form

Field Summary

Fields

Modifier and Type	Field	Description
protected int	doMeSlot
protected int	fieldId
protected ByteArray	preparedLog

Fields inherited from class LogicalPageOperation

recordId, undo

Fields inherited from class PageBasicOperation

containerHdl, foundHere, page

Fields inherited from interface Loggable

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

Constructor Summary

Constructors

Constructor	Description
UpdateFieldOperation()
UpdateFieldOperation(RawTransaction t, BasePage page, int slot, int recordId, int fieldId, Object column, LogicalUndo undo)

Method Summary

Modifier and Type	Method	Description
void	doMe(Transaction xact, LogInstant instant, LimitObjectInput in)	Change the value of a field.
ByteArray	getPreparedLog()	the default for optional data is set to null.
int	getTypeFormatId()	Return my format identifier.
void	readExternal(ObjectInput in)	Read this in
void	restoreLoggedRow(Object[] row, LimitObjectInput in)	Restore the row stored in the optional data of the log record.
void	restoreMe(Transaction xact, BasePage undoPage, LogInstant CLRInstant, LimitObjectInput in)	restore the before image of the page
String	toString()	DEBUG: Print self.
void	undoMe(Transaction xact, BasePage undoPage, int undoRecordId, LogInstant CLRInstant, LimitObjectInput in)	Restore field to its old value.
void	writeExternal(ObjectOutput out)
private void	writeOptionalDataToBuffer(RawTransaction t, Object column)	Write the old column value and and new column value as optional data.

Methods inherited from class LogicalPageOperation

generateUndo, getContainer, getRecordHandle, reclaimPrepareLocks, resetRecordHandle

Methods inherited from class PageBasicOperation

findpage, getPage, getPageForRedoRecovery, getPageId, getPageVersion, group, needsRedo, releaseResource, resetPageNumber

Methods inherited from class Object

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

Methods inherited from interface Loggable

group, needsRedo, releaseResource

Field Details

doMeSlot

protected int doMeSlot

fieldId

protected int fieldId

preparedLog

protected transient ByteArray preparedLog

Constructor Details

UpdateFieldOperation

UpdateFieldOperation(RawTransaction t,
 BasePage page,
 int slot,
 int recordId,
 int fieldId,
 Object column,
 LogicalUndo undo)
              throws StandardException

Throws:

StandardException

UpdateFieldOperation

public UpdateFieldOperation()

Method Details

writeExternal

public void writeExternal(ObjectOutput out)
                   throws IOException

Specified by:

writeExternal in interface Externalizable

Overrides:

writeExternal in class LogicalPageOperation

Throws:

IOException

readExternal

public void readExternal(ObjectInput in)
                  throws IOException,
ClassNotFoundException

Read this in

Specified by:

readExternal in interface Externalizable

Overrides:

readExternal in class LogicalPageOperation

Throws:

IOException - error reading from log stream

ClassNotFoundException - log stream corrupted

getTypeFormatId

public int getTypeFormatId()

Return my format identifier.

Returns:

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

doMe

public void doMe(Transaction xact,
 LogInstant instant,
 LimitObjectInput in)
          throws StandardException,
IOException

Change the value of a field.

Parameters:

xact - the Transaction

instant - the log instant of this operation

in - optional data

Throws:

IOException - Can be thrown by any of the methods of ObjectInput.

StandardException - Standard Derby policy.

See Also:

• Loggable.doMe(Transaction, LogInstant, LimitObjectInput)

undoMe

public void undoMe(Transaction xact,
 BasePage undoPage,
 int undoRecordId,
 LogInstant CLRInstant,
 LimitObjectInput in)
            throws StandardException,
IOException

Restore field to its old value.

Specified by:

undoMe in class LogicalPageOperation

Parameters:

xact - the Transaction doing the rollback

undoPage - the page to rollback changes on

undoRecordId - the recordId to rollback changes on

CLRInstant - the log instant of this (PageUndo) operation

in - optional data for the rollback operation

Throws:

IOException - Can be thrown by any of the methods of ObjectInput.

StandardException - Standard Derby policy.

See Also:

• LogicalPageOperation.undoMe(Transaction, BasePage, int, LogInstant, LimitObjectInput)

restoreLoggedRow

public void restoreLoggedRow(Object[] row,
 LimitObjectInput in)
                      throws StandardException,
IOException

Restore the row stored in the optional data of the log record.

Parameters:

row - an IN/OUT parameter, caller passed in the row with the correct column number and type, the log operation will restore the row with the optional data stored in the log record.

Throws:

IOException - error reading from log stream

StandardException - Standard Derby error policy

See Also:

• LogicalUndo

restoreMe

public void restoreMe(Transaction xact,
 BasePage undoPage,
 LogInstant CLRInstant,
 LimitObjectInput in)
               throws StandardException,
IOException

restore the before image of the page

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

Throws:

StandardException - Standard Derby Error Policy

IOException - problem reading the complete log record from the input stream

getPreparedLog

public 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

writeOptionalDataToBuffer

private void writeOptionalDataToBuffer(RawTransaction t,
 Object column)
                                throws StandardException,
IOException

Write the old column value and and new column value as optional data. If logical undo, writes out the entire row's before image.

Throws:

IOException - Can be thrown by any of the methods of ObjectOutput.

StandardException - Standard Derby policy.

toString

public String toString()

DEBUG: Print self.

Overrides:

toString in class PageBasicOperation