Class SetReservedSpaceOperation

java.lang.Object

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

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

All Implemented Interfaces:

Externalizable, Serializable, Formatable, TypedFormat, Loggable, RePreparable

public final class SetReservedSpaceOperation
extends PageBasicOperation

Represents shrinking of the reserved space of a particular row on a page. This operation is not undoable.

See Also:

• Serialized Form

Field Summary

Fields

Modifier and Type	Field	Description
protected int	doMeSlot
protected int	newValue
protected int	oldValue
protected int	recordId

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
SetReservedSpaceOperation()
SetReservedSpaceOperation(BasePage page, int slot, int recordId, int newValue, int oldValue)

Method Summary

Modifier and Type	Method	Description
void	doMe(Transaction xact, LogInstant instant, LimitObjectInput in)	Apply the change indicated by this operation and optional data.
int	getTypeFormatId()	Return my format identifier.
void	readExternal(ObjectInput in)	Read this in
void	restoreMe(Transaction xact, BasePage undoPage, LogInstant CLRinstant, LimitObjectInput in)	restore the before image of the page
String	toString()	DEBUG: Print self.
void	writeExternal(ObjectOutput out)

Methods inherited from class PageBasicOperation

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

Methods inherited from class Object

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

Field Details

doMeSlot

protected int doMeSlot

recordId

protected int recordId

newValue

protected int newValue

oldValue

protected int oldValue

Constructor Details

SetReservedSpaceOperation

SetReservedSpaceOperation(BasePage page,
 int slot,
 int recordId,
 int newValue,
 int oldValue)

SetReservedSpaceOperation

public SetReservedSpaceOperation()

Method Details

getTypeFormatId

public int getTypeFormatId()

Return my format identifier.

Returns:

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

writeExternal

public void writeExternal(ObjectOutput out)
                   throws IOException

Specified by:

writeExternal in interface Externalizable

Overrides:

writeExternal in class PageBasicOperation

Throws:

IOException

readExternal

public void readExternal(ObjectInput in)
                  throws IOException,
ClassNotFoundException

Read this in

Specified by:

readExternal in interface Externalizable

Overrides:

readExternal in class PageBasicOperation

Throws:

IOException - error reading from log stream

ClassNotFoundException - log stream corrupted

doMe

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

Description copied from interface: Loggable

Apply the change indicated by this operation and optional data. If this method fail, the system will be shut down because the log record has already been written to disk. Moreover, the log record will be replayed during recovery and this doMe method will be called on the same page again, so if it fails again, recovery will fail and the database cannot be started. So it is very important to make sure that every resource you need, such as disk space, has been acquired before the logAndDo method is called!
This method cannot acquire any resource (like latching of a page) since it is called underneath the logging system, ie., the log record has already been written to the log stream.

The available() method of in indicates how much data can be read, i.e. how much was originally written.

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)

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

toString

public String toString()

DEBUG: Print self.

Overrides:

toString in class PageBasicOperation