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

java.lang.Object
  org.apache.derby.impl.store.raw.data.PageBasicOperation
      org.apache.derby.impl.store.raw.data.PhysicalPageOperation
          org.apache.derby.impl.store.raw.data.PurgeOperation

All Implemented Interfaces:

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

public final class PurgeOperation
extends PhysicalPageOperation

USE WITH EXTREME Caution: Purge records from a Page. Represents purging of a range of rows from the page.

See Also:
Page.purgeAtSlot(int, int, boolean), 
Serialized Form
Format ID
LOGOP_PURGE
                the formatId is written by FormatIdOutputStream when this object is
                written out by writeObject
Purpose
purge num_rows from the page
Upgrade

Disk Layout
PagePhysicalOperation	the super class
                slot(CompressedInt)	the slot to start purging
                num_rows(CompressedInt)	number of rows rows to purge
                recordIds(CompressedInt[num_rows]) the recordIds of the purged rows

                OptionalData	the before images of the rows that were purged








Field Summary




protected  int
num_rows



           



protected  ByteArray
preparedLog



           



protected  int[]
recordIds



           



protected  int
slot



           


 
Fields inherited from class org.apache.derby.impl.store.raw.data.PageBasicOperation
containerHdl, foundHere, page
 
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
PurgeOperation()



           
PurgeOperation(RawTransaction t,
               BasePage page,
               int slot,
               int num_rows,
               int[] recordIds,
               boolean needDataLogged)



           
 



Method Summary




 void
doMe(Transaction xact,
     LogInstant instant,
     LimitObjectInput in)



          Apply the purge operation to the page.



 ByteArray
getPreparedLog()



          the default for optional data is set to null.



 int
getTypeFormatId()



          Return my format identifier.



 void
readExternal(java.io.ObjectInput in)



          Read this in



 void
restoreMe(Transaction xact,
          BasePage undoPage,
          LogInstant CLRInstant,
          LimitObjectInput in)



          restore the before image of the page



 java.lang.String
toString()



          DEBUG: Print self.



 void
undoMe(Transaction xact,
       BasePage undoPage,
       LogInstant CLRInstant,
       LimitObjectInput in)



          Undo the purge operation on the page.



 void
writeExternal(java.io.ObjectOutput out)



           



private  void
writeOptionalDataToBuffer(RawTransaction t,
                          boolean needDataLogged)



          Write out the purged record from the page.


 
Methods inherited from class org.apache.derby.impl.store.raw.data.PhysicalPageOperation
generateUndo
 
Methods inherited from class org.apache.derby.impl.store.raw.data.PageBasicOperation
findpage, getPage, getPageForRedoRecovery, getPageId, getPageVersion, group, needsRedo, reclaimPrepareLocks, releaseResource, resetPageNumber
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 
Methods inherited from interface org.apache.derby.iapi.store.raw.Loggable
group, needsRedo, releaseResource
 





Field Detail



slot
protected int slot







num_rows
protected int num_rows







recordIds
protected int[] recordIds







preparedLog
protected transient ByteArray preparedLog








Constructor Detail



PurgeOperation
public PurgeOperation(RawTransaction t,
                      BasePage page,
                      int slot,
                      int num_rows,
                      int[] recordIds,
                      boolean needDataLogged)
               throws StandardException



Throws:
StandardException




PurgeOperation
public PurgeOperation()






Method Detail



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


Specified by:
writeExternal in interface java.io.Externalizable
Overrides:
writeExternal in class PageBasicOperation



Throws:
java.io.IOException





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

Read this in


Specified by:
readExternal in interface java.io.Externalizable
Overrides:
readExternal in class PageBasicOperation



Throws:
java.io.IOException - error reading from log stream
java.lang.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,
                 java.io.IOException

Apply the purge operation to the page.


Parameters:
xact - the Transaction
instant - the log instant of this operation
in - optional data
Throws:
java.io.IOException - Can be thrown by any of the methods of ObjectInput.
StandardException - Standard Derby policy.
See Also:
Loggable.doMe(org.apache.derby.iapi.store.raw.Transaction, org.apache.derby.iapi.store.raw.log.LogInstant, org.apache.derby.iapi.services.io.LimitObjectInput)





undoMe
public void undoMe(Transaction xact,
                   BasePage undoPage,
                   LogInstant CLRInstant,
                   LimitObjectInput in)
            throws StandardException,
                   java.io.IOException

Undo the purge operation on the page.


Specified by:
undoMe in class PhysicalPageOperation


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:
java.io.IOException - Can be thrown by any of the methods of ObjectInput.
StandardException - Standard Derby policy.
See Also:
PhysicalPageOperation.undoMe(org.apache.derby.iapi.store.raw.Transaction, org.apache.derby.impl.store.raw.data.BasePage, org.apache.derby.iapi.store.raw.log.LogInstant, org.apache.derby.iapi.services.io.LimitObjectInput)





restoreMe
public void restoreMe(Transaction xact,
                      BasePage undoPage,
                      LogInstant CLRInstant,
                      LimitObjectInput in)
               throws StandardException,
                      java.io.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
java.io.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,
                                       boolean needDataLogged)
                                throws StandardException,
                                       java.io.IOException

Write out the purged record from the page.  Used for undo only.



Throws:
java.io.IOException - Can be thrown by any of the methods of ObjectOutput.
StandardException - Standard Derby policy.





toString
public java.lang.String toString()

DEBUG: Print self.


Overrides:
toString in class PageBasicOperation