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

java.io.Externalizable, java.io.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
Format ID
LOGOP_UPDATE_FIELD
                the formatId is written by FormatIdOutputStream when this object is
                written out by writeObject
Purpose
update a field of a record on the page
Upgrade

Disk Layout
LogicalPageOperation	the super class
                doMeSlot(CompressedInt) the slot of the record being updated
                fieldId(CompressedInt)	the recordId of the record being updated

                OptionalData	The after image of the column (length included),
                                                follow by the old image of the record (length
                                                included).  If this is logically undoable, then the
                                                before image of the entire row is logged








Field Summary




protected  int
doMeSlot



           



protected  int
fieldId



           



protected  ByteArray
preparedLog



           


 
Fields inherited from class org.apache.derby.impl.store.raw.data.LogicalPageOperation
recordId, undo
 
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
UpdateFieldOperation()



           
UpdateFieldOperation(RawTransaction t,
                     BasePage page,
                     int slot,
                     int recordId,
                     int fieldId,
                     java.lang.Object column,
                     LogicalUndo undo)



           
 



Method Summary




 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(java.io.ObjectInput in)



          Read this in



 void
restoreLoggedRow(java.lang.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



 java.lang.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(java.io.ObjectOutput out)



           



private  void
writeOptionalDataToBuffer(RawTransaction t,
                          java.lang.Object column)



          Write the old column value and and new column value as optional data.


 
Methods inherited from class org.apache.derby.impl.store.raw.data.LogicalPageOperation
generateUndo, getContainer, getRecordHandle, reclaimPrepareLocks, resetRecordHandle
 
Methods inherited from class org.apache.derby.impl.store.raw.data.PageBasicOperation
findpage, getPage, getPageForRedoRecovery, getPageId, getPageVersion, group, needsRedo, 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



doMeSlot
protected int doMeSlot







fieldId
protected int fieldId







preparedLog
protected transient ByteArray preparedLog








Constructor Detail



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



Throws:
StandardException




UpdateFieldOperation
public UpdateFieldOperation()






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 LogicalPageOperation



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 LogicalPageOperation



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

Change the value of a field.


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





restoreLoggedRow
public void restoreLoggedRow(java.lang.Object[] row,
                             LimitObjectInput in)
                      throws StandardException,
                             java.io.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:
java.io.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,
                      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,
                                       java.lang.Object column)
                                throws StandardException,
                                       java.io.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:
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