Class PhysicalPageOperation

java.lang.Object
org.apache.derby.impl.store.raw.data.PageBasicOperation
org.apache.derby.impl.store.raw.data.PhysicalPageOperation
All Implemented Interfaces:
Externalizable, Serializable, Formatable, TypedFormat, Loggable, RePreparable, Undoable
Direct Known Subclasses:
AllocPageOperation, ChainAllocPageOperation, CompressSpacePageOperation, CopyRowsOperation, InitPageOperation, InvalidatePageOperation, PurgeOperation, UpdateOperation

abstract class PhysicalPageOperation extends PageBasicOperation implements Undoable
An abstract class that is used for physical log operation. A physical log operation is one where the undo of the operation must be applied to the same page as the original operation, and the undo operation must store the byte image of the row(s) changed to its before image. (If a logical page operation happened to the page or if another transaction altered other rows on the page, the undo of this operation will only restore the before image of the row(s) affected).
  • Constructor Details

    • PhysicalPageOperation

      PhysicalPageOperation(BasePage page)
    • PhysicalPageOperation

      public PhysicalPageOperation()
  • Method Details

    • generateUndo

      public Compensation generateUndo(Transaction xact, LimitObjectInput in) throws StandardException
      Generate a Compensation (PageUndoOperation) that will rollback the changes of this page operation. If this Page operation cannot or need not be rolled back (redo only), overwrite this function to return null.

      Note
      For operation that needs logical undo, use LogicalUndoOperation instead This implementation just finds the same page that the PageOperation was applied on - i.e., only works for undo on the same page.

      During recovery redo, the logging system is page oriented and will use the pageID stored in the PageUndoOperation to find the page. The page will be latched and released using the default findpage and releaseResource - this.releaseResource() will still be called so it has to know not to release any resource it did not acquire.

      Specified by:
      generateUndo in interface Undoable
      Parameters:
      xact - the transaction doing the compensating
      in - optional input
      Returns:
      the compensation operation that will rollback this change
      Throws:
      StandardException - Standard Derby policy.
      See Also:
    • undoMe

      public abstract void undoMe(Transaction xact, BasePage undoPage, LogInstant CLRinstant, LimitObjectInput in) throws StandardException, IOException
      Undo the change indicated by this log operation and optional data. The page the undo should apply to is the latched undoPage, the recordId is the same as the roll forward operation.
      In this RawStore implementation, should only only be called via CompOp.doMe.

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

      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:
      IOException - Can be thrown by any of the methods of ObjectInput.
      StandardException - Standard Derby policy.