Top Description Fields Constructors Methods
org.apache.derby.impl.store.raw.data

pack-priv abstract Class PageBasicOperation

extends Object
implements Loggable, RePreparable
Class Inheritance
All Implemented Interfaces
org.apache.derby.iapi.store.raw.RePreparable, org.apache.derby.iapi.store.raw.Loggable, org.apache.derby.iapi.services.io.Formatable, org.apache.derby.iapi.services.io.TypedFormat, java.io.Externalizable, java.io.Serializable
Known Direct Subclasses
org.apache.derby.impl.store.raw.data.PhysicalPageOperation, org.apache.derby.impl.store.raw.data.PhysicalUndoOperation, org.apache.derby.impl.store.raw.data.SetReservedSpaceOperation, org.apache.derby.impl.store.raw.data.LogicalPageOperation, org.apache.derby.impl.store.raw.data.LogicalUndoOperation
Imports
org.apache.derby.shared.common.reference.SQLState, org.apache.derby.iapi.store.raw.LockingPolicy, .Loggable, .Page, .RePreparable, .Transaction, .PageKey, .RawStoreFactory, org.apache.derby.iapi.store.raw.xact.RawTransaction, org.apache.derby.iapi.store.raw.data.RawContainerHandle, org.apache.derby.iapi.store.raw.log.LogInstant, org.apache.derby.shared.common.error.StandardException, org.apache.derby.shared.common.sanity.SanityManager, org.apache.derby.iapi.services.io.CompressedNumber, .LimitObjectInput, org.apache.derby.iapi.util.ByteArray, org.apache.derby.iapi.services.property.PropertyUtil, java.io.ObjectOutput, .ObjectInput, .IOException
A PageBasicOperation changed the content of a page, this is the root class of all page oriented operation. Each PageBasicOperation record change(s) that apply to one and only one page. The pageID that is changed must be recorded in the log operation - in other words, redo must be physical (or more correctly, in Gray's term, physiological, since changes are logical within a page).
Undo can be logical, but the undo logic must be hidden in generateUndo. By the time a compensation operation is logged as a LogOperation, the page that needs roll back must be determined. 




See Also

Loggable






Field Summary




Modifier and TypeField and Description

protected transient RawContainerHandle
containerHdl




protected transient boolean
foundHere




protected transient BasePage
page




private PageKey
pageId




private long
pageVersion










Constructor Summary




AccessConstructor and Description

pack-priv
PageBasicOperation(BasePage page)




pack-priv
PageBasicOperation()










Method Summary




Modifier and TypeMethod and Description

public final BasePage
Returns:
 null if container is dropped and committed (possibly
	stubbified), else return the latched page
findpage(Transaction xact)
Find the page the operation applies to and latch it, this only
    uses the segmentId, containerId, and pageId stored in this log
	record to find the page.



public final Page
getPage()




protected BasePage
getPageForRedoRecovery(Transaction xact)
Subclass (e.g., init page) that wishes to do something about missing
pages in load tran should override this method to return the page



protected final PageKey
getPageId()




public final long
getPageVersion()




public ByteArray
getPreparedLog()
Implements org.apache.derby.iapi.store.raw.Loggable.getPreparedLog.


the default for optional data is set to null.



public int
group()
Implements org.apache.derby.iapi.store.raw.Loggable.group.


A page operation is a RAWSTORE log record



public final boolean
needsRedo(Transaction 
The transaction trying to redo this operation
xact)
Implements org.apache.derby.iapi.store.raw.Loggable.needsRedo.


Returns true if this op should be redone during recovery redo,
    if so, get and latched the page.



public void
readExternal(ObjectInput 
the stream to read data from in order to restore the object
in)
Implements java.io.Externalizable.readExternal.


The object implements the readExternal method to restore its
contents by calling the methods of DataInput for primitive
types and readObject for objects, strings and arrays.



public void
reclaimPrepareLocks(Transaction t, LockingPolicy locking_policy)
Implements org.apache.derby.iapi.store.raw.RePreparable.reclaimPrepareLocks.


reclaim locks associated with the changes in this log record.



public void
releaseResource(Transaction xact)
Implements org.apache.derby.iapi.store.raw.Loggable.releaseResource.


Release latched page and any other resources acquired during a previous
findpage, safe to call multiple times.</nl>



protected final void
resetPageNumber(long pageNumber)
Reset the pageNumber



public abstract void
restoreMe(Transaction 
the Transaction doing the rollback
xact, BasePage 
the page to rollback changes on
undoPage, LogInstant 
the log instant of this (PageUndo) operation
CLRinstant, LimitObjectInput 
optional data for the rollback operation
in)
Undo the change indicated by this log operation and optional data.



public String
toString()
Overrides java.lang.Object.toString.


Returns a string representation of the object.



public void
writeExternal(ObjectOutput 
the stream to write the object to
out)
Implements java.io.Externalizable.writeExternal.


The object implements the writeExternal method to save its contents
by calling the methods of DataOutput for its primitive values or
calling the writeObject method of ObjectOutput for objects, strings,
and arrays.







Inherited from java.lang.Object:


cloneequalsfinalizegetClasshashCodenotifynotifyAllwaitwaitwait







Field Detail




containerHdlback to summary

protected transient RawContainerHandle containerHdl






foundHereback to summary

protected transient boolean foundHere






pageback to summary

protected transient BasePage page






pageIdback to summary

private PageKey pageId






pageVersionback to summary

private long pageVersion








Constructor Detail




PageBasicOperationback to summary

pack-priv PageBasicOperation(BasePage page)






PageBasicOperationback to summary

pack-priv PageBasicOperation()








Method Detail




findpageback to summary

public final BasePage findpage(Transaction xact) throws StandardException
Find the page the operation applies to and latch it, this only
    uses the segmentId, containerId, and pageId stored in this log
	record to find the page.



Returns:BasePage
null if container is dropped and committed (possibly
	stubbified), else return the latched page

Exceptions



StandardException:
Standard Derby policy.










getPageback to summary

public final Page getPage()






getPageForRedoRecoveryback to summary

protected BasePage getPageForRedoRecovery(Transaction xact) throws StandardException
Subclass (e.g., init page) that wishes to do something about missing
pages in load tran should override this method to return the page



Exceptions



StandardException:
Derby Standard error policy










getPageIdback to summary

protected final PageKey getPageId()






getPageVersionback to summary

public final long getPageVersion()






getPreparedLogback to summary

public ByteArray getPreparedLog() throws StandardException
Implements org.apache.derby.iapi.store.raw.Loggable.getPreparedLog.

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.





Exceptions



StandardException:
Standard Derby policy.










groupback to summary

public int group()
Implements org.apache.derby.iapi.store.raw.Loggable.group.

A page operation is a RAWSTORE log record






needsRedoback to summary

public final boolean needsRedo(Transaction xact) throws StandardException
Implements org.apache.derby.iapi.store.raw.Loggable.needsRedo.

Returns true if this op should be redone during recovery redo,
    if so, get and latched the page.



Parameters



xact:Transaction
Doc from org.apache.derby.iapi.store.raw.Loggable.needsRedo.

The transaction trying to redo this operation



Returns:boolean
Doc from org.apache.derby.iapi.store.raw.Loggable.needsRedo.

true if operation needs redoing, false if not.

Exceptions



StandardException:
Standard Derby policy.










readExternalback to summary

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

Doc from java.io.Externalizable.readExternal.

The object implements the readExternal method to restore its
contents by calling the methods of DataInput for primitive
types and readObject for objects, strings and arrays.  The
readExternal method must read the values in the same sequence
and with the same types as were written by writeExternal.



Parameters



in:ObjectInput
the stream to read data from in order to restore the object



Exceptions



IOException:
if I/O errors occur

ClassNotFoundException:
If the class for an object being restored cannot be found.










reclaimPrepareLocksback to summary

public void reclaimPrepareLocks(Transaction t, LockingPolicy locking_policy) throws StandardException
Implements org.apache.derby.iapi.store.raw.RePreparable.reclaimPrepareLocks.

reclaim locks associated with the changes in this log record.





Exceptions



StandardException:
Standard exception policy.










releaseResourceback to summary

public void releaseResource(Transaction xact)
Implements org.apache.derby.iapi.store.raw.Loggable.releaseResource.

Release latched page and any other resources acquired during a previous
findpage, safe to call multiple times.

In this RawStore implementataion, resource is acquired by a log
operation in one of two places


  •  during runtime or recovery undo in PageOperation.generateUndo()

  •  during recovery redo in PageBasicOperation.needsRedo()



    • 

    

    resetPageNumberback to summary

    protected final void resetPageNumber(long pageNumber)
    Reset the pageNumber


    

    

    restoreMeback to summary

    public abstract void restoreMe(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 undoPage must be the same page as the doMe page and the undo
operation must restore the before image of the row that changed.  


     this can only be used under special circumstances: namely
table level locking, and no internal or nested transaction, and all
operations are rollec back with restoreMe instead of undoMe.


    This method is here to support BeforeImageLogging

    

    Parameters

    

    xact:Transaction
    the Transaction doing the rollback

    undoPage:BasePage
    the page to rollback changes on

    CLRinstant:LogInstant
    the log instant of this (PageUndo) operation

    in:LimitObjectInput
    optional data for the rollback operation

    

    Exceptions

    

    StandardException:
    Standard Derby policy.

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

    

    


    

    

    toStringback to summary

    public String toString()
    Overrides java.lang.Object.toString.

    Doc from java.lang.Object.toString.

    Returns a string representation of the object. 
	
Satisfying this method's contract implies a non-null
result must be returned.

    

    Returns:String
    a string representation of the object

    


    

    

    writeExternalback to summary

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

    Doc from java.io.Externalizable.writeExternal.

    The object implements the writeExternal method to save its contents
by calling the methods of DataOutput for its primitive values or
calling the writeObject method of ObjectOutput for objects, strings,
and arrays.

    

    Parameters

    

    out:ObjectOutput
    the stream to write the object to

    

    Exceptions

    

    IOException:
    Includes any I/O exceptions that may occur