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

Class RemoveFile

java.lang.Object

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

All Implemented Interfaces:

java.security.PrivilegedExceptionAction, Serviceable

final class RemoveFile
extends java.lang.Object
implements Serviceable, java.security.PrivilegedExceptionAction

Field Summary

Fields

Modifier and Type	Field and Description
private StorageFile	fileToGo

Fields inherited from interface org.apache.derby.iapi.services.daemon.Serviceable

DONE, REQUEUE

Constructor Summary

Constructors

Constructor and Description
RemoveFile(StorageFile fileToGo)

Method Summary

Methods

Modifier and Type	Method and Description
int	performWork(ContextManager context) Do whatever it is that you want the daemon to do for you.
java.lang.Object	run()
boolean	serviceASAP() If this work should be done as soon as possible, then return true.
boolean	serviceImmediately() File deletion is a quick operation and typically releases substantial amount of space very quickly, this work should be done on the user thread.

Methods inherited from class java.lang.Object

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

Field Detail

fileToGo

private final StorageFile fileToGo

Constructor Detail

RemoveFile

RemoveFile(StorageFile fileToGo)

Method Detail

performWork

public int performWork(ContextManager context)
                throws StandardException

Description copied from interface: Serviceable

Do whatever it is that you want the daemon to do for you. There may be multiple daemon objects on different thread calling performWork at the same time. The DaemonService will always call performWork with a context manager set up. the DaemonService will clean up the context if an exception is thrown. However, it is up to performWork to manage its own transaction. If you start a transaction in performWork, you must commit or abort it at the end. You may leave the transaction open so that other serviceable may use the transaction and context without starting a new one. On the same token, there may already be an opened transaction on the context. Serviceable performWork should always check the state of the context before use. A Serviceable object should be well behaved while it is performing the daemon work, i.e., it should not take too many resources or hog the CPU for too long or deadlock with anyone else.

Specified by:

performWork in interface Serviceable

Parameters:

context - the contextManager set up by the DaemonService. There may or may not be the necessary context on it, depending on which other Serviceable object it has done work for.

Returns:

the return status is only significant if the Serviceable client was enqueued instead of subscribed. For subscribed client, the return status is ignored. For enqueue client, it returns DONE or REQUEUE. If a REQUEUEd is returned, it would be desirable if this should not be serviceASAP, although no harm is done if this still maintains that this should be serviced ASAP ...

Throws:

StandardException - Standard Derby exception policy

MT - depends on the work. Be wary of multiple DaemonService thread calling at the same time if you subscribe or enqueue multiple times.

serviceASAP

public boolean serviceASAP()

Description copied from interface: Serviceable

If this work should be done as soon as possible, then return true. If it doesn't make any difference if it is done sooner rather than later, then return false. The difference is whether or not the daemon service will be notified to work on this when this work is enqueued or subscribed, in case the serviceable work is put together but not sent to the daemon service directly, like in post commit processing

MT - MT safe

Specified by:

serviceASAP in interface Serviceable

serviceImmediately

public boolean serviceImmediately()

File deletion is a quick operation and typically releases substantial amount of space very quickly, this work should be done on the user thread.

Specified by:

serviceImmediately in interface Serviceable

Returns:

true, this work needs to done on user thread.

run

public java.lang.Object run()
                     throws StandardException

Specified by:

run in interface java.security.PrivilegedExceptionAction

Throws:

StandardException