Module org.apache.jena.dboe.transaction

Package org.apache.jena.dboe.transaction.txn

Class TransactionalComponentWrapper

java.lang.Object

org.apache.jena.dboe.transaction.txn.TransactionalComponentWrapper

All Implemented Interfaces:

TransactionalComponent

public class TransactionalComponentWrapper
extends Object
implements TransactionalComponent

Constructor Summary

Constructors

Constructor	Description
TransactionalComponentWrapper(TransactionalComponent other)

Method Summary

Modifier and Type	Method	Description
void	abort(Transaction transaction)	Abort a transaction (undo the effect of a transaction)
void	attach(SysTransState systemState)	Set the current thread to be in the transaction.
void	begin(Transaction transaction)	Start a transaction; return an identifier for this components use.
void	cleanStart()	Indicate that no recovery is being done (the journal thinks everything was completed last time)
void	commit(Transaction transaction)	Commit a transaction (make durable).
void	commitEnd(Transaction transaction)	Signal all commits on all components are done and replay from the journal will not happen.
ByteBuffer	commitPrepare(Transaction transaction)	Prepare for a commit.
void	complete(Transaction transaction)	Finalization - the coordinator will not mention the transaction again.
SysTransState	detach()	Detach this component from the transaction of the current thread and return some internal state that can be used in a future call of TransactionalComponent.attach(SysTransState)
void	finishRecovery()	End of the recovery phase
ComponentId	getComponentId()	Every component instance must supplied a unique number.
boolean	promote(Transaction transaction)	Promote a component in a transaction.
void	recover(ByteBuffer ref)	Notification that ref was really committed and is being recovered.
void	shutdown()	Shutdown component, aborting any in-progress transactions.
void	startRecovery()
String	toString()

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Details

TransactionalComponentWrapper

public TransactionalComponentWrapper(TransactionalComponent other)

Method Details

startRecovery

public void startRecovery()

Specified by:

startRecovery in interface TransactionalComponent

recover

public void recover(ByteBuffer ref)

Description copied from interface: TransactionalComponent

Notification that ref was really committed and is being recovered.

Specified by:

recover in interface TransactionalComponent

Parameters:

ref - Same bytes as were written during prepare originally.

finishRecovery

public void finishRecovery()

Description copied from interface: TransactionalComponent

End of the recovery phase

Specified by:

finishRecovery in interface TransactionalComponent

cleanStart

public void cleanStart()

Description copied from interface: TransactionalComponent

Indicate that no recovery is being done (the journal thinks everything was completed last time)

Specified by:

cleanStart in interface TransactionalComponent

getComponentId

public ComponentId getComponentId()

Description copied from interface: TransactionalComponent

Every component instance must supplied a unique number. It is used to route journal entries to subsystems, including across restarts/recovery. Uniqueness scope is within the same TransactionCoordinator, and the same across restarts.

If a component imposes the rule of one-per-TransactionCoordinator, the same number can be used (if different from all other component type instances).

If a component can have multiple instances per TransactionCoordinator, for example indexes, each must have a unique instance id.

Specified by:

getComponentId in interface TransactionalComponent

begin

public void begin(Transaction transaction)

Description copied from interface: TransactionalComponent

Start a transaction; return an identifier for this components use.

Specified by:

begin in interface TransactionalComponent

promote

public boolean promote(Transaction transaction)

Description copied from interface: TransactionalComponent

Promote a component in a transaction.

May return "false" for "can't do that" if the transaction can not be promoted.

May throw UnsupportedOperationException if promotion is not supported.

Specified by:

promote in interface TransactionalComponent

commitPrepare

public ByteBuffer commitPrepare(Transaction transaction)

Description copied from interface: TransactionalComponent

Prepare for a commit. Returns some bytes that will be written to the journal. The journal remains valid until TransactionalComponent.commitEnd(org.apache.jena.dboe.transaction.txn.Transaction) is called.

Specified by:

commitPrepare in interface TransactionalComponent

commit

public void commit(Transaction transaction)

Description copied from interface: TransactionalComponent

Commit a transaction (make durable). The transaction will commit and not abort. Other components may not have committed yet and recovery may occur still causing replay of the commit step.

Specified by:

commit in interface TransactionalComponent

commitEnd

public void commitEnd(Transaction transaction)

Description copied from interface: TransactionalComponent

Signal all commits on all components are done and replay from the journal will not happen. The component can clear up now.

Specified by:

commitEnd in interface TransactionalComponent

abort

public void abort(Transaction transaction)

Description copied from interface: TransactionalComponent

Abort a transaction (undo the effect of a transaction)

Specified by:

abort in interface TransactionalComponent

complete

public void complete(Transaction transaction)

Description copied from interface: TransactionalComponent

Finalization - the coordinator will not mention the transaction again.

Specified by:

complete in interface TransactionalComponent

detach

public SysTransState detach()

Description copied from interface: TransactionalComponent

Detach this component from the transaction of the current thread and return some internal state that can be used in a future call of TransactionalComponent.attach(SysTransState)

After this call, the component is not in a transaction but the existing transaction still exists. The thread may start a new transaction; that transaction is completely independent of the detached transaction.

Returns null if the current thread not in a transaction. The component may return null to indicate it has no state. The return system state should be used in a call to TransactionalComponent.attach(SysTransState) and the transaction ended in the usual way.

Specified by:

detach in interface TransactionalComponent

attach

public void attach(SysTransState systemState)

Description copied from interface: TransactionalComponent

Set the current thread to be in the transaction. The systemState must be obtained from a call of TransactionalComponent.detach(). This method can only be called once per systemState.

Specified by:

attach in interface TransactionalComponent

shutdown

public void shutdown()

Description copied from interface: TransactionalComponent

Shutdown component, aborting any in-progress transactions. This operation is not guaranteed to be called.

Specified by:

shutdown in interface TransactionalComponent

toString

public String toString()

Overrides:

toString in class Object