org.apache.jena.dboe.transaction.txn

Class Transaction

java.lang.Object

org.apache.jena.dboe.transaction.txn.Transaction

All Implemented Interfaces:

TransactionInfo

public final class Transaction
extends Object
implements TransactionInfo

A transaction as the composition of actions on components. Works in conjunction with the TransactionCoordinator to provide the transaction lifecycle.

See Also:

TransactionCoordinator, TransactionalComponent

Constructor Summary

Constructors

Constructor and Description
Transaction(TransactionCoordinator txnMgr, TxnType txnType, ReadWrite readWrite, TxnId txnId, long dataVersion, List<org.apache.jena.dboe.transaction.txn.SysTrans> components)

Method Summary

Modifier and Type	Method and Description
void	abort()
void	begin()
void	commit()
void	end()
void	ensureWriteTxn() Require a WRITE transaction - includes trying to promote.
long	getDataVersion() Each transaction is allocated a serialization point by the transaction coordinator.
ReadWrite	getMode() What mode is this transaction? This may change from READ to WRITE in a transactions lifetime.
TxnState	getState() The transaction lifecycle state
TxnId	getTxnId() Get the transaction id for this transaction.
TxnType	getTxnType() What type is this transaction? This is the initial TxnType and does not change during a transaction's lifetime.
boolean	hasFinalised() Has the transaction gone through all lifecycle states?
boolean	hasFinished() Has the transaction finished (has commit/abort/end been called)?
boolean	hasStarted() Has the transaction started?
boolean	isActiveTxn() Is this a view of a transaction that is active? Equivalent to getState() != INACTIVE
boolean	isReadTxn() Is this a READ transaction? Convenience operation equivalent to (getMode() == READ)
boolean	isWriteTxn() Is this a WRITE transaction? Convenience operation equivalent to (getMode() == WRITE)
void	notifyUpdate()
void	prepare()
boolean	promote()
boolean	promote(boolean readCommitted)
void	requireWriteTxn() Require a WRITE transaction - do not try to promote.

Methods inherited from class java.lang.Object

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

Constructor Detail

Transaction

public Transaction(TransactionCoordinator txnMgr,
                   TxnType txnType,
                   ReadWrite readWrite,
                   TxnId txnId,
                   long dataVersion,
                   List<org.apache.jena.dboe.transaction.txn.SysTrans> components)

Method Detail

getState

public TxnState getState()

Description copied from interface: TransactionInfo

The transaction lifecycle state

Specified by:

getState in interface TransactionInfo

getDataVersion

public long getDataVersion()

Each transaction is allocated a serialization point by the transaction coordinator. Normally, this is related to this number and it increases over time as the data changes. Two readers can have the same serialization point - they are working with the same view of the data.

Specified by:

getDataVersion in interface TransactionInfo

begin

public void begin()

promote

public boolean promote()

promote

public boolean promote(boolean readCommitted)

notifyUpdate

public void notifyUpdate()

prepare

public void prepare()

commit

public void commit()

abort

public void abort()

end

public void end()

requireWriteTxn

public void requireWriteTxn()

Require a WRITE transaction - do not try to promote.

ensureWriteTxn

public void ensureWriteTxn()

Require a WRITE transaction - includes trying to promote.

hasStarted

public boolean hasStarted()

Description copied from interface: TransactionInfo

Has the transaction started?

Specified by:

hasStarted in interface TransactionInfo

hasFinished

public boolean hasFinished()

Description copied from interface: TransactionInfo

Has the transaction finished (has commit/abort/end been called)?

Specified by:

hasFinished in interface TransactionInfo

hasFinalised

public boolean hasFinalised()

Description copied from interface: TransactionInfo

Has the transaction gone through all lifecycle states?

Specified by:

hasFinalised in interface TransactionInfo

getTxnId

public TxnId getTxnId()

Description copied from interface: TransactionInfo

Get the transaction id for this transaction. Unique within this OS process (JVM) at least .

Specified by:

getTxnId in interface TransactionInfo

getTxnType

public TxnType getTxnType()

Description copied from interface: TransactionInfo

What type is this transaction? This is the initial TxnType and does not change during a transaction's lifetime.

Specified by:

getTxnType in interface TransactionInfo

getMode

public ReadWrite getMode()

Description copied from interface: TransactionInfo

What mode is this transaction? This may change from READ to WRITE in a transactions lifetime.

Specified by:

getMode in interface TransactionInfo

isReadTxn

public boolean isReadTxn()

Is this a READ transaction? Convenience operation equivalent to (getMode() == READ)

Specified by:

isReadTxn in interface TransactionInfo

isWriteTxn

public boolean isWriteTxn()

Is this a WRITE transaction? Convenience operation equivalent to (getMode() == WRITE)

Specified by:

isWriteTxn in interface TransactionInfo

isActiveTxn

public boolean isActiveTxn()

Description copied from interface: TransactionInfo

Is this a view of a transaction that is active? Equivalent to getState() != INACTIVE

Specified by:

isActiveTxn in interface TransactionInfo