com.amazon.carbonado.txn

Class TransactionScope<Txn>

java.lang.Object

com.amazon.carbonado.txn.TransactionScope<Txn>

Type Parameters:

Txn - Transaction implementation

public class TransactionScope<Txn>
extends java.lang.Object

Container of thread local, scoped transactions.

Since:

1.2

Author:

Brian S O'Neill

See Also:

TransactionManager

Method Summary

Methods

Modifier and Type	Method and Description
void	attach() Attach this scope to the current thread, if it has been detached.
Transaction	enter(IsolationLevel level) Enters a new transaction scope which becomes the active transaction.
Transaction	enterTop(IsolationLevel level) Enters a new top-level transaction scope which becomes the active transaction.
IsolationLevel	getIsolationLevel() Returns the isolation level of the active transaction, or null if there is no active transaction.
java.util.concurrent.locks.Lock	getLock() Returns lock used by TransactionScope.
Txn	getTxn() Returns the implementation for the active transaction, or null if there is no active transaction.
boolean	isForUpdate() Returns true if an active transaction exists and it is for update.
<S extends Storable> void	register(java.lang.Class<S> type, Cursor<S> cursor) Registers the given cursor against the active transaction, allowing it to be closed on transaction exit or transaction manager close.
<S extends Storable> void	unregister(java.lang.Class<S> type, Cursor<S> cursor) Unregisters a previously registered cursor.

Methods inherited from class java.lang.Object

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

Method Detail

enter

public Transaction enter(IsolationLevel level)

Enters a new transaction scope which becomes the active transaction.

Parameters:

level - desired isolation level (may be null)

Throws:

java.lang.UnsupportedOperationException - if isolation level higher than supported by repository

enterTop

public Transaction enterTop(IsolationLevel level)

Enters a new top-level transaction scope which becomes the active transaction.

Parameters:

level - desired isolation level (may be null)

Throws:

java.lang.UnsupportedOperationException - if isolation level higher than supported by repository

register

public <S extends Storable> void register(java.lang.Class<S> type,
                                 Cursor<S> cursor)

Registers the given cursor against the active transaction, allowing it to be closed on transaction exit or transaction manager close. If there is no active transaction in scope, the cursor is registered as not part of a transaction. Cursors should register when created.

unregister

public <S extends Storable> void unregister(java.lang.Class<S> type,
                                   Cursor<S> cursor)

Unregisters a previously registered cursor. Cursors should unregister when closed.

getLock

public java.util.concurrent.locks.Lock getLock()

Returns lock used by TransactionScope. While holding lock, operations are suspended.

getTxn

public Txn getTxn()
           throws java.lang.Exception

Returns the implementation for the active transaction, or null if there is no active transaction.

Throws:

java.lang.Exception - thrown by createTxn or reuseTxn

isForUpdate

public boolean isForUpdate()

Returns true if an active transaction exists and it is for update.

getIsolationLevel

public IsolationLevel getIsolationLevel()

Returns the isolation level of the active transaction, or null if there is no active transaction.

attach

public void attach()

Attach this scope to the current thread, if it has been detached.

Throws:

java.lang.IllegalStateException - if current thread has a different transaction already attached