org.onosproject.store.primitives.impl

Class Transaction<T>

java.lang.Object

org.onosproject.store.primitives.impl.Transaction<T>

public class Transaction<T>
extends Object

Manages a transaction within the context of a single primitive.

The Transaction object is used to manage the transaction for a single partition primitive that implements the Transactional interface. It's used as a proxy for TransactionContexts to manage the transaction as it relates to a single piece of atomic state.

Field Summary

Fields

Modifier and Type	Field and Description
protected Transactional<T>	transactionalObject
protected TransactionId	transactionId

Constructor Summary

Constructors

Constructor and Description
Transaction(TransactionId transactionId, Transactional<T> transactionalObject)

Method Summary

Modifier and Type	Method and Description
CompletableFuture<Version>	begin() Begins the transaction.
protected void	checkActive() Checks that the transaction state is ACTIVE and throws an IllegalStateException if not.
protected void	checkOpen() Checks that the transaction is open and throws an IllegalStateException if not.
protected void	checkPrepared() Checks that the transaction state is PREPARED and throws an IllegalStateException if not.
CompletableFuture<Void>	commit() Commits the transaction.
boolean	isOpen() Returns a boolean indicating whether the transaction is open.
protected void	open() Opens the transaction, throwing an IllegalStateException if it's already open.
CompletableFuture<Boolean>	prepare(List<T> updates) Prepares the transaction.
CompletableFuture<Boolean>	prepareAndCommit(List<T> updates) Prepares and commits the transaction in a single atomic operation.
CompletableFuture<Void>	rollback() Rolls back the transaction.
protected void	setState(org.onosproject.store.primitives.impl.Transaction.State state) Updates the transaction state.
org.onosproject.store.primitives.impl.Transaction.State	state() Returns the current transaction state.
String	toString()
TransactionId	transactionId() Returns the transaction identifier.

Methods inherited from class java.lang.Object

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

Field Detail

transactionId

protected final TransactionId transactionId

transactionalObject

protected final Transactional<T> transactionalObject

Constructor Detail

Transaction

public Transaction(TransactionId transactionId,
                   Transactional<T> transactionalObject)

Method Detail

transactionId

public TransactionId transactionId()

Returns the transaction identifier.

Returns:

the transaction identifier

state

public org.onosproject.store.primitives.impl.Transaction.State state()

Returns the current transaction state.

Returns:

the current transaction state

isOpen

public boolean isOpen()

Returns a boolean indicating whether the transaction is open.

Returns:

indicates whether the transaction is open

open

protected void open()

Opens the transaction, throwing an IllegalStateException if it's already open.

checkOpen

protected void checkOpen()

Checks that the transaction is open and throws an IllegalStateException if not.

checkActive

protected void checkActive()

Checks that the transaction state is ACTIVE and throws an IllegalStateException if not.

checkPrepared

protected void checkPrepared()

Checks that the transaction state is PREPARED and throws an IllegalStateException if not.

setState

protected void setState(org.onosproject.store.primitives.impl.Transaction.State state)

Updates the transaction state.

Parameters:

state - the updated transaction state

begin

public CompletableFuture<Version> begin()

Begins the transaction.

Locks are acquired when the transaction is begun to prevent concurrent transactions from operating on the shared resource to which this transaction relates.

Returns:

a completable future to be completed once the transaction has been started

prepare

public CompletableFuture<Boolean> prepare(List<T> updates)

Prepares the transaction.

When preparing the transaction, the given list of updates for the shared resource will be prepared, and concurrent modification checks will be performed. The returned future may be completed with a TransactionException if a concurrent modification is detected for an isolation level that does not allow such modifications.

Parameters:

updates - the transaction updates

Returns:

a completable future to be completed once the transaction has been prepared

prepareAndCommit

public CompletableFuture<Boolean> prepareAndCommit(List<T> updates)

Prepares and commits the transaction in a single atomic operation.

Both the prepare and commit phases of the protocol must be executed within a single atomic operation. This method is used to optimize committing transactions that operate only on a single partition within a single primitive.

Parameters:

updates - the transaction updates

Returns:

a completable future to be completed once the transaction has been prepared

commit

public CompletableFuture<Void> commit()

Commits the transaction.

Performs the second phase of the two-phase commit protocol, committing the previously prepared updates.

Returns:

a completable future to be completed once the transaction has been committed

rollback

public CompletableFuture<Void> rollback()

Rolls back the transaction.

Rolls back the first phase of the two-phase commit protocol, cancelling prepared updates.

Returns:

a completable future to be completed once the transaction has been rolled back

toString

public String toString()

Overrides:

toString in class Object