com.thinkaurelius.titan.diskstorage.locking.consistentkey

Class ExpectedValueCheckingTransaction

java.lang.Object

com.thinkaurelius.titan.diskstorage.locking.consistentkey.ExpectedValueCheckingTransaction

All Implemented Interfaces:

BaseTransaction, BaseTransactionConfigurable, StoreTransaction

public class ExpectedValueCheckingTransaction
extends Object
implements StoreTransaction

A StoreTransaction that supports locking via LocalLockMediator and writing and reading lock records in a ExpectedValueCheckingStore.

This class is not safe for concurrent use by multiple threads. Multithreaded access must be prevented or externally synchronized.

Constructor Summary

Constructors

Constructor and Description
ExpectedValueCheckingTransaction(StoreTransaction dataTx, StoreTransaction lockTx, Duration maxReadTime)

Method Summary

Methods

Modifier and Type	Method and Description
void	commit() Commits the transaction and persists all modifications to the backend.
BaseTransactionConfig	getConfiguration() Get the configuration for this transaction
boolean	isMutationStarted() Tells whether this transaction has been used in a ExpectedValueCheckingStore.mutate(StaticBuffer, List, List, StoreTransaction) call.
void	mutationStarted() Signals the transaction that it has been used in a call to ExpectedValueCheckingStore.mutate(StaticBuffer, List, List, StoreTransaction) .
void	rollback() Aborts (or rolls back) the transaction.

Methods inherited from class java.lang.Object

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

Constructor Detail

ExpectedValueCheckingTransaction

public ExpectedValueCheckingTransaction(StoreTransaction dataTx,
                                StoreTransaction lockTx,
                                Duration maxReadTime)

Method Detail

rollback

public void rollback()
              throws StorageException

Description copied from interface: BaseTransaction

Aborts (or rolls back) the transaction. Call either this method or BaseTransaction.commit() at most once per instance.

Specified by:

rollback in interface BaseTransaction

Throws:

StorageException

commit

public void commit()
            throws StorageException

Description copied from interface: BaseTransaction

Commits the transaction and persists all modifications to the backend. Call either this method or BaseTransaction.rollback() at most once per instance.

Specified by:

commit in interface BaseTransaction

Throws:

StorageException

isMutationStarted

public boolean isMutationStarted()

Tells whether this transaction has been used in a ExpectedValueCheckingStore.mutate(StaticBuffer, List, List, StoreTransaction) call. When this returns true, the transaction is no longer allowed in calls to ExpectedValueCheckingStore.acquireLock(StaticBuffer, StaticBuffer, StaticBuffer, StoreTransaction).

Returns:

False until ExpectedValueCheckingStore.mutate(StaticBuffer, List, List, StoreTransaction) is called on this transaction instance. Returns true forever after.

mutationStarted

public void mutationStarted()

Signals the transaction that it has been used in a call to ExpectedValueCheckingStore.mutate(StaticBuffer, List, List, StoreTransaction) . This transaction can't be used in subsequent calls to ExpectedValueCheckingStore.acquireLock(StaticBuffer, StaticBuffer, StaticBuffer, StoreTransaction) .

Calling this method at the appropriate time is handled automatically by ExpectedValueCheckingStore. Titan users don't need to call this method by hand.

getConfiguration

public BaseTransactionConfig getConfiguration()

Description copied from interface: BaseTransactionConfigurable

Get the configuration for this transaction

Specified by:

getConfiguration in interface BaseTransactionConfigurable

Returns: