org.apache.commons.transaction.memory
Class OptimisticTxMap<K,V>

java.lang.Object
  org.apache.commons.transaction.AbstractTransactionalResourceManager<BasicTxMap.MapTxContext>
      org.apache.commons.transaction.memory.BasicTxMap<K,V>
          org.apache.commons.transaction.memory.OptimisticTxMap<K,V>

All Implemented Interfaces:

Map<K,V>, ManageableResourceManager, TxMap<K,V>, TransactionalResourceManager

public class OptimisticTxMap<K,V>
extends BasicTxMap<K,V>
implements TxMap<K,V>

Map featuring transactional control.

By using a naive optimistic transaction control this implementation has better isolation than BasicTxMap, but may also fail to commit.

Caution: This implementation might be slow when large amounts of data is changed in a transaction as much references will need to be copied around.

This implementation wraps a map of type ConcurrentHashMap.

This implementation is thread-safe.

See Also:

BasicTxMap, PessimisticTxMap, ConcurrentHashMap

Nested Class Summary

class

OptimisticTxMap.CopyingTxContext

Nested classes/interfaces inherited from class org.apache.commons.transaction.memory.BasicTxMap

BasicTxMap.HashEntry, BasicTxMap.MapTxContext

Nested classes/interfaces inherited from class org.apache.commons.transaction.AbstractTransactionalResourceManager

AbstractTransactionalResourceManager.AbstractTxContext

Nested classes/interfaces inherited from interface java.util.Map

Map.Entry<K,V>

Field Summary

Fields inherited from class org.apache.commons.transaction.memory.BasicTxMap

wrapped

Fields inherited from class org.apache.commons.transaction.AbstractTransactionalResourceManager

activeTx

Constructor Summary

OptimisticTxMap(String name)

OptimisticTxMap(String name, LockManager<Object,Object> lm)

Method Summary

Object	checkForConflicts()
boolean	commitCanFail() Checks whether a tried commit could possibly fail because of logical reasons.
boolean	commitTransaction() Commits all changes made in the current transaction and deletes the association between the current thread and the transaction.
boolean	commitTransaction(boolean force)
protected void	copyChangesToConcurrentTransactions()
protected OptimisticTxMap.CopyingTxContext	createContext()
long	getAccessTimeout()
long	getCommitTimeout()
void	rollbackTransaction() Discards all changes made in the current transaction and deletes the association between the current thread and the transaction.
void	setAccessTimeout(long accessTimeout)
void	setCommitTimeout(long commitTimeout)
void	startTransaction(long timeout, TimeUnit unit) Starts a new transaction and associates it with the current thread.

Methods inherited from class org.apache.commons.transaction.memory.BasicTxMap

clear, containsKey, containsValue, entrySet, get, getActiveTx, getWrappedMap, isEmpty, keySet, put, putAll, remove, size, values

Methods inherited from class org.apache.commons.transaction.AbstractTransactionalResourceManager

forgetTransaction, getCheckedActiveTx, getLm, getName, isPartofComplexTransaction, isReadOnly, isRollbackOnly, joinTransaction, prepareTransaction, setActiveTx, setLm, setName

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.commons.transaction.memory.TxMap

getWrappedMap

Methods inherited from interface java.util.Map

clear, containsKey, containsValue, entrySet, equals, get, hashCode, isEmpty, keySet, put, putAll, remove, size, values

Methods inherited from interface org.apache.commons.transaction.ManageableResourceManager

forgetTransaction, isReadOnly, isRollbackOnly, joinTransaction, prepareTransaction

Constructor Detail

OptimisticTxMap

public OptimisticTxMap(String name)

OptimisticTxMap

public OptimisticTxMap(String name,
                       LockManager<Object,Object> lm)

Method Detail

startTransaction

public void startTransaction(long timeout,
                             TimeUnit unit)

Description copied from interface: TransactionalResourceManager

Starts a new transaction and associates it with the current thread. All subsequent changes in the same thread made to the resource manager are invisible from other threads until TransactionalResourceManager.commitTransaction() is called. Use TransactionalResourceManager.rollbackTransaction() to discard your changes. After calling either method there will be no transaction associated to the current thread any longer.

Caution: Be careful to finally call one of those methods, as otherwise the transaction will lurk around for ever.

Specified by:

startTransaction in interface TransactionalResourceManager

Overrides:

startTransaction in class AbstractTransactionalResourceManager<BasicTxMap.MapTxContext>

See Also:

TransactionalResourceManager.commitTransaction(), TransactionalResourceManager.rollbackTransaction()

rollbackTransaction

public void rollbackTransaction()

Description copied from interface: TransactionalResourceManager

Discards all changes made in the current transaction and deletes the association between the current thread and the transaction.

Specified by:

rollbackTransaction in interface TransactionalResourceManager

Overrides:

rollbackTransaction in class AbstractTransactionalResourceManager<BasicTxMap.MapTxContext>

See Also:

TransactionalResourceManager.startTransaction(long, TimeUnit), TransactionalResourceManager.commitTransaction()

commitTransaction

public boolean commitTransaction()
                          throws LockException

Description copied from interface: TransactionalResourceManager

Commits all changes made in the current transaction and deletes the association between the current thread and the transaction.

Specified by:

commitTransaction in interface TransactionalResourceManager

Overrides:

commitTransaction in class AbstractTransactionalResourceManager<BasicTxMap.MapTxContext>

Throws:

LockException

See Also:

TransactionalResourceManager.startTransaction(long, TimeUnit), TransactionalResourceManager.rollbackTransaction()

commitTransaction

public boolean commitTransaction(boolean force)
                          throws LockException

Throws:

LockException

checkForConflicts

public Object checkForConflicts()

copyChangesToConcurrentTransactions

protected void copyChangesToConcurrentTransactions()

createContext

protected OptimisticTxMap.CopyingTxContext createContext()

Overrides:

createContext in class BasicTxMap<K,V>

getAccessTimeout

public long getAccessTimeout()

setAccessTimeout

public void setAccessTimeout(long accessTimeout)

getCommitTimeout

public long getCommitTimeout()

setCommitTimeout

public void setCommitTimeout(long commitTimeout)

commitCanFail

public boolean commitCanFail()

Description copied from interface: ManageableResourceManager

Checks whether a tried commit could possibly fail because of logical reasons.

Specified by:

commitCanFail in interface ManageableResourceManager

Overrides:

commitCanFail in class BasicTxMap<K,V>

Returns:

true if a commit could fail