OptimisticMapWrapper (Commons Transaction 1.3-SNAPSHOT API)

java.lang.Object
- org.apache.commons.transaction.memory.TransactionalMapWrapper
- - org.apache.commons.transaction.memory.OptimisticMapWrapper

All Implemented Interfaces:

Map, Status
```
public class OptimisticMapWrapper
extends TransactionalMapWrapper
```
Wrapper that adds transactional control to all kinds of maps that implement the Map interface. By using a naive optimistic transaction control this wrapper has better isolation than TransactionalMapWrapper, but may also fail to commit.
Start a transaction by calling startTransaction(). Then perform the normal actions on the map and finally either call commitTransaction() to make your changes permanent or rollbackTransaction() to undo them.
Caution: Do not modify values retrieved by TransactionalMapWrapper.get(Object) as this will circumvent the transactional mechanism. Rather clone the value or copy it in a way you see fit and store it back using TransactionalMapWrapper.put(Object, Object).
Note: This wrapper guarantees isolation level SERIALIZABLE.
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.

Version:

$Id: OptimisticMapWrapper.java 493628 2007-01-07 01:42:48Z joerg $

See Also:
TransactionalMapWrapper, PessimisticMapWrapper

Nested Class Summary

Nested Classes
Modifier and Type Class and Description

class OptimisticMapWrapper.CopyingTxContext
- Nested classes/interfaces inherited from class org.apache.commons.transaction.memory.TransactionalMapWrapper
  TransactionalMapWrapper.HashEntry, TransactionalMapWrapper.TxContext
- Nested classes/interfaces inherited from interface java.util.Map
  Map.Entry

Nested Classes
Modifier and Type	Class and Description
`class`	`OptimisticMapWrapper.CopyingTxContext`

Field Summary

Fields
Modifier and Type	Field and Description
`protected static int`	`ACCESS_TIMEOUT`
`protected Set`	`activeTransactions`
`protected static int`	`COMMIT_TIMEOUT`
`protected ReadWriteLock`	`commitLock`
`protected LoggerFacade`	`logger`

Fields inherited from class org.apache.commons.transaction.memory.TransactionalMapWrapper
mapFactory, setFactory, wrapped

Fields inherited from interface javax.transaction.Status
STATUS_ACTIVE, STATUS_COMMITTED, STATUS_COMMITTING, STATUS_MARKED_ROLLBACK, STATUS_NO_TRANSACTION, STATUS_PREPARED, STATUS_PREPARING, STATUS_ROLLEDBACK, STATUS_ROLLING_BACK, STATUS_UNKNOWN

Constructor Summary

Constructors
Constructor and Description
`OptimisticMapWrapper(Map wrapped)` Creates a new optimistic transactional map wrapper.
`OptimisticMapWrapper(Map wrapped, MapFactory mapFactory, SetFactory setFactory)` Creates a new optimistic transactional map wrapper.
`OptimisticMapWrapper(Map wrapped, MapFactory mapFactory, SetFactory setFactory, LoggerFacade logger)` Creates a new optimistic transactional map wrapper.

Method Summary

Methods
Modifier and Type	Method and Description
`Object`	`checkForConflicts()`
`void`	`commitTransaction()` Commits all changes made in the current transaction and deletes the association between the current thread and the transaction.
`void`	`commitTransaction(boolean force)`
`protected void`	`copyChangesToConcurrentTransactions()`
`void`	`rollbackTransaction()` Discards all changes made in the current transaction and deletes the association between the current thread and the transaction.
`void`	`startTransaction()` Starts a new transaction and associates it with the current thread.

Methods inherited from class org.apache.commons.transaction.memory.TransactionalMapWrapper
clear, containsKey, containsValue, entrySet, get, getActiveTx, getTransactionState, isEmpty, isReadOnly, isTransactionMarkedForRollback, keySet, markTransactionForRollback, put, putAll, remove, resumeTransaction, setActiveTx, size, suspendTransaction, values

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface java.util.Map
equals, hashCode

- Field Detail
  - COMMIT_TIMEOUT
```
protected static final int COMMIT_TIMEOUT
```
    See Also:
    Constant Field Values
  - ACCESS_TIMEOUT
```
protected static final int ACCESS_TIMEOUT
```
    See Also:
    Constant Field Values
  - activeTransactions
```
protected Set activeTransactions
```
  - logger
```
protected LoggerFacade logger
```
  - commitLock
```
protected ReadWriteLock commitLock
```
- Constructor Detail
  - OptimisticMapWrapper
```
public OptimisticMapWrapper(Map wrapped)
```
    Creates a new optimistic transactional map wrapper. Temporary maps and sets to store transactional data will be instances of HashMap and HashSet.
    
    Parameters:
    wrapped - map to be wrapped
  - OptimisticMapWrapper
```
public OptimisticMapWrapper(Map wrapped,
                    MapFactory mapFactory,
                    SetFactory setFactory)
```
    Creates a new optimistic transactional map wrapper. Temporary maps and sets to store transactional data will be created and disposed using MapFactory and SetFactory.
    
    Parameters:
    wrapped - map to be wrapped
    mapFactory - factory for temporary maps
    setFactory - factory for temporary sets
  - OptimisticMapWrapper
```
public OptimisticMapWrapper(Map wrapped,
                    MapFactory mapFactory,
                    SetFactory setFactory,
                    LoggerFacade logger)
```
    Creates a new optimistic transactional map wrapper. Temporary maps and sets to store transactional data will be created and disposed using MapFactory and SetFactory.
    
    Parameters:
    wrapped - map to be wrapped
    mapFactory - factory for temporary maps
    setFactory - factory for temporary sets
    logger - generic logger used for all kinds of logging
- Method Detail
  - startTransaction
```
public void startTransaction()
```
    Description copied from class: TransactionalMapWrapper
    
    Starts a new transaction and associates it with the current thread. All subsequent changes in the same thread made to the map are invisible from other threads until TransactionalMapWrapper.commitTransaction() is called. Use TransactionalMapWrapper.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.
    
    Overrides:
    
    startTransaction in class TransactionalMapWrapper
    
    See Also:
    TransactionalMapWrapper.commitTransaction(), TransactionalMapWrapper.rollbackTransaction()
  - rollbackTransaction
```
public void rollbackTransaction()
```
    Description copied from class: TransactionalMapWrapper
    
    Discards all changes made in the current transaction and deletes the association between the current thread and the transaction.
    
    Overrides:
    
    rollbackTransaction in class TransactionalMapWrapper
    
    See Also:
    TransactionalMapWrapper.startTransaction(), TransactionalMapWrapper.commitTransaction()
  - commitTransaction
```
public void commitTransaction()
                       throws ConflictException
```
    Description copied from class: TransactionalMapWrapper
    
    Commits all changes made in the current transaction and deletes the association between the current thread and the transaction.
    
    Overrides:
    
    commitTransaction in class TransactionalMapWrapper
    
    Throws:
    
    ConflictException
    See Also:
    TransactionalMapWrapper.startTransaction(), TransactionalMapWrapper.rollbackTransaction()
  - commitTransaction
```
public void commitTransaction(boolean force)
                       throws ConflictException
```
    Throws:
    
    ConflictException
  - checkForConflicts
```
public Object checkForConflicts()
```
  - copyChangesToConcurrentTransactions
```
protected void copyChangesToConcurrentTransactions()
```

Class OptimisticMapWrapper

Nested Class Summary

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

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

Field Summary

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

Fields inherited from interface javax.transaction.Status

Constructor Summary

Method Summary

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

Methods inherited from class java.lang.Object

Methods inherited from interface java.util.Map

Field Detail

COMMIT_TIMEOUT

ACCESS_TIMEOUT

activeTransactions

logger

commitLock

Constructor Detail

OptimisticMapWrapper

OptimisticMapWrapper

OptimisticMapWrapper

Method Detail

startTransaction

rollbackTransaction

commitTransaction

commitTransaction

checkForConflicts

copyChangesToConcurrentTransactions