wt.pom
Class TransactionManager

java.lang.Object
  wt.pom.TransactionManager

Direct Known Subclasses:

OracleTransactionManager

public class TransactionManager

extends Object

TransactionManager manages nested transactions for a user thread. An instance of TransactionManager is held by each user connection. The TransactionManager handles nested transaction blocks and only forwards the actual datastore commit when a commit which matchs an outer level start is received. If a commit is received which does not match a corresponding start, an exception is thrown. A rollback is invoked immediately and if the rollback occurs at a nested level, a "rollback in process" state is triggered. In this case, further start or commit actions will throw an exception until a rollback matching the outer block is received. The interface to transaction blocks is through wt.pom.Transaction.

 Example 1 - normal commit
    Transaction trx1 = new Transaction();
    trx1.start();
    anObj1.insert();
       Transaction trx2 = new Transaction();
       trx2.start();
       anObj2.delete();
       trx2.commit();       // commit is pending
    trx1.commit();          // commit happens

 Example 2 - rollback
    Transaction trx1 = new Transaction();
    trx1.start();
    anObj1.insert();
       Transaction trx2 = new Transaction();
       trx2.start();
       anObj2.delete();
       trx2.rollback();     // rollback happens
    trx1.rollback();        // transaction is cleared (commit not allowed)
 

See Also:

WTConnection, Transaction

Nested Class Summary

(package private) static class	TransactionManager.BeforeCompletionTransactionListener
(package private) static class	TransactionManager.FinishTransactionListener
(package private) static interface	TransactionManager.FireTransactionListener
(package private) static class	TransactionManager.NotifyCommitTransactionListener
(package private) static class	TransactionManager.NotifyRollbackTransactionListener

Field Summary

(package private) static TransactionManager.BeforeCompletionTransactionListener	BEFORE_COMPLETION
(package private) static BeforeCompletionValidationListener	BEFORE_COMPLETION_VALIDATION_LISTENER
private RefreshCache	cache
private static String	CLASSNAME
private HashMap	classoidmap
private int	count
static boolean	DEBUG
(package private) static TransactionManager.FinishTransactionListener	FINISH
private static DebugWriter	LOG
private HashMap	map
(package private) static TransactionManager.NotifyCommitTransactionListener	NOTIFY_COMMIT
(package private) static TransactionManager.NotifyRollbackTransactionListener	NOTIFY_ROLLBACK
private ArrayList	pomOperationListeners
private static String	RESOURCE
private boolean	rollbackInProgress
private int	transactionLevel
private ArrayList	transactionListeners
private int	transactionMode
private ArrayList	transactionStack

Constructor Summary

TransactionManager()

Method Summary

protected void	addEntryInCache(ObjectIdentifier a_oid)
void	addEntryInCache(Persistable a_obj) Adds the specified Persistable to the RefreshCache.
protected void	addPOMOperationListener(POMOperationListener listener)
protected void	addTransactionListener(TransactionListener listener)
protected void	commitTransaction(int aHandle) Commit a transaction flushing changes to the datastore.
protected boolean	containOidInCache(ObjectIdentifier a_oid)
private void	executeCommitTransaction(Savepoint a_savepoint)
private void	executeRollbackTransaction(Savepoint a_savepoint)
private void	executeTransactionOperation(boolean a_commit, Savepoint a_savepoint, String a_traceTimingName)
protected List	findAll(Object a_key) Returns a List of Transactions with a local Map that contains the specified key.
protected Transaction	findFirst(Object a_key) Returns the first Transaction with a local Map that contains the specified key.
protected void	fireTransactionListener(boolean callCommit)
(package private) static void	fireTransactionListener(List a_listeners, TransactionManager.FireTransactionListener a_fireListener)
protected List	getContext() Returns Transactions context.
protected Transaction	getCurrentTransaction() Returns the current Transaction.
Persistable	getEntryFromCache(ObjectIdentifier a_oid, Persistable a_target) Returns a Persistable from the RefreshCache, if it exists.
protected Map	getGlobalTransactionMap() Returns the global Transaction Map.
protected List	getLocalPOMOperationListeners()
protected boolean	getrollbackInProgress()
private Savepoint	getSavepoint()
private Savepoint	getSavepoint(int a_level)
protected int	getTransactionId()
protected int	getTransactionLevel()
protected boolean	hasGlobalTransactionMap() Indicates if a global transaction Map exists.
protected boolean	isTransactionActive()
protected void	releaseSavepoint(Connection a_connection, Savepoint a_savepoint)
protected void	removeEntriesFromCache(String a_className)
protected void	removeEntryFromCache(ObjectIdentifier a_oid)
protected void	removeEntryFromCache(Persistable a_obj)
protected void	removePOMOperationListener(POMOperationListener listener)
protected void	removeTransactionListener(TransactionListener listener)
protected void	rollbackTransaction()
protected void	rollbackTransaction(int aHandle) Rollback a transaction cancelling pending changes to the datastore.
protected void	setrollbackInProgress(boolean state)
protected void	setTransactionIsolation(int a_mode)
protected void	setTransactionLevel(int level)
protected int	startTransaction(Transaction a_transaction) Start a transaction.
private void	validateCommit(int aHandle)
private void	validateStart()

Methods inherited from class java.lang.Object

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

Field Detail

CLASSNAME

private static final String CLASSNAME

DEBUG

public static final boolean DEBUG

LOG

private static final DebugWriter LOG

transactionLevel

private int transactionLevel

transactionMode

private int transactionMode

rollbackInProgress

private boolean rollbackInProgress

transactionListeners

private ArrayList transactionListeners

pomOperationListeners

private ArrayList pomOperationListeners

cache

private RefreshCache cache

count

private int count

transactionStack

private ArrayList transactionStack

map

private HashMap map

classoidmap

private HashMap classoidmap

RESOURCE

private static final String RESOURCE

See Also:

Constant Field Values

FINISH

static final TransactionManager.FinishTransactionListener FINISH

BEFORE_COMPLETION

static final TransactionManager.BeforeCompletionTransactionListener BEFORE_COMPLETION

NOTIFY_COMMIT

static final TransactionManager.NotifyCommitTransactionListener NOTIFY_COMMIT

NOTIFY_ROLLBACK

static final TransactionManager.NotifyRollbackTransactionListener NOTIFY_ROLLBACK

BEFORE_COMPLETION_VALIDATION_LISTENER

static final BeforeCompletionValidationListener BEFORE_COMPLETION_VALIDATION_LISTENER

Constructor Detail

TransactionManager

public TransactionManager()

Method Detail

hasGlobalTransactionMap

protected boolean hasGlobalTransactionMap()

Indicates if a global transaction Map exists.

getGlobalTransactionMap

protected Map getGlobalTransactionMap()

Returns the global Transaction Map.

getCurrentTransaction

protected Transaction getCurrentTransaction()

Returns the current Transaction.

Returns:

current local Transaction or null if no Transaction exists.

findFirst

protected Transaction findFirst(Object a_key)

Returns the first Transaction with a local Map that contains the specified key. The Transaction stack is searched from inner-most to outer-most.

findAll

protected List findAll(Object a_key)

Returns a List of Transactions with a local Map that contains the specified key. The List is ordered from inner-most (index=0) to outer-most (index=size() - 1). If no keys are found, then a null value is returned.

getContext

protected List getContext()

Returns Transactions context.

startTransaction

protected int startTransaction(Transaction a_transaction)
                        throws PersistenceException

Start a transaction.

Returns:

transaction id

Throws:

PersistenceException - Occurs if the persistent object manager cannot start the transaction.

commitTransaction

protected void commitTransaction(int aHandle)
                          throws PersistenceException

Commit a transaction flushing changes to the datastore.

Throws:

PersistenceException - Occurs if the persistent object manager cannot end the transaction.

rollbackTransaction

protected void rollbackTransaction(int aHandle)
                            throws PersistenceException

Rollback a transaction cancelling pending changes to the datastore.

Throws:

PersistenceException - Occurs if the persistent object manager cannot drop the transaction.

rollbackTransaction

protected void rollbackTransaction()
                            throws PersistenceException

Throws:

PersistenceException

addEntryInCache

public void addEntryInCache(Persistable a_obj)

Adds the specified Persistable to the RefreshCache.

Parameters:

a_obj - Persistable object to add

addEntryInCache

protected void addEntryInCache(ObjectIdentifier a_oid)

removeEntryFromCache

protected void removeEntryFromCache(ObjectIdentifier a_oid)

removeEntryFromCache

protected void removeEntryFromCache(Persistable a_obj)

removeEntriesFromCache

protected void removeEntriesFromCache(String a_className)

containOidInCache

protected boolean containOidInCache(ObjectIdentifier a_oid)

getEntryFromCache

public Persistable getEntryFromCache(ObjectIdentifier a_oid,
                                     Persistable a_target)

Returns a Persistable from the RefreshCache, if it exists. The Persitable is specified by ObjectIdentfier. The optional target Persistable can be specified for an in-place refresh.

Parameters:

a_oid - ObjectIdentifier that specifies the Persistable

a_target - Persistable to use for in-place refresh (optional)

addPOMOperationListener

protected void addPOMOperationListener(POMOperationListener listener)
                                throws PersistenceException

Throws:

PersistenceException

removePOMOperationListener

protected void removePOMOperationListener(POMOperationListener listener)
                                   throws PersistenceException

Throws:

PersistenceException

getLocalPOMOperationListeners

protected List getLocalPOMOperationListeners()

addTransactionListener

protected void addTransactionListener(TransactionListener listener)
                               throws PersistenceException

Throws:

PersistenceException

removeTransactionListener

protected void removeTransactionListener(TransactionListener listener)
                                  throws PersistenceException

Throws:

PersistenceException

fireTransactionListener

protected void fireTransactionListener(boolean callCommit)
                                throws PersistenceException

Throws:

PersistenceException

getSavepoint

private Savepoint getSavepoint(int a_level)

getSavepoint

private Savepoint getSavepoint()

executeCommitTransaction

private void executeCommitTransaction(Savepoint a_savepoint)
                               throws PersistenceException

Throws:

PersistenceException

executeRollbackTransaction

private void executeRollbackTransaction(Savepoint a_savepoint)
                                 throws PersistenceException

Throws:

PersistenceException

executeTransactionOperation

private void executeTransactionOperation(boolean a_commit,
                                         Savepoint a_savepoint,
                                         String a_traceTimingName)
                                  throws PersistenceException

Throws:

PersistenceException

releaseSavepoint

protected void releaseSavepoint(Connection a_connection,
                                Savepoint a_savepoint)
                         throws SQLException

Throws:

SQLException

validateStart

private void validateStart()
                    throws PersistenceException

Throws:

PersistenceException

validateCommit

private void validateCommit(int aHandle)
                     throws PersistenceException

Throws:

PersistenceException

isTransactionActive

protected boolean isTransactionActive()

getTransactionId

protected int getTransactionId()

getTransactionLevel

protected int getTransactionLevel()

setTransactionLevel

protected void setTransactionLevel(int level)

getrollbackInProgress

protected boolean getrollbackInProgress()

setrollbackInProgress

protected void setrollbackInProgress(boolean state)

setTransactionIsolation

protected void setTransactionIsolation(int a_mode)
                                throws PersistenceException

Throws:

PersistenceException

fireTransactionListener

static void fireTransactionListener(List a_listeners,
                                    TransactionManager.FireTransactionListener a_fireListener)
                             throws PersistenceException

Throws:

PersistenceException