/// <summary>
/// Execute a ADO.NET operation on a command object using an Object Callback.
/// </summary>
/// <remarks>This allows for implementing arbitrary data access operations
/// on a single command within Spring's managed DB4o environment.</remarks>
/// <param name="callback">The delegate called with a command object.</param>
/// <returns>A result object returned by the action or null</returns>
public Object Execute(IDb4oCallback callback)
{
logger.Debug("Execute Callback");
// get a possibly existing connection
ObjectContainer container = Db4oUtils.GetConnection(DataSource);
object result;
try{
logger.Debug("DoInDb4o");
result = callback.DoInDb4o(container);
} catch (Exception e) {
logger.Error("Exception while executing in Db4o", e);
throw ConvertDb4oAccessException(e);
}
// dispose from the connection
Db4oUtils.DisposeConnection(container, DataSource);
return(result);
}
/// <summary>
/// Begin a new transaction with the given transaction definition.
/// </summary>
/// <param name="transaction">
/// Transaction object returned by
/// <see cref="Spring.Transaction.Support.AbstractPlatformTransactionManager.DoGetTransaction"/>.
/// </param>
/// <param name="definition">
/// <see cref="Spring.Transaction.ITransactionDefinition"/> instance, describing
/// propagation behavior, isolation level, timeout etc.
/// </param>
/// <remarks>
/// Does not have to care about applying the propagation behavior,
/// as this has already been handled by this abstract manager.
/// </remarks>
/// <exception cref="Spring.Transaction.TransactionException">
/// In the case of creation or system errors.
/// </exception>
protected override void DoBegin(Object transaction, ITransactionDefinition definition)
{
logger.Debug("Do Begin Transaction");
if (definition.TransactionIsolationLevel != IsolationLevel.Unspecified)
{
logger.Error("Db4o Does not support Isolation Level");
throw new CannotCreateTransactionException("Db4o does not support an isolation level concept");
}
try{
Db4oTransactionObject txObject = (Db4oTransactionObject)transaction;
if (txObject.ObjectContainerHolder == null)
{
// use the given container
logger.Warn("Are we supposed to be in this case ??");
ObjectContainer container = Db4oUtils.GetConnection(_DataSource);
logger.Debug("Using given objectContainer ["
+ container
+ "] for the current thread transaction");
txObject.ObjectContainerHolder = new ObjectContainerHolder(container);
}
ObjectContainerHolder holder = txObject.ObjectContainerHolder;
//holder. set readonly ??
if (definition.TransactionTimeout != -1)
{
logger.Debug("Setting Transaction Timeout : " + definition.TransactionTimeout);
holder.TimeoutInSeconds = definition.TransactionTimeout;
}
} catch (Exception e) {
logger.Error("Cannot create transaction");
throw new CannotCreateTransactionException("Cannot create transaction", e);
}
}
/// <summary>
/// Convert the Db4o exception to an equivalent one from the
/// the Spring Exception Hierarchy
/// </summary>
/// <returns> An exception from the
/// <see cref="T:Spring.Dao.DataAccessException"> Spring DataAccessException Hierarchy </see>
/// </returns>
public DataAccessException ConvertDb4oAccessException(Exception ex)
{
logger.Debug("Converting Db4o to Spring Exception", ex);
return(Db4oUtils.TranslateException(ex));
}