/// <summary>
/// Adds an <see cref="ExceptionLogEntry"/>. If the <see cref="ExceptionLogEntry"/> cannot be created, the error is logged to the log file instead.
/// </summary>
/// <param name="operationName"></param>
/// <param name="e"></param>
public static void Log(string operationName, Exception e)
{
try
{
// log the error to the database
using (PersistenceScope scope = new PersistenceScope(PersistenceContextType.Update, PersistenceScopeOption.RequiresNew))
{
// disable change-set auditing for this context
((IUpdateContext)PersistenceScope.CurrentContext).ChangeSetRecorder = null;
DefaultExceptionRecorder recorder = new DefaultExceptionRecorder();
ExceptionLogEntry logEntry = recorder.CreateLogEntry(operationName, e);
PersistenceScope.CurrentContext.Lock(logEntry, DirtyState.New);
scope.Complete();
}
}
catch (Exception x)
{
// if we fail to properly log the exception, there is nothing we can do about it
// just log a message to the log file
Platform.Log(LogLevel.Error, x);
// also log the original exception to the log file, since it did not get logged to the DB
Platform.Log(LogLevel.Error, e);
}
}
protected sealed override bool ClaimItem(TItem item)
{
try
{
using (var scope = new PersistenceScope(PersistenceContextType.Update))
{
var context = (IUpdateContext)PersistenceScope.CurrentContext;
context.ChangeSetRecorder.OperationName = this.GetType().FullName;
// need to lock the item in context, to allow loading of extended properties collection by subclass
context.Lock(item);
// mark item as being in process
MarkItemClaimed(item);
// complete the transaction
scope.Complete();
}
return(true);
}
catch (EntityVersionException)
{
// if we get a version exception, the item has already been claimed by another process
// this is not an error
return(false);
}
}
protected sealed override IList <TItem> GetNextBatch(int batchSize)
{
using (var scope = new PersistenceScope(PersistenceContextType.Read))
{
var items = GetNextEntityBatch(batchSize);
scope.Complete();
return(items);
}
}
protected sealed override void ProcessItem(TItem item)
{
Exception error = null;
using (var scope = new PersistenceScope(PersistenceContextType.Update))
{
var context = (IUpdateContext)PersistenceScope.CurrentContext;
context.ChangeSetRecorder.OperationName = this.GetType().FullName;
// need to lock the item in context, to allow loading of extended properties collection by subclass
context.Lock(item);
try
{
// take action based on item
ActOnItem(item);
// ensure that the commit will ultimately succeed
context.SynchState();
// success callback
OnItemSucceeded(item);
// complete the transaction
scope.Complete();
}
catch (Exception e)
{
// one of the actions failed
Platform.Log(LogLevel.Error, e);
error = e;
}
}
// exceptions thrown upon exiting the using block above are intentionally not caught here,
// allow them to be caught by the calling method
// post-processing
if (error == null)
{
AfterCommit(item);
}
else
{
UpdateItemOnError(item, error);
}
}
private void UpdateItemOnError(TItem item, Exception error)
{
// use a new scope to mark the item as failed, because we don't want to commit any changes made in the outer scope
using (var scope = new PersistenceScope(PersistenceContextType.Update, PersistenceScopeOption.RequiresNew))
{
var failContext = (IUpdateContext)PersistenceScope.CurrentContext;
failContext.ChangeSetRecorder.OperationName = this.GetType().FullName;
// bug #7191 : Reload the TItem in this scope; using the existing item results in NHibernate throwing a lazy loading exception
var itemForThisScope = failContext.Load <TItem>(item.GetRef(), EntityLoadFlags.None);
// lock item into this context
failContext.Lock(itemForThisScope);
// failure callback
OnItemFailed(itemForThisScope, error);
// complete the transaction
scope.Complete();
}
}
