/// <summary>
/// Invokes a given function and provides error handling and auditing in case the method causes
/// an exception.
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="auditor"></param>
/// <param name="context"></param>
/// <param name="func"></param>
/// <param name="errorMessage"></param>
/// <returns></returns>
public static T SecureFunc <T>(IAuditor auditor, FileSystemTask context, Func <T> func, Func <string> errorMessage)
{
try
{
return(func());
}
catch (VfsFaultException e)
{
//audit as warning - the error has been properly handled by the service
VfsFault fault = e.Fault;
auditor.AuditException(e, AuditLevel.Warning, context, AuditEvent.Unknown, fault.CreateFaultMessage());
//create a matching exception based on the fault type
throw fault.ToException();
}
catch (VfsException e)
{
//just audit and rethrow VFS exceptions
auditor.AuditException(e, context);
throw;
}
catch (Exception e)
{
//wrap unhandled exception into VFS exception
var exception = new ResourceAccessException(errorMessage(), e);
auditor.AuditException(exception, context);
throw exception;
}
}
public static VfsException ToException(this VfsFault fault)
{
VfsException exception;
switch (fault.FaultType)
{
case VfsFaultType.ResourceNotFound:
exception = new VirtualResourceNotFoundException(fault.CreateFaultMessage());
break;
case VfsFaultType.ResourceAccess:
exception = new ResourceAccessException(fault.CreateFaultMessage());
break;
case VfsFaultType.ResourceOverwrite:
exception = new ResourceOverwriteException(fault.CreateFaultMessage());
break;
case VfsFaultType.ResourceLocked:
exception = new ResourceLockedException(fault.CreateFaultMessage());
break;
case VfsFaultType.ResourcePathInvalid:
exception = new InvalidResourcePathException(fault.CreateFaultMessage());
break;
case VfsFaultType.TransferError:
exception = new TransferException(fault.CreateFaultMessage());
break;
case VfsFaultType.TransferUnknown:
exception = new UnknownTransferException(fault.CreateFaultMessage());
break;
case VfsFaultType.TransferStatusError:
exception = new TransferStatusException(fault.CreateFaultMessage());
break;
case VfsFaultType.DataBlockError:
exception = new DataBlockException(fault.CreateFaultMessage());
break;
case VfsFaultType.Undefined:
exception = new VfsFaultException(fault.CreateFaultMessage(), fault);
break;
default:
Debug.WriteLine("Unsupported VFS fault type: " + fault.FaultType);
exception = new VfsFaultException(fault.CreateFaultMessage(), fault);
break;
}
exception.EventId = fault.EventId;
return(exception);
}
protected T CreateFaultResult <T>(Exception exception, Func <int, VfsFault, T> func) where T : OperationResult
{
//set content type
//Response.Headers.ContentType = new MediaType(VfsHttpHeaders.Default.VfsFaultContentType);
//get exception
VfsException ve = exception as VfsException;
VfsFault fault = ve == null ? new VfsFault {
Message = exception.Message
}
: VfsFault.CreateFromException(ve);
int statusCode = 0;
//set HTTP status code
switch (fault.FaultType)
{
case VfsFaultType.ResourceNotFound:
case VfsFaultType.TransferUnknown:
//404
return(func(404, fault));
case VfsFaultType.ResourceAccess:
case VfsFaultType.ResourceOverwrite:
case VfsFaultType.ResourceLocked:
case VfsFaultType.TransferError:
case VfsFaultType.TransferStatusError:
case VfsFaultType.DataBlockError:
case VfsFaultType.ResourcePathInvalid:
//forbidden
return(func(403, fault));
case VfsFaultType.Undefined:
return(func(500, fault));
default:
string msg = String.Format("Exception contains unknown fault type [{0}]", fault.FaultType);
throw new ArgumentOutOfRangeException("exception", msg);
}
}
