ReturnValues

DIRAC return dictionary

Message values are converted to string

keys are converted to string

exception DIRAC.Core.Utilities.ReturnValues.SErrorException(result)

Bases: Exception

Exception class for use with convertToReturnValue

__init__(result)

Create a new exception return value

If result is a S_ERROR return it directly else convert it to an appropriate value using S_ERROR(result).

Parameters

result – The error to propagate

args
with_traceback()

Exception.with_traceback(tb) – set self.__traceback__ to tb and return self.

DIRAC.Core.Utilities.ReturnValues.S_ERROR(*args, **kwargs)

return value on error condition

Arguments are either Errno and ErrorMessage or just ErrorMessage fro backward compatibility

Parameters

  • errno (int) – Error number

  • message (string) – Error message

  • callStack (list) – Manually override the CallStack attribute better performance

DIRAC.Core.Utilities.ReturnValues.S_OK(value=None)

return value on success

Parameters

value – value of the ‘Value’

Returns

dictionary { ‘OK’ : True, ‘Value’ : value }

DIRAC.Core.Utilities.ReturnValues.convertToReturnValue(func)

Decorate a function to convert return values to S_OK/S_ERROR

If func returns, wrap the return value in S_OK. If func raises SErrorException, return the associated S_ERROR If func raises any other exception type, convert it to an S_ERROR object

Parameters

result – The bare result of a function call

Returns

S_OK/S_ERROR

DIRAC.Core.Utilities.ReturnValues.isReturnStructure(unk)

Check if value is an S_OK/S_ERROR object

DIRAC.Core.Utilities.ReturnValues.isSError(value)

Check if value is an S_ERROR object

DIRAC.Core.Utilities.ReturnValues.reprReturnErrorStructure(struct, full=False)
DIRAC.Core.Utilities.ReturnValues.returnSingleResult(dictRes)

Transform the S_OK{Successful/Failed} dictionary convention into an S_OK/S_ERROR return. To be used when a single returned entity is expected from a generally bulk call.

Parameters

dictRes – S_ERROR or S_OK( “Failed” : {}, “Successful” : {})

Returns

S_ERROR or S_OK(value)

The following rules are applied:

  • if dictRes is an S_ERROR: returns it as is

  • we start by looking at the Failed directory

  • if there are several items in a dictionary, we return the first one

  • if both dictionaries are empty, we return S_ERROR

  • For an item in Failed, we return S_ERROR

  • Far an item in Successful we return S_OK

Behavior examples (would be perfect unit test :-) ):

{'Message': 'Kaput', 'OK': False} -> {'Message': 'Kaput', 'OK': False}
{'OK': True, 'Value': {'Successful': {}, 'Failed': {'a': 1}}} -> {'Message': '1', 'OK': False}
{'OK': True, 'Value': {'Successful': {'b': 2}, 'Failed': {}}} -> {'OK': True, 'Value': 2}
{'OK': True, 'Value': {'Successful': {'b': 2}, 'Failed': {'a': 1}}} -> {'Message': '1', 'OK': False}
{'OK': True, 'Value': {'Successful': {'b': 2}, 'Failed': {'a': 1, 'c': 3}}} -> {'Message': '1', 'OK': False}
{'OK': True, 'Value': {'Successful': {'b': 2, 'd': 4}, 'Failed': {}}} -> {'OK': True, 'Value': 2}
{'OK': True, 'Value': {'Successful': {}, 'Failed': {}}} ->
    {'Message': 'returnSingleResult: Failed and Successful dictionaries are empty', 'OK': False}
DIRAC.Core.Utilities.ReturnValues.returnValueOrRaise(result)

Unwrap an S_OK/S_ERROR response into a value or Exception

This method assists with using exceptions in DIRAC code by raising SErrorException if result is an error. This can then by propagated automatically as an S_ERROR by wrapping public facing functions with @convertToReturnValue.

Parameters

result – Result of a DIRAC function which returns S_OK/S_ERROR

Returns

The value associated with the S_OK object

Raises

If result[“OK”] is falsey the original exception is re-raised. If no exception is known an SErrorException is raised.