Source code for brainstem.result

# Copyright (c) 2018 Acroname Inc. - All Rights Reserved
#
# This file is part of the BrainStem (tm) package which is released under MIT.
# See file LICENSE or go to https://acroname.com for full license details.

"""
A module that provides a result class for returning results of UEI commands.

Results consist of an error attribute and a value attribute. If the error
attribute is set to NO_ERROR, then the result value is the response to the
UEI command that was sent.

For more information about return values for commands and UEI's
see the `Acroname BrainStem Reference`_

.. _Acroname BrainStem Reference:
    https://acroname.com/reference
"""
from . import _BS_C, ffi


[docs]class Result(object): """ Result class for returning results of commands Instances of Result represent the response to a command. The Result class also contains constants representing the possible errors that may be encountered during interaction with a BrainStem module. """ NO_ERROR = _BS_C.aErrNone # 0: No Error occurred. MEMORY_ERROR = _BS_C.aErrMemory # 1: Memory allocation/de-allocation error. PARAMETER_ERROR = _BS_C.aErrParam # 2: Invalid parameters given. NOT_FOUND = _BS_C.aErrNotFound # 3: Entity, module or information not found. FILE_NAME_LENGTH_ERROR = _BS_C.aErrFileNameLength # 4: File name is to long. BUSY = _BS_C.aErrBusy # 5: Module or resource is currently busy. IO_ERROR = _BS_C.aErrIO # 6: An Input/Output error occurred. MODE_ERROR = _BS_C.aErrMode # 7: Invalid Mode or mode not accessible for current state. WRITE_ERROR = _BS_C.aErrWrite # 8: Write error occurred. READ_ERROR = _BS_C.aErrRead # 9: Read error occurred. EOF_ERROR = _BS_C.aErrEOF # 10: Unexpected end of file encountered. NOT_READY = _BS_C.aErrNotReady # 11: Resource not ready. PERMISSION_ERROR = _BS_C.aErrPermission # 12: Insufficient permissions. RANGE_ERROR = _BS_C.aErrRange # 13: Request is outside of valid range. SIZE_ERROR = _BS_C.aErrSize # 14: Size is incorrect for resource. OVERRUN_ERROR = _BS_C.aErrOverrun # 15: Buffer was overrun or will be. PARSE_ERROR = _BS_C.aErrParse # 16: Unable to parse command. CONFIGURATION_ERROR = _BS_C.aErrConfiguration # 17: Configuration is invalid. TIMEOUT = _BS_C.aErrTimeout # 18: Timeout occurred. INITIALIZATION_ERROR = _BS_C.aErrInitialization # 19: Could not initialize resource. VERSION_ERROR = _BS_C.aErrVersion # 20: Version mismatch UNIMPLEMENTED_ERROR = _BS_C.aErrUnimplemented # 21: Functionality unavailable or unimplemented. DUPLICATE = _BS_C.aErrDuplicate # 22: Duplicate request received. CANCELED = _BS_C.aErrCancel # 23: Request was canceled PACKET_ERROR = _BS_C.aErrPacket # 24: packet was invalid or had invalid contents. CONNECTION_ERROR = _BS_C.aErrConnection # 25: connection is no longer valid, or was closed. INDEX_RANGE_ERROR = _BS_C.aErrIndexRange # 26: Requested entity does not exist. SHORT_COMMAND_ERROR = _BS_C.aErrShortCommand # 27: Command to short, not enough data to parse. INVALID_ENTITY_ERROR = _BS_C.aErrInvalidEntity # 28: Entity is not available, or does not exist. INVALID_OPTION_ERROR = _BS_C.aErrInvalidOption # 29: Option for given entity is invalid. RESOURCE_ERROR = _BS_C.aErrResource # 30: Error allocating or acquiring a resource. MEDIA_ERROR = _BS_C.aErrMedia # 31: Media not found or not available. ASYNC_RETURN_ERROR = _BS_C.aErrAsyncReturn # 32: Asynchronous return. STREAM_STALE_ERROR = _BS_C.aErrStreamStale # 33: Stream value is stale. UNKNOWN_ERROR = _BS_C.aErrUnknown # 34: Unknown error encountered. def __init__(self, error, value): """ Initialize a Result object args: error (int): The error value. value (int): the result value. """ self._error = error self._value = value @property def error(self): """ Return the error attribute""" return self._error @property def value(self): """ Return the value attribute""" return self._value
[docs] @staticmethod def getErrorText(error): """ Get the string representation of an error code. Args: error (int | Result): The error to decode. Return (string): The error code in human readable form. """ return Result.__getErrorText(Result.__getError(error))
[docs] @staticmethod def getErrorDescription(error): """ Get the description of an error code. Args: error (int | Result): The error to decode. Return (string): The error code description in human readable form. """ return ffi.string(_BS_C.aError_GetErrorDescription(Result.__getError(error)), 100)
@staticmethod def __getErrorText(error): # Build list of class "constants"/error code strings using reflection. members = [attr for attr in dir(Result) if not callable(getattr(Result, attr)) and not attr.startswith("__") and attr.isupper()] for member in members: # 'error' is an int; 'member' is a string # Using eval we get the value (int) of 'member' if error == eval(__class__.__name__ + "." + member): return member return "" # If we ever align python errors with C errors then we can use this. # return ffi.string(_BS_C.aError_GetErrorText(the_error), 100) @staticmethod def __getError(error): # Strips off the result object to acquire the raw error code. the_error = Result.UNKNOWN_ERROR; if type(error) is Result: the_error = error.error elif type(error) is int: the_error = error return the_error def __repr__(self): """ Return a representation of the Result object""" return "<id(%x) %s>" % (id(self), str(self)) def __str__(self): """ Pretty print the Result object""" return "<Result(%s): %s>" % (self.error, str(self.value))