Source code for canlib.canlib.exceptions

import ctypes as ct

from ..exceptions import CanlibException, DllException
from .enums import Error

_all_errors_by_status = {}


def _remember(cls):
    _all_errors_by_status[cls.status] = cls
    return cls


def can_error(status):
    if status in _all_errors_by_status:
        return _all_errors_by_status[status]()
    else:
        return CanGeneralError(status)


[docs]class CanError(DllException): """Base class for exceptions raised by the canlib class Looks up the error text in the canlib dll and presents it together with the error code and the wrapper function that triggered the exception. """ @staticmethod def _get_error_text(status): try: from .wrapper import dll # import here to prevent circular imports msg_buf = ct.create_string_buffer(80) dll.canGetErrorText(status, msg_buf, ct.sizeof(msg_buf)) msg = msg_buf.value.decode('utf-8') # The important thing is to give original error code. except Exception: msg = "Unknown error text" msg += f' ({status})' return msg
[docs]class CanGeneralError(CanError): """A canlib error that does not (yet) have its own Exception WARNING: Do not explicitly catch this error, instead catch `CanError`. Your error may at any point in the future get its own exception class, and so will no longer be of this type. The actual status code that raised any `CanError` can always be accessed through a `status` attribute. """ def __init__(self, status): self.status = status super().__init__()
[docs]@_remember class CanNoMsg(CanError): """Raised when no matching message was available""" status = Error.NOMSG
[docs]@_remember class CanInvalidHandle(CanError): """CANlib handle is invalid. Raised e.g. when trying to access a CAN channel via a closed channel handle. .. versionadded:: 1.22 """ status = Error.INVHANDLE
[docs]@_remember class CanScriptFail(CanError): """Raised when a script call failed. This exception represents several different failures, for example: * Trying to load a corrupt file or not a .txe file * Trying to start a t script that has not been loaded * Trying to load a t script compiled with the wrong version of the t compiler * Trying to unload a t script that has not been stopped * Trying to use an envvar that does not exist """ status = Error.SCRIPT_FAIL
[docs]@_remember class CanOutOfMemory(CanError): """A memory allocation failed. Raised e.g. when trying to allocate an object buffer, when all available object buffers have already been allocated. .. versionadded:: 1.22 """ status = Error.NOMEM
[docs]@_remember class CanTimeout(CanError): """Raised when a timeout occured Raised when an expected event did not happen within the expected time frame, see e.g. `.canlib.Channel.writeWait()`. .. versionadded:: 1.21 """ status = Error.TIMEOUT
[docs]@_remember class CanNotFound(CanError): """Specified device or channel not found There is no hardware available that matches the given search criteria. For example, you may have specified `Open.REQUIRE_EXTENDED` but there's no controller capable of extended CAN. You may have specified a channel number that is out of the range for the hardware in question. You may have requested exclusive access to a channel, but the channel is already occupied. .. versionadded:: 1.6 """ status = Error.NOTFOUND
@_remember class CanNotImplementedError(CanError): """Not implemented The requested feature or function is not implemented in the device you are trying to use it on. """ status = Error.NOT_IMPLEMENTED
[docs]@_remember class IoPinConfigurationNotConfirmed(CanError): """I/O pin configuration is not confirmed Before accessing any I/O pin value, the device I/O pin configuration must be confirmed, using e.g. `Channel.io_confirm_config`. See also `iopin.Configuration`. .. versionadded:: 1.8 """ status = Error.IO_NOT_CONFIRMED
[docs]@_remember class IoNoValidConfiguration(CanError): """I/O pin configuration is invalid No I/O pins was found, or unknown I/O pins was discovered. .. versionadded:: 1.8 """ status = Error.IO_NO_VALID_CONFIG
@_remember class CanOverflowError(CanError): """Transmit buffer overflow While trying to send a CAN message, there was no room in the transmit buffer so the frame was dropped. .. versionadded:: 1.21 """ status = Error.TXBUFOFL
[docs]class EnvvarException(CanlibException): """Base class for exceptions related to environment variables.""" pass
[docs]class EnvvarValueError(EnvvarException): """ Raised when the type of the value does not match the type of the environment variable. """ def __init__(self, envvar, type_, value): msg = "invalid literal for envvar ({envvar}) with" " type {type_}: {value}" msg = msg.format(envvar=envvar, type_=type_, value=value) super().__init__(msg)
[docs]class EnvvarNameError(EnvvarException): """ Raised when the name of the environment variable is illegal. """ def __init__(self, envvar): msg = "envvar names must not start with an underscore: {envvar}" msg = msg.format(envvar=envvar) super().__init__(msg)
[docs]class TxeFileIsEncrypted(CanlibException): """ Raised when trying to access `Txe.source` and the source and byte-code sections of the .txe binary have been encrypted. .. versionadded:: 1.6 """ pass