110 lines
2.9 KiB
Python
110 lines
2.9 KiB
Python
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"""create errno-specific classes for IO or os calls."""
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from __future__ import annotations
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import errno
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import os
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import sys
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from typing import Callable
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from typing import TYPE_CHECKING
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from typing import TypeVar
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if TYPE_CHECKING:
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from typing_extensions import ParamSpec
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P = ParamSpec("P")
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R = TypeVar("R")
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class Error(EnvironmentError):
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def __repr__(self) -> str:
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return "{}.{} {!r}: {} ".format(
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self.__class__.__module__,
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self.__class__.__name__,
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self.__class__.__doc__,
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" ".join(map(str, self.args)),
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# repr(self.args)
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)
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def __str__(self) -> str:
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s = "[{}]: {}".format(
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self.__class__.__doc__,
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" ".join(map(str, self.args)),
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)
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return s
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_winerrnomap = {
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2: errno.ENOENT,
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3: errno.ENOENT,
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17: errno.EEXIST,
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18: errno.EXDEV,
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13: errno.EBUSY, # empty cd drive, but ENOMEDIUM seems unavailiable
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22: errno.ENOTDIR,
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20: errno.ENOTDIR,
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267: errno.ENOTDIR,
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5: errno.EACCES, # anything better?
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}
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class ErrorMaker:
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"""lazily provides Exception classes for each possible POSIX errno
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(as defined per the 'errno' module). All such instances
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subclass EnvironmentError.
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"""
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_errno2class: dict[int, type[Error]] = {}
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def __getattr__(self, name: str) -> type[Error]:
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if name[0] == "_":
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raise AttributeError(name)
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eno = getattr(errno, name)
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cls = self._geterrnoclass(eno)
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setattr(self, name, cls)
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return cls
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def _geterrnoclass(self, eno: int) -> type[Error]:
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try:
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return self._errno2class[eno]
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except KeyError:
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clsname = errno.errorcode.get(eno, "UnknownErrno%d" % (eno,))
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errorcls = type(
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clsname,
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(Error,),
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{"__module__": "py.error", "__doc__": os.strerror(eno)},
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)
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self._errno2class[eno] = errorcls
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return errorcls
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def checked_call(
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self, func: Callable[P, R], *args: P.args, **kwargs: P.kwargs
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) -> R:
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"""Call a function and raise an errno-exception if applicable."""
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__tracebackhide__ = True
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try:
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return func(*args, **kwargs)
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except Error:
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raise
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except OSError as value:
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if not hasattr(value, "errno"):
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raise
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errno = value.errno
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if sys.platform == "win32":
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try:
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cls = self._geterrnoclass(_winerrnomap[errno])
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except KeyError:
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raise value
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else:
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# we are not on Windows, or we got a proper OSError
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cls = self._geterrnoclass(errno)
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raise cls(f"{func.__name__}{args!r}")
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_error_maker = ErrorMaker()
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checked_call = _error_maker.checked_call
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def __getattr__(attr: str) -> type[Error]:
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return getattr(_error_maker, attr) # type: ignore[no-any-return]
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