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