|
| 1 | +"""create errno-specific classes for IO or os calls.""" |
| 2 | +from __future__ import annotations |
| 3 | + |
| 4 | +import errno |
| 5 | +import os |
| 6 | +import sys |
| 7 | +from typing import Callable |
| 8 | +from typing import TYPE_CHECKING |
| 9 | +from typing import TypeVar |
| 10 | + |
| 11 | +if TYPE_CHECKING: |
| 12 | + from typing_extensions import ParamSpec |
| 13 | + |
| 14 | + P = ParamSpec("P") |
| 15 | + |
| 16 | +R = TypeVar("R") |
| 17 | + |
| 18 | + |
| 19 | +class Error(EnvironmentError): |
| 20 | + def __repr__(self) -> str: |
| 21 | + return "{}.{} {!r}: {} ".format( |
| 22 | + self.__class__.__module__, |
| 23 | + self.__class__.__name__, |
| 24 | + self.__class__.__doc__, |
| 25 | + " ".join(map(str, self.args)), |
| 26 | + # repr(self.args) |
| 27 | + ) |
| 28 | + |
| 29 | + def __str__(self) -> str: |
| 30 | + s = "[{}]: {}".format( |
| 31 | + self.__class__.__doc__, |
| 32 | + " ".join(map(str, self.args)), |
| 33 | + ) |
| 34 | + return s |
| 35 | + |
| 36 | + |
| 37 | +_winerrnomap = { |
| 38 | + 2: errno.ENOENT, |
| 39 | + 3: errno.ENOENT, |
| 40 | + 17: errno.EEXIST, |
| 41 | + 18: errno.EXDEV, |
| 42 | + 13: errno.EBUSY, # empty cd drive, but ENOMEDIUM seems unavailiable |
| 43 | + 22: errno.ENOTDIR, |
| 44 | + 20: errno.ENOTDIR, |
| 45 | + 267: errno.ENOTDIR, |
| 46 | + 5: errno.EACCES, # anything better? |
| 47 | +} |
| 48 | + |
| 49 | + |
| 50 | +class ErrorMaker: |
| 51 | + """lazily provides Exception classes for each possible POSIX errno |
| 52 | + (as defined per the 'errno' module). All such instances |
| 53 | + subclass EnvironmentError. |
| 54 | + """ |
| 55 | + |
| 56 | + _errno2class: dict[int, type[Error]] = {} |
| 57 | + |
| 58 | + def __getattr__(self, name: str) -> type[Error]: |
| 59 | + if name[0] == "_": |
| 60 | + raise AttributeError(name) |
| 61 | + eno = getattr(errno, name) |
| 62 | + cls = self._geterrnoclass(eno) |
| 63 | + setattr(self, name, cls) |
| 64 | + return cls |
| 65 | + |
| 66 | + def _geterrnoclass(self, eno: int) -> type[Error]: |
| 67 | + try: |
| 68 | + return self._errno2class[eno] |
| 69 | + except KeyError: |
| 70 | + clsname = errno.errorcode.get(eno, "UnknownErrno%d" % (eno,)) |
| 71 | + errorcls = type( |
| 72 | + clsname, |
| 73 | + (Error,), |
| 74 | + {"__module__": "py.error", "__doc__": os.strerror(eno)}, |
| 75 | + ) |
| 76 | + self._errno2class[eno] = errorcls |
| 77 | + return errorcls |
| 78 | + |
| 79 | + def checked_call( |
| 80 | + self, func: Callable[P, R], *args: P.args, **kwargs: P.kwargs |
| 81 | + ) -> R: |
| 82 | + """Call a function and raise an errno-exception if applicable.""" |
| 83 | + __tracebackhide__ = True |
| 84 | + try: |
| 85 | + return func(*args, **kwargs) |
| 86 | + except Error: |
| 87 | + raise |
| 88 | + except OSError as value: |
| 89 | + if not hasattr(value, "errno"): |
| 90 | + raise |
| 91 | + errno = value.errno |
| 92 | + if sys.platform == "win32": |
| 93 | + try: |
| 94 | + cls = self._geterrnoclass(_winerrnomap[errno]) |
| 95 | + except KeyError: |
| 96 | + raise value |
| 97 | + else: |
| 98 | + # we are not on Windows, or we got a proper OSError |
| 99 | + cls = self._geterrnoclass(errno) |
| 100 | + |
| 101 | + raise cls(f"{func.__name__}{args!r}") |
| 102 | + |
| 103 | + |
| 104 | +_error_maker = ErrorMaker() |
| 105 | +checked_call = _error_maker.checked_call |
| 106 | + |
| 107 | + |
| 108 | +def __getattr__(attr: str) -> type[Error]: |
| 109 | + return getattr(_error_maker, attr) # type: ignore[no-any-return] |
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