# type: ignore
from functools import wraps, partial
import os
import types
import pathlib
import trio
from trio._util import async_wraps, Final
# re-wrap return value from methods that return new instances of pathlib.Path
def rewrap_path(value):
if isinstance(value, pathlib.Path):
value = Path(value)
return value
def _forward_factory(cls, attr_name, attr):
@wraps(attr)
def wrapper(self, *args, **kwargs):
attr = getattr(self._wrapped, attr_name)
value = attr(*args, **kwargs)
return rewrap_path(value)
return wrapper
def _forward_magic(cls, attr):
sentinel = object()
@wraps(attr)
def wrapper(self, other=sentinel):
if other is sentinel:
return attr(self._wrapped)
if isinstance(other, cls):
other = other._wrapped
value = attr(self._wrapped, other)
return rewrap_path(value)
return wrapper
def iter_wrapper_factory(cls, meth_name):
@async_wraps(cls, cls._wraps, meth_name)
async def wrapper(self, *args, **kwargs):
meth = getattr(self._wrapped, meth_name)
func = partial(meth, *args, **kwargs)
# Make sure that the full iteration is performed in the thread
# by converting the generator produced by pathlib into a list
items = await trio.to_thread.run_sync(lambda: list(func()))
return (rewrap_path(item) for item in items)
return wrapper
def thread_wrapper_factory(cls, meth_name):
@async_wraps(cls, cls._wraps, meth_name)
async def wrapper(self, *args, **kwargs):
meth = getattr(self._wrapped, meth_name)
func = partial(meth, *args, **kwargs)
value = await trio.to_thread.run_sync(func)
return rewrap_path(value)
return wrapper
def classmethod_wrapper_factory(cls, meth_name):
@classmethod
@async_wraps(cls, cls._wraps, meth_name)
async def wrapper(cls, *args, **kwargs):
meth = getattr(cls._wraps, meth_name)
func = partial(meth, *args, **kwargs)
value = await trio.to_thread.run_sync(func)
return rewrap_path(value)
return wrapper
class AsyncAutoWrapperType(Final):
def __init__(cls, name, bases, attrs):
super().__init__(name, bases, attrs)
cls._forward = []
type(cls).generate_forwards(cls, attrs)
type(cls).generate_wraps(cls, attrs)
type(cls).generate_magic(cls, attrs)
type(cls).generate_iter(cls, attrs)
def generate_forwards(cls, attrs):
# forward functions of _forwards
for attr_name, attr in cls._forwards.__dict__.items():
if attr_name.startswith("_") or attr_name in attrs:
continue
if isinstance(attr, property):
cls._forward.append(attr_name)
elif isinstance(attr, types.FunctionType):
wrapper = _forward_factory(cls, attr_name, attr)
setattr(cls, attr_name, wrapper)
else:
raise TypeError(attr_name, type(attr))
def generate_wraps(cls, attrs):
# generate wrappers for functions of _wraps
for attr_name, attr in cls._wraps.__dict__.items():
# .z. exclude cls._wrap_iter
if attr_name.startswith("_") or attr_name in attrs:
continue
if isinstance(attr, classmethod):
wrapper = classmethod_wrapper_factory(cls, attr_name)
setattr(cls, attr_name, wrapper)
elif isinstance(attr, types.FunctionType):
wrapper = thread_wrapper_factory(cls, attr_name)
setattr(cls, attr_name, wrapper)
else:
raise TypeError(attr_name, type(attr))
def generate_magic(cls, attrs):
# generate wrappers for magic
for attr_name in cls._forward_magic:
attr = getattr(cls._forwards, attr_name)
wrapper = _forward_magic(cls, attr)
setattr(cls, attr_name, wrapper)
def generate_iter(cls, attrs):
# generate wrappers for methods that return iterators
for attr_name, attr in cls._wraps.__dict__.items():
if attr_name in cls._wrap_iter:
wrapper = iter_wrapper_factory(cls, attr_name)
setattr(cls, attr_name, wrapper)
class Path(metaclass=AsyncAutoWrapperType):
"""A :class:`pathlib.Path` wrapper that executes blocking methods in
:meth:`trio.to_thread.run_sync`.
"""
_wraps = pathlib.Path
_forwards = pathlib.PurePath
_forward_magic = [
"__str__",
"__bytes__",
"__truediv__",
"__rtruediv__",
"__eq__",
"__lt__",
"__le__",
"__gt__",
"__ge__",
"__hash__",
]
_wrap_iter = ["glob", "rglob", "iterdir"]
def __init__(self, *args):
self._wrapped = pathlib.Path(*args)
def __getattr__(self, name):
if name in self._forward:
value = getattr(self._wrapped, name)
return rewrap_path(value)
raise AttributeError(name)
def __dir__(self):
return super().__dir__() + self._forward
def __repr__(self):
return "trio.Path({})".format(repr(str(self)))
def __fspath__(self):
return os.fspath(self._wrapped)
@wraps(pathlib.Path.open)
async def open(self, *args, **kwargs):
"""Open the file pointed to by the path, like the :func:`trio.open_file`
function does.
"""
func = partial(self._wrapped.open, *args, **kwargs)
value = await trio.to_thread.run_sync(func)
return trio.wrap_file(value)
Path.iterdir.__doc__ = """
Like :meth:`pathlib.Path.iterdir`, but async.
This is an async method that returns a synchronous iterator, so you
use it like::
for subpath in await mypath.iterdir():
...
Note that it actually loads the whole directory list into memory
immediately, during the initial call. (See `issue #501
<https://github.com/python-trio/trio/issues/501>`__ for discussion.)
"""
# The value of Path.absolute.__doc__ makes a reference to
# :meth:~pathlib.Path.absolute, which does not exist. Removing this makes more
# sense than inventing our own special docstring for this.
del Path.absolute.__doc__
os.PathLike.register(Path)
