import copy
import math
import operator
import sys
import typing as t
import warnings
from functools import partial
from functools import update_wrapper
from .wsgi import ClosingIterator
if t.TYPE_CHECKING:
from _typeshed.wsgi import StartResponse
from _typeshed.wsgi import WSGIApplication
from _typeshed.wsgi import WSGIEnvironment
F = t.TypeVar("F", bound=t.Callable[..., t.Any])
try:
from greenlet import getcurrent as _get_ident
except ImportError:
from threading import get_ident as _get_ident
def get_ident() -> int:
warnings.warn(
"'get_ident' is deprecated and will be removed in Werkzeug"
" 2.1. Use 'greenlet.getcurrent' or 'threading.get_ident' for"
" previous behavior.",
DeprecationWarning,
stacklevel=2,
)
return _get_ident() # type: ignore
class _CannotUseContextVar(Exception):
pass
try:
from contextvars import ContextVar
if "gevent" in sys.modules or "eventlet" in sys.modules:
# Both use greenlet, so first check it has patched
# ContextVars, Greenlet <0.4.17 does not.
import greenlet
greenlet_patched = getattr(greenlet, "GREENLET_USE_CONTEXT_VARS", False)
if not greenlet_patched:
# If Gevent is used, check it has patched ContextVars,
# <20.5 does not.
try:
from gevent.monkey import is_object_patched
except ImportError:
# Gevent isn't used, but Greenlet is and hasn't patched
raise _CannotUseContextVar()
else:
if is_object_patched("threading", "local") and not is_object_patched(
"contextvars", "ContextVar"
):
raise _CannotUseContextVar()
except (ImportError, _CannotUseContextVar):
class ContextVar: # type: ignore
"""A fake ContextVar based on the previous greenlet/threading
ident function. Used on Python 3.6, eventlet, and old versions
of gevent.
"""
def __init__(self, _name: str) -> None:
self.storage: t.Dict[int, t.Dict[str, t.Any]] = {}
def get(self, default: t.Dict[str, t.Any]) -> t.Dict[str, t.Any]:
return self.storage.get(_get_ident(), default)
def set(self, value: t.Dict[str, t.Any]) -> None:
self.storage[_get_ident()] = value
def release_local(local: t.Union["Local", "LocalStack"]) -> None:
"""Releases the contents of the local for the current context.
This makes it possible to use locals without a manager.
Example::
>>> loc = Local()
>>> loc.foo = 42
>>> release_local(loc)
>>> hasattr(loc, 'foo')
False
With this function one can release :class:`Local` objects as well
as :class:`LocalStack` objects. However it is not possible to
release data held by proxies that way, one always has to retain
a reference to the underlying local object in order to be able
to release it.
.. versionadded:: 0.6.1
"""
local.__release_local__()
class Local:
__slots__ = ("_storage",)
def __init__(self) -> None:
object.__setattr__(self, "_storage", ContextVar("local_storage"))
@property
def __storage__(self) -> t.Dict[str, t.Any]:
warnings.warn(
"'__storage__' is deprecated and will be removed in Werkzeug 2.1.",
DeprecationWarning,
stacklevel=2,
)
return self._storage.get({}) # type: ignore
@property
def __ident_func__(self) -> t.Callable[[], int]:
warnings.warn(
"'__ident_func__' is deprecated and will be removed in"
" Werkzeug 2.1. It should not be used in Python 3.7+.",
DeprecationWarning,
stacklevel=2,
)
return _get_ident # type: ignore
@__ident_func__.setter
def __ident_func__(self, func: t.Callable[[], int]) -> None:
warnings.warn(
"'__ident_func__' is deprecated and will be removed in"
" Werkzeug 2.1. Setting it no longer has any effect.",
DeprecationWarning,
stacklevel=2,
)
def __iter__(self) -> t.Iterator[t.Tuple[int, t.Any]]:
return iter(self._storage.get({}).items())
def __call__(self, proxy: str) -> "LocalProxy":
"""Create a proxy for a name."""
return LocalProxy(self, proxy)
def __release_local__(self) -> None:
self._storage.set({})
def __getattr__(self, name: str) -> t.Any:
values = self._storage.get({})
try:
return values[name]
except KeyError:
raise AttributeError(name)
def __setattr__(self, name: str, value: t.Any) -> None:
values = self._storage.get({}).copy()
values[name] = value
self._storage.set(values)
def __delattr__(self, name: str) -> None:
values = self._storage.get({}).copy()
try:
del values[name]
self._storage.set(values)
except KeyError:
raise AttributeError(name)
class LocalStack:
"""This class works similar to a :class:`Local` but keeps a stack
of objects instead. This is best explained with an example::
>>> ls = LocalStack()
>>> ls.push(42)
>>> ls.top
42
>>> ls.push(23)
>>> ls.top
23
>>> ls.pop()
23
>>> ls.top
42
They can be force released by using a :class:`LocalManager` or with
the :func:`release_local` function but the correct way is to pop the
item from the stack after using. When the stack is empty it will
no longer be bound to the current context (and as such released).
By calling the stack without arguments it returns a proxy that resolves to
the topmost item on the stack.
.. versionadded:: 0.6.1
"""
def __init__(self) -> None:
self._local = Local()
def __release_local__(self) -> None:
self._local.__release_local__()
@property
def __ident_func__(self) -> t.Callable[[], int]:
return self._local.__ident_func__
@__ident_func__.setter
def __ident_func__(self, value: t.Callable[[], int]) -> None:
object.__setattr__(self._local, "__ident_func__", value)
def __call__(self) -> "LocalProxy":
def _lookup() -> t.Any:
rv = self.top
if rv is None:
raise RuntimeError("object unbound")
return rv
return LocalProxy(_lookup)
def push(self, obj: t.Any) -> t.List[t.Any]:
"""Pushes a new item to the stack"""
rv = getattr(self._local, "stack", []).copy()
rv.append(obj)
self._local.stack = rv
return rv # type: ignore
def pop(self) -> t.Any:
"""Removes the topmost item from the stack, will return the
old value or `None` if the stack was already empty.
"""
stack = getattr(self._local, "stack", None)
if stack is None:
return None
elif len(stack) == 1:
release_local(self._local)
return stack[-1]
else:
return stack.pop()
@property
def top(self) -> t.Any:
"""The topmost item on the stack. If the stack is empty,
`None` is returned.
"""
try:
return self._local.stack[-1]
except (AttributeError, IndexError):
return None
class LocalManager:
"""Local objects cannot manage themselves. For that you need a local
manager. You can pass a local manager multiple locals or add them
later y appending them to `manager.locals`. Every time the manager
cleans up, it will clean up all the data left in the locals for this
context.
.. versionchanged:: 2.0
``ident_func`` is deprecated and will be removed in Werkzeug
2.1.
.. versionchanged:: 0.6.1
The :func:`release_local` function can be used instead of a
manager.
.. versionchanged:: 0.7
The ``ident_func`` parameter was added.
"""
def __init__(
self,
locals: t.Optional[t.Iterable[t.Union[Local, LocalStack]]] = None,
ident_func: None = None,
) -> None:
if locals is None:
self.locals = []
elif isinstance(locals, Local):
self.locals = [locals]
else:
self.locals = list(locals)
if ident_func is not None:
warnings.warn(
"'ident_func' is deprecated and will be removed in"
" Werkzeug 2.1. Setting it no longer has any effect.",
DeprecationWarning,
stacklevel=2,
)
@property
def ident_func(self) -> t.Callable[[], int]:
warnings.warn(
"'ident_func' is deprecated and will be removed in Werkzeug 2.1.",
DeprecationWarning,
stacklevel=2,
)
return _get_ident # type: ignore
@ident_func.setter
def ident_func(self, func: t.Callable[[], int]) -> None:
warnings.warn(
"'ident_func' is deprecated and will be removedin Werkzeug"
" 2.1. Setting it no longer has any effect.",
DeprecationWarning,
stacklevel=2,
)
def get_ident(self) -> int:
"""Return the context identifier the local objects use internally for
this context. You cannot override this method to change the behavior
but use it to link other context local objects (such as SQLAlchemy's
scoped sessions) to the Werkzeug locals.
.. deprecated:: 2.0
Will be removed in Werkzeug 2.1.
.. versionchanged:: 0.7
You can pass a different ident function to the local manager that
will then be propagated to all the locals passed to the
constructor.
"""
warnings.warn(
"'get_ident' is deprecated and will be removed in Werkzeug 2.1.",
DeprecationWarning,
stacklevel=2,
)
return self.ident_func()
def cleanup(self) -> None:
"""Manually clean up the data in the locals for this context. Call
this at the end of the request or use `make_middleware()`.
"""
for local in self.locals:
release_local(local)
def make_middleware(self, app: "WSGIApplication") -> "WSGIApplication":
"""Wrap a WSGI application so that cleaning up happens after
request end.
"""
def application(
environ: "WSGIEnvironment", start_response: "StartResponse"
) -> t.Iterable[bytes]:
return ClosingIterator(app(environ, start_response), self.cleanup)
return application
def middleware(self, func: "WSGIApplication") -> "WSGIApplication":
"""Like `make_middleware` but for decorating functions.
Example usage::
@manager.middleware
def application(environ, start_response):
...
The difference to `make_middleware` is that the function passed
will have all the arguments copied from the inner application
(name, docstring, module).
"""
return update_wrapper(self.make_middleware(func), func)
def __repr__(self) -> str:
return f"<{type(self).__name__} storages: {len(self.locals)}>"
class _ProxyLookup:
"""Descriptor that handles proxied attribute lookup for
:class:`LocalProxy`.
:param f: The built-in function this attribute is accessed through.
Instead of looking up the special method, the function call
is redone on the object.
:param fallback: Call this method if the proxy is unbound instead of
raising a :exc:`RuntimeError`.
:param class_value: Value to return when accessed from the class.
Used for ``__doc__`` so building docs still works.
"""
__slots__ = ("bind_f", "fallback", "class_value", "name")
def __init__(
self,
f: t.Optional[t.Callable] = None,
fallback: t.Optional[t.Callable] = None,
class_value: t.Optional[t.Any] = None,
) -> None:
bind_f: t.Optional[t.Callable[["LocalProxy", t.Any], t.Callable]]
if hasattr(f, "__get__"):
# A Python function, can be turned into a bound method.
def bind_f(instance: "LocalProxy", obj: t.Any) -> t.Callable:
return f.__get__(obj, type(obj)) # type: ignore
elif f is not None:
# A C function, use partial to bind the first argument.
def bind_f(instance: "LocalProxy", obj: t.Any) -> t.Callable:
return partial(f, obj) # type: ignore
else:
# Use getattr, which will produce a bound method.
bind_f = None
self.bind_f = bind_f
self.fallback = fallback
self.class_value = class_value
def __set_name__(self, owner: "LocalProxy", name: str) -> None:
self.name = name
def __get__(self, instance: "LocalProxy", owner: t.Optional[type] = None) -> t.Any:
if instance is None:
if self.class_value is not None:
return self.class_value
return self
try:
obj = instance._get_current_object()
except RuntimeError:
if self.fallback is None:
raise
return self.fallback.__get__(instance, owner) # type: ignore
if self.bind_f is not None:
return self.bind_f(instance, obj)
return getattr(obj, self.name)
def __repr__(self) -> str:
return f"proxy {self.name}"
def __call__(self, instance: "LocalProxy", *args: t.Any, **kwargs: t.Any) -> t.Any:
"""Support calling unbound methods from the class. For example,
this happens with ``copy.copy``, which does
``type(x).__copy__(x)``. ``type(x)`` can't be proxied, so it
returns the proxy type and descriptor.
"""
return self.__get__(instance, type(instance))(*args, **kwargs)
class _ProxyIOp(_ProxyLookup):
"""Look up an augmented assignment method on a proxied object. The
method is wrapped to return the proxy instead of the object.
"""
__slots__ = ()
def __init__(
self, f: t.Optional[t.Callable] = None, fallback: t.Optional[t.Callable] = None
) -> None:
super().__init__(f, fallback)
def bind_f(instance: "LocalProxy", obj: t.Any) -> t.Callable:
def i_op(self: t.Any, other: t.Any) -> "LocalProxy":
f(self, other) # type: ignore
return instance
return i_op.__get__(obj, type(obj)) # type: ignore
self.bind_f = bind_f
def _l_to_r_op(op: F) -> F:
"""Swap the argument order to turn an l-op into an r-op."""
def r_op(obj: t.Any, other: t.Any) -> t.Any:
return op(other, obj)
return t.cast(F, r_op)
class LocalProxy:
"""A proxy to the object bound to a :class:`Local`. All operations
on the proxy are forwarded to the bound object. If no object is
bound, a :exc:`RuntimeError` is raised.
.. code-block:: python
from werkzeug.local import Local
l = Local()
# a proxy to whatever l.user is set to
user = l("user")
from werkzeug.local import LocalStack
_request_stack = LocalStack()
# a proxy to _request_stack.top
request = _request_stack()
# a proxy to the session attribute of the request proxy
session = LocalProxy(lambda: request.session)
``__repr__`` and ``__class__`` are forwarded, so ``repr(x)`` and
``isinstance(x, cls)`` will look like the proxied object. Use
``issubclass(type(x), LocalProxy)`` to check if an object is a
proxy.
.. code-block:: python
repr(user) # <User admin>
isinstance(user, User) # True
issubclass(type(user), LocalProxy) # True
:param local: The :class:`Local` or callable that provides the
proxied object.
:param name: The attribute name to look up on a :class:`Local`. Not
used if a callable is given.
.. versionchanged:: 2.0
Updated proxied attributes and methods to reflect the current
data model.
.. versionchanged:: 0.6.1
The class can be instantiated with a callable.
"""
__slots__ = ("__local", "__name", "__wrapped__")
def __init__(
self,
local: t.Union["Local", t.Callable[[], t.Any]],
name: t.Optional[str] = None,
) -> None:
object.__setattr__(self, "_LocalProxy__local", local)
object.__setattr__(self, "_LocalProxy__name", name)
if callable(local) and not hasattr(local, "__release_local__"):
# "local" is a callable that is not an instance of Local or
# LocalManager: mark it as a wrapped function.
object.__setattr__(self, "__wrapped__", local)
def _get_current_object(self) -> t.Any:
"""Return the current object. This is useful if you want the real
object behind the proxy at a time for performance reasons or because
you want to pass the object into a different context.
"""
if not hasattr(self.__local, "__release_local__"): # type: ignore
return self.__local() # type: ignore
try:
return getattr(self.__local, self.__name) # type: ignore
except AttributeError:
raise RuntimeError(f"no object bound to {self.__name}") # type: ignore
__doc__ = _ProxyLookup( # type: ignore
class_value=__doc__, fallback=lambda self: type(self).__doc__
)
# __del__ should only delete the proxy
__repr__ = _ProxyLookup( # type: ignore
repr, fallback=lambda self: f"<{type(self).__name__} unbound>"
)
__str__ = _ProxyLookup(str) # type: ignore
__bytes__ = _ProxyLookup(bytes)
__format__ = _ProxyLookup() # type: ignore
__lt__ = _ProxyLookup(operator.lt)
__le__ = _ProxyLookup(operator.le)
__eq__ = _ProxyLookup(operator.eq) # type: ignore
__ne__ = _ProxyLookup(operator.ne) # type: ignore
__gt__ = _ProxyLookup(operator.gt)
__ge__ = _ProxyLookup(operator.ge)
__hash__ = _ProxyLookup(hash) # type: ignore
__bool__ = _ProxyLookup(bool, fallback=lambda self: False)
__getattr__ = _ProxyLookup(getattr)
# __getattribute__ triggered through __getattr__
__setattr__ = _ProxyLookup(setattr) # type: ignore
__delattr__ = _ProxyLookup(delattr) # type: ignore
__dir__ = _ProxyLookup(dir, fallback=lambda self: []) # type: ignore
# __get__ (proxying descriptor not supported)
# __set__ (descriptor)
# __delete__ (descriptor)
# __set_name__ (descriptor)
# __objclass__ (descriptor)
# __slots__ used by proxy itself
# __dict__ (__getattr__)
# __weakref__ (__getattr__)
# __init_subclass__ (proxying metaclass not supported)
# __prepare__ (metaclass)
__class__ = _ProxyLookup(fallback=lambda self: type(self)) # type: ignore
__instancecheck__ = _ProxyLookup(lambda self, other: isinstance(other, self))
__subclasscheck__ = _ProxyLookup(lambda self, other: issubclass(other, self))
# __class_getitem__ triggered through __getitem__
__call__ = _ProxyLookup(lambda self, *args, **kwargs: self(*args, **kwargs))
__len__ = _ProxyLookup(len)
__length_hint__ = _ProxyLookup(operator.length_hint)
__getitem__ = _ProxyLookup(operator.getitem)
__setitem__ = _ProxyLookup(operator.setitem)
__delitem__ = _ProxyLookup(operator.delitem)
# __missing__ triggered through __getitem__
__iter__ = _ProxyLookup(iter)
__next__ = _ProxyLookup(next)
__reversed__ = _ProxyLookup(reversed)
__contains__ = _ProxyLookup(operator.contains)
__add__ = _ProxyLookup(operator.add)
__sub__ = _ProxyLookup(operator.sub)
__mul__ = _ProxyLookup(operator.mul)
__matmul__ = _ProxyLookup(operator.matmul)
__truediv__ = _ProxyLookup(operator.truediv)
__floordiv__ = _ProxyLookup(operator.floordiv)
__mod__ = _ProxyLookup(operator.mod)
__divmod__ = _ProxyLookup(divmod)
__pow__ = _ProxyLookup(pow)
__lshift__ = _ProxyLookup(operator.lshift)
__rshift__ = _ProxyLookup(operator.rshift)
__and__ = _ProxyLookup(operator.and_)
__xor__ = _ProxyLookup(operator.xor)
__or__ = _ProxyLookup(operator.or_)
__radd__ = _ProxyLookup(_l_to_r_op(operator.add))
__rsub__ = _ProxyLookup(_l_to_r_op(operator.sub))
__rmul__ = _ProxyLookup(_l_to_r_op(operator.mul))
__rmatmul__ = _ProxyLookup(_l_to_r_op(operator.matmul))
__rtruediv__ = _ProxyLookup(_l_to_r_op(operator.truediv))
__rfloordiv__ = _ProxyLookup(_l_to_r_op(operator.floordiv))
__rmod__ = _ProxyLookup(_l_to_r_op(operator.mod))
__rdivmod__ = _ProxyLookup(_l_to_r_op(divmod))
__rpow__ = _ProxyLookup(_l_to_r_op(pow))
__rlshift__ = _ProxyLookup(_l_to_r_op(operator.lshift))
__rrshift__ = _ProxyLookup(_l_to_r_op(operator.rshift))
__rand__ = _ProxyLookup(_l_to_r_op(operator.and_))
__rxor__ = _ProxyLookup(_l_to_r_op(operator.xor))
__ror__ = _ProxyLookup(_l_to_r_op(operator.or_))
__iadd__ = _ProxyIOp(operator.iadd)
__isub__ = _ProxyIOp(operator.isub)
__imul__ = _ProxyIOp(operator.imul)
__imatmul__ = _ProxyIOp(operator.imatmul)
__itruediv__ = _ProxyIOp(operator.itruediv)
__ifloordiv__ = _ProxyIOp(operator.ifloordiv)
__imod__ = _ProxyIOp(operator.imod)
__ipow__ = _ProxyIOp(operator.ipow)
__ilshift__ = _ProxyIOp(operator.ilshift)
__irshift__ = _ProxyIOp(operator.irshift)
__iand__ = _ProxyIOp(operator.iand)
__ixor__ = _ProxyIOp(operator.ixor)
__ior__ = _ProxyIOp(operator.ior)
__neg__ = _ProxyLookup(operator.neg)
__pos__ = _ProxyLookup(operator.pos)
__abs__ = _ProxyLookup(abs)
__invert__ = _ProxyLookup(operator.invert)
__complex__ = _ProxyLookup(complex)
__int__ = _ProxyLookup(int)
__float__ = _ProxyLookup(float)
__index__ = _ProxyLookup(operator.index)
__round__ = _ProxyLookup(round)
__trunc__ = _ProxyLookup(math.trunc)
__floor__ = _ProxyLookup(math.floor)
__ceil__ = _ProxyLookup(math.ceil)
__enter__ = _ProxyLookup()
__exit__ = _ProxyLookup()
__await__ = _ProxyLookup()
__aiter__ = _ProxyLookup()
__anext__ = _ProxyLookup()
__aenter__ = _ProxyLookup()
__aexit__ = _ProxyLookup()
__copy__ = _ProxyLookup(copy.copy)
__deepcopy__ = _ProxyLookup(copy.deepcopy)
# __getnewargs_ex__ (pickle through proxy not supported)
# __getnewargs__ (pickle)
# __getstate__ (pickle)
# __setstate__ (pickle)
# __reduce__ (pickle)
# __reduce_ex__ (pickle)