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authorJames Taylor <user234683@users.noreply.github.com>2019-08-09 22:01:04 -0700
committerJames Taylor <user234683@users.noreply.github.com>2019-08-09 22:01:04 -0700
commit2e75c6d9603f8a5edf6495f8d4fb3115a67d823c (patch)
tree8fb2d1bec2cf0e50c5fce6bc718f755485419db0 /python/werkzeug/local.py
parentcc9283ad5332f59a69a91d9d0fab299779de513c (diff)
parentadc40bc760345a23678a01f27d7697dfd3811914 (diff)
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Merge flask framework and other stuff from master
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+# -*- coding: utf-8 -*-
+"""
+ werkzeug.local
+ ~~~~~~~~~~~~~~
+
+ This module implements context-local objects.
+
+ :copyright: 2007 Pallets
+ :license: BSD-3-Clause
+"""
+import copy
+from functools import update_wrapper
+
+from ._compat import implements_bool
+from ._compat import PY2
+from .wsgi import ClosingIterator
+
+# since each thread has its own greenlet we can just use those as identifiers
+# for the context. If greenlets are not available we fall back to the
+# current thread ident depending on where it is.
+try:
+ from greenlet import getcurrent as get_ident
+except ImportError:
+ try:
+ from thread import get_ident
+ except ImportError:
+ from _thread import get_ident
+
+
+def release_local(local):
+ """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(object):
+ __slots__ = ("__storage__", "__ident_func__")
+
+ def __init__(self):
+ object.__setattr__(self, "__storage__", {})
+ object.__setattr__(self, "__ident_func__", get_ident)
+
+ def __iter__(self):
+ return iter(self.__storage__.items())
+
+ def __call__(self, proxy):
+ """Create a proxy for a name."""
+ return LocalProxy(self, proxy)
+
+ def __release_local__(self):
+ self.__storage__.pop(self.__ident_func__(), None)
+
+ def __getattr__(self, name):
+ try:
+ return self.__storage__[self.__ident_func__()][name]
+ except KeyError:
+ raise AttributeError(name)
+
+ def __setattr__(self, name, value):
+ ident = self.__ident_func__()
+ storage = self.__storage__
+ try:
+ storage[ident][name] = value
+ except KeyError:
+ storage[ident] = {name: value}
+
+ def __delattr__(self, name):
+ try:
+ del self.__storage__[self.__ident_func__()][name]
+ except KeyError:
+ raise AttributeError(name)
+
+
+class LocalStack(object):
+ """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):
+ self._local = Local()
+
+ def __release_local__(self):
+ self._local.__release_local__()
+
+ def _get__ident_func__(self):
+ return self._local.__ident_func__
+
+ def _set__ident_func__(self, value):
+ object.__setattr__(self._local, "__ident_func__", value)
+
+ __ident_func__ = property(_get__ident_func__, _set__ident_func__)
+ del _get__ident_func__, _set__ident_func__
+
+ def __call__(self):
+ def _lookup():
+ rv = self.top
+ if rv is None:
+ raise RuntimeError("object unbound")
+ return rv
+
+ return LocalProxy(_lookup)
+
+ def push(self, obj):
+ """Pushes a new item to the stack"""
+ rv = getattr(self._local, "stack", None)
+ if rv is None:
+ self._local.stack = rv = []
+ rv.append(obj)
+ return rv
+
+ def pop(self):
+ """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):
+ """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(object):
+ """Local objects cannot manage themselves. For that you need a local
+ manager. You can pass a local manager multiple locals or add them later
+ by 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.
+
+ The `ident_func` parameter can be added to override the default ident
+ function for the wrapped locals.
+
+ .. versionchanged:: 0.6.1
+ Instead of a manager the :func:`release_local` function can be used
+ as well.
+
+ .. versionchanged:: 0.7
+ `ident_func` was added.
+ """
+
+ def __init__(self, locals=None, ident_func=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:
+ self.ident_func = ident_func
+ for local in self.locals:
+ object.__setattr__(local, "__ident_func__", ident_func)
+ else:
+ self.ident_func = get_ident
+
+ def get_ident(self):
+ """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.
+
+ .. 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.
+ """
+ return self.ident_func()
+
+ def cleanup(self):
+ """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):
+ """Wrap a WSGI application so that cleaning up happens after
+ request end.
+ """
+
+ def application(environ, start_response):
+ return ClosingIterator(app(environ, start_response), self.cleanup)
+
+ return application
+
+ def middleware(self, func):
+ """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):
+ return "<%s storages: %d>" % (self.__class__.__name__, len(self.locals))
+
+
+@implements_bool
+class LocalProxy(object):
+ """Acts as a proxy for a werkzeug local. Forwards all operations to
+ a proxied object. The only operations not supported for forwarding
+ are right handed operands and any kind of assignment.
+
+ Example usage::
+
+ from werkzeug.local import Local
+ l = Local()
+
+ # these are proxies
+ request = l('request')
+ user = l('user')
+
+
+ from werkzeug.local import LocalStack
+ _response_local = LocalStack()
+
+ # this is a proxy
+ response = _response_local()
+
+ Whenever something is bound to l.user / l.request the proxy objects
+ will forward all operations. If no object is bound a :exc:`RuntimeError`
+ will be raised.
+
+ To create proxies to :class:`Local` or :class:`LocalStack` objects,
+ call the object as shown above. If you want to have a proxy to an
+ object looked up by a function, you can (as of Werkzeug 0.6.1) pass
+ a function to the :class:`LocalProxy` constructor::
+
+ session = LocalProxy(lambda: get_current_request().session)
+
+ .. versionchanged:: 0.6.1
+ The class can be instantiated with a callable as well now.
+ """
+
+ __slots__ = ("__local", "__dict__", "__name__", "__wrapped__")
+
+ def __init__(self, local, name=None):
+ object.__setattr__(self, "_LocalProxy__local", local)
+ object.__setattr__(self, "__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):
+ """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__"):
+ return self.__local()
+ try:
+ return getattr(self.__local, self.__name__)
+ except AttributeError:
+ raise RuntimeError("no object bound to %s" % self.__name__)
+
+ @property
+ def __dict__(self):
+ try:
+ return self._get_current_object().__dict__
+ except RuntimeError:
+ raise AttributeError("__dict__")
+
+ def __repr__(self):
+ try:
+ obj = self._get_current_object()
+ except RuntimeError:
+ return "<%s unbound>" % self.__class__.__name__
+ return repr(obj)
+
+ def __bool__(self):
+ try:
+ return bool(self._get_current_object())
+ except RuntimeError:
+ return False
+
+ def __unicode__(self):
+ try:
+ return unicode(self._get_current_object()) # noqa
+ except RuntimeError:
+ return repr(self)
+
+ def __dir__(self):
+ try:
+ return dir(self._get_current_object())
+ except RuntimeError:
+ return []
+
+ def __getattr__(self, name):
+ if name == "__members__":
+ return dir(self._get_current_object())
+ return getattr(self._get_current_object(), name)
+
+ def __setitem__(self, key, value):
+ self._get_current_object()[key] = value
+
+ def __delitem__(self, key):
+ del self._get_current_object()[key]
+
+ if PY2:
+ __getslice__ = lambda x, i, j: x._get_current_object()[i:j]
+
+ def __setslice__(self, i, j, seq):
+ self._get_current_object()[i:j] = seq
+
+ def __delslice__(self, i, j):
+ del self._get_current_object()[i:j]
+
+ __setattr__ = lambda x, n, v: setattr(x._get_current_object(), n, v)
+ __delattr__ = lambda x, n: delattr(x._get_current_object(), n)
+ __str__ = lambda x: str(x._get_current_object())
+ __lt__ = lambda x, o: x._get_current_object() < o
+ __le__ = lambda x, o: x._get_current_object() <= o
+ __eq__ = lambda x, o: x._get_current_object() == o
+ __ne__ = lambda x, o: x._get_current_object() != o
+ __gt__ = lambda x, o: x._get_current_object() > o
+ __ge__ = lambda x, o: x._get_current_object() >= o
+ __cmp__ = lambda x, o: cmp(x._get_current_object(), o) # noqa
+ __hash__ = lambda x: hash(x._get_current_object())
+ __call__ = lambda x, *a, **kw: x._get_current_object()(*a, **kw)
+ __len__ = lambda x: len(x._get_current_object())
+ __getitem__ = lambda x, i: x._get_current_object()[i]
+ __iter__ = lambda x: iter(x._get_current_object())
+ __contains__ = lambda x, i: i in x._get_current_object()
+ __add__ = lambda x, o: x._get_current_object() + o
+ __sub__ = lambda x, o: x._get_current_object() - o
+ __mul__ = lambda x, o: x._get_current_object() * o
+ __floordiv__ = lambda x, o: x._get_current_object() // o
+ __mod__ = lambda x, o: x._get_current_object() % o
+ __divmod__ = lambda x, o: x._get_current_object().__divmod__(o)
+ __pow__ = lambda x, o: x._get_current_object() ** o
+ __lshift__ = lambda x, o: x._get_current_object() << o
+ __rshift__ = lambda x, o: x._get_current_object() >> o
+ __and__ = lambda x, o: x._get_current_object() & o
+ __xor__ = lambda x, o: x._get_current_object() ^ o
+ __or__ = lambda x, o: x._get_current_object() | o
+ __div__ = lambda x, o: x._get_current_object().__div__(o)
+ __truediv__ = lambda x, o: x._get_current_object().__truediv__(o)
+ __neg__ = lambda x: -(x._get_current_object())
+ __pos__ = lambda x: +(x._get_current_object())
+ __abs__ = lambda x: abs(x._get_current_object())
+ __invert__ = lambda x: ~(x._get_current_object())
+ __complex__ = lambda x: complex(x._get_current_object())
+ __int__ = lambda x: int(x._get_current_object())
+ __long__ = lambda x: long(x._get_current_object()) # noqa
+ __float__ = lambda x: float(x._get_current_object())
+ __oct__ = lambda x: oct(x._get_current_object())
+ __hex__ = lambda x: hex(x._get_current_object())
+ __index__ = lambda x: x._get_current_object().__index__()
+ __coerce__ = lambda x, o: x._get_current_object().__coerce__(x, o)
+ __enter__ = lambda x: x._get_current_object().__enter__()
+ __exit__ = lambda x, *a, **kw: x._get_current_object().__exit__(*a, **kw)
+ __radd__ = lambda x, o: o + x._get_current_object()
+ __rsub__ = lambda x, o: o - x._get_current_object()
+ __rmul__ = lambda x, o: o * x._get_current_object()
+ __rdiv__ = lambda x, o: o / x._get_current_object()
+ if PY2:
+ __rtruediv__ = lambda x, o: x._get_current_object().__rtruediv__(o)
+ else:
+ __rtruediv__ = __rdiv__
+ __rfloordiv__ = lambda x, o: o // x._get_current_object()
+ __rmod__ = lambda x, o: o % x._get_current_object()
+ __rdivmod__ = lambda x, o: x._get_current_object().__rdivmod__(o)
+ __copy__ = lambda x: copy.copy(x._get_current_object())
+ __deepcopy__ = lambda x, memo: copy.deepcopy(x._get_current_object(), memo)