diff options
author | nkozlovskiy <[email protected]> | 2023-09-29 12:24:06 +0300 |
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committer | nkozlovskiy <[email protected]> | 2023-09-29 12:41:34 +0300 |
commit | e0e3e1717e3d33762ce61950504f9637a6e669ed (patch) | |
tree | bca3ff6939b10ed60c3d5c12439963a1146b9711 /contrib/python/Flask/py3/flask/ctx.py | |
parent | 38f2c5852db84c7b4d83adfcb009eb61541d1ccd (diff) |
add ydb deps
Diffstat (limited to 'contrib/python/Flask/py3/flask/ctx.py')
-rw-r--r-- | contrib/python/Flask/py3/flask/ctx.py | 489 |
1 files changed, 489 insertions, 0 deletions
diff --git a/contrib/python/Flask/py3/flask/ctx.py b/contrib/python/Flask/py3/flask/ctx.py new file mode 100644 index 00000000000..47465fd4e19 --- /dev/null +++ b/contrib/python/Flask/py3/flask/ctx.py @@ -0,0 +1,489 @@ +import sys +import typing as t +from functools import update_wrapper +from types import TracebackType + +from werkzeug.exceptions import HTTPException + +from .globals import _app_ctx_stack +from .globals import _request_ctx_stack +from .signals import appcontext_popped +from .signals import appcontext_pushed +from .typing import AfterRequestCallable + +if t.TYPE_CHECKING: + from .app import Flask + from .sessions import SessionMixin + from .wrappers import Request + + +# a singleton sentinel value for parameter defaults +_sentinel = object() + + +class _AppCtxGlobals: + """A plain object. Used as a namespace for storing data during an + application context. + + Creating an app context automatically creates this object, which is + made available as the :data:`g` proxy. + + .. describe:: 'key' in g + + Check whether an attribute is present. + + .. versionadded:: 0.10 + + .. describe:: iter(g) + + Return an iterator over the attribute names. + + .. versionadded:: 0.10 + """ + + # Define attr methods to let mypy know this is a namespace object + # that has arbitrary attributes. + + def __getattr__(self, name: str) -> t.Any: + try: + return self.__dict__[name] + except KeyError: + raise AttributeError(name) from None + + def __setattr__(self, name: str, value: t.Any) -> None: + self.__dict__[name] = value + + def __delattr__(self, name: str) -> None: + try: + del self.__dict__[name] + except KeyError: + raise AttributeError(name) from None + + def get(self, name: str, default: t.Optional[t.Any] = None) -> t.Any: + """Get an attribute by name, or a default value. Like + :meth:`dict.get`. + + :param name: Name of attribute to get. + :param default: Value to return if the attribute is not present. + + .. versionadded:: 0.10 + """ + return self.__dict__.get(name, default) + + def pop(self, name: str, default: t.Any = _sentinel) -> t.Any: + """Get and remove an attribute by name. Like :meth:`dict.pop`. + + :param name: Name of attribute to pop. + :param default: Value to return if the attribute is not present, + instead of raising a ``KeyError``. + + .. versionadded:: 0.11 + """ + if default is _sentinel: + return self.__dict__.pop(name) + else: + return self.__dict__.pop(name, default) + + def setdefault(self, name: str, default: t.Any = None) -> t.Any: + """Get the value of an attribute if it is present, otherwise + set and return a default value. Like :meth:`dict.setdefault`. + + :param name: Name of attribute to get. + :param default: Value to set and return if the attribute is not + present. + + .. versionadded:: 0.11 + """ + return self.__dict__.setdefault(name, default) + + def __contains__(self, item: str) -> bool: + return item in self.__dict__ + + def __iter__(self) -> t.Iterator[str]: + return iter(self.__dict__) + + def __repr__(self) -> str: + top = _app_ctx_stack.top + if top is not None: + return f"<flask.g of {top.app.name!r}>" + return object.__repr__(self) + + +def after_this_request(f: AfterRequestCallable) -> AfterRequestCallable: + """Executes a function after this request. This is useful to modify + response objects. The function is passed the response object and has + to return the same or a new one. + + Example:: + + @app.route('/') + def index(): + @after_this_request + def add_header(response): + response.headers['X-Foo'] = 'Parachute' + return response + return 'Hello World!' + + This is more useful if a function other than the view function wants to + modify a response. For instance think of a decorator that wants to add + some headers without converting the return value into a response object. + + .. versionadded:: 0.9 + """ + top = _request_ctx_stack.top + + if top is None: + raise RuntimeError( + "This decorator can only be used when a request context is" + " active, such as within a view function." + ) + + top._after_request_functions.append(f) + return f + + +def copy_current_request_context(f: t.Callable) -> t.Callable: + """A helper function that decorates a function to retain the current + request context. This is useful when working with greenlets. The moment + the function is decorated a copy of the request context is created and + then pushed when the function is called. The current session is also + included in the copied request context. + + Example:: + + import gevent + from flask import copy_current_request_context + + @app.route('/') + def index(): + @copy_current_request_context + def do_some_work(): + # do some work here, it can access flask.request or + # flask.session like you would otherwise in the view function. + ... + gevent.spawn(do_some_work) + return 'Regular response' + + .. versionadded:: 0.10 + """ + top = _request_ctx_stack.top + + if top is None: + raise RuntimeError( + "This decorator can only be used when a request context is" + " active, such as within a view function." + ) + + reqctx = top.copy() + + def wrapper(*args, **kwargs): + with reqctx: + return f(*args, **kwargs) + + return update_wrapper(wrapper, f) + + +def has_request_context() -> bool: + """If you have code that wants to test if a request context is there or + not this function can be used. For instance, you may want to take advantage + of request information if the request object is available, but fail + silently if it is unavailable. + + :: + + class User(db.Model): + + def __init__(self, username, remote_addr=None): + self.username = username + if remote_addr is None and has_request_context(): + remote_addr = request.remote_addr + self.remote_addr = remote_addr + + Alternatively you can also just test any of the context bound objects + (such as :class:`request` or :class:`g`) for truthness:: + + class User(db.Model): + + def __init__(self, username, remote_addr=None): + self.username = username + if remote_addr is None and request: + remote_addr = request.remote_addr + self.remote_addr = remote_addr + + .. versionadded:: 0.7 + """ + return _request_ctx_stack.top is not None + + +def has_app_context() -> bool: + """Works like :func:`has_request_context` but for the application + context. You can also just do a boolean check on the + :data:`current_app` object instead. + + .. versionadded:: 0.9 + """ + return _app_ctx_stack.top is not None + + +class AppContext: + """The application context binds an application object implicitly + to the current thread or greenlet, similar to how the + :class:`RequestContext` binds request information. The application + context is also implicitly created if a request context is created + but the application is not on top of the individual application + context. + """ + + def __init__(self, app: "Flask") -> None: + self.app = app + self.url_adapter = app.create_url_adapter(None) + self.g = app.app_ctx_globals_class() + + # Like request context, app contexts can be pushed multiple times + # but there a basic "refcount" is enough to track them. + self._refcnt = 0 + + def push(self) -> None: + """Binds the app context to the current context.""" + self._refcnt += 1 + _app_ctx_stack.push(self) + appcontext_pushed.send(self.app) + + def pop(self, exc: t.Optional[BaseException] = _sentinel) -> None: # type: ignore + """Pops the app context.""" + try: + self._refcnt -= 1 + if self._refcnt <= 0: + if exc is _sentinel: + exc = sys.exc_info()[1] + self.app.do_teardown_appcontext(exc) + finally: + rv = _app_ctx_stack.pop() + assert rv is self, f"Popped wrong app context. ({rv!r} instead of {self!r})" + appcontext_popped.send(self.app) + + def __enter__(self) -> "AppContext": + self.push() + return self + + def __exit__( + self, exc_type: type, exc_value: BaseException, tb: TracebackType + ) -> None: + self.pop(exc_value) + + +class RequestContext: + """The request context contains all request relevant information. It is + created at the beginning of the request and pushed to the + `_request_ctx_stack` and removed at the end of it. It will create the + URL adapter and request object for the WSGI environment provided. + + Do not attempt to use this class directly, instead use + :meth:`~flask.Flask.test_request_context` and + :meth:`~flask.Flask.request_context` to create this object. + + When the request context is popped, it will evaluate all the + functions registered on the application for teardown execution + (:meth:`~flask.Flask.teardown_request`). + + The request context is automatically popped at the end of the request + for you. In debug mode the request context is kept around if + exceptions happen so that interactive debuggers have a chance to + introspect the data. With 0.4 this can also be forced for requests + that did not fail and outside of ``DEBUG`` mode. By setting + ``'flask._preserve_context'`` to ``True`` on the WSGI environment the + context will not pop itself at the end of the request. This is used by + the :meth:`~flask.Flask.test_client` for example to implement the + deferred cleanup functionality. + + You might find this helpful for unittests where you need the + information from the context local around for a little longer. Make + sure to properly :meth:`~werkzeug.LocalStack.pop` the stack yourself in + that situation, otherwise your unittests will leak memory. + """ + + def __init__( + self, + app: "Flask", + environ: dict, + request: t.Optional["Request"] = None, + session: t.Optional["SessionMixin"] = None, + ) -> None: + self.app = app + if request is None: + request = app.request_class(environ) + self.request = request + self.url_adapter = None + try: + self.url_adapter = app.create_url_adapter(self.request) + except HTTPException as e: + self.request.routing_exception = e + self.flashes = None + self.session = session + + # Request contexts can be pushed multiple times and interleaved with + # other request contexts. Now only if the last level is popped we + # get rid of them. Additionally if an application context is missing + # one is created implicitly so for each level we add this information + self._implicit_app_ctx_stack: t.List[t.Optional["AppContext"]] = [] + + # indicator if the context was preserved. Next time another context + # is pushed the preserved context is popped. + self.preserved = False + + # remembers the exception for pop if there is one in case the context + # preservation kicks in. + self._preserved_exc = None + + # Functions that should be executed after the request on the response + # object. These will be called before the regular "after_request" + # functions. + self._after_request_functions: t.List[AfterRequestCallable] = [] + + @property + def g(self) -> AppContext: + return _app_ctx_stack.top.g + + @g.setter + def g(self, value: AppContext) -> None: + _app_ctx_stack.top.g = value + + def copy(self) -> "RequestContext": + """Creates a copy of this request context with the same request object. + This can be used to move a request context to a different greenlet. + Because the actual request object is the same this cannot be used to + move a request context to a different thread unless access to the + request object is locked. + + .. versionadded:: 0.10 + + .. versionchanged:: 1.1 + The current session object is used instead of reloading the original + data. This prevents `flask.session` pointing to an out-of-date object. + """ + return self.__class__( + self.app, + environ=self.request.environ, + request=self.request, + session=self.session, + ) + + def match_request(self) -> None: + """Can be overridden by a subclass to hook into the matching + of the request. + """ + try: + result = self.url_adapter.match(return_rule=True) # type: ignore + self.request.url_rule, self.request.view_args = result # type: ignore + except HTTPException as e: + self.request.routing_exception = e + + def push(self) -> None: + """Binds the request context to the current context.""" + # If an exception occurs in debug mode or if context preservation is + # activated under exception situations exactly one context stays + # on the stack. The rationale is that you want to access that + # information under debug situations. However if someone forgets to + # pop that context again we want to make sure that on the next push + # it's invalidated, otherwise we run at risk that something leaks + # memory. This is usually only a problem in test suite since this + # functionality is not active in production environments. + top = _request_ctx_stack.top + if top is not None and top.preserved: + top.pop(top._preserved_exc) + + # Before we push the request context we have to ensure that there + # is an application context. + app_ctx = _app_ctx_stack.top + if app_ctx is None or app_ctx.app != self.app: + app_ctx = self.app.app_context() + app_ctx.push() + self._implicit_app_ctx_stack.append(app_ctx) + else: + self._implicit_app_ctx_stack.append(None) + + _request_ctx_stack.push(self) + + # Open the session at the moment that the request context is available. + # This allows a custom open_session method to use the request context. + # Only open a new session if this is the first time the request was + # pushed, otherwise stream_with_context loses the session. + if self.session is None: + session_interface = self.app.session_interface + self.session = session_interface.open_session(self.app, self.request) + + if self.session is None: + self.session = session_interface.make_null_session(self.app) + + # Match the request URL after loading the session, so that the + # session is available in custom URL converters. + if self.url_adapter is not None: + self.match_request() + + def pop(self, exc: t.Optional[BaseException] = _sentinel) -> None: # type: ignore + """Pops the request context and unbinds it by doing that. This will + also trigger the execution of functions registered by the + :meth:`~flask.Flask.teardown_request` decorator. + + .. versionchanged:: 0.9 + Added the `exc` argument. + """ + app_ctx = self._implicit_app_ctx_stack.pop() + clear_request = False + + try: + if not self._implicit_app_ctx_stack: + self.preserved = False + self._preserved_exc = None + if exc is _sentinel: + exc = sys.exc_info()[1] + self.app.do_teardown_request(exc) + + request_close = getattr(self.request, "close", None) + if request_close is not None: + request_close() + clear_request = True + finally: + rv = _request_ctx_stack.pop() + + # get rid of circular dependencies at the end of the request + # so that we don't require the GC to be active. + if clear_request: + rv.request.environ["werkzeug.request"] = None + + # Get rid of the app as well if necessary. + if app_ctx is not None: + app_ctx.pop(exc) + + assert ( + rv is self + ), f"Popped wrong request context. ({rv!r} instead of {self!r})" + + def auto_pop(self, exc: t.Optional[BaseException]) -> None: + if self.request.environ.get("flask._preserve_context") or ( + exc is not None and self.app.preserve_context_on_exception + ): + self.preserved = True + self._preserved_exc = exc # type: ignore + else: + self.pop(exc) + + def __enter__(self) -> "RequestContext": + self.push() + return self + + def __exit__( + self, exc_type: type, exc_value: BaseException, tb: TracebackType + ) -> None: + # do not pop the request stack if we are in debug mode and an + # exception happened. This will allow the debugger to still + # access the request object in the interactive shell. Furthermore + # the context can be force kept alive for the test client. + # See flask.testing for how this works. + self.auto_pop(exc_value) + + def __repr__(self) -> str: + return ( + f"<{type(self).__name__} {self.request.url!r}" + f" [{self.request.method}] of {self.app.name}>" + ) |