add code for analysis of data

1 files changed, 379 insertions, 0 deletions

diff --git a/venv/lib/python3.8/site-packages/flask/sessions.py b/venv/lib/python3.8/site-packages/flask/sessions.py
new file mode 100644
index 0000000..ee19ad6
--- /dev/null
+++ b/venv/lib/python3.8/site-packages/flask/sessions.py
@@ -0,0 +1,379 @@
+from __future__ import annotations
+
+import hashlib
+import typing as t
+from collections.abc import MutableMapping
+from datetime import datetime
+from datetime import timezone
+
+from itsdangerous import BadSignature
+from itsdangerous import URLSafeTimedSerializer
+from werkzeug.datastructures import CallbackDict
+
+from .json.tag import TaggedJSONSerializer
+
+if t.TYPE_CHECKING:  # pragma: no cover
+    import typing_extensions as te
+
+    from .app import Flask
+    from .wrappers import Request
+    from .wrappers import Response
+
+
+# TODO generic when Python > 3.8
+class SessionMixin(MutableMapping):  # type: ignore[type-arg]
+    """Expands a basic dictionary with session attributes."""
+
+    @property
+    def permanent(self) -> bool:
+        """This reflects the ``'_permanent'`` key in the dict."""
+        return self.get("_permanent", False)
+
+    @permanent.setter
+    def permanent(self, value: bool) -> None:
+        self["_permanent"] = bool(value)
+
+    #: Some implementations can detect whether a session is newly
+    #: created, but that is not guaranteed. Use with caution. The mixin
+    # default is hard-coded ``False``.
+    new = False
+
+    #: Some implementations can detect changes to the session and set
+    #: this when that happens. The mixin default is hard coded to
+    #: ``True``.
+    modified = True
+
+    #: Some implementations can detect when session data is read or
+    #: written and set this when that happens. The mixin default is hard
+    #: coded to ``True``.
+    accessed = True
+
+
+# TODO generic when Python > 3.8
+class SecureCookieSession(CallbackDict, SessionMixin):  # type: ignore[type-arg]
+    """Base class for sessions based on signed cookies.
+
+    This session backend will set the :attr:`modified` and
+    :attr:`accessed` attributes. It cannot reliably track whether a
+    session is new (vs. empty), so :attr:`new` remains hard coded to
+    ``False``.
+    """
+
+    #: When data is changed, this is set to ``True``. Only the session
+    #: dictionary itself is tracked; if the session contains mutable
+    #: data (for example a nested dict) then this must be set to
+    #: ``True`` manually when modifying that data. The session cookie
+    #: will only be written to the response if this is ``True``.
+    modified = False
+
+    #: When data is read or written, this is set to ``True``. Used by
+    # :class:`.SecureCookieSessionInterface` to add a ``Vary: Cookie``
+    #: header, which allows caching proxies to cache different pages for
+    #: different users.
+    accessed = False
+
+    def __init__(self, initial: t.Any = None) -> None:
+        def on_update(self: te.Self) -> None:
+            self.modified = True
+            self.accessed = True
+
+        super().__init__(initial, on_update)
+
+    def __getitem__(self, key: str) -> t.Any:
+        self.accessed = True
+        return super().__getitem__(key)
+
+    def get(self, key: str, default: t.Any = None) -> t.Any:
+        self.accessed = True
+        return super().get(key, default)
+
+    def setdefault(self, key: str, default: t.Any = None) -> t.Any:
+        self.accessed = True
+        return super().setdefault(key, default)
+
+
+class NullSession(SecureCookieSession):
+    """Class used to generate nicer error messages if sessions are not
+    available.  Will still allow read-only access to the empty session
+    but fail on setting.
+    """
+
+    def _fail(self, *args: t.Any, **kwargs: t.Any) -> t.NoReturn:
+        raise RuntimeError(
+            "The session is unavailable because no secret "
+            "key was set.  Set the secret_key on the "
+            "application to something unique and secret."
+        )
+
+    __setitem__ = __delitem__ = clear = pop = popitem = update = setdefault = _fail  # type: ignore # noqa: B950
+    del _fail
+
+
+class SessionInterface:
+    """The basic interface you have to implement in order to replace the
+    default session interface which uses werkzeug's securecookie
+    implementation.  The only methods you have to implement are
+    :meth:`open_session` and :meth:`save_session`, the others have
+    useful defaults which you don't need to change.
+
+    The session object returned by the :meth:`open_session` method has to
+    provide a dictionary like interface plus the properties and methods
+    from the :class:`SessionMixin`.  We recommend just subclassing a dict
+    and adding that mixin::
+
+        class Session(dict, SessionMixin):
+            pass
+
+    If :meth:`open_session` returns ``None`` Flask will call into
+    :meth:`make_null_session` to create a session that acts as replacement
+    if the session support cannot work because some requirement is not
+    fulfilled.  The default :class:`NullSession` class that is created
+    will complain that the secret key was not set.
+
+    To replace the session interface on an application all you have to do
+    is to assign :attr:`flask.Flask.session_interface`::
+
+        app = Flask(__name__)
+        app.session_interface = MySessionInterface()
+
+    Multiple requests with the same session may be sent and handled
+    concurrently. When implementing a new session interface, consider
+    whether reads or writes to the backing store must be synchronized.
+    There is no guarantee on the order in which the session for each
+    request is opened or saved, it will occur in the order that requests
+    begin and end processing.
+
+    .. versionadded:: 0.8
+    """
+
+    #: :meth:`make_null_session` will look here for the class that should
+    #: be created when a null session is requested.  Likewise the
+    #: :meth:`is_null_session` method will perform a typecheck against
+    #: this type.
+    null_session_class = NullSession
+
+    #: A flag that indicates if the session interface is pickle based.
+    #: This can be used by Flask extensions to make a decision in regards
+    #: to how to deal with the session object.
+    #:
+    #: .. versionadded:: 0.10
+    pickle_based = False
+
+    def make_null_session(self, app: Flask) -> NullSession:
+        """Creates a null session which acts as a replacement object if the
+        real session support could not be loaded due to a configuration
+        error.  This mainly aids the user experience because the job of the
+        null session is to still support lookup without complaining but
+        modifications are answered with a helpful error message of what
+        failed.
+
+        This creates an instance of :attr:`null_session_class` by default.
+        """
+        return self.null_session_class()
+
+    def is_null_session(self, obj: object) -> bool:
+        """Checks if a given object is a null session.  Null sessions are
+        not asked to be saved.
+
+        This checks if the object is an instance of :attr:`null_session_class`
+        by default.
+        """
+        return isinstance(obj, self.null_session_class)
+
+    def get_cookie_name(self, app: Flask) -> str:
+        """The name of the session cookie. Uses``app.config["SESSION_COOKIE_NAME"]``."""
+        return app.config["SESSION_COOKIE_NAME"]  # type: ignore[no-any-return]
+
+    def get_cookie_domain(self, app: Flask) -> str | None:
+        """The value of the ``Domain`` parameter on the session cookie. If not set,
+        browsers will only send the cookie to the exact domain it was set from.
+        Otherwise, they will send it to any subdomain of the given value as well.
+
+        Uses the :data:`SESSION_COOKIE_DOMAIN` config.
+
+        .. versionchanged:: 2.3
+            Not set by default, does not fall back to ``SERVER_NAME``.
+        """
+        return app.config["SESSION_COOKIE_DOMAIN"]  # type: ignore[no-any-return]
+
+    def get_cookie_path(self, app: Flask) -> str:
+        """Returns the path for which the cookie should be valid.  The
+        default implementation uses the value from the ``SESSION_COOKIE_PATH``
+        config var if it's set, and falls back to ``APPLICATION_ROOT`` or
+        uses ``/`` if it's ``None``.
+        """
+        return app.config["SESSION_COOKIE_PATH"] or app.config["APPLICATION_ROOT"]  # type: ignore[no-any-return]
+
+    def get_cookie_httponly(self, app: Flask) -> bool:
+        """Returns True if the session cookie should be httponly.  This
+        currently just returns the value of the ``SESSION_COOKIE_HTTPONLY``
+        config var.
+        """
+        return app.config["SESSION_COOKIE_HTTPONLY"]  # type: ignore[no-any-return]
+
+    def get_cookie_secure(self, app: Flask) -> bool:
+        """Returns True if the cookie should be secure.  This currently
+        just returns the value of the ``SESSION_COOKIE_SECURE`` setting.
+        """
+        return app.config["SESSION_COOKIE_SECURE"]  # type: ignore[no-any-return]
+
+    def get_cookie_samesite(self, app: Flask) -> str | None:
+        """Return ``'Strict'`` or ``'Lax'`` if the cookie should use the
+        ``SameSite`` attribute. This currently just returns the value of
+        the :data:`SESSION_COOKIE_SAMESITE` setting.
+        """
+        return app.config["SESSION_COOKIE_SAMESITE"]  # type: ignore[no-any-return]
+
+    def get_expiration_time(self, app: Flask, session: SessionMixin) -> datetime | None:
+        """A helper method that returns an expiration date for the session
+        or ``None`` if the session is linked to the browser session.  The
+        default implementation returns now + the permanent session
+        lifetime configured on the application.
+        """
+        if session.permanent:
+            return datetime.now(timezone.utc) + app.permanent_session_lifetime
+        return None
+
+    def should_set_cookie(self, app: Flask, session: SessionMixin) -> bool:
+        """Used by session backends to determine if a ``Set-Cookie`` header
+        should be set for this session cookie for this response. If the session
+        has been modified, the cookie is set. If the session is permanent and
+        the ``SESSION_REFRESH_EACH_REQUEST`` config is true, the cookie is
+        always set.
+
+        This check is usually skipped if the session was deleted.
+
+        .. versionadded:: 0.11
+        """
+
+        return session.modified or (
+            session.permanent and app.config["SESSION_REFRESH_EACH_REQUEST"]
+        )
+
+    def open_session(self, app: Flask, request: Request) -> SessionMixin | None:
+        """This is called at the beginning of each request, after
+        pushing the request context, before matching the URL.
+
+        This must return an object which implements a dictionary-like
+        interface as well as the :class:`SessionMixin` interface.
+
+        This will return ``None`` to indicate that loading failed in
+        some way that is not immediately an error. The request
+        context will fall back to using :meth:`make_null_session`
+        in this case.
+        """
+        raise NotImplementedError()
+
+    def save_session(
+        self, app: Flask, session: SessionMixin, response: Response
+    ) -> None:
+        """This is called at the end of each request, after generating
+        a response, before removing the request context. It is skipped
+        if :meth:`is_null_session` returns ``True``.
+        """
+        raise NotImplementedError()
+
+
+session_json_serializer = TaggedJSONSerializer()
+
+
+def _lazy_sha1(string: bytes = b"") -> t.Any:
+    """Don't access ``hashlib.sha1`` until runtime. FIPS builds may not include
+    SHA-1, in which case the import and use as a default would fail before the
+    developer can configure something else.
+    """
+    return hashlib.sha1(string)
+
+
+class SecureCookieSessionInterface(SessionInterface):
+    """The default session interface that stores sessions in signed cookies
+    through the :mod:`itsdangerous` module.
+    """
+
+    #: the salt that should be applied on top of the secret key for the
+    #: signing of cookie based sessions.
+    salt = "cookie-session"
+    #: the hash function to use for the signature.  The default is sha1
+    digest_method = staticmethod(_lazy_sha1)
+    #: the name of the itsdangerous supported key derivation.  The default
+    #: is hmac.
+    key_derivation = "hmac"
+    #: A python serializer for the payload.  The default is a compact
+    #: JSON derived serializer with support for some extra Python types
+    #: such as datetime objects or tuples.
+    serializer = session_json_serializer
+    session_class = SecureCookieSession
+
+    def get_signing_serializer(self, app: Flask) -> URLSafeTimedSerializer | None:
+        if not app.secret_key:
+            return None
+        signer_kwargs = dict(
+            key_derivation=self.key_derivation, digest_method=self.digest_method
+        )
+        return URLSafeTimedSerializer(
+            app.secret_key,
+            salt=self.salt,
+            serializer=self.serializer,
+            signer_kwargs=signer_kwargs,
+        )
+
+    def open_session(self, app: Flask, request: Request) -> SecureCookieSession | None:
+        s = self.get_signing_serializer(app)
+        if s is None:
+            return None
+        val = request.cookies.get(self.get_cookie_name(app))
+        if not val:
+            return self.session_class()
+        max_age = int(app.permanent_session_lifetime.total_seconds())
+        try:
+            data = s.loads(val, max_age=max_age)
+            return self.session_class(data)
+        except BadSignature:
+            return self.session_class()
+
+    def save_session(
+        self, app: Flask, session: SessionMixin, response: Response
+    ) -> None:
+        name = self.get_cookie_name(app)
+        domain = self.get_cookie_domain(app)
+        path = self.get_cookie_path(app)
+        secure = self.get_cookie_secure(app)
+        samesite = self.get_cookie_samesite(app)
+        httponly = self.get_cookie_httponly(app)
+
+        # Add a "Vary: Cookie" header if the session was accessed at all.
+        if session.accessed:
+            response.vary.add("Cookie")
+
+        # If the session is modified to be empty, remove the cookie.
+        # If the session is empty, return without setting the cookie.
+        if not session:
+            if session.modified:
+                response.delete_cookie(
+                    name,
+                    domain=domain,
+                    path=path,
+                    secure=secure,
+                    samesite=samesite,
+                    httponly=httponly,
+                )
+                response.vary.add("Cookie")
+
+            return
+
+        if not self.should_set_cookie(app, session):
+            return
+
+        expires = self.get_expiration_time(app, session)
+        val = self.get_signing_serializer(app).dumps(dict(session))  # type: ignore
+        response.set_cookie(
+            name,
+            val,  # type: ignore
+            expires=expires,
+            httponly=httponly,
+            domain=domain,
+            path=path,
+            secure=secure,
+            samesite=samesite,
+        )
+        response.vary.add("Cookie")