# Source code for cherrypy._cptools

    """CherryPy tools. A "tool" is any helper, adapted to CP.

    Tools are usually designed to be used in a variety of ways (although
    some may only offer one if they choose):

        Library calls
            All tools are callables that can be used wherever needed.
            The arguments are straightforward and should be detailed within the
            docstring.

        Function decorators
            All tools, when called, may be used as decorators which configure
            individual CherryPy page handlers (methods on the CherryPy tree).
            That is, "@tools.anytool()" should "turn on" the tool via the
            decorated function's _cp_config attribute.

        CherryPy config
            If a tool exposes a "_setup" callable, it will be called
            once per Request (if the feature is "turned on" via config).

    Tools may be implemented as any object with a namespace. The builtins
    are generally either modules or instances of the tools.Tool class.
    """

    import cherrypy
    from cherrypy._helper import expose

    from cherrypy.lib import cptools, encoding, static, jsontools
    from cherrypy.lib import sessions as _sessions, xmlrpcutil as _xmlrpc
    from cherrypy.lib import caching as _caching
    from cherrypy.lib import auth_basic, auth_digest

    def _getargs(func):
        """Return the names of all static arguments to the given function."""
        # Use this instead of importing inspect for less mem overhead.
        import types
        if isinstance(func, types.MethodType):
            func = func.__func__
        co = func.__code__
        return co.co_varnames[:co.co_argcount]

    _attr_error = (
        'CherryPy Tools cannot be turned on directly. Instead, turn them '
        'on via config, or use them as decorators on your page handlers.'
    )

    class Tool(object):
        """A registered function for use with CherryPy request-processing hooks.

        help(tool.callable) should give you more information about this
        Tool.
        """

        namespace = 'tools'

        def __init__(self, point, callable, name=None, priority=50):
            self._point = point
            self.callable = callable
            self._name = name
            self._priority = priority
            self.__doc__ = self.callable.__doc__
            self._setargs()

        @property
        def on(self):
            raise AttributeError(_attr_error)

        @on.setter
        def on(self, value):
            raise AttributeError(_attr_error)

        def _setargs(self):
            """Copy func parameter names to obj attributes."""
            try:
                for arg in _getargs(self.callable):
                    setattr(self, arg, None)
            except (TypeError, AttributeError):
                if hasattr(self.callable, '__call__'):
                    for arg in _getargs(self.callable.__call__):
                        setattr(self, arg, None)
            # IronPython 1.0 raises NotImplementedError because
            # inspect.getargspec tries to access Python bytecode
            # in co_code attribute.
            except NotImplementedError:
                pass
            # IronPython 1B1 may raise IndexError in some cases,
            # but if we trap it here it doesn't prevent CP from working.
            except IndexError:
                pass

        def _merged_args(self, d=None):
            """Return a dict of configuration entries for this Tool."""
            if d:
                conf = d.copy()
            else:
                conf = {}

            tm = cherrypy.serving.request.toolmaps[self.namespace]
            if self._name in tm:
                conf.update(tm[self._name])

            if 'on' in conf:
                del conf['on']

            return conf

        def __call__(self, *args, **kwargs):
            """Compile-time decorator (turn on the tool in config).

            For example::

                @expose
                @tools.proxy()
                def whats_my_base(self):
                    return cherrypy.request.base
            """
            if args:
                raise TypeError('The %r Tool does not accept positional '
                                'arguments; you must use keyword arguments.'
                                % self._name)

            def tool_decorator(f):
                if not hasattr(f, '_cp_config'):
                    f._cp_config = {}
                subspace = self.namespace + '.' + self._name + '.'
                f._cp_config[subspace + 'on'] = True
                for k, v in kwargs.items():
                    f._cp_config[subspace + k] = v
                return f
            return tool_decorator

        def _setup(self):
            """Hook this tool into cherrypy.request.

            The standard CherryPy request object will automatically call
            this method when the tool is "turned on" in config.
            """
            conf = self._merged_args()
            p = conf.pop('priority', None)
            if p is None:
                p = getattr(self.callable, 'priority', self._priority)
            cherrypy.serving.request.hooks.attach(self._point, self.callable,
                                                  priority=p, **conf)

    class HandlerTool(Tool):
        """Tool which is called 'before main', that may skip normal handlers.

        If the tool successfully handles the request (by setting
        response.body), if should return True. This will cause CherryPy to
        skip any 'normal' page handler. If the tool did not handle the
        request, it should return False to tell CherryPy to continue on and
        call the normal page handler. If the tool is declared AS a page
        handler (see the 'handler' method), returning False will raise
        NotFound.
        """

        def __init__(self, callable, name=None):
            Tool.__init__(self, 'before_handler', callable, name)

        def handler(self, *args, **kwargs):
            """Use this tool as a CherryPy page handler.

            For example::

                class Root:
                    nav = tools.staticdir.handler(section="/nav", dir="nav",
                                                  root=absDir)
            """
            @expose
            def handle_func(*a, **kw):
                handled = self.callable(*args, **self._merged_args(kwargs))
                if not handled:
                    raise cherrypy.NotFound()
                return cherrypy.serving.response.body
            return handle_func

        def _wrapper(self, **kwargs):
            if self.callable(**kwargs):
                cherrypy.serving.request.handler = None

        def _setup(self):
            """Hook this tool into cherrypy.request.

            The standard CherryPy request object will automatically call
            this method when the tool is "turned on" in config.
            """
            conf = self._merged_args()
            p = conf.pop('priority', None)
            if p is None:
                p = getattr(self.callable, 'priority', self._priority)
            cherrypy.serving.request.hooks.attach(self._point, self._wrapper,
                                                  priority=p, **conf)

    class HandlerWrapperTool(Tool):
        """Tool which wraps request.handler in a provided wrapper function.

        The 'newhandler' arg must be a handler wrapper function that takes a
        'next_handler' argument, plus ``*args`` and ``**kwargs``. Like all
        page handler
        functions, it must return an iterable for use as cherrypy.response.body.

        For example, to allow your 'inner' page handlers to return dicts
        which then get interpolated into a template::

            def interpolator(next_handler, *args, **kwargs):
                filename = cherrypy.request.config.get('template')
                cherrypy.response.template = env.get_template(filename)
                response_dict = next_handler(*args, **kwargs)
                return cherrypy.response.template.render(**response_dict)
            cherrypy.tools.jinja = HandlerWrapperTool(interpolator)
        """

        def __init__(self, newhandler, point='before_handler', name=None,
                     priority=50):
            self.newhandler = newhandler
            self._point = point
            self._name = name
            self._priority = priority

        def callable(self, *args, **kwargs):
            innerfunc = cherrypy.serving.request.handler

            def wrap(*args, **kwargs):
                return self.newhandler(innerfunc, *args, **kwargs)
            cherrypy.serving.request.handler = wrap

    class ErrorTool(Tool):
        """Tool which is used to replace the default request.error_response."""

        def __init__(self, callable, name=None):
            Tool.__init__(self, None, callable, name)

        def _wrapper(self):
            self.callable(**self._merged_args())

        def _setup(self):
            """Hook this tool into cherrypy.request.

            The standard CherryPy request object will automatically call
            this method when the tool is "turned on" in config.
            """
            cherrypy.serving.request.error_response = self._wrapper

    #                              Builtin tools                              #

    class SessionTool(Tool):
        """Session Tool for CherryPy.

        sessions.locking
            When 'implicit' (the default), the session will be locked for you,
            just before running the page handler.

            When 'early', the session will be locked before reading the request
            body. This is off by default for safety reasons; for example,
            a large upload would block the session, denying an AJAX
            progress meter
            (`issue <https://github.com/cherrypy/cherrypy/issues/630>`_).

            When 'explicit' (or any other value), you need to call
            cherrypy.session.acquire_lock() yourself before using
            session data.
        """

        def __init__(self):
            # _sessions.init must be bound after headers are read
            Tool.__init__(self, 'before_request_body', _sessions.init)

        def _lock_session(self):
            cherrypy.serving.session.acquire_lock()

        def _setup(self):
            """Hook this tool into cherrypy.request.

            The standard CherryPy request object will automatically call
            this method when the tool is "turned on" in config.
            """
            hooks = cherrypy.serving.request.hooks

            conf = self._merged_args()

            p = conf.pop('priority', None)
            if p is None:
                p = getattr(self.callable, 'priority', self._priority)

            hooks.attach(self._point, self.callable, priority=p, **conf)

            locking = conf.pop('locking', 'implicit')
            if locking == 'implicit':
                hooks.attach('before_handler', self._lock_session)
            elif locking == 'early':
                # Lock before the request body (but after _sessions.init runs!)
                hooks.attach('before_request_body', self._lock_session,
                             priority=60)
            else:
                # Don't lock
                pass

            hooks.attach('before_finalize', _sessions.save)
            hooks.attach('on_end_request', _sessions.close)

        def regenerate(self):
            """Drop the current session and make a new one (with a new id)."""
            sess = cherrypy.serving.session
            sess.regenerate()

            # Grab cookie-relevant tool args
            relevant = 'path', 'path_header', 'name', 'timeout', 'domain', 'secure'
            conf = dict(
                (k, v)
                for k, v in self._merged_args().items()
                if k in relevant
            )
            _sessions.set_response_cookie(**conf)

    class XMLRPCController(object):
        """A Controller (page handler collection) for XML-RPC.

        To use it, have your controllers subclass this base class (it will
        turn on the tool for you).

        You can also supply the following optional config entries::

            tools.xmlrpc.encoding: 'utf-8'
            tools.xmlrpc.allow_none: 0

        XML-RPC is a rather discontinuous layer over HTTP; dispatching to the
        appropriate handler must first be performed according to the URL, and
        then a second dispatch step must take place according to the RPC method
        specified in the request body. It also allows a superfluous "/RPC2"
        prefix in the URL, supplies its own handler args in the body, and
        requires a 200 OK "Fault" response instead of 404 when the desired
        method is not found.

        Therefore, XML-RPC cannot be implemented for CherryPy via a Tool alone.
        This Controller acts as the dispatch target for the first half (based
        on the URL); it then reads the RPC method from the request body and
        does its own second dispatch step based on that method. It also reads
        body params, and returns a Fault on error.

        The XMLRPCDispatcher strips any /RPC2 prefix; if you aren't using /RPC2
        in your URL's, you can safely skip turning on the XMLRPCDispatcher.
        Otherwise, you need to use declare it in config::

            request.dispatch: cherrypy.dispatch.XMLRPCDispatcher()
        """

        # Note we're hard-coding this into the 'tools' namespace. We could do
        # a huge amount of work to make it relocatable, but the only reason why
        # would be if someone actually disabled the default_toolbox. Meh.
        _cp_config = {'tools.xmlrpc.on': True}

        @expose
        def default(self, *vpath, **params):
            rpcparams, rpcmethod = _xmlrpc.process_body()

            subhandler = self
            for attr in str(rpcmethod).split('.'):
                subhandler = getattr(subhandler, attr, None)

            if subhandler and getattr(subhandler, 'exposed', False):
                body = subhandler(*(vpath + rpcparams), **params)

            else:
                # https://github.com/cherrypy/cherrypy/issues/533
                # if a method is not found, an xmlrpclib.Fault should be returned
                # raising an exception here will do that; see
                # cherrypy.lib.xmlrpcutil.on_error
                raise Exception('method "%s" is not supported' % attr)

            conf = cherrypy.serving.request.toolmaps['tools'].get('xmlrpc', {})
            _xmlrpc.respond(body,
                            conf.get('encoding', 'utf-8'),
                            conf.get('allow_none', 0))
            return cherrypy.serving.response.body

    class SessionAuthTool(HandlerTool):
        pass

    class CachingTool(Tool):
        """Caching Tool for CherryPy."""

        def _wrapper(self, **kwargs):
            request = cherrypy.serving.request
            if _caching.get(**kwargs):
                request.handler = None
            else:
                if request.cacheable:
                    # Note the devious technique here of adding hooks on the fly
                    request.hooks.attach('before_finalize', _caching.tee_output,
                                         priority=100)

        _wrapper.priority = 90

        def _setup(self):
            """Hook caching into cherrypy.request."""
            conf = self._merged_args()

            p = conf.pop('priority', None)
            cherrypy.serving.request.hooks.attach('before_handler', self._wrapper,
                                                  priority=p, **conf)

    class Toolbox(object):
        """A collection of Tools.

        This object also functions as a config namespace handler for itself.
        Custom toolboxes should be added to each Application's toolboxes
        dict.
        """

        def __init__(self, namespace):
            self.namespace = namespace

        def __setattr__(self, name, value):
            # If the Tool._name is None, supply it from the attribute name.
            if isinstance(value, Tool):
                if value._name is None:
                    value._name = name
                value.namespace = self.namespace
            object.__setattr__(self, name, value)

        def __enter__(self):
            """Populate request.toolmaps from tools specified in config."""
            cherrypy.serving.request.toolmaps[self.namespace] = map = {}

            def populate(k, v):
                toolname, arg = k.split('.', 1)
                bucket = map.setdefault(toolname, {})
                bucket[arg] = v
            return populate

        def __exit__(self, exc_type, exc_val, exc_tb):
            """Run tool._setup() for each tool in our toolmap."""
            map = cherrypy.serving.request.toolmaps.get(self.namespace)
            if map:
                for name, settings in map.items():
                    if settings.get('on', False):
                        tool = getattr(self, name)
                        tool._setup()

        def register(self, point, **kwargs):
            """
            Return a decorator which registers the function
            at the given hook point.
            """
            def decorator(func):
                attr_name = kwargs.get('name', func.__name__)
                tool = Tool(point, func, **kwargs)
                setattr(self, attr_name, tool)
                return func
            return decorator

    default_toolbox = _d = Toolbox('tools')
    _d.session_auth = SessionAuthTool(cptools.session_auth)
    _d.allow = Tool('on_start_resource', cptools.allow)
    _d.proxy = Tool('before_request_body', cptools.proxy, priority=30)
    _d.response_headers = Tool('on_start_resource', cptools.response_headers)
    _d.log_tracebacks = Tool('before_error_response', cptools.log_traceback)
    _d.log_headers = Tool('before_error_response', cptools.log_request_headers)
    _d.log_hooks = Tool('on_end_request', cptools.log_hooks, priority=100)
    _d.err_redirect = ErrorTool(cptools.redirect)
    _d.etags = Tool('before_finalize', cptools.validate_etags, priority=75)
    _d.decode = Tool('before_request_body', encoding.decode)
    # the order of encoding, gzip, caching is important
    _d.encode = Tool('before_handler', encoding.ResponseEncoder, priority=70)
    _d.gzip = Tool('before_finalize', encoding.gzip, priority=80)
    _d.staticdir = HandlerTool(static.staticdir)
    _d.staticfile = HandlerTool(static.staticfile)
    _d.sessions = SessionTool()
    _d.xmlrpc = ErrorTool(_xmlrpc.on_error)
    _d.caching = CachingTool('before_handler', _caching.get, 'caching')
    _d.expires = Tool('before_finalize', _caching.expires)
    _d.ignore_headers = Tool('before_request_body', cptools.ignore_headers)
    _d.referer = Tool('before_request_body', cptools.referer)
    _d.trailing_slash = Tool('before_handler', cptools.trailing_slash, priority=60)
    _d.flatten = Tool('before_finalize', cptools.flatten)
    _d.accept = Tool('on_start_resource', cptools.accept)
    _d.redirect = Tool('on_start_resource', cptools.redirect)
    _d.autovary = Tool('on_start_resource', cptools.autovary, priority=0)
    _d.json_in = Tool('before_request_body', jsontools.json_in, priority=30)
    _d.json_out = Tool('before_handler', jsontools.json_out, priority=30)
    _d.auth_basic = Tool('before_handler', auth_basic.basic_auth, priority=1)
    _d.auth_digest = Tool('before_handler', auth_digest.digest_auth, priority=1)
    _d.params = Tool('before_handler', cptools.convert_params, priority=15)

    del _d, cptools, encoding, static