sanic/sanic/router.py

483 lines
17 KiB
Python

import re
import uuid
from collections import defaultdict, namedtuple
from collections.abc import Iterable
from functools import lru_cache
from urllib.parse import unquote
from sanic.exceptions import MethodNotSupported, NotFound
from sanic.views import CompositionView
Route = namedtuple(
"Route", ["handler", "methods", "pattern", "parameters", "name", "uri"]
)
Parameter = namedtuple("Parameter", ["name", "cast"])
REGEX_TYPES = {
"string": (str, r"[^/]+"),
"int": (int, r"\d+"),
"number": (float, r"[0-9\\.]+"),
"alpha": (str, r"[A-Za-z]+"),
"path": (str, r"[^/].*?"),
"uuid": (
uuid.UUID,
r"[A-Fa-f0-9]{8}-[A-Fa-f0-9]{4}-"
r"[A-Fa-f0-9]{4}-[A-Fa-f0-9]{4}-[A-Fa-f0-9]{12}",
),
}
ROUTER_CACHE_SIZE = 1024
def url_hash(url):
return url.count("/")
class RouteExists(Exception):
pass
class RouteDoesNotExist(Exception):
pass
class ParameterNameConflicts(Exception):
pass
class Router:
"""Router supports basic routing with parameters and method checks
Usage:
.. code-block:: python
@sanic.route('/my/url/<my_param>', methods=['GET', 'POST', ...])
def my_route(request, my_param):
do stuff...
or
.. code-block:: python
@sanic.route('/my/url/<my_param:my_type>', methods['GET', 'POST', ...])
def my_route_with_type(request, my_param: my_type):
do stuff...
Parameters will be passed as keyword arguments to the request handling
function. Provided parameters can also have a type by appending :type to
the <parameter>. Given parameter must be able to be type-casted to this.
If no type is provided, a string is expected. A regular expression can
also be passed in as the type. The argument given to the function will
always be a string, independent of the type.
"""
routes_static = None
routes_dynamic = None
routes_always_check = None
parameter_pattern = re.compile(r"<(.+?)>")
def __init__(self):
self.routes_all = {}
self.routes_names = {}
self.routes_static_files = {}
self.routes_static = {}
self.routes_dynamic = defaultdict(list)
self.routes_always_check = []
self.hosts = set()
@classmethod
def parse_parameter_string(cls, parameter_string):
"""Parse a parameter string into its constituent name, type, and
pattern
For example::
parse_parameter_string('<param_one:[A-z]>')` ->
('param_one', str, '[A-z]')
:param parameter_string: String to parse
:return: tuple containing
(parameter_name, parameter_type, parameter_pattern)
"""
# We could receive NAME or NAME:PATTERN
name = parameter_string
pattern = "string"
if ":" in parameter_string:
name, pattern = parameter_string.split(":", 1)
if not name:
raise ValueError(
"Invalid parameter syntax: {}".format(parameter_string)
)
default = (str, pattern)
# Pull from pre-configured types
_type, pattern = REGEX_TYPES.get(pattern, default)
return name, _type, pattern
def add(
self,
uri,
methods,
handler,
host=None,
strict_slashes=False,
version=None,
name=None,
):
"""Add a handler to the route list
:param uri: path to match
:param methods: sequence of accepted method names. If none are
provided, any method is allowed
:param handler: request handler function.
When executed, it should provide a response object.
:param strict_slashes: strict to trailing slash
:param version: current version of the route or blueprint. See
docs for further details.
:return: Nothing
"""
if version is not None:
version = re.escape(str(version).strip("/").lstrip("v"))
uri = "/".join(["/v{}".format(version), uri.lstrip("/")])
# add regular version
self._add(uri, methods, handler, host, name)
if strict_slashes:
return
if not isinstance(host, str) and host is not None:
# we have gotten back to the top of the recursion tree where the
# host was originally a list. By now, we've processed the strict
# slashes logic on the leaf nodes (the individual host strings in
# the list of host)
return
# Add versions with and without trailing /
slashed_methods = self.routes_all.get(uri + "/", frozenset({}))
unslashed_methods = self.routes_all.get(uri[:-1], frozenset({}))
if isinstance(methods, Iterable):
_slash_is_missing = all(
method in slashed_methods for method in methods
)
_without_slash_is_missing = all(
method in unslashed_methods for method in methods
)
else:
_slash_is_missing = methods in slashed_methods
_without_slash_is_missing = methods in unslashed_methods
slash_is_missing = not uri[-1] == "/" and not _slash_is_missing
without_slash_is_missing = (
uri[-1] == "/" and not _without_slash_is_missing and not uri == "/"
)
# add version with trailing slash
if slash_is_missing:
self._add(uri + "/", methods, handler, host, name)
# add version without trailing slash
elif without_slash_is_missing:
self._add(uri[:-1], methods, handler, host, name)
def _add(self, uri, methods, handler, host=None, name=None):
"""Add a handler to the route list
:param uri: path to match
:param methods: sequence of accepted method names. If none are
provided, any method is allowed
:param handler: request handler function.
When executed, it should provide a response object.
:param name: user defined route name for url_for
:return: Nothing
"""
if host is not None:
if isinstance(host, str):
uri = host + uri
self.hosts.add(host)
else:
if not isinstance(host, Iterable):
raise ValueError(
"Expected either string or Iterable of "
"host strings, not {!r}".format(host)
)
for host_ in host:
self.add(uri, methods, handler, host_, name)
return
# Dict for faster lookups of if method allowed
if methods:
methods = frozenset(methods)
parameters = []
parameter_names = set()
properties = {"unhashable": None}
def add_parameter(match):
name = match.group(1)
name, _type, pattern = self.parse_parameter_string(name)
if name in parameter_names:
raise ParameterNameConflicts(
"Multiple parameter named <{name}> "
"in route uri {uri}".format(name=name, uri=uri)
)
parameter_names.add(name)
parameter = Parameter(name=name, cast=_type)
parameters.append(parameter)
# Mark the whole route as unhashable if it has the hash key in it
if re.search(r"(^|[^^]){1}/", pattern):
properties["unhashable"] = True
# Mark the route as unhashable if it matches the hash key
elif re.search(r"/", pattern):
properties["unhashable"] = True
return "({})".format(pattern)
pattern_string = re.sub(self.parameter_pattern, add_parameter, uri)
pattern = re.compile(r"^{}$".format(pattern_string))
def merge_route(route, methods, handler):
# merge to the existing route when possible.
if not route.methods or not methods:
# method-unspecified routes are not mergeable.
raise RouteExists("Route already registered: {}".format(uri))
elif route.methods.intersection(methods):
# already existing method is not overloadable.
duplicated = methods.intersection(route.methods)
raise RouteExists(
"Route already registered: {} [{}]".format(
uri, ",".join(list(duplicated))
)
)
if isinstance(route.handler, CompositionView):
view = route.handler
else:
view = CompositionView()
view.add(route.methods, route.handler)
view.add(methods, handler)
route = route._replace(
handler=view, methods=methods.union(route.methods)
)
return route
if parameters:
# TODO: This is too complex, we need to reduce the complexity
if properties["unhashable"]:
routes_to_check = self.routes_always_check
ndx, route = self.check_dynamic_route_exists(
pattern, routes_to_check, parameters
)
else:
routes_to_check = self.routes_dynamic[url_hash(uri)]
ndx, route = self.check_dynamic_route_exists(
pattern, routes_to_check, parameters
)
if ndx != -1:
# Pop the ndx of the route, no dups of the same route
routes_to_check.pop(ndx)
else:
route = self.routes_all.get(uri)
# prefix the handler name with the blueprint name
# if available
# special prefix for static files
is_static = False
if name and name.startswith("_static_"):
is_static = True
name = name.split("_static_", 1)[-1]
if hasattr(handler, "__blueprintname__"):
handler_name = "{}.{}".format(
handler.__blueprintname__, name or handler.__name__
)
else:
handler_name = name or getattr(handler, "__name__", None)
if route:
route = merge_route(route, methods, handler)
else:
route = Route(
handler=handler,
methods=methods,
pattern=pattern,
parameters=parameters,
name=handler_name,
uri=uri,
)
self.routes_all[uri] = route
if is_static:
pair = self.routes_static_files.get(handler_name)
if not (pair and (pair[0] + "/" == uri or uri + "/" == pair[0])):
self.routes_static_files[handler_name] = (uri, route)
else:
pair = self.routes_names.get(handler_name)
if not (pair and (pair[0] + "/" == uri or uri + "/" == pair[0])):
self.routes_names[handler_name] = (uri, route)
if properties["unhashable"]:
self.routes_always_check.append(route)
elif parameters:
self.routes_dynamic[url_hash(uri)].append(route)
else:
self.routes_static[uri] = route
@staticmethod
def check_dynamic_route_exists(pattern, routes_to_check, parameters):
for ndx, route in enumerate(routes_to_check):
if route.pattern == pattern and route.parameters == parameters:
return ndx, route
else:
return -1, None
def remove(self, uri, clean_cache=True, host=None):
if host is not None:
uri = host + uri
try:
route = self.routes_all.pop(uri)
for handler_name, pairs in self.routes_names.items():
if pairs[0] == uri:
self.routes_names.pop(handler_name)
break
for handler_name, pairs in self.routes_static_files.items():
if pairs[0] == uri:
self.routes_static_files.pop(handler_name)
break
except KeyError:
raise RouteDoesNotExist("Route was not registered: {}".format(uri))
if route in self.routes_always_check:
self.routes_always_check.remove(route)
elif (
url_hash(uri) in self.routes_dynamic
and route in self.routes_dynamic[url_hash(uri)]
):
self.routes_dynamic[url_hash(uri)].remove(route)
else:
self.routes_static.pop(uri)
if clean_cache:
self._get.cache_clear()
@lru_cache(maxsize=ROUTER_CACHE_SIZE)
def find_route_by_view_name(self, view_name, name=None):
"""Find a route in the router based on the specified view name.
:param view_name: string of view name to search by
:param kwargs: additional params, usually for static files
:return: tuple containing (uri, Route)
"""
if not view_name:
return (None, None)
if view_name == "static" or view_name.endswith(".static"):
return self.routes_static_files.get(name, (None, None))
return self.routes_names.get(view_name, (None, None))
def get(self, request):
"""Get a request handler based on the URL of the request, or raises an
error
:param request: Request object
:return: handler, arguments, keyword arguments
"""
# No virtual hosts specified; default behavior
if not self.hosts:
return self._get(request.path, request.method, "")
# virtual hosts specified; try to match route to the host header
try:
return self._get(
request.path, request.method, request.headers.get("Host", "")
)
# try default hosts
except NotFound:
return self._get(request.path, request.method, "")
def get_supported_methods(self, url):
"""Get a list of supported methods for a url and optional host.
:param url: URL string (including host)
:return: frozenset of supported methods
"""
route = self.routes_all.get(url)
# if methods are None then this logic will prevent an error
return getattr(route, "methods", None) or frozenset()
@lru_cache(maxsize=ROUTER_CACHE_SIZE)
def _get(self, url, method, host):
"""Get a request handler based on the URL of the request, or raises an
error. Internal method for caching.
:param url: request URL
:param method: request method
:return: handler, arguments, keyword arguments
"""
url = unquote(host + url)
# Check against known static routes
route = self.routes_static.get(url)
method_not_supported = MethodNotSupported(
"Method {} not allowed for URL {}".format(method, url),
method=method,
allowed_methods=self.get_supported_methods(url),
)
if route:
if route.methods and method not in route.methods:
raise method_not_supported
match = route.pattern.match(url)
else:
route_found = False
# Move on to testing all regex routes
for route in self.routes_dynamic[url_hash(url)]:
match = route.pattern.match(url)
route_found |= match is not None
# Do early method checking
if match and method in route.methods:
break
else:
# Lastly, check against all regex routes that cannot be hashed
for route in self.routes_always_check:
match = route.pattern.match(url)
route_found |= match is not None
# Do early method checking
if match and method in route.methods:
break
else:
# Route was found but the methods didn't match
if route_found:
raise method_not_supported
raise NotFound("Requested URL {} not found".format(url))
kwargs = {
p.name: p.cast(value)
for value, p in zip(match.groups(1), route.parameters)
}
route_handler = route.handler
if hasattr(route_handler, "handlers"):
route_handler = route_handler.handlers[method]
return route_handler, [], kwargs, route.uri
def is_stream_handler(self, request):
""" Handler for request is stream or not.
:param request: Request object
:return: bool
"""
try:
handler = self.get(request)[0]
except (NotFound, MethodNotSupported):
return False
if hasattr(handler, "view_class") and hasattr(
handler.view_class, request.method.lower()
):
handler = getattr(handler.view_class, request.method.lower())
return hasattr(handler, "is_stream")