Mabasej_Team/.venv/lib/python3.9/site-packages/starlette/routing.py
Untriex Programming ed6afdb5c9 new
2021-03-17 08:57:57 +01:00

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import asyncio
import inspect
import re
import traceback
import typing
from enum import Enum
from starlette.concurrency import run_in_threadpool
from starlette.convertors import CONVERTOR_TYPES, Convertor
from starlette.datastructures import URL, Headers, URLPath
from starlette.exceptions import HTTPException
from starlette.requests import Request
from starlette.responses import PlainTextResponse, RedirectResponse
from starlette.types import ASGIApp, Receive, Scope, Send
from starlette.websockets import WebSocket, WebSocketClose
class NoMatchFound(Exception):
"""
Raised by `.url_for(name, **path_params)` and `.url_path_for(name, **path_params)`
if no matching route exists.
"""
class Match(Enum):
NONE = 0
PARTIAL = 1
FULL = 2
def request_response(func: typing.Callable) -> ASGIApp:
"""
Takes a function or coroutine `func(request) -> response`,
and returns an ASGI application.
"""
is_coroutine = asyncio.iscoroutinefunction(func)
async def app(scope: Scope, receive: Receive, send: Send) -> None:
request = Request(scope, receive=receive, send=send)
if is_coroutine:
response = await func(request)
else:
response = await run_in_threadpool(func, request)
await response(scope, receive, send)
return app
def websocket_session(func: typing.Callable) -> ASGIApp:
"""
Takes a coroutine `func(session)`, and returns an ASGI application.
"""
# assert asyncio.iscoroutinefunction(func), "WebSocket endpoints must be async"
async def app(scope: Scope, receive: Receive, send: Send) -> None:
session = WebSocket(scope, receive=receive, send=send)
await func(session)
return app
def get_name(endpoint: typing.Callable) -> str:
if inspect.isfunction(endpoint) or inspect.isclass(endpoint):
return endpoint.__name__
return endpoint.__class__.__name__
def replace_params(
path: str,
param_convertors: typing.Dict[str, Convertor],
path_params: typing.Dict[str, str],
) -> typing.Tuple[str, dict]:
for key, value in list(path_params.items()):
if "{" + key + "}" in path:
convertor = param_convertors[key]
value = convertor.to_string(value)
path = path.replace("{" + key + "}", value)
path_params.pop(key)
return path, path_params
# Match parameters in URL paths, eg. '{param}', and '{param:int}'
PARAM_REGEX = re.compile("{([a-zA-Z_][a-zA-Z0-9_]*)(:[a-zA-Z_][a-zA-Z0-9_]*)?}")
def compile_path(
path: str,
) -> typing.Tuple[typing.Pattern, str, typing.Dict[str, Convertor]]:
"""
Given a path string, like: "/{username:str}", return a three-tuple
of (regex, format, {param_name:convertor}).
regex: "/(?P<username>[^/]+)"
format: "/{username}"
convertors: {"username": StringConvertor()}
"""
path_regex = "^"
path_format = ""
idx = 0
param_convertors = {}
for match in PARAM_REGEX.finditer(path):
param_name, convertor_type = match.groups("str")
convertor_type = convertor_type.lstrip(":")
assert (
convertor_type in CONVERTOR_TYPES
), f"Unknown path convertor '{convertor_type}'"
convertor = CONVERTOR_TYPES[convertor_type]
path_regex += re.escape(path[idx : match.start()])
path_regex += f"(?P<{param_name}>{convertor.regex})"
path_format += path[idx : match.start()]
path_format += "{%s}" % param_name
param_convertors[param_name] = convertor
idx = match.end()
path_regex += re.escape(path[idx:]) + "$"
path_format += path[idx:]
return re.compile(path_regex), path_format, param_convertors
class BaseRoute:
def matches(self, scope: Scope) -> typing.Tuple[Match, Scope]:
raise NotImplementedError() # pragma: no cover
def url_path_for(self, name: str, **path_params: str) -> URLPath:
raise NotImplementedError() # pragma: no cover
async def handle(self, scope: Scope, receive: Receive, send: Send) -> None:
raise NotImplementedError() # pragma: no cover
async def __call__(self, scope: Scope, receive: Receive, send: Send) -> None:
"""
A route may be used in isolation as a stand-alone ASGI app.
This is a somewhat contrived case, as they'll almost always be used
within a Router, but could be useful for some tooling and minimal apps.
"""
match, child_scope = self.matches(scope)
if match == Match.NONE:
if scope["type"] == "http":
response = PlainTextResponse("Not Found", status_code=404)
await response(scope, receive, send)
elif scope["type"] == "websocket":
websocket_close = WebSocketClose()
await websocket_close(scope, receive, send)
return
scope.update(child_scope)
await self.handle(scope, receive, send)
class Route(BaseRoute):
def __init__(
self,
path: str,
endpoint: typing.Callable,
*,
methods: typing.List[str] = None,
name: str = None,
include_in_schema: bool = True,
) -> None:
assert path.startswith("/"), "Routed paths must start with '/'"
self.path = path
self.endpoint = endpoint
self.name = get_name(endpoint) if name is None else name
self.include_in_schema = include_in_schema
if inspect.isfunction(endpoint) or inspect.ismethod(endpoint):
# Endpoint is function or method. Treat it as `func(request) -> response`.
self.app = request_response(endpoint)
if methods is None:
methods = ["GET"]
else:
# Endpoint is a class. Treat it as ASGI.
self.app = endpoint
if methods is None:
self.methods = None
else:
self.methods = set(method.upper() for method in methods)
if "GET" in self.methods:
self.methods.add("HEAD")
self.path_regex, self.path_format, self.param_convertors = compile_path(path)
def matches(self, scope: Scope) -> typing.Tuple[Match, Scope]:
if scope["type"] == "http":
match = self.path_regex.match(scope["path"])
if match:
matched_params = match.groupdict()
for key, value in matched_params.items():
matched_params[key] = self.param_convertors[key].convert(value)
path_params = dict(scope.get("path_params", {}))
path_params.update(matched_params)
child_scope = {"endpoint": self.endpoint, "path_params": path_params}
if self.methods and scope["method"] not in self.methods:
return Match.PARTIAL, child_scope
else:
return Match.FULL, child_scope
return Match.NONE, {}
def url_path_for(self, name: str, **path_params: str) -> URLPath:
seen_params = set(path_params.keys())
expected_params = set(self.param_convertors.keys())
if name != self.name or seen_params != expected_params:
raise NoMatchFound()
path, remaining_params = replace_params(
self.path_format, self.param_convertors, path_params
)
assert not remaining_params
return URLPath(path=path, protocol="http")
async def handle(self, scope: Scope, receive: Receive, send: Send) -> None:
if self.methods and scope["method"] not in self.methods:
if "app" in scope:
raise HTTPException(status_code=405)
else:
response = PlainTextResponse("Method Not Allowed", status_code=405)
await response(scope, receive, send)
else:
await self.app(scope, receive, send)
def __eq__(self, other: typing.Any) -> bool:
return (
isinstance(other, Route)
and self.path == other.path
and self.endpoint == other.endpoint
and self.methods == other.methods
)
class WebSocketRoute(BaseRoute):
def __init__(
self, path: str, endpoint: typing.Callable, *, name: str = None
) -> None:
assert path.startswith("/"), "Routed paths must start with '/'"
self.path = path
self.endpoint = endpoint
self.name = get_name(endpoint) if name is None else name
if inspect.isfunction(endpoint) or inspect.ismethod(endpoint):
# Endpoint is function or method. Treat it as `func(websocket)`.
self.app = websocket_session(endpoint)
else:
# Endpoint is a class. Treat it as ASGI.
self.app = endpoint
self.path_regex, self.path_format, self.param_convertors = compile_path(path)
def matches(self, scope: Scope) -> typing.Tuple[Match, Scope]:
if scope["type"] == "websocket":
match = self.path_regex.match(scope["path"])
if match:
matched_params = match.groupdict()
for key, value in matched_params.items():
matched_params[key] = self.param_convertors[key].convert(value)
path_params = dict(scope.get("path_params", {}))
path_params.update(matched_params)
child_scope = {"endpoint": self.endpoint, "path_params": path_params}
return Match.FULL, child_scope
return Match.NONE, {}
def url_path_for(self, name: str, **path_params: str) -> URLPath:
seen_params = set(path_params.keys())
expected_params = set(self.param_convertors.keys())
if name != self.name or seen_params != expected_params:
raise NoMatchFound()
path, remaining_params = replace_params(
self.path_format, self.param_convertors, path_params
)
assert not remaining_params
return URLPath(path=path, protocol="websocket")
async def handle(self, scope: Scope, receive: Receive, send: Send) -> None:
await self.app(scope, receive, send)
def __eq__(self, other: typing.Any) -> bool:
return (
isinstance(other, WebSocketRoute)
and self.path == other.path
and self.endpoint == other.endpoint
)
class Mount(BaseRoute):
def __init__(
self,
path: str,
app: ASGIApp = None,
routes: typing.Sequence[BaseRoute] = None,
name: str = None,
) -> None:
assert path == "" or path.startswith("/"), "Routed paths must start with '/'"
assert (
app is not None or routes is not None
), "Either 'app=...', or 'routes=' must be specified"
self.path = path.rstrip("/")
if app is not None:
self.app = app # type: ASGIApp
else:
self.app = Router(routes=routes)
self.name = name
self.path_regex, self.path_format, self.param_convertors = compile_path(
self.path + "/{path:path}"
)
@property
def routes(self) -> typing.List[BaseRoute]:
return getattr(self.app, "routes", None)
def matches(self, scope: Scope) -> typing.Tuple[Match, Scope]:
if scope["type"] in ("http", "websocket"):
path = scope["path"]
match = self.path_regex.match(path)
if match:
matched_params = match.groupdict()
for key, value in matched_params.items():
matched_params[key] = self.param_convertors[key].convert(value)
remaining_path = "/" + matched_params.pop("path")
matched_path = path[: -len(remaining_path)]
path_params = dict(scope.get("path_params", {}))
path_params.update(matched_params)
root_path = scope.get("root_path", "")
child_scope = {
"path_params": path_params,
"app_root_path": scope.get("app_root_path", root_path),
"root_path": root_path + matched_path,
"path": remaining_path,
"endpoint": self.app,
}
return Match.FULL, child_scope
return Match.NONE, {}
def url_path_for(self, name: str, **path_params: str) -> URLPath:
if self.name is not None and name == self.name and "path" in path_params:
# 'name' matches "<mount_name>".
path_params["path"] = path_params["path"].lstrip("/")
path, remaining_params = replace_params(
self.path_format, self.param_convertors, path_params
)
if not remaining_params:
return URLPath(path=path)
elif self.name is None or name.startswith(self.name + ":"):
if self.name is None:
# No mount name.
remaining_name = name
else:
# 'name' matches "<mount_name>:<child_name>".
remaining_name = name[len(self.name) + 1 :]
path_kwarg = path_params.get("path")
path_params["path"] = ""
path_prefix, remaining_params = replace_params(
self.path_format, self.param_convertors, path_params
)
if path_kwarg is not None:
remaining_params["path"] = path_kwarg
for route in self.routes or []:
try:
url = route.url_path_for(remaining_name, **remaining_params)
return URLPath(
path=path_prefix.rstrip("/") + str(url), protocol=url.protocol
)
except NoMatchFound:
pass
raise NoMatchFound()
async def handle(self, scope: Scope, receive: Receive, send: Send) -> None:
await self.app(scope, receive, send)
def __eq__(self, other: typing.Any) -> bool:
return (
isinstance(other, Mount)
and self.path == other.path
and self.app == other.app
)
class Host(BaseRoute):
def __init__(self, host: str, app: ASGIApp, name: str = None) -> None:
self.host = host
self.app = app
self.name = name
self.host_regex, self.host_format, self.param_convertors = compile_path(host)
@property
def routes(self) -> typing.List[BaseRoute]:
return getattr(self.app, "routes", None)
def matches(self, scope: Scope) -> typing.Tuple[Match, Scope]:
if scope["type"] in ("http", "websocket"):
headers = Headers(scope=scope)
host = headers.get("host", "").split(":")[0]
match = self.host_regex.match(host)
if match:
matched_params = match.groupdict()
for key, value in matched_params.items():
matched_params[key] = self.param_convertors[key].convert(value)
path_params = dict(scope.get("path_params", {}))
path_params.update(matched_params)
child_scope = {"path_params": path_params, "endpoint": self.app}
return Match.FULL, child_scope
return Match.NONE, {}
def url_path_for(self, name: str, **path_params: str) -> URLPath:
if self.name is not None and name == self.name and "path" in path_params:
# 'name' matches "<mount_name>".
path = path_params.pop("path")
host, remaining_params = replace_params(
self.host_format, self.param_convertors, path_params
)
if not remaining_params:
return URLPath(path=path, host=host)
elif self.name is None or name.startswith(self.name + ":"):
if self.name is None:
# No mount name.
remaining_name = name
else:
# 'name' matches "<mount_name>:<child_name>".
remaining_name = name[len(self.name) + 1 :]
host, remaining_params = replace_params(
self.host_format, self.param_convertors, path_params
)
for route in self.routes or []:
try:
url = route.url_path_for(remaining_name, **remaining_params)
return URLPath(path=str(url), protocol=url.protocol, host=host)
except NoMatchFound:
pass
raise NoMatchFound()
async def handle(self, scope: Scope, receive: Receive, send: Send) -> None:
await self.app(scope, receive, send)
def __eq__(self, other: typing.Any) -> bool:
return (
isinstance(other, Host)
and self.host == other.host
and self.app == other.app
)
class Router:
def __init__(
self,
routes: typing.Sequence[BaseRoute] = None,
redirect_slashes: bool = True,
default: ASGIApp = None,
on_startup: typing.Sequence[typing.Callable] = None,
on_shutdown: typing.Sequence[typing.Callable] = None,
lifespan: typing.Callable[[typing.Any], typing.AsyncGenerator] = None,
) -> None:
self.routes = [] if routes is None else list(routes)
self.redirect_slashes = redirect_slashes
self.default = self.not_found if default is None else default
self.on_startup = [] if on_startup is None else list(on_startup)
self.on_shutdown = [] if on_shutdown is None else list(on_shutdown)
async def default_lifespan(app: typing.Any) -> typing.AsyncGenerator:
await self.startup()
yield
await self.shutdown()
self.lifespan_context = default_lifespan if lifespan is None else lifespan
async def not_found(self, scope: Scope, receive: Receive, send: Send) -> None:
if scope["type"] == "websocket":
websocket_close = WebSocketClose()
await websocket_close(scope, receive, send)
return
# If we're running inside a starlette application then raise an
# exception, so that the configurable exception handler can deal with
# returning the response. For plain ASGI apps, just return the response.
if "app" in scope:
raise HTTPException(status_code=404)
else:
response = PlainTextResponse("Not Found", status_code=404)
await response(scope, receive, send)
def url_path_for(self, name: str, **path_params: str) -> URLPath:
for route in self.routes:
try:
return route.url_path_for(name, **path_params)
except NoMatchFound:
pass
raise NoMatchFound()
async def startup(self) -> None:
"""
Run any `.on_startup` event handlers.
"""
for handler in self.on_startup:
if asyncio.iscoroutinefunction(handler):
await handler()
else:
handler()
async def shutdown(self) -> None:
"""
Run any `.on_shutdown` event handlers.
"""
for handler in self.on_shutdown:
if asyncio.iscoroutinefunction(handler):
await handler()
else:
handler()
async def lifespan(self, scope: Scope, receive: Receive, send: Send) -> None:
"""
Handle ASGI lifespan messages, which allows us to manage application
startup and shutdown events.
"""
first = True
app = scope.get("app")
message = await receive()
try:
if inspect.isasyncgenfunction(self.lifespan_context):
async for item in self.lifespan_context(app):
assert first, "Lifespan context yielded multiple times."
first = False
await send({"type": "lifespan.startup.complete"})
message = await receive()
else:
for item in self.lifespan_context(app): # type: ignore
assert first, "Lifespan context yielded multiple times."
first = False
await send({"type": "lifespan.startup.complete"})
message = await receive()
except BaseException:
if first:
exc_text = traceback.format_exc()
await send({"type": "lifespan.startup.failed", "message": exc_text})
raise
else:
await send({"type": "lifespan.shutdown.complete"})
async def __call__(self, scope: Scope, receive: Receive, send: Send) -> None:
"""
The main entry point to the Router class.
"""
assert scope["type"] in ("http", "websocket", "lifespan")
if "router" not in scope:
scope["router"] = self
if scope["type"] == "lifespan":
await self.lifespan(scope, receive, send)
return
partial = None
for route in self.routes:
# Determine if any route matches the incoming scope,
# and hand over to the matching route if found.
match, child_scope = route.matches(scope)
if match == Match.FULL:
scope.update(child_scope)
await route.handle(scope, receive, send)
return
elif match == Match.PARTIAL and partial is None:
partial = route
partial_scope = child_scope
if partial is not None:
#  Handle partial matches. These are cases where an endpoint is
# able to handle the request, but is not a preferred option.
# We use this in particular to deal with "405 Method Not Allowed".
scope.update(partial_scope)
await partial.handle(scope, receive, send)
return
if scope["type"] == "http" and self.redirect_slashes and scope["path"] != "/":
redirect_scope = dict(scope)
if scope["path"].endswith("/"):
redirect_scope["path"] = redirect_scope["path"].rstrip("/")
else:
redirect_scope["path"] = redirect_scope["path"] + "/"
for route in self.routes:
match, child_scope = route.matches(redirect_scope)
if match != Match.NONE:
redirect_url = URL(scope=redirect_scope)
response = RedirectResponse(url=str(redirect_url))
await response(scope, receive, send)
return
await self.default(scope, receive, send)
def __eq__(self, other: typing.Any) -> bool:
return isinstance(other, Router) and self.routes == other.routes
# The following usages are now discouraged in favour of configuration
#  during Router.__init__(...)
def mount(self, path: str, app: ASGIApp, name: str = None) -> None:
route = Mount(path, app=app, name=name)
self.routes.append(route)
def host(self, host: str, app: ASGIApp, name: str = None) -> None:
route = Host(host, app=app, name=name)
self.routes.append(route)
def add_route(
self,
path: str,
endpoint: typing.Callable,
methods: typing.List[str] = None,
name: str = None,
include_in_schema: bool = True,
) -> None:
route = Route(
path,
endpoint=endpoint,
methods=methods,
name=name,
include_in_schema=include_in_schema,
)
self.routes.append(route)
def add_websocket_route(
self, path: str, endpoint: typing.Callable, name: str = None
) -> None:
route = WebSocketRoute(path, endpoint=endpoint, name=name)
self.routes.append(route)
def route(
self,
path: str,
methods: typing.List[str] = None,
name: str = None,
include_in_schema: bool = True,
) -> typing.Callable:
def decorator(func: typing.Callable) -> typing.Callable:
self.add_route(
path,
func,
methods=methods,
name=name,
include_in_schema=include_in_schema,
)
return func
return decorator
def websocket_route(self, path: str, name: str = None) -> typing.Callable:
def decorator(func: typing.Callable) -> typing.Callable:
self.add_websocket_route(path, func, name=name)
return func
return decorator
def add_event_handler(self, event_type: str, func: typing.Callable) -> None:
assert event_type in ("startup", "shutdown")
if event_type == "startup":
self.on_startup.append(func)
else:
self.on_shutdown.append(func)
def on_event(self, event_type: str) -> typing.Callable:
def decorator(func: typing.Callable) -> typing.Callable:
self.add_event_handler(event_type, func)
return func
return decorator