def prepare_middleware(middleware=None):
"""Check middleware interface and prepare it to iterate.
Args:
middleware: list (or object) of input middleware
Returns:
A middleware list
"""
# PERF(kgriffs): do getattr calls once, in advance, so we don't
# have to do them every time in the request path.
prepared_middleware = []
if middleware is None:
middleware = []
else:
if not isinstance(middleware, list):
middleware = [middleware]
for component in middleware:
process_request = util.get_bound_method(component, "process_request")
process_resource = util.get_bound_method(component, "process_resource")
process_response = util.get_bound_method(component, "process_response")
if not (process_request or process_resource or process_response):
msg = "{0} does not implement the middleware interface"
raise TypeError(msg.format(component))
prepared_middleware.append((process_request, process_resource, process_response))
return prepared_middleware
def prepare_middleware(middleware=None):
"""Check middleware interface and prepare it to iterate.
Args:
middleware: list (or object) of input middleware
Returns:
A middleware list
"""
# PERF(kgriffs): do getattr calls once, in advance, so we don't
# have to do them every time in the request path.
prepared_middleware = []
if middleware is None:
middleware = []
else:
if not isinstance(middleware, list):
middleware = [middleware]
for component in middleware:
process_request = util.get_bound_method(component, 'process_request')
process_resource = util.get_bound_method(component, 'process_resource')
process_response = util.get_bound_method(component, 'process_response')
if not (process_request or process_resource or process_response):
msg = '{0} does not implement the middleware interface'
raise TypeError(msg.format(component))
prepared_middleware.append(
(process_request, process_resource, process_response))
return prepared_middleware
def prepare_middleware(middleware=None, independent_middleware=False):
"""Check middleware interface and prepare it to iterate.
Args:
middleware: list (or object) of input middleware
independent_middleware: bool whether should prepare request and
response middleware independently
Returns:
list: A tuple of prepared middleware tuples
"""
# PERF(kgriffs): do getattr calls once, in advance, so we don't
# have to do them every time in the request path.
request_mw = []
resource_mw = []
response_mw = []
if middleware is None:
middleware = []
else:
if not isinstance(middleware, list):
middleware = [middleware]
for component in middleware:
process_request = util.get_bound_method(component,
'process_request')
process_resource = util.get_bound_method(component,
'process_resource')
process_response = util.get_bound_method(component,
'process_response')
if not (process_request or process_resource or process_response):
msg = '{0} does not implement the middleware interface'
raise TypeError(msg.format(component))
# NOTE: depending on whether we want to execute middleware
# independently, we group response and request middleware either
# together or separately.
if independent_middleware:
if process_request:
request_mw.append(process_request)
if process_response:
response_mw.insert(0, process_response)
else:
if process_request or process_response:
request_mw.append((process_request, process_response))
if process_resource:
resource_mw.append(process_resource)
return (tuple(request_mw), tuple(resource_mw), tuple(response_mw))
def prepare_middleware(middleware=None, independent_middleware=False):
"""Check middleware interface and prepare it to iterate.
Args:
middleware: list (or object) of input middleware
independent_middleware: bool whether should prepare request and
response middleware independently
Returns:
list: A tuple of prepared middleware tuples
"""
# PERF(kgriffs): do getattr calls once, in advance, so we don't
# have to do them every time in the request path.
request_mw = []
resource_mw = []
response_mw = []
if middleware is None:
middleware = []
else:
if not isinstance(middleware, list):
middleware = [middleware]
for component in middleware:
process_request = util.get_bound_method(component,
'process_request')
process_resource = util.get_bound_method(component,
'process_resource')
process_response = util.get_bound_method(component,
'process_response')
if not (process_request or process_resource or process_response):
msg = '{0} does not implement the middleware interface'
raise TypeError(msg.format(component))
# NOTE: depending on whether we want to execute middleware
# independently, we group response and request middleware either
# together or separately.
if independent_middleware:
if process_request:
request_mw.append(process_request)
if process_response:
response_mw.insert(0, process_response)
else:
if process_request or process_response:
request_mw.append((process_request, process_response))
if process_resource:
resource_mw.append(process_resource)
return (tuple(request_mw), tuple(resource_mw), tuple(response_mw))
def add_middleware(self, mw):
process_request = util.get_bound_method(mw, 'process_request')
process_resource = util.get_bound_method(mw, 'process_resource')
process_response = util.get_bound_method(mw, 'process_response')
if process_request:
self.req_mw.append(process_request)
if process_resource:
self.resc_mw.append(process_resource)
if process_response:
self.resp_mw.append(process_response)
def prepare_middleware(middleware=None):
"""Check middleware interface and prepare it to iterate.
Args:
middleware: list (or object) of input middleware
Returns:
list: A list of prepared middleware tuples
"""
# PERF(kgriffs): do getattr calls once, in advance, so we don't
# have to do them every time in the request path.
prepared_middleware = []
if middleware is None:
middleware = []
else:
if not isinstance(middleware, list):
middleware = [middleware]
for component in middleware:
process_request = util.get_bound_method(component,
'process_request')
process_resource = util.get_bound_method(component,
'process_resource')
process_response = util.get_bound_method(component,
'process_response')
if not (process_request or process_resource or process_response):
msg = '{0} does not implement the middleware interface'
raise TypeError(msg.format(component))
if process_response:
# NOTE(kgriffs): Shim older implementations to ensure
# backwards-compatibility.
args = util.get_argnames(process_response)
if len(args) == 3: # (req, resp, resource)
def let(process_response=process_response):
@wraps(process_response)
def shim(req, resp, resource, req_succeeded):
process_response(req, resp, resource)
return shim
process_response = let()
prepared_middleware.append((process_request, process_resource,
process_response))
return prepared_middleware
def prepare_middleware_ws(middleware):
"""Check middleware interfaces and prepare WebSocket methods for request handling.
Note:
This method is only applicable to ASGI apps.
Arguments:
middleware (iterable): An iterable of middleware objects.
Returns:
tuple: A two-item ``(request_mw, resource_mw)`` tuple, where
*request_mw* is an ordered list of ``process_request_ws()`` methods,
and *resource_mw* is an ordered list of ``process_resource_ws()``
methods.
"""
# PERF(kgriffs): do getattr calls once, in advance, so we don't
# have to do them every time in the request path.
request_mw = []
resource_mw = []
for component in middleware:
process_request_ws = util.get_bound_method(component,
'process_request_ws')
process_resource_ws = util.get_bound_method(component,
'process_resource_ws')
for m in (process_request_ws, process_resource_ws):
if not m:
continue
# NOTE(kgriffs): iscoroutinefunction() always returns False
# for cythonized functions.
#
# https://github.com/cython/cython/issues/2273
# https://bugs.python.org/issue38225
#
if not iscoroutinefunction(m) and util.is_python_func(m):
msg = '{} must be implemented as an awaitable coroutine.'
raise CompatibilityError(msg.format(m))
if process_request_ws:
request_mw.append(process_request_ws)
if process_resource_ws:
resource_mw.append(process_resource_ws)
return request_mw, resource_mw
def prepare_middleware(middleware, independent_middleware=False, asgi=False):
"""Check middleware interfaces and prepare the methods for request handling.
Arguments:
middleware (iterable): An iterable of middleware objects.
Keyword Args:
independent_middleware (bool): ``True`` if the request and
response middleware methods should be treated independently
(default ``False``)
asgi (bool): ``True`` if an ASGI app, ``False`` otherwise
(default ``False``)
Returns:
tuple: A tuple of prepared middleware method tuples
"""
# PERF(kgriffs): do getattr calls once, in advance, so we don't
# have to do them every time in the request path.
request_mw = []
resource_mw = []
response_mw = []
for component in middleware:
# NOTE(kgriffs): Middleware that uses parts of the Request and Response
# interfaces that are the same between ASGI and WSGI (most of it is,
# and we should probably define this via ABC) can just implement
# the method names without the *_async postfix. If a middleware
# component wants to provide an alternative implementation that
# does some work that requires async def, or something specific about
# the ASGI Request/Response classes, the component can implement the
# *_async method in that case.
#
# Middleware that is WSGI-only or ASGI-only can simply implement all
# methods without the *_async postfix. Regardless, components should
# clearly document their compatibility with WSGI vs. ASGI.
if asgi:
process_request = (
util.get_bound_method(component, 'process_request_async') or
_wrap_non_coroutine_unsafe(
util.get_bound_method(component, 'process_request')
)
)
process_resource = (
util.get_bound_method(component, 'process_resource_async') or
_wrap_non_coroutine_unsafe(
util.get_bound_method(component, 'process_resource')
)
)
process_response = (
util.get_bound_method(component, 'process_response_async') or
_wrap_non_coroutine_unsafe(
util.get_bound_method(component, 'process_response')
)
)
for m in (process_request, process_resource, process_response):
if m and not iscoroutinefunction(m):
msg = (
'{} must be implemented as an awaitable coroutine. If '
'you would like to retain compatibility '
'with WSGI apps, the coroutine versions of the '
'middleware methods may be implemented side-by-side '
'by applying an *_async postfix to the method names. '
)
raise CompatibilityError(msg.format(m))
else:
process_request = util.get_bound_method(component, 'process_request')
process_resource = util.get_bound_method(component, 'process_resource')
process_response = util.get_bound_method(component, 'process_response')
for m in (process_request, process_resource, process_response):
if m and iscoroutinefunction(m):
msg = (
'{} may not implement coroutine methods and '
'remain compatible with WSGI apps without '
'using the *_async postfix to explicitly identify '
'the coroutine version of a given middleware '
'method.'
)
raise CompatibilityError(msg.format(component))
if not (process_request or process_resource or process_response):
if asgi and (
hasattr(component, 'process_startup') or hasattr(component, 'process_shutdown')
):
# NOTE(kgriffs): This middleware only has ASGI lifespan
# event handlers
continue
msg = '{0} must implement at least one middleware method'
raise TypeError(msg.format(component))
# NOTE: depending on whether we want to execute middleware
# independently, we group response and request middleware either
# together or separately.
if independent_middleware:
if process_request:
request_mw.append(process_request)
if process_response:
response_mw.insert(0, process_response)
else:
if process_request or process_response:
request_mw.append((process_request, process_response))
if process_resource:
resource_mw.append(process_resource)
return (tuple(request_mw), tuple(resource_mw), tuple(response_mw))
def prepare_middleware(middleware, independent_middleware=False, asgi=False):
"""Check middleware interfaces and prepare the methods for request handling.
Arguments:
middleware (iterable): An iterable of middleware objects.
Keyword Args:
independent_middleware (bool): ``True`` if the request and
response middleware methods should be treated independently
(default ``False``)
asgi (bool): ``True`` if an ASGI app, ``False`` otherwise
(default ``False``)
Returns:
tuple: A tuple of prepared middleware method tuples
"""
# PERF(kgriffs): do getattr calls once, in advance, so we don't
# have to do them every time in the request path.
request_mw = []
resource_mw = []
response_mw = []
for component in middleware:
# NOTE(kgriffs): Middleware that supports both WSGI and ASGI can
# append an *_async postfix to the ASGI version of the method
# to distinguish the two. Otherwise, the prefix is unnecessary.
if asgi:
process_request = (
util.get_bound_method(component, 'process_request_async')
or _wrap_non_coroutine_unsafe(
util.get_bound_method(component, 'process_request')))
process_resource = (
util.get_bound_method(component, 'process_resource_async')
or _wrap_non_coroutine_unsafe(
util.get_bound_method(component, 'process_resource')))
process_response = (
util.get_bound_method(component, 'process_response_async')
or _wrap_non_coroutine_unsafe(
util.get_bound_method(component, 'process_response')))
for m in (process_request, process_resource, process_response):
# NOTE(kgriffs): iscoroutinefunction() always returns False
# for cythonized functions.
#
# https://github.com/cython/cython/issues/2273
# https://bugs.python.org/issue38225
#
if m and not iscoroutinefunction(m) and util.is_python_func(m):
msg = (
'{} must be implemented as an awaitable coroutine. If '
'you would like to retain compatibility '
'with WSGI apps, the coroutine versions of the '
'middleware methods may be implemented side-by-side '
'by applying an *_async postfix to the method names. ')
raise CompatibilityError(msg.format(m))
else:
process_request = util.get_bound_method(component,
'process_request')
process_resource = util.get_bound_method(component,
'process_resource')
process_response = util.get_bound_method(component,
'process_response')
for m in (process_request, process_resource, process_response):
if m and iscoroutinefunction(m):
msg = ('{} may not implement coroutine methods and '
'remain compatible with WSGI apps without '
'using the *_async postfix to explicitly identify '
'the coroutine version of a given middleware '
'method.')
raise CompatibilityError(msg.format(component))
if not (process_request or process_resource or process_response):
if asgi and (hasattr(component, 'process_startup')
or hasattr(component, 'process_shutdown')):
# NOTE(kgriffs): This middleware only has ASGI lifespan
# event handlers
continue
msg = '{0} must implement at least one middleware method'
raise TypeError(msg.format(component))
# NOTE: depending on whether we want to execute middleware
# independently, we group response and request middleware either
# together or separately.
if independent_middleware:
if process_request:
request_mw.append(process_request)
if process_response:
response_mw.insert(0, process_response)
else:
if process_request or process_response:
request_mw.append((process_request, process_response))
if process_resource:
resource_mw.append(process_resource)
return (tuple(request_mw), tuple(resource_mw), tuple(response_mw))