284 lines
9.3 KiB
Python
284 lines
9.3 KiB
Python
"""
|
|
Serve Shared Static Files
|
|
=========================
|
|
|
|
.. autoclass:: SharedDataMiddleware
|
|
:members: is_allowed
|
|
|
|
:copyright: 2007 Pallets
|
|
:license: BSD-3-Clause
|
|
"""
|
|
|
|
from __future__ import annotations
|
|
|
|
import collections.abc as cabc
|
|
import importlib.util
|
|
import mimetypes
|
|
import os
|
|
import posixpath
|
|
import typing as t
|
|
from datetime import datetime
|
|
from datetime import timezone
|
|
from io import BytesIO
|
|
from time import time
|
|
from zlib import adler32
|
|
|
|
from ..http import http_date
|
|
from ..http import is_resource_modified
|
|
from ..security import safe_join
|
|
from ..utils import get_content_type
|
|
from ..wsgi import get_path_info
|
|
from ..wsgi import wrap_file
|
|
|
|
_TOpener = t.Callable[[], tuple[t.IO[bytes], datetime, int]]
|
|
_TLoader = t.Callable[[t.Optional[str]], tuple[t.Optional[str], t.Optional[_TOpener]]]
|
|
|
|
if t.TYPE_CHECKING:
|
|
from _typeshed.wsgi import StartResponse
|
|
from _typeshed.wsgi import WSGIApplication
|
|
from _typeshed.wsgi import WSGIEnvironment
|
|
|
|
|
|
class SharedDataMiddleware:
|
|
"""A WSGI middleware which provides static content for development
|
|
environments or simple server setups. Its usage is quite simple::
|
|
|
|
import os
|
|
from werkzeug.middleware.shared_data import SharedDataMiddleware
|
|
|
|
app = SharedDataMiddleware(app, {
|
|
'/shared': os.path.join(os.path.dirname(__file__), 'shared')
|
|
})
|
|
|
|
The contents of the folder ``./shared`` will now be available on
|
|
``http://example.com/shared/``. This is pretty useful during development
|
|
because a standalone media server is not required. Files can also be
|
|
mounted on the root folder and still continue to use the application because
|
|
the shared data middleware forwards all unhandled requests to the
|
|
application, even if the requests are below one of the shared folders.
|
|
|
|
If `pkg_resources` is available you can also tell the middleware to serve
|
|
files from package data::
|
|
|
|
app = SharedDataMiddleware(app, {
|
|
'/static': ('myapplication', 'static')
|
|
})
|
|
|
|
This will then serve the ``static`` folder in the `myapplication`
|
|
Python package.
|
|
|
|
The optional `disallow` parameter can be a list of :func:`~fnmatch.fnmatch`
|
|
rules for files that are not accessible from the web. If `cache` is set to
|
|
`False` no caching headers are sent.
|
|
|
|
Currently the middleware does not support non-ASCII filenames. If the
|
|
encoding on the file system happens to match the encoding of the URI it may
|
|
work but this could also be by accident. We strongly suggest using ASCII
|
|
only file names for static files.
|
|
|
|
The middleware will guess the mimetype using the Python `mimetype`
|
|
module. If it's unable to figure out the charset it will fall back
|
|
to `fallback_mimetype`.
|
|
|
|
:param app: the application to wrap. If you don't want to wrap an
|
|
application you can pass it :exc:`NotFound`.
|
|
:param exports: a list or dict of exported files and folders.
|
|
:param disallow: a list of :func:`~fnmatch.fnmatch` rules.
|
|
:param cache: enable or disable caching headers.
|
|
:param cache_timeout: the cache timeout in seconds for the headers.
|
|
:param fallback_mimetype: The fallback mimetype for unknown files.
|
|
|
|
.. versionchanged:: 1.0
|
|
The default ``fallback_mimetype`` is
|
|
``application/octet-stream``. If a filename looks like a text
|
|
mimetype, the ``utf-8`` charset is added to it.
|
|
|
|
.. versionadded:: 0.6
|
|
Added ``fallback_mimetype``.
|
|
|
|
.. versionchanged:: 0.5
|
|
Added ``cache_timeout``.
|
|
"""
|
|
|
|
def __init__(
|
|
self,
|
|
app: WSGIApplication,
|
|
exports: (
|
|
cabc.Mapping[str, str | tuple[str, str]]
|
|
| t.Iterable[tuple[str, str | tuple[str, str]]]
|
|
),
|
|
disallow: None = None,
|
|
cache: bool = True,
|
|
cache_timeout: int = 60 * 60 * 12,
|
|
fallback_mimetype: str = "application/octet-stream",
|
|
) -> None:
|
|
self.app = app
|
|
self.exports: list[tuple[str, _TLoader]] = []
|
|
self.cache = cache
|
|
self.cache_timeout = cache_timeout
|
|
|
|
if isinstance(exports, cabc.Mapping):
|
|
exports = exports.items()
|
|
|
|
for key, value in exports:
|
|
if isinstance(value, tuple):
|
|
loader = self.get_package_loader(*value)
|
|
elif isinstance(value, str):
|
|
if os.path.isfile(value):
|
|
loader = self.get_file_loader(value)
|
|
else:
|
|
loader = self.get_directory_loader(value)
|
|
else:
|
|
raise TypeError(f"unknown def {value!r}")
|
|
|
|
self.exports.append((key, loader))
|
|
|
|
if disallow is not None:
|
|
from fnmatch import fnmatch
|
|
|
|
self.is_allowed = lambda x: not fnmatch(x, disallow)
|
|
|
|
self.fallback_mimetype = fallback_mimetype
|
|
|
|
def is_allowed(self, filename: str) -> bool:
|
|
"""Subclasses can override this method to disallow the access to
|
|
certain files. However by providing `disallow` in the constructor
|
|
this method is overwritten.
|
|
"""
|
|
return True
|
|
|
|
def _opener(self, filename: str) -> _TOpener:
|
|
return lambda: (
|
|
open(filename, "rb"),
|
|
datetime.fromtimestamp(os.path.getmtime(filename), tz=timezone.utc),
|
|
int(os.path.getsize(filename)),
|
|
)
|
|
|
|
def get_file_loader(self, filename: str) -> _TLoader:
|
|
return lambda x: (os.path.basename(filename), self._opener(filename))
|
|
|
|
def get_package_loader(self, package: str, package_path: str) -> _TLoader:
|
|
load_time = datetime.now(timezone.utc)
|
|
spec = importlib.util.find_spec(package)
|
|
reader = spec.loader.get_resource_reader(package) # type: ignore[union-attr]
|
|
|
|
def loader(
|
|
path: str | None,
|
|
) -> tuple[str | None, _TOpener | None]:
|
|
if path is None:
|
|
return None, None
|
|
|
|
path = safe_join(package_path, path)
|
|
|
|
if path is None:
|
|
return None, None
|
|
|
|
basename = posixpath.basename(path)
|
|
|
|
try:
|
|
resource = reader.open_resource(path)
|
|
except OSError:
|
|
return None, None
|
|
|
|
if isinstance(resource, BytesIO):
|
|
return (
|
|
basename,
|
|
lambda: (resource, load_time, len(resource.getvalue())),
|
|
)
|
|
|
|
return (
|
|
basename,
|
|
lambda: (
|
|
resource,
|
|
datetime.fromtimestamp(
|
|
os.path.getmtime(resource.name), tz=timezone.utc
|
|
),
|
|
os.path.getsize(resource.name),
|
|
),
|
|
)
|
|
|
|
return loader
|
|
|
|
def get_directory_loader(self, directory: str) -> _TLoader:
|
|
def loader(
|
|
path: str | None,
|
|
) -> tuple[str | None, _TOpener | None]:
|
|
if path is not None:
|
|
path = safe_join(directory, path)
|
|
|
|
if path is None:
|
|
return None, None
|
|
else:
|
|
path = directory
|
|
|
|
if os.path.isfile(path):
|
|
return os.path.basename(path), self._opener(path)
|
|
|
|
return None, None
|
|
|
|
return loader
|
|
|
|
def generate_etag(self, mtime: datetime, file_size: int, real_filename: str) -> str:
|
|
fn_str = os.fsencode(real_filename)
|
|
timestamp = mtime.timestamp()
|
|
checksum = adler32(fn_str) & 0xFFFFFFFF
|
|
return f"wzsdm-{timestamp}-{file_size}-{checksum}"
|
|
|
|
def __call__(
|
|
self, environ: WSGIEnvironment, start_response: StartResponse
|
|
) -> t.Iterable[bytes]:
|
|
path = get_path_info(environ)
|
|
file_loader = None
|
|
|
|
for search_path, loader in self.exports:
|
|
if search_path == path:
|
|
real_filename, file_loader = loader(None)
|
|
|
|
if file_loader is not None:
|
|
break
|
|
|
|
if not search_path.endswith("/"):
|
|
search_path += "/"
|
|
|
|
if path.startswith(search_path):
|
|
real_filename, file_loader = loader(path[len(search_path) :])
|
|
|
|
if file_loader is not None:
|
|
break
|
|
|
|
if file_loader is None or not self.is_allowed(real_filename): # type: ignore
|
|
return self.app(environ, start_response)
|
|
|
|
guessed_type = mimetypes.guess_type(real_filename) # type: ignore
|
|
mime_type = get_content_type(guessed_type[0] or self.fallback_mimetype, "utf-8")
|
|
f, mtime, file_size = file_loader()
|
|
|
|
headers = [("Date", http_date())]
|
|
|
|
if self.cache:
|
|
timeout = self.cache_timeout
|
|
etag = self.generate_etag(mtime, file_size, real_filename) # type: ignore
|
|
headers += [
|
|
("Etag", f'"{etag}"'),
|
|
("Cache-Control", f"max-age={timeout}, public"),
|
|
]
|
|
|
|
if not is_resource_modified(environ, etag, last_modified=mtime):
|
|
f.close()
|
|
start_response("304 Not Modified", headers)
|
|
return []
|
|
|
|
headers.append(("Expires", http_date(time() + timeout)))
|
|
else:
|
|
headers.append(("Cache-Control", "public"))
|
|
|
|
headers.extend(
|
|
(
|
|
("Content-Type", mime_type),
|
|
("Content-Length", str(file_size)),
|
|
("Last-Modified", http_date(mtime)),
|
|
)
|
|
)
|
|
start_response("200 OK", headers)
|
|
return wrap_file(environ, f)
|