diff options
Diffstat (limited to 'venv/lib/python3.8/site-packages/werkzeug/middleware/shared_data.py')
| -rw-r--r-- | venv/lib/python3.8/site-packages/werkzeug/middleware/shared_data.py | 283 |
1 files changed, 283 insertions, 0 deletions
diff --git a/venv/lib/python3.8/site-packages/werkzeug/middleware/shared_data.py b/venv/lib/python3.8/site-packages/werkzeug/middleware/shared_data.py new file mode 100644 index 0000000..0f467f2 --- /dev/null +++ b/venv/lib/python3.8/site-packages/werkzeug/middleware/shared_data.py @@ -0,0 +1,283 @@ +""" +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[[], t.Tuple[t.IO[bytes], datetime, int]] +_TLoader = t.Callable[[t.Optional[str]], t.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) |