import hashlib import importlib.util import os import stat import typing from email.utils import formatdate, parsedate from urllib.parse import quote import anyio from fastapi import BackgroundTasks from starlette.datastructures import URL, Headers from starlette.exceptions import HTTPException from starlette.responses import FileResponse, RedirectResponse, Response from starlette.types import Receive, Scope, Send PathLike = typing.Union[str, "os.PathLike[str]"] mimetypes = [ ("html", "text/html"), ("htm", "text/html"), ("css", "text/css"), ("js", "application/javascript"), ("json", "application/json"), ("jpg", "image/jpeg"), ("jpeg", "image/jpeg"), ("png", "image/png"), ("gif", "image/gif"), ("ico", "image/x-icon"), ("svg", "image/svg+xml"), ("swf", "application/x-shockwave-flash"), ("flv", "video/x-flv"), ("mp3", "audio/mpeg"), ("mp4", "video/mp4"), ("ogg", "application/ogg"), ("ogv", "video/ogg"), ("wav", "audio/x-wav"), ("wma", "audio/x-ms-wma"), ("wmv", "video/x-ms-wmv"), ("pdf", "application/pdf"), ("doc", "application/msword"), ("xls", "application/vnd.ms-excel"), ("ppt", "application/vnd.ms-powerpoint"), ("txt", "text/plain"), ("zip", "application/zip"), ("rar", "application/x-rar-compressed"), ("gz", "application/x-gzip"), ("bz2", "application/x-bzip2"), ("tar", "application/x-tar"), ("bmp", "image/bmp"), ("tiff", "image/tiff"), ("tif", "image/tiff"), ("rtf", "application/rtf"), ("xml", "text/xml"), ("xsl", "text/xml"), ("xsd", "text/xml"), ("ttf", "application/x-font-ttf"), ("otf", "application/x-font-otf"), ("woff", "application/x-font-woff"), ("woff2", "application/x-font-woff2"), ("eot", "application/vnd.ms-fontobject"), ("sfnt", "application/font-sfnt"), ("font", "application/font-sfnt"), ("cur", "image/vnd.microsoft.icon"), ] def guess_type(filename: str) -> str: for mime in mimetypes: if filename.endswith('.'+mime[0]): return mime[1] return "text/plain" class NotModifiedResponse(Response): NOT_MODIFIED_HEADERS = ( "cache-control", "content-location", "date", "etag", "expires", "vary", ) def __init__(self, headers: Headers): super().__init__( status_code=304, headers={ name: value for name, value in headers.items() if name in self.NOT_MODIFIED_HEADERS }, ) class Renderer: def __init__( self, *, directory: PathLike = None, packages: typing.List[str] = None, html: bool = False, check_dir: bool = True, ) -> None: self.directory = directory self.packages = packages self.all_directories = self.get_directories(directory, packages) self.html = html self.config_checked = False if check_dir and directory is not None and not os.path.isdir(directory): raise RuntimeError(f"Directory '{directory}' does not exist") def get_directories( self, directory: PathLike = None, packages: typing.List[str] = None ) -> typing.List[PathLike]: """ Given `directory` and `packages` arguments, return a list of all the directories that should be used for serving static files from. """ directories = [] if directory is not None: directories.append(directory) for package in packages or []: spec = importlib.util.find_spec(package) assert spec is not None, f"Package {package!r} could not be found." assert ( spec.origin is not None ), f"Directory 'statics' in package {package!r} could not be found." package_directory = os.path.normpath( os.path.join(spec.origin, "..", "statics") ) assert os.path.isdir( package_directory ), f"Directory 'statics' in package {package!r} could not be found." directories.append(package_directory) return directories async def __call__(self, scope: Scope, receive: Receive, send: Send) -> None: """ The ASGI entry point. """ assert scope["type"] == "http" if not self.config_checked: await self.check_config() self.config_checked = True path = self.get_path(scope) response = await self.get_response(path, scope) await response(scope, receive, send) def get_path(self, scope: Scope) -> str: """ Given the ASGI scope, return the `path` string to serve up, with OS specific path seperators, and any '..', '.' components removed. """ return os.path.normpath(os.path.join(*scope["path"].split("/"))) async def get_response(self, path: str, scope: Scope) -> Response: """ Returns an HTTP response, given the incoming path, method and request headers. """ if scope["method"] not in ("GET", "HEAD"): raise HTTPException(status_code=405) try: full_path, stat_result = await anyio.to_thread.run_sync( self.lookup_path, path ) except PermissionError: raise HTTPException(status_code=401) except OSError: raise if stat_result and stat.S_ISREG(stat_result.st_mode): # We have a static file to serve. return self.file_response(full_path, stat_result, scope) elif stat_result and stat.S_ISDIR(stat_result.st_mode) and self.html: # We're in HTML mode, and have got a directory URL. # Check if we have 'index.html' file to serve. index_path = os.path.join(path, "index.html") full_path, stat_result = await anyio.to_thread.run_sync( self.lookup_path, index_path ) if stat_result is not None and stat.S_ISREG(stat_result.st_mode): if not scope["path"].endswith("/"): # Directory URLs should redirect to always end in "/". url = URL(scope=scope) url = url.replace(path=url.path + "/") return RedirectResponse(url=url) return self.file_response(full_path, stat_result, scope) if self.html: return self.file_response(self.directory+"/index.html", stat_result, scope) raise HTTPException(status_code=404) def lookup_path( self, path: str ) -> typing.Tuple[str, typing.Optional[os.stat_result]]: for directory in self.all_directories: full_path = os.path.realpath(os.path.join(directory, path)) directory = os.path.realpath(directory) if os.path.commonprefix([full_path, directory]) != directory: # Don't allow misbehaving clients to break out of the static files # directory. continue try: return full_path, os.stat(full_path) except (FileNotFoundError, NotADirectoryError): continue return "", None def file_response( self, full_path: PathLike, stat_result: os.stat_result, scope: Scope, status_code: int = 200, ) -> Response: method = scope["method"] request_headers = Headers(scope=scope) response = AutoFileResponse( full_path, status_code=status_code, stat_result=stat_result, method=method ) if self.is_not_modified(response.headers, request_headers): return NotModifiedResponse(response.headers) return response async def check_config(self) -> None: """ Perform a one-off configuration check that StaticFiles is actually pointed at a directory, so that we can raise loud errors rather than just returning 404 responses. """ if self.directory is None: return try: stat_result = await anyio.to_thread.run_sync(os.stat, self.directory) except FileNotFoundError: raise RuntimeError( f"StaticFiles directory '{self.directory}' does not exist." ) if not (stat.S_ISDIR(stat_result.st_mode) or stat.S_ISLNK(stat_result.st_mode)): raise RuntimeError( f"StaticFiles path '{self.directory}' is not a directory." ) def is_not_modified( self, response_headers: Headers, request_headers: Headers ) -> bool: """ Given the request and response headers, return `True` if an HTTP "Not Modified" response could be returned instead. """ try: if_none_match = request_headers["if-none-match"] etag = response_headers["etag"] if if_none_match == etag: return True except KeyError: pass try: if_modified_since = parsedate(request_headers["if-modified-since"]) last_modified = parsedate(response_headers["last-modified"]) if ( if_modified_since is not None and last_modified is not None and if_modified_since >= last_modified ): return True except KeyError: pass return False class AutoFileResponse(Response): chunk_size = 4096 def __init__( self, path: typing.Union[str, "os.PathLike[str]"], status_code: int = 200, headers: dict = None, media_type: str = None, background: BackgroundTasks = None, filename: str = None, stat_result: os.stat_result = None, method: str = None, ) -> None: self.path = path self.status_code = status_code self.filename = filename self.send_header_only = method is not None and method.upper() == "HEAD" if media_type is None: media_type = guess_type(filename or path) or "text/plain" self.media_type = media_type self.background = background self.init_headers(headers) if self.filename is not None: content_disposition_filename = quote(self.filename) if content_disposition_filename != self.filename: content_disposition = "attachment; filename*=utf-8''{}".format( content_disposition_filename ) else: content_disposition = f'attachment; filename="{self.filename}"' self.headers.setdefault("content-disposition", content_disposition) self.stat_result = stat_result if stat_result is not None: self.set_stat_headers(stat_result) def set_stat_headers(self, stat_result: os.stat_result) -> None: content_length = str(stat_result.st_size) last_modified = formatdate(stat_result.st_mtime, usegmt=True) etag_base = str(stat_result.st_mtime) + "-" + str(stat_result.st_size) etag = hashlib.md5(etag_base.encode()).hexdigest() self.headers.setdefault("content-length", content_length) self.headers.setdefault("last-modified", last_modified) self.headers.setdefault("etag", etag) async def __call__(self, scope: Scope, receive: Receive, send: Send) -> None: if self.stat_result is None: try: stat_result = await anyio.to_thread.run_sync(os.stat, self.path) self.set_stat_headers(stat_result) except FileNotFoundError: raise RuntimeError(f"File at path {self.path} does not exist.") else: mode = stat_result.st_mode if not stat.S_ISREG(mode): raise RuntimeError( f"File at path {self.path} is not a file.") await send( { "type": "http.response.start", "status": self.status_code, "headers": self.raw_headers, } ) if self.send_header_only: await send({"type": "http.response.body", "body": b"", "more_body": False}) else: async with await anyio.open_file(self.path, mode="rb") as file: more_body = True while more_body: chunk = await file.read(self.chunk_size) more_body = len(chunk) == self.chunk_size await send( { "type": "http.response.body", "body": chunk, "more_body": more_body, } ) if self.background is not None: await self.background()