Class FileResponse

starlette/responses.py:298–579

class FileResponse(Response):
    chunk_size = 64 * 1024
    max_ranges = 100

    def __init__(
        self,
        path: str | os.PathLike[str],
        status_code: int = 200,
        headers: Mapping[str, str] | None = None,
        media_type: str | None = None,
        background: BackgroundTask | None = None,
        filename: str | None = None,
        stat_result: os.stat_result | None = None,
        content_disposition_type: str = "attachment",
    ) -> None:
        self.path = path
        self.status_code = status_code
        self.filename = filename
        if media_type is None:
            media_type = guess_type(filename or path)[0] or "application/octet-stream"
        self.media_type = media_type
        self.background = background
        self.init_headers(headers)
        self.headers.setdefault("accept-ranges", "bytes")
        if self.filename is not None:
            content_disposition_filename = quote(self.filename)
            if content_disposition_filename != self.filename:
                content_disposition = f"{content_disposition_type}; filename*=utf-8''{content_disposition_filename}"
            else:
                content_disposition = f'{content_disposition_type}; 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 = f'"{hashlib.md5(etag_base.encode(), usedforsecurity=False).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:
        scope_type = scope["type"]
        send_header_only = scope_type == "http" and scope["method"].upper() == "HEAD"
        send_pathsend = scope_type == "http" and "http.response.pathsend" in scope.get("extensions", {})
        if scope_type == "websocket":
            send = self._wrap_websocket_denial_send(send)

        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.")