Function read_response

src/websockets/legacy/http.py:94–143

Read an HTTP/1.1 response and return ``(status_code, reason, headers)``. ``reason`` and ``headers`` are expected to contain only ASCII characters. Other characters are represented with surrogate escapes. :func:`read_request` doesn't attempt to read the response body because We

(stream: asyncio.StreamReader)

async def read_response(stream: asyncio.StreamReader) -> tuple[int, str, Headers]:
    """
    Read an HTTP/1.1 response and return ``(status_code, reason, headers)``.

    ``reason`` and ``headers`` are expected to contain only ASCII characters.
    Other characters are represented with surrogate escapes.

    :func:`read_request` doesn't attempt to read the response body because
    WebSocket handshake responses don't have one. If the response contains a
    body, it may be read from ``stream`` after this coroutine returns.

    Args:
        stream: Input to read the response from.

    Raises:
        EOFError: If the connection is closed without a full HTTP response.
        SecurityError: If the response exceeds a security limit.
        ValueError: If the response isn't well formatted.

    """
    # https://datatracker.ietf.org/doc/html/rfc7230#section-3.1.2

    # As in read_request, parsing is simple because a fixed value is expected
    # for version, status_code is a 3-digit number, and reason can be ignored.

    try:
        status_line = await read_line(stream)
    except EOFError as exc:
        raise EOFError("connection closed while reading HTTP status line") from exc

    try:
        version, raw_status_code, raw_reason = status_line.split(b" ", 2)
    except ValueError:  # not enough values to unpack (expected 3, got 1-2)
        raise ValueError(f"invalid HTTP status line: {d(status_line)}") from None

    if version != b"HTTP/1.1":
        raise ValueError(f"unsupported HTTP version: {d(version)}")
    try:
        status_code = int(raw_status_code)
    except ValueError:  # invalid literal for int() with base 10
        raise ValueError(f"invalid HTTP status code: {d(raw_status_code)}") from None
    if not 100 <= status_code < 1000:
        raise ValueError(f"unsupported HTTP status code: {d(raw_status_code)}")
    if not _value_re.fullmatch(raw_reason):
        raise ValueError(f"invalid HTTP reason phrase: {d(raw_reason)}")
    reason = raw_reason.decode()

    headers = await read_headers(stream)

    return status_code, reason, headers


async def read_headers(stream: asyncio.StreamReader) -> Headers: