Function decode_startup

src/pgwire-common/src/codec.rs:83–125

(mut conn: A)

}

pub async fn decode_startup<A>(mut conn: A) -> Result<Option<FrontendStartupMessage>, io::Error>
where
    A: AsyncRead + Unpin,
{
    let mut frame_len = [0; 4];
    let nread = netio::read_exact_or_eof(&mut conn, &mut frame_len).await?;
    match nread {
        // Complete frame length. Continue.
        4 => (),
        // Connection closed cleanly. Indicate that the startup sequence has
        // been terminated by the client.
        0 => return Ok(None),
        // Partial frame length. Likely a client bug or network glitch, so
        // surface the unexpected EOF.
        _ => return Err(io::Error::new(io::ErrorKind::UnexpectedEof, "early eof")),
    };
    let frame_len = parse_frame_len(&frame_len)?;

    let mut buf = BytesMut::new();
    buf.resize(frame_len, b'0');
    conn.read_exact(&mut buf).await?;

    let mut buf = Cursor::new(&buf);
    let version = buf.read_i32()?;
    let message = match version {
        VERSION_CANCEL => FrontendStartupMessage::CancelRequest {
            conn_id: buf.read_u32()?,
            secret_key: buf.read_u32()?,
        },
        VERSION_SSL => FrontendStartupMessage::SslRequest,
        VERSION_GSSENC => FrontendStartupMessage::GssEncRequest,
        _ => {
            let mut params = BTreeMap::new();
            while buf.peek_byte()? != 0 {
                let name = buf.read_cstr()?.to_owned();
                let value = buf.read_cstr()?.to_owned();
                params.insert(name, value);
            }
            FrontendStartupMessage::Startup { version, params }
        }
    };
    Ok(Some(message))
}

impl FrontendStartupMessage {
    /// Encodes self into dst.