Method encode

src/pgwire-common/src/codec.rs:129–168

Encodes self into dst.

(&self, dst: &mut BytesMut)

impl FrontendStartupMessage {
    /// Encodes self into dst.
    pub fn encode(&self, dst: &mut BytesMut) -> Result<(), io::Error> {
        // Write message length placeholder. The true length is filled in later.
        let base = dst.len();
        dst.put_u32(0);

        // Write message contents.
        match self {
            FrontendStartupMessage::Startup { version, params } => {
                dst.put_i32(*version);
                for (k, v) in params {
                    dst.put_string(k);
                    dst.put_string(v);
                }
                dst.put_i8(0);
            }
            FrontendStartupMessage::CancelRequest {
                conn_id,
                secret_key,
            } => {
                dst.put_i32(VERSION_CANCEL);
                dst.put_u32(*conn_id);
                dst.put_u32(*secret_key);
            }
            FrontendStartupMessage::SslRequest {} => dst.put_i32(VERSION_SSL),
            FrontendStartupMessage::GssEncRequest => panic!("unsupported"),
        }

        let len = dst.len() - base;

        // Overwrite length placeholder with true length.
        let len = i32::try_from(len).map_err(|_| {
            io::Error::new(
                io::ErrorKind::InvalidData,
                "length of encoded message does not fit into an i32",
            )
        })?;
        dst[base..base + 4].copy_from_slice(&len.to_be_bytes());

        Ok(())
    }
}

impl FrontendMessage {