Function read_until_header_end 

pub async fn read_until_header_end<R>(
    stdout: R,
    deadline: Instant,
) -> Result<(Vec<u8>, Vec<u8>, R), HeaderReadError>
where
    R: AsyncRead + Unpin + Send,

Read from stdout until the RFC 3875 header / body separator (\r\n\r\n), or until deadline. Returns the header block (up to and including the separator), the leftover bytes that arrived in the same read() past the separator, and the still-open reader for downstream body streaming.

Errors

• HeaderReadError::Eof when the reader closes / errors before the separator.
• HeaderReadError::Timeout when deadline expires first.