pub fn parse_preamble(
input: &[u8],
max_header_bytes: u64,
) -> Result<(Preamble, usize), PreambleError>Expand description
Parses a preamble from the front of input.
Returns the preamble and how many bytes it occupied. max_header_bytes is
the local limit; a larger advertised length is rejected here, which is the
only place where that check can happen before memory is committed.