Function decode_bigsize

plugins/lsps-plugin/src/core/tlv.rs:261–300

(input: &[u8])

}

fn decode_bigsize(input: &[u8]) -> Result<(u64, usize)> {
    if input.is_empty() {
        return Err(TlvError::Truncated.into());
    }
    match input[0] {
        n @ 0x00..=0xfc => Ok((n as u64, 1)),
        0xfd => {
            if input.len() < 3 {
                return Err(TlvError::Truncated.into());
            }
            let v = u16::from_be_bytes([input[1], input[2]]) as u64;
            if v < 0xfd {
                return Err(TlvError::NonCanonicalBigSize.into());
            }
            Ok((v, 3))
        }
        0xfe => {
            if input.len() < 5 {
                return Err(TlvError::Truncated.into());
            }
            let v = u32::from_be_bytes([input[1], input[2], input[3], input[4]]) as u64;
            if v <= 0xffff {
                return Err(TlvError::NonCanonicalBigSize.into());
            }
            Ok((v, 5))
        }
        0xff => {
            if input.len() < 9 {
                return Err(TlvError::Truncated.into());
            }
            let v = u64::from_be_bytes([
                input[1], input[2], input[3], input[4], input[5], input[6], input[7], input[8],
            ]);
            if v <= 0xffff_ffff {
                return Err(TlvError::NonCanonicalBigSize.into());
            }
            Ok((v, 9))
        }
    }
}

/// Encode a BOLT #1 `tu64`: big-endian, minimal length (no leading 0x00).
/// Value 0 is encoded as zero-length.