tobytcp 0.9.3

A little library for sending messages over a raw tcp stream
Documentation 
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//! This module has a helper for encoding data to TobyTcp
use std::convert::TryFrom;

/// Call this with your data, and the returned buffer will be a properly
/// encoded `TobyTcp` message that can be sent!
pub fn encode_tobytcp(mut message: Vec<u8>) -> Vec<u8> {
    let data_len_64 = message.len() as u64;
    data_len_64.to_le();

    let mut encoded = bytes_from(data_len_64).to_vec();
    encoded.append(&mut message);
    encoded
}

/// Goes from a single u64 to 8xu8
fn bytes_from(mut num: u64) -> [u8; 8] {
    let mut ret = [0u8; 8];

    for (i, _) in (0..7).enumerate() {
        ret[7 - i] = u8::try_from(num & 0b1111_1111_u64).unwrap();
        num = num >> 8;
    }
    ret
}

#[cfg(test)]
mod tests {
    #[test]
    fn encode_single_byte() {
        let message = vec![100, 13, 69, 17];
        let encoded = super::encode_tobytcp(message);
        // We had 4 bytes of data
        assert_eq!(vec![0, 0, 0, 0, 0, 0, 0, 4, 100, 13, 69, 17], encoded);
    }

    // TODO: Figure out how to merge 2 vecs, then merge message to the expected prefix..
    // #[test]
    // fn encode_three_byte() {
    //     let message = vec![69; 257];
    //     let encoded = super::encode_tobytcp(message);
    //     // We had 4 bytes of data
    //     assert_eq!(vec![0, 0, 0, 0, 0, 0, 1, 1, 100, 13, 69, 17], encoded);
    // }
}