mc_gate/mc/
codec.rs

1use std::io::{Error, ErrorKind};
2use tokio::io::AsyncReadExt;
3
4pub async fn read_varint<R: AsyncReadExt + Unpin>(reader: &mut R) -> tokio::io::Result<i32> {
5    let mut value = 0;
6    let mut position = 0;
7    let mut byte_buf = [0u8; 1];
8    loop {
9        reader.read_exact(&mut byte_buf[..]).await?;
10        let byte = byte_buf[0];
11        value |= ((byte & 0x7F) as i32) << position;
12        if (byte & 0x80) == 0 {
13            break;
14        }
15        position += 7;
16        if position >= 32 {
17            return Err(Error::new(ErrorKind::InvalidData, "VarInt too big"));
18        }
19    }
20    Ok(value)
21}
22
23pub fn write_varint(buf: &mut Vec<u8>, mut value: i32) {
24    loop {
25        if (value & !0x7F) == 0 {
26            buf.push(value as u8);
27            return;
28        }
29        buf.push(((value & 0x7F) | 0x80) as u8);
30        value >>= 7;
31    }
32}
33
34pub async fn read_string<R: AsyncReadExt + Unpin>(reader: &mut R) -> tokio::io::Result<String> {
35    let len = read_varint(reader).await?;
36    let mut buf = vec![0u8; len as usize];
37    reader.read_exact(&mut buf[..]).await?;
38    Ok(String::from_utf8_lossy(&buf).to_string())
39}
40
41pub fn write_string(buf: &mut Vec<u8>, s: &str) {
42    write_varint(buf, s.len() as i32);
43    buf.extend_from_slice(s.as_bytes());
44}
mc_gate/mc/codec.rs

mc_gate/mc/
codec.rs
