nbtq/
lib.rs

1use std::{
2    fs::File,
3    io::{self, Read, Seek},
4};
5
6pub fn detect_and_read_nbt(input: &mut File) -> io::Result<nbt::Blob> {
7    input.seek(std::io::SeekFrom::Start(0))?;
8    let mut header = [0; 2];
9    input.read_exact(&mut header)?;
10    input.seek(std::io::SeekFrom::Start(0))?;
11    match header {
12        // Common ZLIB headers: https://stackoverflow.com/a/17176881
13        [0x78, 0x01] | [0x78, 0x9C] | [0x78, 0xDA] => Ok(nbt::from_zlib_reader(input)?),
14        // GZIP header: https://en.wikipedia.org/wiki/Gzip#File_format
15        [0x1f, 0x8b] => Ok(nbt::from_gzip_reader(input)?),
16        // Assume we have raw (uncompressed) NBT
17        _ => Ok(nbt::from_reader(input)?),
18    }
19}