A simple but effective & fast writer / reader for Minecrafts Region Files (mca).
use std::{fs::File, io::Read};
use mca::RegionReader;
let mut data = Vec::new();
File::open("r.0.0.mca")?.read_to_end(&mut data)?;
// Initialize the region
// This mostly just validates the header
let region = RegionReader::new(&data)?;
// Get a specific chunk based of it's chunk coordinates
let chunk = region.get_chunk(0, 0)?.unwrap();
// Decompress the chunk data
// This will most commonly be either ZLib or LZ4 compressed
let decompressed = chunk.decompress()?;
// You can now bring your own NBT parser to parse the actual chunk data here
// I recommend either `simdnbt` or `fastnbt` for this.use std::{fs::File};
use mca::RegionWriter;
let data = vec![]; // some chunk data to write
// Initialize the region writer
let mut writer = RegionWriter::new();
// Push a chunk to the writer
writer.push_chunk(&data, 0, 0)?;
// Write the writer to a buffer
let mut buf = vec![];
writer.write(&mut buf)?;
// Write the buffer to a file
File::create("r.0.0.mca")?.write_all(&buf)?;Toggling the unsafe feature will add unsafe get_unchecked calls to the code.
And this improves the performance by about 50% - 100% (were talking 2-3ns faster).
I think i have added enough manual bound checks to make this safe, but i can't guarantee it.
I've tested this on a few hundred MBs of region files and no issues at all.
Do note that enabling unsafe changes the function signature of RegionReader::get_timestamp to return a result
There is one benchmark included that compares against the only other
mca parser that i could find (mca-parser) and this crate is just like 1-3ns faster (with unsafe).
A very stupid, marginal error difference, but uhh this seems "faster".
you can run it with cargo bench or cargo bench --features unsafe for the unsafe version.