Mercurial > lbo > hg > leveldb-rs
view examples/mcpe/src/main.rs @ 636:fa893d39b0ae
Fix mcpe example
author | kaiyohugo <41114603+KAIYOHUGO@users.noreply.github.com> |
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date | Sun, 12 May 2024 16:30:11 +0800 |
parents | 3cfa3633c012 |
children | 2e83675d5c47 |
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use miniz_oxide::deflate::{compress_to_vec, compress_to_vec_zlib}; use miniz_oxide::inflate::{decompress_to_vec, decompress_to_vec_zlib}; use rusty_leveldb::compressor::NoneCompressor; use rusty_leveldb::{Compressor, CompressorList, Options, DB}; use std::rc::Rc; /// A zlib compressor that with zlib wrapper struct ZlibCompressor(u8); impl ZlibCompressor { /// level 0-10 pub fn new(level: u8) -> Self { assert!(level <= 10); Self(level) } } impl Compressor for ZlibCompressor { fn encode(&self, block: Vec<u8>) -> rusty_leveldb::Result<Vec<u8>> { Ok(compress_to_vec_zlib(&block, self.0)) } fn decode(&self, block: Vec<u8>) -> rusty_leveldb::Result<Vec<u8>> { decompress_to_vec_zlib(&block).map_err(|e| rusty_leveldb::Status { code: rusty_leveldb::StatusCode::CompressionError, err: e.to_string(), }) } } /// A zlib compressor that without zlib wrapper /// /// > windowBits can also be –8..–15 for raw deflate. In this case, -windowBits determines the window size. deflate() will then generate raw deflate data with no zlib header or trailer, and will not compute a check value. /// > /// > From [zlib manual](https://zlib.net/manual.html) /// /// It seems like mojang use this most /// /// A copy of mojang's implementation can be find [here](https://github.com/reedacartwright/rbedrock/blob/fb32a899da4e15c1aaa0d6de2b459e914e183516/src/leveldb-mcpe/db/zlib_compressor.cc#L119). struct RawZlibCompressor(u8); impl RawZlibCompressor { /// level 0-10 pub fn new(level: u8) -> Self { assert!(level <= 10); Self(level) } } impl Compressor for RawZlibCompressor { fn encode(&self, block: Vec<u8>) -> rusty_leveldb::Result<Vec<u8>> { Ok(compress_to_vec(&block, self.0)) } fn decode(&self, block: Vec<u8>) -> rusty_leveldb::Result<Vec<u8>> { decompress_to_vec(&block).map_err(|e| rusty_leveldb::Status { code: rusty_leveldb::StatusCode::CompressionError, err: e.to_string(), }) } } pub fn mcpe_options(compression_level: u8) -> Options { let mut opt = Options::default(); // compressor id list can be find in [mojang's implementation](https://github.com/reedacartwright/rbedrock/blob/fb32a899da4e15c1aaa0d6de2b459e914e183516/src/leveldb-mcpe/include/leveldb/c.h#L194-L200) // And it seems like mojang don't use slippy or zstd of minecraft bedrock // // If you need to open old world, old world fallback compressor can be find [here](https://github.com/reedacartwright/rbedrock/blob/fb32a899da4e15c1aaa0d6de2b459e914e183516/src/bedrock_leveldb.c#L152-L153) let mut list = CompressorList::new(); list.set_with_id(0, NoneCompressor::default()); list.set_with_id(2, ZlibCompressor::new(compression_level)); list.set_with_id(4, RawZlibCompressor::new(compression_level)); opt.compressor_list = Rc::new(list); // Set compressor // Minecraft bedrock may use other id than 4 // // There is a bug in this library that you have to open a database with the same compression type as it was written to. opt.compressor = 4; opt } fn main() { let path = "mcpe_db"; const COMPRESSION_LEVEL: u8 = 10; let opt = mcpe_options(COMPRESSION_LEVEL); let mut db = DB::open(path, opt).unwrap(); db.put(b"~local_player", b"NBT data goes here").unwrap(); let value = db.get(b"~local_player").unwrap(); assert_eq!(&value, b"NBT data goes here") }