This commit is contained in:
griffi-gh 2023-11-19 19:19:37 +01:00
parent 2cdc79cb18
commit e40e394bd8

View file

@ -11,9 +11,13 @@ use anyhow::Result;
use crate::{block::Block, chunk::{CHUNK_SIZE, BlockDataRef}};
const SECTOR_SIZE: usize = CHUNK_SIZE * CHUNK_SIZE * CHUNK_SIZE * size_of::<Block>();
const RESERVED_SIZE: usize = 524288; //512kb (16 sectors assuming 32x32x32 world of 1byte blocks)
const RESERVED_SIZE: usize = 1048576; //~1mb (16 sectors assuming 32x32x32 world of 1byte blocks)
const RESERVED_SECTOR_COUNT: usize = RESERVED_SIZE / SECTOR_SIZE;
//magic = "KUBI" + IDENTITY (4 bytes)
const HEADER_MAGIC_SIZE: usize = 8;
const HEADER_MAGIC_STR: [u8; 4] = *b"KUBI";
const HEADER_MAGIC_IDENTITY: u32 = 1;
// #[repr(transparent)]
// struct IVec2Hash(IVec2);
@ -22,7 +26,7 @@ struct WorldSaveDataHeader {
pub name: Cow<'static, str>,
pub seed: u64,
sector_count: u32,
chunk_map: HashMap<IVec2, u32>
chunk_map: HashMap<IVec2, u32>,
}
impl Default for WorldSaveDataHeader {
@ -51,13 +55,29 @@ impl WorldSaveFile {
fn read_header(&mut self) -> Result<()> {
self.file.rewind()?;
self.header = bincode::deserialize_from((&self.file).take(RESERVED_SIZE as u64))?;
let mut subheader = [0u8; HEADER_MAGIC_SIZE];
self.file.read_exact(&mut subheader)?;
if subheader[0..4] != HEADER_MAGIC_STR {
return Err(anyhow::anyhow!("invalid file header"));
}
if subheader[4..8] != HEADER_MAGIC_IDENTITY.to_be_bytes() {
return Err(anyhow::anyhow!("this save file cannot be loaded by this version of the game"));
}
let limit = (RESERVED_SIZE - HEADER_MAGIC_SIZE) as u64;
self.header = bincode::deserialize_from((&self.file).take(limit))?;
Ok(())
}
fn write_header(&mut self) -> Result<()> {
self.file.rewind()?;
///XXX: this can cause the header to destroy chunk data (if it's WAY too long)
self.file.write_all(&HEADER_MAGIC_STR)?;
self.file.write_all(&HEADER_MAGIC_IDENTITY.to_be_bytes())?;
//XXX: this can cause the header to destroy chunk data (if it's WAY too long)
// read has checks against this, but write doesn't
// 1mb is pretty generous tho, so it's not a *big* deal
bincode::serialize_into(&self.file, &self.header)?;
Ok(())
}